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Let's set the record straight on Crop cameras and telephoto advantage?


landscape_shooter

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<p>I keep hearing different opinions as to whether crop cameras have an advantage with tele photo lenses or not. Some people say full frame will produce the same image quality by using let' say a 300mm photo and cropping in your computer compared to a 1.6 camera with the same lens. It probably is nicer to see let's say a bird closer when looking through your camera with a 1.6 camera than the smaller view of the bird in a full frame camera. Looking for answers from people that have tried both full frame and crop cameras side by side or fact based reviews etc. </p>
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<p>Some people say full frame will produce the same image quality by using let' say a 300mm photo and cropping in your computer compared to a 1.6 camera with the same lens</p>

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<p>What cameras are you talking about here? If you use a 5D Mk II (21 mpx) and crop the image to an equivalent image of a 1.6 crop camera taken with the same lens I believe you would get an image of about 8 megapixel. So yes, same image quality as the old 20/30D but not as good as the newer 40D and the 50D.</p>

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<p>This is going to turn out to be a very long thread and will no doubt cause a few arguments.</p>

<p>Here's my theory anyway:</p>

<p>It is definitely nicer to see the bird fully in the viewfinder using a crop camera than it is to see it in the distance when using a full frame camera, knowing that you will end up cropping away 60% of what you see. That is definitely a crop camera advantage as far as I am concerned.</p>

<p>With the latest crop cameras like the 50D which squeezes a massive 15MP onto it's APS-C sensor, you will get more pixels overall than you would if you cropped a 21MP 5D2 full frame shot down to the size of a 50D shot. Cropping a 21 megapixel full frame image down to one the size of the 50D would actually give you around a 9 megapixel image. In that respect, theoretically, the 50D image should give higher pixel resolution and better image quality.</p>

<p>However, when you take into consideration the other benefit of full frame sensors - low noise and a generally cleaner image - then the gap is closed again. I have not done any testing but I really don't think there will be much difference between the two when printed to 16" x 12".</p>

<p>If 80% of my work was long telephoto work I would probably go for a 50D if it was going to be my only camera. As it happens, my photography varies greatly and for that purpose full frame cameras definitely reign supreme.</p>

<p>OK, let the arguments begin...</p>

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<p><em>However, when you take into consideration the other benefit of full frame sensors - low noise and a generally cleaner image - then the gap is closed again.</em></p>

<p>It's more complex than that because when you crop and then enlarge a 35mm sensor image, you're also enlarging noise. A camera with higher per pixel noise can appear to have less overall noise in print if it has a higher density of pixels, i.e. each pixel is smaller on the print and has less visible impact. I'm not so sure the 9 MP center of a 5D mkII would look cleaner than a full 15 MP 50D image, though I must admit without testing I can't tell you which would be cleaner in print. Either way, this is only an issue at high ISO.</p>

<p>I think there is an APS sensor telephoto advantage, but it's probably not a huge difference compared to a 5D mkII. It would be larger compared to the 12 MP sensors.</p>

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<p>I follow Chris Jensen's train of thought here.<br>

To my way of thinking, you see a subject fill more of the view finder and the final image with a crop camera than with a full frame camera. So if I want to use a telephoto lens, that's going to go on a crop camera and if I want to use a shorter lens, it's going to go on the full frame body.</p>

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<p><em>I keep hearing different opinions as to whether crop cameras have an advantage with tele photo lenses or not.</em><br>

In my view, this has very little to do with the facts and much more with the different definitions of 'advantage', which is a very subjective word. As is 'image quality'. There's many things to weigh against each other: price, weight, availability of lenses, noise, resolution, dynamic range, viewfinder image, etc.<br>

