# *question answered, thank*Could someone post a bokeh test between FF and APS-C??



## 00Q (Feb 5, 2012)

Just modyfying the question as it seems its not clear:

The question is, if I take a picture using a 24-70 f/2.8 for example, on a FF and an APSC. If I then cropp the FF picture by a factor of 1.6 so it is the same size as that on the APS-C, do I get more background blur? ie, does the FF give me more background blur using the same lens? 

---The original post is below: 

I've been told that the FF camera produces more bokeh. I wonder how much this is true. For example, I have a 24-70 f/2.8. I know that the APS-C camera will give me a cropped view. If the above is true, it seems to suggest that its not just a cropped view, but there's more bokeh. Can someone verify this? It'd be nice to compare this. Ive not seen any online comparisons. 

e.g. using a 24-70 at 2.8, put it on FF and APS-C and see how much the bokeh changes. Maybe someone could post 2 pics below for comparison? 

thanks loads,


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## Mt Spokane Photography (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

There is no standard test for Bokeh, its a sort of vaguely defined property of out of focus highlights. The highlights take on different shapes and shadings. Round ones with little or no color fringing are considered best.

It is a property of a lens, not the body, so it does not make a whole lot of sense comparing the same lens on two different bodies, except to confirm what is already well known.

You can view examples of Bokeh at photozone that are likely as good as any, because the same lens and subject is used on both types of camera.

APS-C http://www.photozone.de/canon-eos/501-canon85f12mk2apsc?start=1

Full Frame http://www.photozone.de/canon_eos_ff/502-canon_85f12ff?start=1


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



Mt Spokane Photography said:


> There is no standard test for Bokeh, its a sort of vaguely defined property of out of focus highlights. The highlights take on different shapes and shadings. Round ones with little or no color fringing are considered best.
> 
> It is a property of a lens, not the body, so it does not make a whole lot of sense comparing the same lens on two different bodies, except to confirm what is already well known.
> 
> ...



thanks for the link. It seems that the bokeh stays the same then. Which means that the only difference between the two is that the FF gets more view , and the APS-C is just a cropped view. But according to this link, it means that what ever is cropped is the same as in the FF in terms of bokeh. 

Whey I asked is because I saw a video of a comparison between a Point and Shoot camera and a DSLR, and the DSLR is able to give more bokeh ( things more blurred), than the point and shoot. Which the video attributes to the size of the sensor. Hence I asked if FF sensors blur out the background more than the cropped sensors.


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## Picsfor (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

Suspect that is more to do with lens fitted to P&S.

Remember they're fitted with a sort of 'all in one' lens - where as your DSLR is fitted with a lens designed to do just one or two jobs - which in turn, gives better bokeh control...


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## briansquibb (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

Perhaps you are thinking of background blur?


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



briansquibb said:


> Perhaps you are thinking of background blur?



yes, the same thing. Does FF camera blur out the background more than the aps-c sensors using the same lens at the same f stop?


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## neuroanatomist (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

You're using the term 'bokeh' incorrectly. Bokeh is the quality of the out-of-focus blur, and you're referring to the quantity, I think. As for true bokeh, that's a property of the lens mostly; in some cases, bokeh can be better on APS-C than FF for the same lens, for example, a lens with strong vignetting will have cats-eye shapes for highlights at the edge of the frame, and vignetting is reduced on APS-C for an EF lens. 

As for a comparison of the amount of OOF blur, you can simulate that yourself - it's just math. A FF sensor gives 1.3-stops shallower DoF for the same subject framing (because you're further from the subject with APS-C for the same framing). So, set your 24-70 to 70mm f/4.5 and take a pic, then change the aperture to f/2.8 and that's the DoF you'd get if you took the same shot on FF at f/4.5. 

You're also misinterpreting the links given above, the framing isn't the same. There is more OOF blur with FF for the same framing.


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## Mt Spokane Photography (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



briansquibb said:


> Perhaps you are thinking of background blur?



+1

You beat me to it!

Also, Bokeh os not described as more or less, its a quality thing, while background blur can be more or less, and is definitely less in a typical point and shoot. That can be good, if everything needs to be in focus, it depends on what you like.


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## LostArk (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



00Q said:


> I've been told that the FF camera produces more bokeh.



Whoever told you this was probably trying to tell you that at an equivalent field of view FF gives smaller depth of field. For example, because of the 1.6x crop factor, to get the equivalent field of view of a 50mm lens on FF, you'd have to use a 30mm lens on APS-C. The difference in depth of field is because of the different focal lengths, not due to sensor size. Depth of field is a function of focal length and aperture only, and has nothing to do with sensor size. In the simplest terms, APS-C gives about 1 f/stop greater depth of field than FF at any given field of view. Hope this clears up any confusion.


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



LostArk said:


> 00Q said:
> 
> 
> > I've been told that the FF camera produces more bokeh.
> ...



The question is, if I take a picture using a 24-70 f/2.8 for example, on a FF and an APSC. If I then cropp the FF picture by a factor of 1.6 so it is the same size as that on the APS-C, do I get more background blur? ie, does the FF give me more background blur using the same lens?


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## LostArk (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



00Q said:


> The question is, if I take a picture using a 24-70 f/2.8 for example, on a FF and an APSC. If I then cropp the FF picture by a factor of 1.6 so it is the same size as that on the APS-C, do I get more background blur? ie, does the FF give me more background blur using the same lens?



