# 7D vs 5D3 noise @ ISO400



## Hydrogen (Mar 31, 2013)

This subject has been beaten into the ground, but I was surprised at how much noise I was seeing in even ISO 400 images in broad daylight with a 7D compared to my 5D3. See comparison below.

The short story is I have two 5D2 refurb's and two 7D refurb's that I am evaluating as a backup body to my 5D3.

I believe I am going to stick with the 5D2. Using Reikan's FoCal, both 5D2's OUTER AF points outperformed all 19 points from both 7D bodies in both Quality of Focus (QoF) and AF accuracy. I will post a separate comparison of them in a new thread tomorrow.

Both are 100% crops of shots of the northern sky at ISO 400, RAW OOC, zero NR. First is the 5D3; second is the better of two 7D copies I am evaluating. You will need to download/save them to see the noise more clearly.


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## Radiating (Mar 31, 2013)

ISO 400 on the 7D and 5D3 are completely different sensetivity levels and it's misleading to directly compare them.

Cameras are a function of geometry. 

People have been misled with crop to full frame conversions for years.

The "35mm equivalent" is what is really important and nothing else. Your images on 35mm equivalent will always look the same no matter what.

From a physics perspective the "35mm equivalent" is capturing identical information. What really matters is the geometry of the light hitting the sensor, and with 35mm equivalent the geometry will always be the same for a given equivalence. Not only that but your flash settings etc will be identical:

On 7D compared the the 5D Mark III


The sensor is 1.6 x 1.6 times smaller.

35mm equivalent aperture - Multiply F-Number by (1.6 ) . (an f stop is a base 2 log, so even though we have 1.6x1.6 times as much light we take the square root, which is 1.6 to multiply the F number by. (example 2.8 x 1.6 = 4.48, 4.0 x 1.6 = 6.4))

35mm equivalent focal length - Multiply by 1.6

35mm equivalent ISO or light sensitivity - Multiply by (1.6 x 1.6) (bet you haven't heard of that, but if you do the math the 7D's sensor amplifies the signal 1.6x1.6 times more at a given ISO than the 5D3, so even if both say ISO 800, ISO 800 on the 7D is multiplying the pixels the same as ISO 2000 on the 5D Mark III)

It's like saying:

I have a million dollars, and then failing to mention these are Zimbabwe dollars worth $20 not, American dollars.

Yes aperture ISO and focal length are fixed numbers, but so are monetary figures, and the most important thing even the most basic dealing of currency has is WHAT currency you're dealing with, and 99% of people require an "equivalent" frame of refference to understand foreign currency or need to do a conversion. Likewise with cameras, geometry (type of currency) is the most important thing when dealing with the performance of a camera system, and the first thing anyone needs to do is bring up a conversion to the local frame of reference.


So it is misleading to compare the 7D vs 5D3 at equal ISO because for a given depth of field they will have different apertures


So in other words theoretically a Crop set to:

#1. 17mm - f/2.8 - ISO 800 - 1/50th - with 1/4 flash
#2. 55mm - f/2.8 - ISO 800 - 1/50th - with 1/2 flash

Will produce a 100% identical image with no difference in exposure, lighting, depth of field, field of view or composition when compared to a full frame set to:

#1. 27mm - f/4.48 - ISO 2048 - 1/50th - with 1/4 flash
#2. 88mm - f/4.48 - ISO 2048 - 1/50th - with 1/2 flash

Literally no difference.

Now of course each lens will have it's own characteristics and each body will likewise have it's own, and full frame lenses will delivery much better image quality than crop typically as will any full frame body, but if both bodies and lenses were theoretically perfect and had the same resolution these settings would deliver the exact same with completely identical pixels.

Hope that helps.


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## Hydrogen (Mar 31, 2013)

Radiating said:


> ISO 400 on the 7D and 5D3 are completely different sensetivity levels and it's misleading to directly compare them.
> 
> Cameras are a function of geometry.
> 
> People have been misled with crop to full frame conversions for years.



The 5D3 was my first FF camera body. I previously used crops... 20D and 40D. As stated, I am evaluating either a 7D or 5D2 as a backup to the 5D3.

I am not a physics major and thus, I am not going to dispute Radiating's calculations and references to physics. I understand that it isn't a 1:1 comparison, but...

What I do know is that a photon of light is still the same size regardless of sensor and that a crop sensor 'extrapolates' the equivalent pixel dimensions due to the fact that pixel density is so great and thus pixel size is so small, that is is practically splitting a single photon of light.