Remember that pixel pitch and sensor size are not necessarily related.</p>

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<p>I have never owned a Canon crop camera but have tested my Nikon DX (1.5 crop factor) vs FX (full frame) vs Canon full frame 5D). I have found in my testing that the 'cropped' full frame images (about 6mp) deliver equal or better results than the cropped cameras (12mp). It appears that fewer 'larger' pixels are better than more 'smaller' pixels under many shooting conditions (I am generalizing).</p>
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<p>I'm going birding for Eagles today. I'm leaving the 5D at home and taking the crop-sensor, and it's not for no reason. I love the 5D but having the birds bigger in the viewfinder, and shot on a crop sensor, with 400 and 500mm lenses, after much research and my own testing, is my preference. I also suspect that having the birds bigger in the viewfinder will help with in-flight AF, but that's just my opinion. Smaller viewfinder equals less space for the AF to focus on and get right.</p>

<p>If I have the time to sit and frame a bird with a telephoto, then the 5D is great, but when the conditions require faster response time and faster FPS, I'm more comfortable with the crop.<br>

I know it's debated what the crop from a FF provides versus what the crop-sensor provides, but if you ask me they're similar enough (in my case) that I'd rather have the faster performance than the FF, at least today.</p>

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<p>I would love to hear from someone who has a 5DII or 1DsIII to see the size of the advantage of a 50D over the FF. The price of a 50D is small compared to that of my long lenses for birds, where I still find that I am most often heavily cropping with the 1DsIII. </p>

<p>All things being equal (all things never are, and I'm guessing here that all pixels are not equal) it would take a 40mp FF to equal the pixel density of a 50D. I know that the 1DsIII has less noise, but given the above arguement that a greater enlargement factor increases noise, I'm really wondering if there indeed would be an advantage with the 50D in cases where the images of a FF would definitely be cropped. </p>

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<p>Desmond</p>

<p>I tend to think of the crop cameras as 1.6x extenders now. If you're shooitng with your 1Ds3 and need more reach, instead of reaching for the 1.4x extender simply use a cheap Rebel (450D) or 40D etc. This will give you the same effect as adding the extender (actually 1.6x instead of 1.4x) but without adding the extra glass of the extender into the equation. The other major advantage is you'll keep the same aperture value. The 1.4x extender will cost you a stop of exposure, but you don't lose anything if you use a Rebel instead.</p>

<p>I am waiting for a 5D2 to arrive. When it does I will be keeping my old 350D to use instead of a 1.4x extender. Think about it... you can buy a decent Rebel or 400D for the same price as a 1.4x extender these days!</p>

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<p>If you use full frame and never need more reach than your longest telephoto lens, this whole subject is moot.</p>

<p>I don't own a crop body, and I never need to crop into my images to get more reach as I have sufficient focal lengths for my needs. However, if I found myself needing longer telephoto lenses all the time and was cropping my images constantly, I would buy a crop sensor camera in a heartbeat. I think in terms of "pixels on a duck" the advantage is very real, and I also see how how framing would be more precise and satisfying.</p>

<p>It's just a matter of choosing the right tool for the job within any budgetary constraints - this really isn't rocket science.</p>

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<p>I use a 5D & a 50D for birding. The lenses are Canon EF 300mm F4 L IS & Canon EF 400mm F5.6 L. <br>

The 50D does take images with more detail, then if I crop the 5D. I have tested this multiple times with various subjects and always reach the same conclusion. <br>

The 5D is better when the light is dim and you must use high ISO above about 500.<br>

The 50D makes the 300mm F4 L IS more usable for birds then the 5D. It also makes the 400mm a nice birding lens for those of us who cannot afford one of the ulta-expensive uber-birding lenses such as 500mm F4, or 600mm.</p>

<p> </p>

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<p>I keep hearing different opinions as to whether crop cameras have an advantage with tele photo lenses or not</p>

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<p>Crop sensors win every time if you end up with significantly more pixels than you would by cropping a full frame image (which is almost always the case). There's no "controversy" or doubt or discussion about this. It's a simple fact.</p>

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<p>But Bob, what the "facts" are is a matter of interpretation, at least according to those who have thought longer and harder about this issue than you or I (Nietzsche, for one).</p>

