# Confused about Crop Effect...after I thought I had it.



## rmfagan (Dec 12, 2014)

Hello all-

I've seen several posts lately which have left me confused. My understanding of the crop factor (1.6x in Canon's case) is that FOV is decreased by 1.6x, effectively cropping the photo. It doesn't replace focal length in that you do not gain additional telephoto compression. However, this crop effect could still be useful to the focal length limited photographer (let's say 300IS II + 2x TC III as opposed to a 500 or 600 prime) because to crop a FF image in post throws out pixels, while a sensor forced crop puts relatively greater number of pixels on target (ie a 7d2 vs a 5d3).

Now I've read posts alluding to a "real" benefit of closer to 1.2x due to increased camera movement. Why? Would this camera movement not also occur at a comparable FOV on FF? Would a 300 + 1.4x not have roughly the same movement as a 400? 

Thanks in advance for clearing this up.


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## jrista (Dec 12, 2014)

This has been a relatively great debate on these forums, for many years.


Personally, I'm of the opinion that your second paragraph sums it up perfectly. Your going to experience the same camera shake with FF and APS-C, so if it's enough to diminish IQ, it's going to diminish it regardless of what your using. On the flip side, if you work to minimize shake, smaller pixels mean you have the potential to resolve more detail. It doesn't matter if those smaller pixels are in a big or small sensor...smaller pixels are smaller pixels. When your reach limited, smaller pixels mean greater potential for more detail.


I don't care if you have to work harder to get that detail, the potential is still there. I primarily use a 5D III now, but I still believe my sharpest photos ever when reach limited were taken with the 7D and 500mm f/4 and 600mm f/4 lenses at faster apertures (so not diffraction limited.)


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## rmfagan (Dec 13, 2014)

I tend to agree, but I don't know enough about the physics to be certain. The reason I ask is I am torn between buying a 300 IS II plus 7d ii or a 500 IS VER 1 for wildlife. Really tough call and this talk about only 1.2x advantage in reality is confounding.


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## Terry Rogers (Dec 13, 2014)

https://www.youtube.com/watch?v=DtDotqLx6nA

https://www.youtube.com/watch?v=f5zN6NVx-hY

These are some of the best explanations I've seen explaining crop and how it relates to focal length and iso


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## takesome1 (Dec 13, 2014)

The camera shake issue is two fold.
Imagine holding a beam of light like a lazer on two squares, one square over twice the size of the other. Imagine your hand shaking so the light is moving up and down at the same amount on each square. The movement of the light on the smaller square will cover a larger percentage of its area than it will on a large square. Your hand shake is equal, but the area of the sensor on a crop is smaller and magnifying it. Most people don't get this, distance and FOV do not matter, they are not moving your hand is.
Second your pixels are smaller and if your vibration is over a pixel width your resolution advantage drops quick.

Camera shake is a small part of it, it can be increased by other factors.
You loose some light with the crop. Add to this you have to shoot at lower ISO than FF because of noise. To compensate for this you may be shooting at slower shutter speeds.

Those are just hand held problems, on a sturdy tripod where none of those issues matter I see about a 1.2 improvement.

But here is the deal with the improvement, you will only realize the improvement in resolution if you are focal length limited. If you can take a few steps closer a 5D III has a substantial advantage over the 7D II.

Clear as mud, right?


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## takesome1 (Dec 13, 2014)

GraFax said:


> takesome1 said:
> 
> 
> > But here is the deal with the improvement, you will only realize the improvement in resolution if you are focal length limited. If you can take a few steps closer a 5D III has a substantial advantage over the 7D II.
> ...



What you do not hear much is the difference of the crop camera vs a FF with equal framing, for instance the FF at 100' and the crop at 160. In that situation the FF has a substantial resolution benefit.


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## ritholtz (Dec 13, 2014)

takesome1 said:


> You loose some light with the crop. Add to this you have to shoot at lower ISO than FF because of noise. To compensate for this you may be shooting at slower shutter speeds.


Hi takesome1,
Why do you think, we loose some light with the crop and shooting at slower speeds. Exposure values are same for both. In order to get picture with similar dof, one needs to stop down by 1 1/3 stop with FF and increase ISO by that much. 

Thanks


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## Ryan85 (Dec 13, 2014)

GraFax said:


> There is much disagreement on this subject and no easy answers.
> 
> My explanation, for which I am charging you nothing, is more or less this:
> 
> ...



This is how I understad it too. The more I think about it the more confused I get. You summed it up nicely.


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## ritholtz (Dec 13, 2014)

takesome1 said:


> What you do not hear much is the difference of the crop camera vs a FF with equal framing, for instance the FF at 100' and the crop at 160. In that situation the FF has a substantial resolution benefit.


I think, that is how TDP lens comparison tests are done. Crop is always looks bad in those tests.


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## Ryan85 (Dec 13, 2014)

GraFax said:


> In my experience, closer is always better, regardless of equipment. Just don't get eaten by a bear...or whatever toothy critters live in your neck of the woods...