I also know that at the end of the day, if any of us were to print either OOC image to their largest extent @ 300 dpi, that we would see the difference between the 7D and the 5D3 as seen clearly by these 100% crops and therefore, the reality is that a crop body's sensor is simply inferior.

Desiring to hold on to the 'reach' (cringe) benefits of APS-C, I wanted very much to keep the 7D as an all-around versatile camera and as a backup to the 5D3. After the pictures I took today, and the grain I see in them even at 50% (heck, even looking at the entire image sized to fit on a 15" laptop display) there is clearly an improvement in IQ from a FF body.

After evaluating the 7D, it's clear an APS-C is inferior. It's just the reality of physics. We can't shrink light any further, but we are trying to over-resolve it. Here come the arrows and darts...


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## bdunbar79 (Mar 31, 2013)

Radiating said:


> ISO 400 on the 7D and 5D3 are completely different sensetivity levels and it's misleading to directly compare them.
> 
> Cameras are a function of geometry.
> 
> ...



Ah yes, ok. So it's okay and just normal to have noise at ISO 400 on a 7D. Thanks.


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## kirispupis (Mar 31, 2013)

I used to own a 7D, owned a 5D2 at the same time, and now own a 5D3.

The 7D has abysmal image quality at high ISO. You are correct that even at ISO 400 it was noticeable. The max I shot at with the 7D was ISO 800, because after that the image quality was simply unacceptable. With my 5D2 I was comfortable shooting up to ISO 3200 and on the 5D3 I comfortably shoot at 6400 and sometimes at 12800 depending on the subject.


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## mmason (Mar 31, 2013)

H2

(I assume you are named after a molecule and not an atom).

Anyway, something that has been hinted at but not stated outright regards inspecting photos from 2 different cameras with 2 different pixel densities and comparing both at 100%. The camera with the greater pixel density is at a disadvantage. To be fair, compare photos standardized to the same conditions.

That being said, all us 7D owners know that noise reduction is standard procedure. Hearing that the 5D mk 3 has less noise is wonderful news, as it has a larger, less dense, newer design sensor. It should be better at pretty much everything IQ wise.

If you really need the reach, you may want to give the 7D another try. Process as you would expect to for a useable photo and resist the temptation to peek at 100%.

Personally, if the 7D mk 2 is less than a year out and does indeed have a significantly upgraded sensor, I would wait.

Mark


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## steven kessel (Mar 31, 2013)

"The 7D has abysmal image quality at high ISO. You are correct that even at ISO 400 it was noticeable. The max I shot at with the 7D was ISO 800, because after that the image quality was simply unacceptable."

My experience exactly. I own both a 5D iii and a 7D. I do a lot of wildlife photography and the most lens that I can afford is the 100-400 F4-5.6 L IS. It's a fine lens and very sharp but it doesn't have all that much reach for tiny birds and distant animals. So, I do a lot of cropping in order to make my images viewable. Sometimes I crop 50% or more of the original image.

With the 7D and that much cropping, the highest ISO I can work with, even in bright daylight, is 320. I sometimes go as high as 400 but there is noticeable image degradation and noise at that ISO with a big crop. The 5D iii is a totally different story. My "go to" ISO with the 5D iii is 640. Frequently, I bump that up to 800, and occasionally, to 1200. All of these ISOs produce nearly noise free images for me, even in very low life. 

For my money, the 5D iii produces the most noise free images of any camera I've worked with. It runs rings around the 7D.


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## MichaelHodges (Mar 31, 2013)

No question that the 7D is noisier than the 5D2 and 5D3. I see a lot of blue channel noise at low ISO. And yes, the IQ overall is better on the FF cameras. The images are a level or two sharper and cleaner when viewing RAW files.

I primarily shoot wildlife, and there are some tricks to employ for the 7D. First, for wildlife, I find that using spot metering helps to make sure the subject is exposed properly. The 7D is not kind to anyone who is underexposing, and wildlife will often be in shady areas (bushes, under the canopy, etc). This compounds the problem.

If you are careful with exposure on the 7D and employ spot metering, I find you can use up to ISO 1600 in RAW, even with cropping. I have found that Lightroom seems to be superior for this as well. It does a better job of preserving detail while reducing noise than DPP.

