1.4x TC - still an option ?

[ulrich_brandl]

<p>Does a 1.4x TC bring more image quality on current 24 MP+ FX cameras than cropping ? Cropping by 1.4 results in pixel counts similar to the total pixels of the previous camera generation. The crop usually uses the "sweet spot" of lens sharpness and should be slightly above the results of the same lens on DX. A TC degrades lens performance but you have more pixels (resulting in less enlargement for the same print size). Test sites like photozone.de seem to have given up testing lens-TC combos. Ok, there is still the advantage of better seeing what you shoot - but at the price of one F-stop. I would like to know the personal experiences of those who have tried a TC against cropping on current FX cameras (using quality tele zooms like the 2.8 70-200).</p>

[ilkka_nissila]

<p>You can get more detail using a TC than just cropping, but there is some contrast loss and to get good clarity of the image at the pixel level you typically need to stop down 1-2 stops. I.e. with the 70-200+TC-14EII, maximum aperture is f/4 and the sharpness is very good at f/5.6. With the VR 200/2 (v.1; I haven't yet shot this combination with the v. 2), the TC-14E II gives a maximum aperture of f/2.8, which is soft with considerable internal flare at high-contrast boundaries. At f/3.5 it's already quite sharp, and by f/4.5 really sharp. But detail isn't the whole picture; the TC takes away some of the clarity and contrast and also it makes the setup a bit longer and heavier to hand-hold.</p>

<p>Practical advantages of TC use is that it lets you shoot with a larger viewfinder image and "normal" AF point layout whereas cropping without TC leaves you with a very small viewfinder section corresponding to the final framing. Some would actually prefer the cropped AF point layout (i.e. filling the frame but with more sparse spacing).</p>

<p>I can't really answer that question you have conclusively. It depends. What informal tests I have done lead to the conclusion that the TC does give more detail than just cropping but I don't like the flare and reduced contrast. It is a very divisive subject; some use TCs regularly and others not at all. In practice I use the TC-14E II with the 70-200II from time to time, when needed, and the TC-20EIII with the 200/2 again when needed, but I don't that often use the TC-14EII with the 200/2, as I find that the quality of a 1.4X crop (no TC) from the 200/2 is excellent especially with the D800. However, I know the TC-20E III is useful with the 200/2; it gives me a substantially larger viewfinder image (than shooting at 200mm and then cropping by 2X) and the quality loss is not that bad considering the increase in magnification. I shoot the 200/2+TC-20EIII at f/5.6 most commonly. At f/4 the bokeh effect is very beautiful but the image sharpness isn't quite as good as it is stopped down to f/5.6. For best quality I need to place the 200+2X on tripod as the focal length of 400mm is quite hard to hand hold steady enough for the best results. I can easily see the difference of using a tripod vs. hand-holding the 200/2+2X in A4 size print (this should surprise few). Also with the 2X TC mounted, the lens gets quite heavy on the left hand. For short spurts I can use it but for shooting any longer than a few minutes I consider the tripod nearly mandatory (a monopod would also be ok and takes away the weight from the hands, but I don't like working with them).</p>

<p>There seem to be some outstanding combinations of TC and main lens in existence: e.g. Canon's EF 300/2.8 IS II with their latest 2X TC appears to give phenomenal sharpness even at 600mm, f/5.6 according to tests I found on the digital camera net. I have no real world experience with this Canon lens but the results of that test suggest that the use of TCs in supertele work is by no means at an end, even if the high resolution bodies and cropping flexibility has made it possible to avoid using TCs in many situations if the photographer so chooses. Either choice has advantages and disadvantages. There is certainly something to be said for the simplicity of shooting as tight as you can and then cropping as needed. It reduces time lost shuffling TCs on and off, and the results are often still very good. Still if I know that I will need 400mm, I will certainly bring the TC-20EIII along, even if for smaller crops I'll just rely on pixel density.</p>