+1 I totaly agree. I've had one close call with a brown bear in Skagway Alaska. So yeah be careful of bears!


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## Ryan85 (Dec 13, 2014)

Lol I hear you and absolutely agree!


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## takesome1 (Dec 13, 2014)

ritholtz said:


> takesome1 said:
> 
> 
> > You loose some light with the crop. Add to this you have to shoot at lower ISO than FF because of noise. To compensate for this you may be shooting at slower shutter speeds.
> ...



Try metering side by side and see if what you say is true. I am getting a 1/3 to 2/3 stop light advantage with the 5D II and 1D IV.

The problem with stoping down is that is fine during bright daylight hours, but the advantage of the crop is at you longest focal length. In my case that is a 500mm F/4. Anything less I can cover with a FF. So with the 500mm I need a fast shutter speed to compensate for the long lens and often to stop action. It is always a struggle for light at the prime wildlife times and I seldom shoot over F/4.5. 

YMMV since your longest lens and shooting interests may be different.


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## Mt Spokane Photography (Dec 13, 2014)

The reason you need to take more care with a crop body is because of the longer effective focal length.

A shutter speed of 1/2 X eff focal length means a faster shutter speed to prevent blur from vibration. Once a user takes that into account, things get better as far as blur from camera vibration. The smaller pixels add another increment of vibration blur, so even more care is needed. Once again, understanding the situation means you can deal with it, unless the light is low. 
\
APS-C cameras struggle a bit more in low light, and a faster shutter speed means less light on the sensor. In bright daylight, that's usually not a big issue, but adding TC's to a already small aperture telephoto lens combined with faster shutter speeds and the resulting higher ISO settings can mean lost opportunities.

In limited light, my old 7D really struggled with a slow telephoto. The 7D MK II is going to be a lot better at high ISO's.


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## Ryan85 (Dec 13, 2014)

Mt Spokane Photography said:


> The reason you need to take more care with a crop body is because of the longer effective focal length.
> 
> A shutter speed of 1/2 X eff focal length means a faster shutter speed to prevent blur from vibration. Once a user takes that into account, things get better as far as blur from camera vibration. The smaller pixels add another increment of vibration blur, so even more care is needed. Once again, understanding the situation means you can deal with it, unless the light is low.
> \
> ...



+1


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## jrista (Dec 13, 2014)

takesome1 said:


> The camera shake issue is two fold.
> Imagine holding a beam of light like a lazer on two squares, one square over twice the size of the other. Imagine your hand shaking so the light is moving up and down at the same amount on each square. The movement of the light on the smaller square will cover a larger percentage of its area than it will on a large square. Your hand shake is equal, but the area of the sensor on a crop is smaller and magnifying it. Most people don't get this, distance and FOV do not matter, they are not moving your hand is.
> Second your pixels are smaller and if your vibration is over a pixel width your resolution advantage drops quick.




Neat little example. A single point of light pointing at the center of a square. Now, compound the number of squares a few million fold, and instead of one beam of light, you have trillions. All shaking concurrently and synchronously all over this array of a few million squares. Camera shake is camera shake. It's going to soften the image regardless. Light that should fall onto one square is going to fall on more than one square. Acutance is going to drop off precipitously at the first tiny bit of camera shake, and after that it's a diminishing effect. 


I have to hold my 5D III as steady as I have to hold my 7D to get the most crisp, sharp shot. In the field, there isn't any difference...I don't think "I can handle X amount of shake with the 5D III" or "I can shake N times more than with my 7D"...I simply hold the lens steady, as steady as humanly possible period, and burst my shots to get a good number of frames so I can pick the sharpest one. There isn't any difference in tactic here, you use FF and APS-C the same way, birds, wildlife, or otherwise. 


Do you want to maximize the potential of the system, or not? That's either yes, or no. If yes, then you do everything you can to extract the absolute best out of the system. There is no difference in effort to do that regardless of format...we can't compensate for the microscopic differences in pixels when were out in the field concentrating on a bird. You AFMA with both FF and APS-C. You use IS with both FF and APS-C. 


There isn't any difference here. Either you maximize your camera system's potential, or not. You either hold the lens as steady as possible, or not. No one thinks about the size of a pixel or the relative differences in pixel sizes in the field...they simply think: "Keep it stable." 




takesome1 said:


> Camera shake is a small part of it, it can be increased by other factors. You loose some light with the crop. Add to this you have to shoot at lower ISO than FF because of noise. To compensate for this you may be shooting at slower shutter speeds.




Conversely, you have to shoot at a higher ISO and a narrower aperture with FF to get the same depth of field. I have been shooting at 1200mm f/8+ for most of the week, to fill the frame with small birds. That results in an incredibly thin DoF. Shooting at 1200mm f/8 roughly normalizes the 5D III FoV, normalizes the DoF, normalizes the amount of light at the sensor, normalizes the amount of noise with an APS-C. If were talking equivalence here, let's truly be equivalent. For all my efforts at 1200mm on FF, I still get even sharper results with a 7D and a 500/4 (which should be expected...at f/8+ I'm getting diffraction limited...at f/4, the 7D is at a perfectly ideal aperture for maximum sharpness).

