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Full Frame vs. APC (1 Viewer)

toothtango

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Full Frame vs. APS-c

Is there a preference one over the other for taking photos of birds in the field. Does the APS's smaller sensor give more focal length for a given lens over the full frame camera. If it is true that you can gain a certain percentage of focal length for a lens with the smaller sensor, then would it be cheaper to buy an APC body over a more costly longer lens. I have a !Ds MII and want more focal length than 400mm from my 100-400 zoom. A teleconverter may drop me from autofocus to manual. An APS body may give me more focal length while retaining AF. What am I missing here?
 
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As a rule of thumb, the larger the sensor the better the image quality, particularly at high ISO ratings.
 
As a rule of thumb, the larger the sensor the better the image quality, particularly at high ISO ratings.


It can lead to noise as well on a non full frame sensor.Your not really gaining much with crop factors of 1.6x-1.3x.To benefit from a full frame sensor you really need to use a high quality lens because cheaper lenses are optimized to sharp in the centre (for a crop factor camera)the image quality will drop off at the edges.So in short I would keep the 1ds & save up for a prime lens that takes teleconvertors something like the Canon 300mm f2.8 which works well with a 1.4 & 2x teleconvertor.

Steve.B :)
 
Your 1 series camera should auto focus with a TC so you can have the extra reach you want and maintain AF. Also modern D-SLR's manage high ISO's very well so you can have the extra 'reach' of the 1.6 crop and have good IQ.
Here's one I took yesterday with a Canon 7d and a 100-400mm. Light levels were poor so I pushed my ISO to 2500. You'll have to excuse my post processing as its not very good, I'm sure someone who's better at PP would have had a better end result than me.
 

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If you start from a couple of assumptions - that you can't get any closer and you're using your longest lens, yet you still can't fill the frame - then the 7D is better. Because it has a higher density of pixels on its sensor the image of the bird covers more pixels and, hence, shows more detail.

Romy Ocon, otherwise known as Liquistone, is a first-class bird photographer. He did a test to show that the higher pixel-density of the 7D does give more detail that a 5D when shooting the same subject, with the same lens, from the same distance. LINKY.
 
Anyone who "insists" that FF images are inherently better in IQ terms than crop images simply doesn't know how to process their files properly - there's only a tiny (and largely irrelevant in birding terms) set of circumstances where that's even likely to be true.
 
I have got a question that's related to this and that is:

Why did digital camera manufacturers not start off with full frame sensors across all their cameras from the start? Why was APS-C the chosen size?
 
I have got a question that's related to this and that is:

Why did digital camera manufacturers not start off with full frame sensors across all their cameras from the start? Why was APS-C the chosen size?

Historically large digital sensors were difficult and expensive to manufacture. There's still a large premium for going full frame. The 5D and the D700 are the two cheapest, but there a bit more than the most expensive cropped sensor cameras, like the D300s or the 7D.
 
Is there a preference one over the other for taking photos of birds in the field. Does the APS's smaller sensor give more focal length for a given lens over the full frame camera. If it is true that you can gain a certain percentage of focal length for a lens with the smaller sensor, then would it be cheaper to buy an APC body over a more costly longer lens. I have a !Ds MII and want more focal length than 400mm from my 100-400 zoom. A teleconverter may drop me from autofocus to manual. An APS body may give me more focal length while retaining AF. What am I missing here?

To answer your question, can APS sized cameras give a longer focal length, this answer is no. The focal length of your system is governed by your lens, so if you have a 300mm F2.8 lens, the FL of 300mm will be fixed no matter what the size of chip. The smaller APS chips are giving you a smaller field of view, thats all. Because the view finder is the same size (more or less) on cameras, the APS camera's expand the image to fit the size of the viewfinder, so in essence the image appears larger with a narrower FOV, imitating a longer FL.

Generally if you compare a FF camera and an APS camera that both have the same pixel size, then there is no difference, except a larger field of view with the FF camera.

Magnification relates to the pixel size, the smaller the greater the magnification, everything else being equal.

Just think of this: if you have a smaller chip (APS camera). then you get a longer focal length - yes? well expand this logic further and lets go for a small chip of 10x10 pixels, wow, what an amazing focal length, I could see all the kingfishers from 10 miles lol. But of course, that is not the reality.

Adrian
 
To answer your question, can APS sized cameras give a longer focal length, this answer is no.

Adrian
Absolutely right of course Adrian, it is just the FOV that changes. But I do think that Cameras like the 7D can give you an advantage if you are 'reach' limited. The crop gives you all the pixels in the business part of the frame (the centre) - this can give you a bit more 'cropabiliy' as opposed to cropping a full frame or 1.3 cropper to the same FOV. To get the the same number of pixels in the 1.6 cropped portion of the image (7D) a FF camera would need to be about 46 MP and a 1.3 cropper would need to be around 30 MP

Another added bonus is that lenses perform best in the centre and tend to deteriorate as they reach the edges so with a 1.6 cropper you are only seing the best part of the lens.

In summary I would say that if you can get near to your subjects (shooting from hides and the like) then I would probably go for a FF or 1.3 cropper but if you are generally reach limited then the 7D can help.

Just my 2p's worth
 
Absolutely right of course Adrian, it is just the FOV that changes. But I do think that Cameras like the 7D can give you an advantage if you are 'reach' limited. The crop gives you all the pixels in the business part of the frame (the centre) - this can give you a bit more 'cropabiliy' as opposed to cropping a full frame or 1.3 cropper to the same FOV. To get the the same number of pixels in the 1.6 cropped portion of the image (7D) a FF camera would need to be about 46 MP and a 1.3 cropper would need to be around 30 MP

Another added bonus is that lenses perform best in the centre and tend to deteriorate as they reach the edges so with a 1.6 cropper you are only seing the best part of the lens.

In summary I would say that if you can get near to your subjects (shooting from hides and the like) then I would probably go for a FF or 1.3 cropper but if you are generally reach limited then the 7D can help.

Just my 2p's worth

Hi Roy

For birding, you are quite right to argue that the APS camera's are probably more appropriate as it is fairly uncommon to get close enough to fill the frame and generally there is a lot of wasted space. I have a 1Ds MkIII which I also use for landscapes etc, so do like the FF.

Also the pixel density is generally higher for the latest APS camera's, so you do get a bit more magnification than current FF camera's, so again good for photographing birds.

Overall, I think the 7D would be an excellent choice for just photographing birds, but I did want to dispel this myth regarding the crop factor and focal length which comes up time and again, particularly in magazines.
Adrian
 
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