Also consider how much you will have to crop on the FF to get the 7D's perceived reach. In my comparisons, having to crop so much on the 5D's puts them on lesser footing than the 7D in IQ. If I did not shoot wildlife and my focus was people, I would still own the full frame cameras. But the 7D is an outstanding wildlife camera when you become familiar with it. I'd still recommend it for that in a second.

------------

http://michaelhodgesfiction.com/


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## neuroanatomist (Mar 31, 2013)

MichaelHodges said:


> Also consider how much you will have to crop on the FF to get the 7D's perceived reach. In my comparisons, having to crop so much on the 5D's puts them on lesser footing than the 7D in IQ. If I did not shoot wildlife and my focus was people, I would still own the full frame cameras. But the 7D is an outstanding wildlife camera when you become familiar with it.



Interesting. My testing (and that of others here) suggest that low ISO, the cropped FF image has equivalent IQ (but fewer MP), and at high ISO, the cropped FF is clearly superior. I'm quite familiar with the 7D - and since getting the 1D X, my 7D has become quite familiar with the inside of a Storm case, and has forgotten what it's like to have a lens mounted.


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## ashmadux (Mar 31, 2013)

This is one of the craziest comparisons ever. 7d is certainly no noise champion. 

Lord help you if you receive a 7d with wacky AF...once my AF went, the camera was completely unusable fort the last year i had it. The most frustratingly under performing camera i have ever come across.


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## maxcolefilms (Mar 31, 2013)

Try shooting your 7D on iso multiples of 160. 160, 320, 640 and so on. I've noticed a big difference in noise when I use ISO multiples of 160. One my fellow 7D owners turned me on this and I've never gone back. After reading this thread, 160ISOs seem to make more sense to me when factoring in the 1.6 crop.


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## alexanderferdinand (Mar 31, 2013)

So the sensor of the Sony RX100 is a very good piece of engineering. It has only 1/7 of the sqare size of an FF, and shows very good results, when I have to push them because of underexposure.
I had an 50D as a backup to my 5D2, didnt want to use it on higher ISO than 800....
I would like to see a better APS-C sensor from Canon, doenst matter if it has 12, 16 or 24 MP......


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## Radiating (Mar 31, 2013)

Hydrogen said:


> Radiating said:
> 
> 
> > ISO 400 on the 7D and 5D3 are completely different sensetivity levels and it's misleading to directly compare them.
> ...



See that's where your wrong, the 7D isn't working with less light because it has a smaller sensor, and it's getting nowhere near splitting photons. This isn't the issue. The amount of noise you get in an image is based on the amount of light being emitted by the object. Noise (for the most post) is a result of the quantum properties of light in that light exists as a gausian distribution of photons, light isn't emitted uniformly but photons hit an object at random. The difference in light and dark areas in an image resulting from noise are caused therefore because in the light area you had 16 photons and in the dark area you had say 9. Because of random probabily the light from your subject doesn't arrive at a uniform time. Overall the random noise will average out so if you leave the shutter open for twice as long you might get 25 photons in the light area, and say 26 in the dark area of two pixels. The reason different cameras have different noise levels is because for the most part cameras throw away some of the photons because the whole surface of a sensor doesn't absorb light, and some of the light is absorbed by the micro lenses and bayer dye. Then on top of that cameras introduce a slight amount of electrical noise (though electrical noise can be a big issue in astro photography).

For the most part though noise comes from the subject, and the difference between noise comes from the amount of light the camera throws away.

Though the 5D3 does throw away less noise and introduce less electrical noise than the 7D. (5D3 throws away 51% of light, 7D throws away 59%)

Anyways like I said 

So in other words theoretically a Crop set to:

#1. 17mm - f/2.8 - ISO 800 - 1/50th - with 1/4 flash
#2. 55mm - f/2.8 - ISO 800 - 1/50th - with 1/2 flash

Will produce a 100% identical image with no difference in exposure, lighting, depth of field, field of view or composition when compared to a full frame set to:

#1. 27mm - f/4.48 - ISO 2048 - 1/50th - with 1/4 flash
#2. 88mm - f/4.48 - ISO 2048 - 1/50th - with 1/2 flash

Literally no difference.

What I mean by this is you would technically capture even the exact same photons. 


To photograph something clearly part of the light coming from the object must be ignored because when light hits an object it is scattered in all directions. To see the details of an object clearly, you have to selectivly remove the light which isn't paralell to the line of sight between you and the object. Otherwise the image will be blurry.