APS-C has an advantage when it comes to DoF and getting pixels on subject. Yes, it's when your reach limited...but that is most often the case when your not a pro with tens of thousands of dollars worth of gear, or the ability to spend every day of the weak learning how to get extremely close to your subjects.


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## Ryan85 (Dec 13, 2014)

I always try to hold my cameras as steady as possible too. But if I'm using a crop sensor I'll use a faster shutter speed while hand holding because of the crop factor. I try to follow the the 1 over the focal length for my minimum shutter speed. So if I'm shooting a 400 mm lens on my FF I generally won't shoot under 1/400th with a 400mm on a crop sensor I generally won't shoot under 1/640th.


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## jrista (Dec 13, 2014)

Ryan85 said:


> I always try to hold my cameras as steady as possible too. But if I'm using a crop sensor I'll use a faster shutter speed while hand holding because of the crop factor. I try to follow the the 1 over the focal length for my minimum shutter speed. So if I'm shooting a 400 mm lens on my FF I generally won't shoot under 1/400th with a 400mm on a crop sensor I generally won't shoot under 1/640th.




I used to follow those rules, but I think once you get a handle on stability, they don't matter as much. I have shots as low as 1/100th and even slower, hand-held, with IS enabled on my 600mm f/4. At that point, burst rate is really what matters most...as it's the movement of the subject that matters most. The faster the burst, the more likely you are to nab a razor sharp shot, even down to shutter speeds a fraction of the focal length. 


For example...Chickadee, 1200mm f/10 1/100s ISO 800. This is 1/100s! SIX STOPS lower than the 1/focalLength rule would dictate I shoot at, and two stops lower than my IS system supposedly allows for. Shot at f/10 with a 2x TC (diffraction limited, which is probably where the sharpness limit is ultimately coming from, although I may be a notch or two off on my AFMA as well):

Original:






Sharpened:





Processed:







You maximize the potential of the system in hand. The amount of effort you put in is high regardless of whether your shooting APS-C or FF. So, personally, I don't really believe the notion that bigger pixels mitigate issues from camera shake or anything like that, or that just taking a step or two forward is going to fix the reach issue. I was getting shots like this with a 500mm f/4 on the 7D. F/4...the diffraction-limited performance of an ideal lens at that aperture is higher than any current DSLR sensor on the market, significantly higher than the diffraction-limited performance of a lens at f/10 (key benefit of using faster lenses on APS-C...smaller pixels that can maximize the performance of a high resolution lens at a fast diffraction-limited aperture). 


Faster aperture, more light, sharper details from nearly the same distance as a 1200mm FF in the end (pretty much right on top of the MFD). 


Like this:






Or this:





Now, these days I can get close enough to use my bare 600 at f/4-f/6.3 and get phenomenally sharp results with the 5D III. I've just been having fun with the 1200mm f/8 focal length this week, and have been seeing how much I can extract from that particular system. It's useful out in the field, vs. in my back yard, where it is a lot harder to get close to the songbirds I want to photograph.


You maximize the system in hand...and you don't skimp on doing everything that's possible to maximize your results (not if you want the best results possible, anyway). I don't put less effort in to keep my lens stable when using FF than when using APS-C...I put in the maximum effort either way. I think the notion that you cannot get the most out of a sensor like the 7D, or the 70D/7D II, or the even higher resolution NX1, that your perpetually limited to barely any better than what FF can do...I think it's all a myth. If you learn how, and put in the effort, if you use all the features of your system (lens IS, sensor IS, any kind of stabilization, external supports like tripods, beanbags, bracing your arms against your body when handheld, etc.) you can experience camera shake so small that it doesn't affect even the smaller pixels of an APS-C (or the pixels of say the D800, which are quite smaller than anything from Canon's FF sensors...and thus, one would expect, susceptible to the same problems.)


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## takesome1 (Dec 13, 2014)

jrista said:


> takesome1 said:
> 
> 
> > The camera shake issue is two fold.
> ...



Maximizing your equipment is knowing your equipment. The crop has limitations and it has benefits.

You shoot at faster shutter speeds to overcome camera shake. You can use a flash. If you are shooting in ample light with a fast enough shutter speed then camera shake isn't much of an issue. My 500mm I prefer 1/1000, at 1/500 I can still get fair wildlife pics off the monopod. Go less it starts getting difficult. Light starts to drop close to sunset, my ISO limit is set at 1/1600 on the 7D II and I will push to 1/3200 on FF. Camera gets pushed there to get the speed I need. Same is true of aperture, it goes to F /4. So normalizing for DOF in low light conditions just doesn't happen, you take what you get.