[John Crowe]

<p>A 1.4x is definitely worth using, over cropping images. They take very little away in terms of image quality. The Nikon 200/2 (AI to AIS and now even the current model, it seems) has always been a bit of an exception for some reason. I assume it is it's finely tuned optical formula making it just about the sharpest lens ever made at f2 to f2.8. </p>

<p>My experience with 1.4x and 2x converters spans close to 30 years and primarily the following lenses, Canon FD 200/2.8, FD 300/2.8 L, FD 400/4.5, FD 400/2.8 L, Nikon 200/2 AI, 400/2.8 AIS, 80-200/2.8 AF-D, 80-200/2.8 AF-S, Canon EF 300/4 L, and 17/4 L TS-E. I may have forgotten one or two, and I have used all of these on digital cameras at one point or another, both FX and DX and have compared all the various combinations.</p>

<p>Long ago I completely gave up on 2x converters but that was with very slow superfine grain film and I have recently considered revisiting this option given digital performance at ISO 100-400 providing the ability to shoot at higher shutter speeds, and the ability to confirm focus using the rear LCD. I do know that the best DX camera with just the lens can trump what the best FX camera can do with a 1.4x converter on the same lens. I shot with a DX/FX combo for 4 years but am currently limited to FX only, and very much looking forward to getting a DX back in my camera bag (for the most part pixel density in DX has stayed ahead of pixel density in FX). For a point of reference the 12 MP D2X with 400/2.8 AIS and TC-14E II provides superior image quality than the 21 MP 5D II with 400/2.8 AIS and EF 1.4x. The 12 MP D2X with just the 400/2.8 was pretty much equal to the 11 MP Canon 1Ds with the 400/2.8 and 1.4x combo. I know this gets away from your original question a bit but I think it expresses my confidence in what a 1.4x can do but also how the use of a DX body can help limit the use of 1.4x and especially 2x converters for telephoto photgraphy.</p>

<p>I have found it odd over the years but I have seen repeated instances where a 1.4x converter provided superior image quality over the bare lens when maintaining the same subject size by changing the subject distance. That is to say with the 1.4x attached the camera is moved 1.4x times farther away from the subject. This has always confounded me because the opposite should be true. I can only put it down to the converter limiting the attached lens to a one stop sweeter spot in the lens glass. The other possibility is the lens formula itself operates better at a slightly greater distance from the subject. </p>

[ulrich_brandl]

<p>Many thanks for your thorough answers. There are obviously more arguments on the "pro" side. Ilkka has a good point about having better distributed AF points over the frame , but unfortunately my D600 doesn't deliver in this area. OTOH camera bodies come and go. So, finally, I will give the 1,4x TC a try.</p>

[ulrich_brandl]

<p>Many thanks for your thorough answers. There are obviously more arguments on the "pro" side. Ilkka has a good point about having better distributed AF points over the frame , but unfortunately my D600 doesn't deliver in this area. OTOH camera bodies come and go. So, finally, I will give the 1,4x TC a try.</p>

[elliot1]

<p>It is certainly worth a try to see if it meets your needs, but with so much cropping ability of the D600, a 1.4x TC may not be necessary, especially if you are trying to achieve approximately 300mm with your 200mm lens. If that is the case, I would suggest a reasonably priced 300mm lens which may perform better in every regard and cost about the same as the TC. For example, the 70-300mm G lens is actually quite good at 300mm and I suspect would offer equal or possibly better IQ than the 70-200mm with the 1.4x TC. And at about $325 - $350 or less used, it is a bargain for what you get.</p>

<p><em>"</em><em>better distributed AF points over the frame"</em> Not sure if all the AF will work with a TC. Have you checked?</p>

[Kent Shafer]