To accomplish this all that is needed is an aperture, or something that blocks the path of the light which blurs blur your image. The thing is that the sensor size is part of the aperture too in that it removes light that is less parallel to the line of sight.







This is why when you use a 1.4x teleconverter it projects an image circle that is greater than your sensor size, and it therefore reports the lens as having an aperture 1 stop lower, because the lens allows light which is less parallel to the line of sight to make it onto the captured image circle. We measure aperture values from the lens' perspective and ignore the camera though which is why this is confusing. 

Full frame lenses on crop simply project an image circle that is greater than the sensor and so they are always fundamentally stopped down a little. To compensate the light is multiplied in intensity so our exposure calculations aren't off, so a given sensor sensetivity is labled ISO 2048 on full frame but is labled ISO 800 on crop instead of labling aperture f/2.8 aperture f/4.48. By using a 1.6 teleconverter or 1.6 crop camera with a theoretically perfect lens at a 35mm equivalent: aperture, ISO and focal length you will be ignoring the exact same photons as you would on full frame and you will literally be collecting the exact same photons, and if we use a theoretically perfect camera, you would get the exact same image photon for photon, pixel for pixel. Light doesn't care how dense it is because light is 99.99999999999% empty space, all that matters is bending the optical path correctly to capture the nessesary photons.

The problem we run into of course is just that the manufacturers don't make lenses that can bend a crop camera's photons the way we want. There's no 17-55mm f/1.8 lens. And the reason why full frame is better is because when you're bending the optical path on a crop camera it has to be more precisely done for a given resolution, so with a given level of precision in the manufacturing process, particularly our abbility to polish and assemble the lenses precisely, full frame lenses will have more resolution due to magnifying the flaws in our manufacturing process less. Likewise medium format cameras magnify the flaws in the manufacturing process even less so we have even better lens resolution from them.

Crop cameras currently have slightly worse sensors too. As I mentioned the 5D3 absorbs 20% more light than the 7D and it's electronics introduce less noise for a cleaner result. Overall we're talking a half stop or more at euqivalent aperture and ISO.


With that said the 7D also can't be stopped down as far, it would have to shoot at ISO 19 to get an image with as little noise as a 5D3 at "low" ISO. 

So on crop you have worse sensors, worse ISO ranges, worse lens resolution, and they don't make fast enough lenses for crop cameras like 17-55mm f/1.8 lenses. 

On the other hand some will argue they don't make long enough lenses for full frame, so crop is better for reach, especially compared to teleconverting, as you will have a theoretically perfect teleconverter with better autofocus.


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## MichaelHodges (Apr 1, 2013)

neuroanatomist said:


> Interesting. My testing (and that of others here) suggest that low ISO, the cropped FF image has equivalent IQ (but fewer MP), and at high ISO, the cropped FF is clearly superior. I'm quite familiar with the 7D - and since getting the 1D X, my 7D has become quite familiar with the inside of a Storm case, and has forgotten what it's like to have a lens mounted.



I used both cameras, shot squirrels and birds (objects that usually require substantial cropping), then cropped the FF to equal the 7D view. What I found, upon printing was the 7D images were superior...and the 7D hasn't even been cropped yet. 

Other than that, the FF cameras are a couple levels better all around. I wouldn't hesitate to recommend the 7D for wildlife over the others. For everything else, go with the FF. In viewing RAW files, without cropping, they have a significant IQ advantage over the 7D.


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## neuroanatomist (Apr 1, 2013)

MichaelHodges said:


> neuroanatomist said:
> 
> 
> > Interesting. My testing (and that of others here) suggest that low ISO, the cropped FF image has equivalent IQ (but fewer MP), and at high ISO, the cropped FF is clearly superior. I'm quite familiar with the 7D - and since getting the 1D X, my 7D has become quite familiar with the inside of a Storm case, and has forgotten what it's like to have a lens mounted.
> ...



I've done both contrived testing (static scene and ISO 12233-type chart) and real-world (birds/squirrels) comparisons of the 5DII vs. 7D and 1D X vs. 7D. In a controlled environment, cropped FF = 7D for IQ (at high ISO the 1D X has a significant advantage). In the real world testing, the 7D was better than the 5DII due to the AF; the 1D X beats the 7D there, and ties (low ISO) or wins (high ISO). 