Of course as I said YMMV, if a persons longest lens is 300mm they would notice camera shake and loss of light even less. With focal length limited situations one should analyze how much they usually crop. If you have more pictures that are properly framed than need to be cropped then the benefit of FF on the majority of your pics may be greater than benefit you receive on your cropped photos.


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## neuroanatomist (Dec 13, 2014)

jrista said:


> You maximize the potential of the system in hand. The amount of effort you put in is high regardless of whether your shooting APS-C or FF. So, personally, I don't really believe the notion that bigger pixels mitigate issues from camera shake or anything like that...



Your belief or lack thereof doesn't change the underlying geometry that determines the relationship between pixel size and the effect of angular motion. 




jrista said:


> I don't put less effort in to keep my lens stable when using FF than when using APS-C...I put in the maximum effort either way.



I'm sure that's true, but it's irrelevant...what matters is the results. You can put in your maximum effort in running as fast as possible on a 5% grade hill either way, but you'll go much faster if you're running down that hill than up.


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## TexPhoto (Dec 13, 2014)

Could this be the next AF vs MF? IS vs no IS? Dare I say it?, UV filter vs bare glass?


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## jrista (Dec 13, 2014)

neuroanatomist said:


> jrista said:
> 
> 
> > You maximize the potential of the system in hand. The amount of effort you put in is high regardless of whether your shooting APS-C or FF. So, personally, I don't really believe the notion that bigger pixels mitigate issues from camera shake or anything like that...
> ...




I'm not denying the math. I'm denying we can account for the minuscule differences in pixel size out in the field. People experience blurring from camera shake with every system, with a wide range of lenses, regardless of sensor size or pixel size.


My simple point is, you either hold the lens stable, or you use IS, or not. If you don't, your GOING to experience the effects of camera shake no matter how big your pixels or your sensor.


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## neuroanatomist (Dec 14, 2014)

jrista said:


> My simple point is, you either hold the lens stable, or you use IS, or not. If you don't, your GOING to experience the effects of camera shake no matter how big your pixels or your sensor.



Sure...you'll just experience those effects _more_ with smaller pixels.


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## ejenner (Dec 14, 2014)

takesome1 said:


> Try metering side by side and see if what you say is true. I am getting a 1/3 to 2/3 stop light advantage with the 5D II and 1D IV.



I've had a t1i, 7D, 5DII and 5DIII and if I take the same shot at exactly the same aperture, SS and ISO they will all be different by 1/3-2/3 stop. Nothing to do with crop and everything to do with how the amplification in-camera is done and how they mark the ISO values. In fact 7D was 2/3 stop darker than t1i at all ISO's above 100. Ti1 ISO 100 was not a full stop darker than at 200 - only 1/3 stop, so that was a little weird. 

Maybe I'm just cynical, but I figured Canon did that so that when tested at a particular ISO the 7D would look better than the rebels and previous 15MP 'older' and people would think the sensor was better (I think that actually happened too). Of course no-one noticed that the testers had to use a lower SS by 1/3-2/3 stop. OF course if you actually shot at the same exposure the results were essentially identical.


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## Mt Spokane Photography (Dec 14, 2014)

jrista said:


> takesome1 said:
> 
> 
> > The camera shake issue is two fold.
> ...


 
When the Nikon D800 came out, DPR had to beef up their tripods, and take extreme care to get the sharpness that the extra pixels could give. They spent a lot of extra time and effort in their testing before they learned how to get the expected resolution. Its virtually impossible for hand held images at normal shutter speeds to make use of that available 36 MP resolution. So, yes, if you want to get the full resolution that a camera is capable of, sometimes you have to adopt new tactics that were not necessary before. Those tiny photo sites could fill a 51.7 MP FF sensor, and with a long lens, almost any vibration is going to reduce resolution. That doesn't mean that images will be blurred, just that they will not be as good as they could be. I learned that quickly with my 7D, and when hand holding my camera, I doubled shutter speeds or even tripled them where possible. Then, my images really improved. I had to force the camera to use high shutter speeds, using Av turned out to be a bad idea. I believe the 7D MK II allows you the option of faster shutter speeds for a given focal length. That's a worthwhile feature for those who want to use Av or full automatic. 

You are right, I do take the same care with my 5D MK III as I did with my 7D. I use faster shutter speeds than with the old 12 MP sensors because it makes a difference. With my D800, I used it the same way as my 5D MK III, and except for a few bright sunlight, high shutter speed images, there was no noticeable sharpness advantage. I did appreciate the extra DR for those bright sun low ISO images, but for me, they were the exception, not the rule, because I was shooting in extreme low light much of the time, and struggled to get sharp images with the D800.


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## Ryan85 (Dec 14, 2014)

TexPhoto said:


> Could this be the next AF vs MF? IS vs no IS? Dare I say it?, UV filter vs bare glass?