<p>I did some informal tests using the DX crop mode on a D800E, comparing the two versions of the 70-200 f/2.8 with and without a TC-14EII and shooting at about ten feet from the target. All shot at f/5.6. The tightest framing came from the original version plus the TC, while the VR II was handicapped by its focal length breathing at that distance. I cropped the other three images to match the framing of the VR I + TC combination and printed them all at the equivalent of 8 x 12 inches.</p>

<p>Here's what I concluded:</p>

<ul>

<li>Surprisingly perhaps, the VR I alone was best in terms of resolution, though a bit less contrasty than the VR II images.</li>

<li>VR II + TC came in second place.</li>

<li>VR II alone (the most severely cropped of the four) was third.</li>

<li>The VR I + TC combination, even though it required no cropping, was by far the worst.</li>

</ul>

<p>So assuming you have the VR II lens, which you really should with an FX camera, my conclusion is that it's definitely worth using the TC-14EII instead of cropping. I would stay away from the TC with the original version of the lens, however.</p>

<p>Caveats: These were just home brewed tests—I don't claim to be an expert on this stuff. Also, I was only looking at the DX frame. And finally, results might be different with larger prints or shooting from a greater distance (where the VR II breathing would be less of an issue).</p>

<p>While the prints really told the tale, FWIW here's a jpeg showing the center of each of the four images</p><div></div>

[ilkka_nissila]

<p>Elliot, all the AF points (of the D800 and other Multi-CAM 3500 cameras)) do work with TCs as long as the maximum aperture with TC if f/5.6 or better (in my case both the 200/2+TC-20EIII and 70-200/2.8II+TC-14EII lead to f/4 maximum aperture, well within the working range). With f/8 combinations, only some of the AF points will work. I don't know the limitations of the D600 with f/8 lenses; there must be some.</p>

<p>Kent, your results are not surprising (although I prefer the VR II + TC1.4 image). If I recall correctly, Marianne Oelund's comparison showed the VR 70-200/2.8 1st version has better center sharpness stopped down to f/4-5.6 especially at longer distances. The 2nd version excels at f/2.8 / at short distances / towards the corners of the frame (and any combination of those). Finally the 2nd version seems to be better specifically at the long end of the zoom range whereas the 1st version in the middle to short end (seen e.g. at dpreview's lens reviews). It's complicated! I use the v2 because it has more even sharpness across the frame, less vignetting, better VR, and I find the 200mm performance the most important to me as the image at 200mm is often used with some cropping so the extra sharpness really helps. I find it very backwards that many telezooms are weakest at their long end wide open (which is where the lens would be used most often at least in my case!) If the VR 70-300 were as good at 300mm, f/5.6 as it is at its short end, I would happily use it.</p>

[elliot1]

<p>In rereading my post above, I stated "the 70-300mm G lens is actually quite good at 300mm". This is incorrect as is and should have been written as "the 70-300mm G <strong>VR</strong> lens is actually quite good at 300mm". The old G lens is is not (at least the one I had).<br>

<br>

</p>

[elliot1]

<p>Kent, I have done some testing with several lenses and the TC-20EIII and find that IQ in general is better with the TC because of the magnification. To my surprise, I found the results with the 70-200mm VRII to be only OK while it performed well on two other lenses I test on. I bought it specifically to use with one of my 400mm lenses to get 800mm and and quite pleased with its performance and IQ on the D800 at 800mm. But I always consider the TC a choice of last resort, although to my surpise, it works surprisingly well on my 105mm VR macro.</p>

[ulrich_brandl]

<p>Many thanks again. Kent's post seems to underline that its worth to try the 1.4x TC with the VRII lens. <br>

@Elliot: A 70-300 VR is one of the options I considered too. The problem is that it will add around 500 grams more to my bag when I already carry the 70-200 and only occasionally need more focal length. Clearly, its advantage is that I can go out without the heavy 70-200 when I don't need its speed and still have significant reach. Maybe I will get both on the long run. Currently I seek for a quick adjustment for my needs on the long end after changing from DX to FX. </p>