<p>Anyway, as other posters have said, it's best to choose the tools most appropriate for your intended tasks. And, clearly, crop sensor bodies are better for remote subjects, while full frame bodies are better for almost everything else. Why else would Puppy Face, for example, have both a 5D Mark II and a 50D? He doesn't strike me as the kind of photographer who buys all the latest gear just for the sake of bragging that he has all the latest gear.</p>

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<p>But Bob, what the "facts" are is a matter of interpretation</p>

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<p>No they aren't. With the same lens shooting from the same position a higher resolution sensor will give you a higher resolution image. Since many (and currently most if not all) crop sensor cameras such as the Rebel XT, XTi, XSi, 40D and 50D have higher resolution sensors than any full frame camera (5D MkII, 1Ds MkIII, Nikon D3x, Sony A900), they yield higher resolution images.</p>

<p>If you have to crop a full frame image down because your lens isn't long enough and it ends up with fewer pixels than the equivalent crop sensor image, then the crop sensor image has higher resolution. It's not a matter of interpretation or philosophical debate, it's a simple matter of math and physics.</p>

<p>I covered this in some detail in an old article I wrote comparing the 5D and 20D - <a href="http://www.bobatkins.com/photography/digital/canon_eos_5d_or_20d.html">http://www.bobatkins.com/photography/digital/canon_eos_5d_or_20d.html</a></p>

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<p>I don't think there is any great point in generalizing. Nikon people are working/playing with a different mix when it comes to cameras, the D3/D700, D300 and D3x than are the Sony people with the A900/A700 and the Canon folks with their ff and smaller frame cameras. I don't think that there are a lot of people in a position to swap systems every time one or another camera comes out that changes things a bit in another line.</p>

<p>There are complaints about the "small" finder image on aps-c/dx cameras - is that bird filling that frame but when viewed in the FF camera finder, the same size but with all that extra space returned to view that was framed out?</p>

<p>Probably more important is that if that bird is standing quietly, the results/considerations may be radically different than if it's flying about depending on how responsive the camera systems are, spread of focus points, types of focus points, etc. It may also make a difference how close that bird actually is.</p>

<p>I happen to have a D200 now but still have some Maxxum lenses. If I were to want to go full frame, I could go to the Nikon D700 or Sony A900 with similar pain to the wallet and probably need to choose somewhat differently on how to best refit my lens selections and focal ranges. It would seem that for docile subject matter, quiet birds and landscapes, the A900 might be better, if chasing BIF, the D700 might be more responsive and the higher iso considerations might be relevant in other uses. However, my conclusions fit me and may not "fit" others.</p>

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All other things being equal, the smaller the pixel, the less sensitive to light it is. This will have an effect on contrast, color

and tone.

<br><br>

In astrophotograpy, there are explicit calcuations based on the image resolution (arc seconds) you require to match the

sensor (pixel size) with the telescope (focal length) you have. But it is a bit more straight forward, as the subjects don't

move closer and farther during an imaging session. But also, you are limited in the objects you can fully image, based on

the sensor size.

<br><br>

There is no one answer to this question. Comparing an older generation full frame to a newer generation small sensor may

seem unfair, but if the costs for the equipment are equivalent, then go with the one that gives the better performance for the

imaging task at hand. Or for the range of imaging projects, if you can only afford one camera (system).

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<p>While I have not attempted the tests you describe, I have read extensively about this subject. I keep coming back to the same question: Why are we still asking and comparing? All comparisons are are based on a film format! Sensor sizes are quite likely not going to become standardized as there are desirable traits to both "FF" and "Crop". The difference is technical. Shouldn't we be focused instead on what matters most. That we record the image we are after! Does it truly matter, other than in the mind's eye, what the sensor size or focal length of the lens in 35mm terms was? I believe this debate should settle as most are using sensors, which are not limited to a set size, and focus on the images instead.</p>

<p>I realize that this is a very simplified reply and will likely get hammered as to the intricacies of FF and Crop, but please do not miss the point of my response. When will we stop the insanity?</p>

<p>"A picture is worth a thousand words, a great picture is worth a thousand bucks."<br>

-Anonymous</p>

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