Lol I'm thinking it might


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## chromophore (Dec 14, 2014)

A camera system has many components and a change in one aspect of the system design can have effects on several different properties of that system. An "apples-to-apples" comparison of two systems is not always feasible or meaningful.

So, suppose we take a 24x36 mm "full-frame" sensor and replicate it at 1/1.6 times the scale, without changing its position relative to the lens, resulting in an APS-C sensor with the same number of pixels. We can ask a number of questions about the effect of this scaling, such as:

1. What is the effect on the depth of focus and depth of field?
2. What is the impact on imaging resolution?
3. How does the noise characteristics of the image change?
4. Does the slowest hand-holdable shutter speed change?
5. How is the resulting field of view different?
6. Does the focal length change?
7. Is the f-number the same?
8. What effect is there on diffraction?

All else in the system being equal, there are good theoretical answers to these questions. But the problem is that other aspects of the system and the scene to be imaged--even if kept constant between full frame and APS-C--can have a greater impact on the result than the size of the effect: for instance, an perfect lens shot at f/1.4 for a perfectly flat target scene will show more resolution for higher pixel density. But lenses are not perfect, diffraction losses can negate pixel density advantages, and the objects to be imaged are frequently not flat.

So what happens is that when trying to explain the effect of different sensor sizes, there invariably are numerous caveats and criteria involved. It is difficult to pin these things down and talk about these effects as if they are universal rules. Some aspects, like the effect on field of view, are straightforward. Others, like resolution, are complex and influenced by many other factors.


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## Joey (Dec 14, 2014)

ejenner said:


> takesome1 said:
> 
> 
> > Try metering side by side and see if what you say is true. I am getting a 1/3 to 2/3 stop light advantage with the 5D II and 1D IV.
> ...


Glad to see someone commented about that. Correct exposure is not dependant on sensor size or pixel density. Otherwise external light meters would need to be configured for sensor size.


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## AlanF (Dec 14, 2014)

The remark was made that no one understands the physics. Here one person who knows enough: Roger Clark. Read his review of the 7D II and follow the links in it:

http://www.clarkvision.com/reviews/evaluation-canon-7dii/index.html


Quote: "_The 7D mark II has very small pixels for a DSLR. To get all the detail in an image that the sensor is capable of delivering, you need very sharp lenses. Most zoom lenses, especially consumer zoom lenses will result in soft images from this sensor as the lenses can't deliver the image quality. Also, one needs to use excellent technique to take advantage of this sensor. Remember, it is the lens plus the exposure time that delivers the light and the detail to the sensor. The sensor just collects the light delivered by the lens and exposure time. Deliver the light to the 7D2 and it will record stunning images_."

You need the best lenses, like the big whites (and it looks like the new 100-400mm II is in that category) to get the best out of the small pixel sizes. Shake you can eliminate with good technique, but a soft lens you can't except by getting a better one.


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## takesome1 (Dec 14, 2014)

Mt Spokane Photography said:


> jrista said:
> 
> 
> > takesome1 said:
> ...



I started to mention the D800 example, I remember when it was released and the discussions on camera stabilization.
The point made to the OP and the discussion in this thread is that for the full benefit of the crop camera and it's pixel density you have to remove vibration. 

On the extreme that would be a mirror up, time delayed shot with your hand not on the camera on very sturdy tripod legs and a head. Shoot in dead calm on a solid surface also. But the crop benefit is usually debated as a focal length limited option. For wild animals time delay and mirror up are rarely going to happen. Big lenses are heavy so you have to exhaust every method to stay stable. Shutter speed is one of these things and it is lowered sooner on a crop than a FF.

For me I see the resolution advantage of the crop body as a sliding scale starting high with the tripod as described above and disappearing hand held as light goes away. Whether someone sees a benefit from it will be determined by what, when and how they are shooting.


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## takesome1 (Dec 14, 2014)

ejenner said:


> takesome1 said:
> 
> 
> > Try metering side by side and see if what you say is true. I am getting a 1/3 to 2/3 stop light advantage with the 5D II and 1D IV.
> ...



So the theory might be that Canon is doing this to give us a false perception of high ISO noise improvement?
I like conspiracy theories and that is easy to buy.

Of course either way we loose that 1/3 to 2/3 stop whether it be with altered ISO numbers or in camera exposure values.