Here are a pair of 100% crops of squirrel noses at ISO 3200. Can you tell which is the 1D X and which is the 7D? :


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## MichaelHodges (Apr 1, 2013)

I haven't shot the 1DX, but it looks like an awesome camera. 

What's nice about the 7D versus full frame is large prints. I found I was cropping too deeply with the 5D's, and this was affecting print quality at the sizes I prefer to print.

Another poster mentioned the wacky auto focus. I had one of those 7D's, too (and a peeling grip). Luckily, Canon was able to fix both.

Since fine-tuning my 7D, I find myself lusting less and less for camera bodies. Yes, it's a pretty noisy camera, but Lightroom does a masterful job of keeping detail while removing noise. I'm much more interested in location, location, location. I doubt I'd even upgrade to the 7DII.


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## AlanF (Apr 1, 2013)

Radiating said:


> The amount of noise you get in an image is based on the amount of light being emitted by the object. Noise (for the most post) is a result of the quantum properties of light in that light exists as a gausian distribution of photons, light isn't emitted uniformly but photons hit an object at random. The difference in light and dark areas in an image resulting from noise are caused therefore because in the light area you had 16 photons and in the dark area you had say 9. Because of random probabily the light from your subject doesn't arrive at a uniform time..



Photon noise is caused by the number of photons collected during exposure being small and hence subject to statistical variation. The number collected follows a Poisson distribution, not a Gaussian. The Poisson distribution approximates to a Gaussian when the number becomes very large, and noise is then no longer a problem. The noise varies as the square root (sqrt) of the number of photons collected, N. So signal/noise varies as N/sqrtN, that is sqrtN. Although an APS-C pixel is smaller in area by approximately 1.6x1.6 times, and thus collects 1.6x1.6 less photons, the sqrt dependence of signal/noise on N means that it is only 1.6x noisier than an FF pixel for photon noise, which is the dominant noise source.


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## Kiboko (Apr 1, 2013)

My 7D replaced a 1D MKIIn, an 8MP camera, (cost well over £2000 when new), - the 7D was a revelation yet the 1D was very much a professional camera at the top of the pecking order when I first got it. 
And all this talk of high ISO and noise! When I used film, (not SO long ago - all my travel and wildlife images are still with Latitude stock library), I shot on Fuji Velvia, 50 ISO, rated at 40 ISO, or Provia, rated at 80. Latitude's current submission requirements state "ensure ISO does not exceed 200 unless absolutely necessary." So I shoot at 100, sometimes 200, and infrequently, if necessary, at 400 ISO. How easy photographers have it these days with the availability and functional use of high ISO's, - yet expectations are SO high, - I wonder how they'd cope if they suddenly found themselves with Velvia loaded in their film camera? I reckon we'd see a load of blurry images!


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## AlanF (Apr 1, 2013)

If you specialise in photographing squirrels noses at iso 3200 at 30 yards and doing 100% crops, then the 7D is not for you. But, here is one of my favourite photos: a kingfisher caught leaving his roost at the speed of a rocket using a 7D with f/2.8 300 II plus 2xTC III at 1600 iso, 1/4000, f/8 in Raw with absolutely no noise reduction. It is the whole frame. When you pixel peep you see the noise, but you don't need pixel peeping to see this photo.


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## SPG (Jun 20, 2013)

The physics of photons is all well and good, but the reality is that the image on the 5D3 is going to be less noisy simply due to the fact that it's a much newer sensor with better technology. Count all the photons you like, multiply by 1.6, divide by pi, whatever...the 5D3 will be less noisy. However, the 5D3 can't come anywhere close to the fps of the 7D so as someone who owns both, I'm not getting rid of mine any time soon.


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## JM Photography (Jun 21, 2013)

An exceptional image does not equal exceptional image quality. A 7D is capable of capturing an exceptional image, especially under ideal conditions; however, it has never had exceptional image quality. There are more factors than just image quality benefits when comparing 7D to newer full frame tech - color rendition, depth of focus, focus points, etc., which all ultimately alter the final product.

Our 7D sits nicely on the TV stand, occasionally being dusted off to test new lenses, used as the occasional backup, and as a training tool. Overall, I'm more inclined to crop our full frame images and enjoy the other benefits provided by the 5D3 rather than utilizing the extra reach of the 7D.


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## Pi (Jun 21, 2013)

Everything said about equivalence, etc., is correct but it is also a well kept secret that the 7D has problems with blue skies, even for a crop body. The crop Nikon cameras are much better in that respect.


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