Depth of field is a function of focal length and aperture *only* (and subject distance). If you took a picture on FF and APS-C at the same focal length, aperture, and subject distance then cropped the FF image, you'd end up with the exact same image as the APS-C photo.


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



LostArk said:


> 00Q said:
> 
> 
> > The question is, if I take a picture using a 24-70 f/2.8 for example, on a FF and an APSC. If I then cropp the FF picture by a factor of 1.6 so it is the same size as that on the APS-C, do I get more background blur? ie, does the FF give me more background blur using the same lens?
> ...



Right, thanks. That answers the question!  Just as what I thought. In which case, nothing to do with the sensor.


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## LostArk (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

Not quite. While technically depth of field has nothing to do with the sensor, like I said in my earlier post FF gives narrower depth of field at the same _field of view_, because a shorter focal length must be used on APS-C to give an equivalent field of view. Depending on your application, this can be an advantage or disadvantage.


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



LostArk said:


> Not quite. While technically depth of field has nothing to do with the sensor, like I said in my earlier post FF gives narrower depth of field at the same _field of view_, because a shorter focal length must be used on APS-C to give an equivalent field of view. Depending on your application, this can be an advantage or disadvantage.



you are confusing me. Why don't some some just take a photo and we can end this discussion. I dont have a FF. Take a photo using FF, crop it so it is the size of an APS-C. Then take the same photo on the APS-C, everything else unchaged. and we can compare the background blur.


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## neuroanatomist (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



00Q said:


> Just as what I thought. In which case, nothing to do with the sensor.



For the same image, true - you get the same effect by using a crop sensor as by cropping an image from a larger sensor. But that's not the whole story...there's no way to 'anti-crop' an APS-C image, so the shallowest DoF possible on APS-C with an EF lens is f/1.2, equivalent to f/1.9 on FF. To get DoF any shallower, you need a bigger sensor. Put another way, to achieve the DoF of f/1.2 on FF using an APS-C sensor, you'd need an f/0.75 lens - good luck finding one!


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



neuroanatomist said:


> 00Q said:
> 
> 
> > Just as what I thought. In which case, nothing to do with the sensor.
> ...



Im so confused. Isnt the DoF totally dependent on the aperature of the lens? ie if I use the same lens at the same aperature, I will get the same amout of thing sin focus whether on FF or APSC


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## epsiloneri (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



00Q said:


> you are confusing me. Why don't some some just take a photo and we can end this discussion. I dont have a FF. Take a photo using FF, crop it so it is the size of an APS-C. Then take the same photo on the APS-C, everything else unchaged. and we can compare the background blur.



Let me try to de-confuse you. If you have the same lens at the same settings, then a 7D would register the same image as a 5D2 cropped to APS-C, just like was said before. So background blur, bokeh, everything would be the same (except the number of pixels). No point in taking photos. 

BUT: If you _don't_ crop the 5D2 image, then you would, for the exact same lens etc, detect a wider field on the FF sensor. In order to get the same framing with the 5D2 as with the 7D, you would have to zoom in a factor of 1.6. If you kept everything else the same, that change in focal length would change the image so that it would no longer be exactly the same. That is what LostArk and neuroanatomist are trying to tell you.


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## 00Q (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



epsiloneri said:


> 00Q said:
> 
> 
> > you are confusing me. Why don't some some just take a photo and we can end this discussion. I dont have a FF. Take a photo using FF, crop it so it is the size of an APS-C. Then take the same photo on the APS-C, everything else unchaged. and we can compare the background blur.
> ...



+1

thanks !


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## neuroanatomist (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*

Let's try it this way. 

The second image is from a crop sensor, so it has less OOF blur.  












Please take this in the spirit in which it's intended - I recognize that discussions like this can get confusing, and it could be worse - I didn't even bring up the concept of the Circle of Confusion, which is relevant here.


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## elflord (Feb 5, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



00Q said:


> Im so confused. Isnt the DoF totally dependent on the aperature of the lens? ie if I use the same lens at the same aperature, I will get the same amout of thing sin focus whether on FF or APSC



Depth of field depends on focal length, aperture, and how close the subject is to the camera.

If you do the following: 

(1) take a picture on a full frame at 50mm f/1.4 standing 10m from the subject
(2) take a picture on an APS-C at 50mm f/1.4 standing 10m from the subject 

the depth of field is the same, but the field of view will be greater with the full frame. If you crop, you will get the same picture. 

But suppose instead, you: 

(1) take a picture on a full frame at 80mm f/1.4 standing 10m from the subject 
(2) take a picture on an APS-C at 50mm f/1.4 standing 10m from the subject 

The field of view is the same (that is, you get "the same picture"), but in the full frame example, the focal length is larger, which means you get shallower depth of field. You could get the same dof by putting 80mm on a crop and shooting at f/1.4, but then you wouldn't have the same picture any more -- the full frame user could switch to a longer focal length (128mm) and get the same picture with shallow depth of field.


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## 00Q (Feb 6, 2012)

*Re: Could someone post a bokeh test between FF and APS-C??*



elflord said:
 

> 00Q said:
> 
> 
> > Im so confused. Isnt the DoF totally dependent on the aperature of the lens? ie if I use the same lens at the same aperature, I will get the same amout of thing sin focus whether on FF or APSC
> ...



thanks, question settled


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