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## jrista (Dec 14, 2014)

Mt Spokane Photography said:


> When the Nikon D800 came out, DPR had to beef up their tripods, and take extreme care to get the sharpness that the extra pixels could give. They spent a lot of extra time and effort in their testing before they learned how to get the expected resolution. Its virtually impossible for hand held images at normal shutter speeds to make use of that available 36 MP resolution. So, yes, if you want to get the full resolution that a camera is capable of, sometimes you have to adopt new tactics that were not necessary before. Those tiny photo sites could fill a 51.7 MP FF sensor, and with a long lens, almost any vibration is going to reduce resolution. That doesn't mean that images will be blurred, just that they will not be as good as they could be. I learned that quickly with my 7D, and when hand holding my camera, I doubled shutter speeds or even tripled them where possible. Then, my images really improved. I had to force the camera to use high shutter speeds, using Av turned out to be a bad idea. I believe the 7D MK II allows you the option of faster shutter speeds for a given focal length. That's a worthwhile feature for those who want to use Av or full automatic.
> 
> You are right, I do take the same care with my 5D MK III as I did with my 7D. I use faster shutter speeds than with the old 12 MP sensors because it makes a difference. With my D800, I used it the same way as my 5D MK III, and except for a few bright sunlight, high shutter speed images, there was no noticeable sharpness advantage. I did appreciate the extra DR for those bright sun low ISO images, but for me, they were the exception, not the rule, because I was shooting in extreme low light much of the time, and struggled to get sharp images with the D800.




Again, I'm not denying the theory. I simply don't see any real-world difference in the impact to my photos when I shoot with the 7D or the 5D III.



Perhaps it is simply because I started with a camera that had 4.3 micron pixels, I don't know. But I tend to get the sharpest shots of all with the 7D and 600mm lens. I had no option but to force myself with the 7D to learn how to stabilize as much as possible to get the best sharpness possible out of that system. I also really DO use the sharpest glass available...perhaps that is skewing my perceptions here. I don't shoot any differently with the 5D III, but unless I'm right on top of my subject at the shortest focal length and fastest apertures possible, the images from that, although maybe less noisy, are usually not sharper than what I get from the 7D. If I shake...it ruins the shot, it doesn't matter which camera I'm using.


Shutter speed is also of paramount importance. With either camera, getting the shutter speed high enough to freeze motion is also critical. I have some skill in freezing motion of fast little birds at very low shutter speeds, but it takes a lot of effort, regardless of the camera. It also usually takes longer bursts to get that one sharp frame (to which the 7D/7D II is going to be more advantaged than the 5D III). These days I just say to hell with it, and jack up the ISO nearly as high as it will go, 3200 on the 7D II, 6400-12800 on the 5D III. That motion-freezing shutter results in critical sharpness, which in and of itself helps diminish the impact of noise. 


One thing I will say, diffraction does certainly present earlier with cameras that have smaller pixels. The 5D III is FAR more forgiving of smaller apertures than the 7D ever was. If I was normally shooting at f/8, then I don't think I'd see much of a real-world difference between the two cameras. In a reach-limited situation, I am usually at a faster aperture with the 7D (i.e. 600mm f/4 vs. 1200mm f/8)...the diffraction limited resolving power of a lens at f/4 is significantly higher than at f/8, and assuming a stable frame (I always burst, so there is pretty much always a frame that's razor sharp), that gives the 7D's smaller pixels what they need to be as sharp as possible.


There is also the fact that at 1200mm I suffer from the effects of less camera shake a touch sooner than the 7D at 600mm. So, for any given amount of camera shake, the impact to the image is pretty much the same. There are a number of normalizing forces when it comes to getting the same kind of framing in the real world, and those forces, in a reach limited situation, tend to balance out the "benefit" of larger pixels as far as camera shake goes.


The only time the difference between larger pixels/larger frame and smaller actually matters from a shake standpoint is when you are NOT reach limited, and you can get about twice as close with the same focal length using the larger sensor. In that situation, then your packing far more pixels onto the subject...the larger sensor, pretty much regardless of the pixel size, is going to be easier to manage.


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## AlanF (Dec 14, 2014)

GraFax said:


> AlanF said:
> 
> 
> > The remark was made that no one understands the physics. Here one person who knows enough: Roger Clark. Read his review of the 7D II and follow the links in it:
> ...



What are the problems with the wave-particle duality of light and the Heisenberg uncertainty principle and quantum effects at a level that is going to affect the observed resolution of a lens and sensor that we can detect in our images? The wave nature of light is sufficient that we can calculate the diffraction patterns at different wavelengths and work out the how they depend on f number, the particle nature means that we can apply Poissonian statistics to photon noise, and regarding the uncertainty and effects; are they large enough to affect us in any practical way? 

Even though we don't fully understand the laws of physics, we can design a car without using Einstein's theory of relativity, just based on Newtonian mechanics, and land a space vehicle on a comet. We are dealing with practicalities, not metaphysics. You don't need a "theory of everything" for most practical aspects of engineering.


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## AlanF (Dec 14, 2014)

GraFax said:


> AlanF said:
> 
> 
> > GraFax said:
> ...



In which case, stop bickering. You raised the non-existent issue of the inadequacy of physics.


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## takesome1 (Dec 15, 2014)

jrista said:


> The only time the difference between larger pixels/larger frame and smaller actually matters from a shake standpoint is when you are NOT reach limited, and you can get about twice as close with the same focal length using the larger sensor. In that situation, then your packing far more pixels onto the subject...the larger sensor, pretty much regardless of the pixel size, is going to be easier to manage.



The statement is a bit skewed. I like these kind of statements because they are half based in reality and enough outside that only pieces of it can be disputed. 

However

You need to check how this idea works out in the real world. The distance you need to get closer is no where near 2x as close. 

More like 20% closer, maybe a bit more. I have already shot a few test shots on this one with the 7D II. 
This is one real world test I have been thinking about doing a bit more. Shoot a test shot with FF at say 30' and then 6 shots at 3' intervals till I am at the same framing 1.6x out. I have already done comparisons at about 1.4x to 1.6 and the FF had much better resolution. It might be a good way to see how much benefit the crop factor really is.

In the concept you offer camera shake is a smaller part of the resolution equation.


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## Ryan85 (Dec 15, 2014)

I think as long as your happy and your clients if you have them are happy with the the outcome that's all that matters. I have some shots with my old rebel xsi and 70-300 non L lens I'm happy with and I didn't even know what I was doing then.


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## Ryan85 (Dec 15, 2014)

GraFax said:


> AlanF said:
> 
> 
> > In which case, stop bickering. You raised the non-existent issue of the inadequacy of physics.
> ...



+1


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## jrista (Dec 15, 2014)

takesome1 said:


> jrista said:
> 
> 
> > The only time the difference between larger pixels/larger frame and smaller actually matters from a shake standpoint is when you are NOT reach limited, and you can get about twice as close with the same focal length using the larger sensor. In that situation, then your packing far more pixels onto the subject...the larger sensor, pretty much regardless of the pixel size, is going to be easier to manage.
> ...




I said 2x because that would generally normalize composition within the area of the frame as well (not exactly, but enough). No, you probably don't need to move that full distance forward to start seeing an improvement, but I try to stick to equivalency...otherwise the size of the subject in the frame/the number of pixels on the target, is entirely arbitrary. I think about OOC composition I guess...is the bird framed, in camera, how I want it to be framed? I used to crop...heavily. The only time I crop these days is to straiten or tweak composition...I'm not dropping down to 10-20% of the frame like I did the first six months I had my 7D and 100-400mm. To that end, FF is actually more than 2x the area of APS-C (2.6x, actually), so I wasn't actually stating that you should halve your distance to subject anyway. 


This is all beside the point anyway, as all it takes is ONE step, or even to stand up or start standing up, and your target could flee. Birds of the heron family in particular, for example, are extremely skittish birds. If you manage to get close enough to get a decent shot at all, then smaller pixels are going to be a bigger friend to you than getting closer. I can't count how many times just seeing my head barely rise over the top of a ridge was enough to make every heron and egret in the area fly off. Hawks are similar...they can be perfectly content with you sitting there watching them if your not moving. The moment you stand up, they'll leap off their perch and fly right over your head!  (I've had this happen a few times.) Deer are content to get right up in your face so long as your sitting on the ground...stand up, they'll dance around and huff a few times, then wander off. Outside of wearing a ghillie suit, even in camo deer will spot me. If I stand up, they at the very least stand rigid and take notice. Start moving towards them, and they will often bolt. 


It's not necessarily always as easy as taking a few steps closer to your target.


If you are willing to expend the greater amount of time to get closer to really make a difference with FF, you can indeed get some phenomenal shots...but not everyone has that kind of skill or time. That's why the reach argument exists in the first place. A 7D II with a 400mm or 150-600mm lens is going to get a lot more people excellent shots in fairly difficult situations with birds and wildlife than a 5D III with the same lenes. To take it to the next level, a 500mm or 600mm f/4 and some TCs so you can get 1000mm to 1200mm on FF (which would also normalize composition with APS-C at the same distance), is well beyond most people's budgets.


Now, I'm not saying you get more resolution with smaller pixels for free. It takes a lot of effort to hold and KEEP a lens steady while your shooting it. Especially longer lenses, which magnify ever smaller movements. It is possible to maximize the potential of your system, though, small pixels or large. That's my point. We can throw around numbers like 20% or 1.2x or 1.4x or whatever it is all day long. In the end...does your tactic change? Do you actually think in the field, I have 20% bigger pixels, so I can relax my hand-holding technique by 20%? No one does that. You hold yourself, and your gear, steady, as steady as humanly possible, period. You cannot account for the differences in the field...if you try, the chances of experiencing blurry shots with FF are going to be higher, as your not putting your full attention on what matters. Keeping yourself and your gear stable, as stable as you possibly can, with whatever tools are at your disposal to do so (IS, tripod, monopod, beanbags, whatever.)


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## BozillaNZ (Dec 18, 2014)

Focal length itself does not mean anything.

Focal length combined with sensor size (diagonal) determines the angle of view. Angle of view determines "telephoto compression"

So, 135mm on APS-C (1.6x) and 216mm on FF will give you the exact same "telephoto compression".

And 135mm on 20MP APS-C and 216mm on 20MP FF will give you the same degree of angle of view per pixel, hence being affected by camera shake exactly same too.

Note that we haven't touched about depth of field yet, which is another big can of worms.


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## Ryan85 (Dec 18, 2014)

BozillaNZ said:


> Focal length itself does not mean anything.
> 
> Focal length combined with sensor size (diagonal) determines the angle of view. Angle of view determines "telephoto compression"
> 
> ...



Let's not get everyone riled up with that lol


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## neuroanatomist (Dec 18, 2014)

BozillaNZ said:


> Focal length itself does not mean anything.
> 
> Focal length combined with sensor size (diagonal) determines the angle of view. Angle of view determines "telephoto compression"
> 
> So, 135mm on APS-C (1.6x) and 216mm on FF will give you the exact same "telephoto compression".



'Telephoto compression' and 'wide angle distortion' are aspects of perspective – the apparent size and distance relationships between objects in 3D space when projected onto a 2D medium. Perspective is determined *solely* by distance to subject – focal length, sensor size and AoV are irrelevant. 

So your example happens to be correct, but the reasoning is not.


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## Don Haines (Dec 18, 2014)

jrista said:


> This is all beside the point anyway, as all it takes is ONE step, or even to stand up or start standing up, and your target could flee. Birds of the heron family in particular, for example, are extremely skittish birds. If you manage to get close enough to get a decent shot at all, then smaller pixels are going to be a bigger friend to you than getting closer. I can't count how many times just seeing my head barely rise over the top of a ridge was enough to make every heron and egret in the area fly off. Hawks are similar...they can be perfectly content with you sitting there watching them if your not moving. The moment you stand up, they'll leap off their perch and fly right over your head!  (I've had this happen a few times.) Deer are content to get right up in your face so long as your sitting on the ground...stand up, they'll dance around and huff a few times, then wander off. Outside of wearing a ghillie suit, even in camo deer will spot me. If I stand up, they at the very least stand rigid and take notice. Start moving towards them, and they will often bolt.
> 
> It's not necessarily always as easy as taking a few steps closer to your target.


+1

I have a startling inability to walk on water so zooming with my feet rarely works.....


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## takesome1 (Dec 18, 2014)

Don Haines said:


> jrista said:
> 
> 
> > This is all beside the point anyway, as all it takes is ONE step, or even to stand up or start standing up, and your target could flee. Birds of the heron family in particular, for example, are extremely skittish birds. If you manage to get close enough to get a decent shot at all, then smaller pixels are going to be a bigger friend to you than getting closer. I can't count how many times just seeing my head barely rise over the top of a ridge was enough to make every heron and egret in the area fly off. Hawks are similar...they can be perfectly content with you sitting there watching them if your not moving. The moment you stand up, they'll leap off their perch and fly right over your head!  (I've had this happen a few times.) Deer are content to get right up in your face so long as your sitting on the ground...stand up, they'll dance around and huff a few times, then wander off. Outside of wearing a ghillie suit, even in camo deer will spot me. If I stand up, they at the very least stand rigid and take notice. Start moving towards them, and they will often bolt.
> ...



Obviously you need a duck boat with a blind on it. The old FF with a boat blind vs the crop on the bank debate. 

Then there is the opposite question, how do the animals react when you have to get up and run away from them because you are framed to close with a crop body.


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## AlanF (Dec 18, 2014)

takesome1 said:


> Don Haines said:
> 
> 
> > jrista said:
> ...



Use a zoom - the new 100-400.


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## jrista (Dec 18, 2014)

Don Haines said:


> jrista said:
> 
> 
> > This is all beside the point anyway, as all it takes is ONE step, or even to stand up or start standing up, and your target could flee. Birds of the heron family in particular, for example, are extremely skittish birds. If you manage to get close enough to get a decent shot at all, then smaller pixels are going to be a bigger friend to you than getting closer. I can't count how many times just seeing my head barely rise over the top of a ridge was enough to make every heron and egret in the area fly off. Hawks are similar...they can be perfectly content with you sitting there watching them if your not moving. The moment you stand up, they'll leap off their perch and fly right over your head!  (I've had this happen a few times.) Deer are content to get right up in your face so long as your sitting on the ground...stand up, they'll dance around and huff a few times, then wander off. Outside of wearing a ghillie suit, even in camo deer will spot me. If I stand up, they at the very least stand rigid and take notice. Start moving towards them, and they will often bolt.
> ...




+1


LOL, there are indeed all those physical limitations as well...water, cliffs, birds up in trees, etc.


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## jrista (Dec 18, 2014)

takesome1 said:


> Don Haines said:
> 
> 
> > jrista said:
> ...




Well, that one's easy. Switch to a shorter lens, drop a TC, or use a zoom. I think a 150-600 would be an ideal pairing with a 7D II these days...and give you all the versatility you need for framing. Opening up your FoV isn't really an issue, there are options. You can also just wait for your subject to move off a bit to get better framing. There are plenty of easy ways to deal with a subject that is too close. If you really had to, you could crawl away to get farther. I've never had an animal run because I was moving away from it. ;P


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