APS-C lens on Nikon full frame

[larry_johnson6]

<p>Lloyd Chambers recently tested the Zeiss Touit lenses (APS-C) on a Sony A7r and found, by using the camera's format change set to 4x5, he could benefit from the quality of the glass and the good sensor performance. The image circle covered the squarer proportions. I'm wondering what I might expect if I did something similar, using the Sigma 18-35 f1.8 on a Nikon D610. What would the *effective* focal range be? Does the D610 allow for selecting a different format, as the Sony did? The Sigma reviews are quite strong and has a very usable walk-around focal range, and the sensor and processor in the D610 is excellent. I'd expect the "crop" circle to yield about 18-20 mp on the Nikon, which, considering the D4, should be adequate for a lot of situations. Your thoughts?</p>

[Matt Laur]

The effective focal length would still be 18-35.

 

The d610 can be set up to realize you've got a DX (APS-C) lens mounted, and it automatically use just that smaller part of

the sensor. You can always disable that feature and record the whole frame, choosing to just crop away the unwanted

vignette in post, later.

[Hector Javkin]

<blockquote>

<p>The effective focal length would still be 18-35.</p>

</blockquote>

<p>Well . . . no. Of course the focal length doesn't change, it's still 18-35mm no matter what. The "effective focal length" is used to describe the field of view. The image will have a smaller (cropped) field of view (making the "effective focal length" longer) whether you use the DX mode or crop it yourself.</p>

<p>As to whether you want to do this, it makes sense if you already have the 18-35mm. Buying a DX lens to use it on an FX camera is a waste of good pixels.</p>

[JDMvW]

<p>So much of the argument about what "focal length equivalent" means has been said on a FAQ basis here:<br>

http://www.photo.net/beginner-photography-questions-forum/00cayA<br>

most recently regarding EOS but you can substitute 1.5X for the Canon 1.6X in the discussion</p>

<p>What has been said already</p>

<blockquote>

<p>Buying a DX lens to use it on an FX camera is a waste of good pixels.</p>

</blockquote>

<p>is all too true</p>

[Matt Laur]

<blockquote>

<p>Well . . . no. Of course the focal length doesn't change, it's still 18-35mm no matter what. The "effective focal length" is used to describe the field of view. The image will have a smaller (cropped) field of view (making the "effective focal length" longer) whether you use the DX mode or crop it yourself.</p>

</blockquote>

<p>It will look exactly the same on a DX camera as it will on an FX body in DX mode. No change in field of view.</p>

[Dieter Schaefer]

<blockquote>

<p>Does the D610 allow for selecting a different format, as the Sony did?</p>

</blockquote>

<p>No, but the D800/D800E does - in addition to DX (1.5x), there's also 1.2x and 5:4. The dimensions of the latter are 30mm x 24mm so the angle of view with respect to the smaller side is the same as FX and the angle of view over the longer side is reduced by a factor of 1.2. Overall, the diagonal is a about 2mm longer than the one for the 1.2x crop factor and roughly 5mm shorter than the FX diagonal. The 18-35 would have a FOV like a 21.5 - 42mm lens along the one side and exactly the same as a 18-35 along the other.</p>

<p>As I said, moot point on the D610 as you can't select 5:4 in camera - but you could of course crop to that ratio in post.</p>

[ShunCheung]

<p>The Zeiss Touit lenses are fixed focal length lenses. However, here the OP is talking about a zoom, the Sigma 18-35mm/f1.8.</p>

<p>The problem with a DX zoom on FX is that typically, it can cover the full FX frame much better on its long end than it can with its short end. Therefore, unless you are really careful about exactly which focal length you are using in every occasion, the quality of the image in the area outside of the DX frame becomes somewhat unpredictable.</p>

<p>As a general rule, it is not a good idea to buy a DX lens for an FX body for regular usage. Since you have a D610, presumably you wanted FX. If you are that interested in the Sigma 18-35mm/f1.8, I would add a DX body for it.</p>

[john_harper9]

<p>The Nikon 12-24 DX is reputed to cover FF and I was hoping to use at shorter focal lengths than my 24 PC-E on my D800E for wide interior shots. The zoom was usable in the 20-24mm range with severe vignetting starting at 18mm. The surprise was it compared well against the 24 PC-E at 24mm f/8 with less CA on the edges. At 20mm, the corners were soft. While a lens may cover an image circle larger than the target format, the outer edges of the circle will probably suffer from optical aberrations so you need to test it and determine whether the performance outside of the design format is acceptable. My conclusion after testing the 12-24 DX lens was it is a good AF-S 24mm lens on FF but if I wanted something wider, I must budget for a FF wide angle zoom.</p>

[larry_johnson6]

<p>Thanks for the sound input on this question. So, here's a logical follow up to it: is there a full-frame fast wide zoom for the D610 (or even the D800e) that compares by price, quality and range to Sigma's 18-35 f1.8 zoom for APS-C? Any brand?</p>

[zafar1]

<blockquote>

<p>Thanks for the sound input on this question. So, here's a logical follow up to it: is there a full-frame fast wide zoom for the D610 (or even the D800e) that compares by price, quality and range to Sigma's 18-35 f1.8 zoom for APS-C? Any brand?</p>

</blockquote>

<p>Why are you interested in 18-35 f/1.8? Usually people want wide aperture lens for low light or for Bokeh. In both cases a 24-70 f/2.8 on FF will be equivalent of 18-35 f/1.8 on APS-C (and will have more zoom range).</p>

<p>Tamron 24-70 VC is supposed to be good and and closer in cost to Sigma 18-35.</p>

[larry_johnson6]

<p>I think I'm simply impressed with the Sigma lens's quality after more than a dozen glowing written and video reviews, and seeing the DxO test figures. On top of that, I've recently analyzed my past ten years of "keepers" and probably 75% of them were shot between (FF equiv) 28mm and 45mm. I tend to shoot what "they" call Intimate Landscapes. I'd like to find one high-quality lens that would stay on the body 75% of the time, maximizing readiness and cutting down on lens juggling or opening the body to the elements any more than is necessary. You're right about the 24-70 lenses being in the category, but the Nikon is far more costly and I haven't found the same level of regard for the Tamron as I'd found with the Sigma. So, I'm still in data-gathering mode. I appreciate your input.</p>

[ShunCheung]

<blockquote>

<p>probably 75% of them were shot between (FF equiv) 28mm and 45mm. I tend to shoot what "they" call Intimate Landscapes.</p>

</blockquote>

<p>If your objective is to concentrate in the 28-45mm range for FX, I wouldn't get a 18-35mm zoom unless you are using it on a DX body, and landscape photography usually doesn't require fast lenses such as f1.8.</p>

<p>Nikon's 24-70mm/f2.8 AF-S is indeed expensive. I have the older 28-70mm/f2.8 AF-S and it is still very good on the demanding D800E. If you prefer a lighter lens and don't need f2.8, Nikon's new 24-85 AF-S VR is very good: http://www.photo.net/equipment/nikon/lenses/review/24-85mm-f3.5-4.5-af-s-vr/<br>

<br />Nikon makes a 18-35mm AF-S that covers the entire FX frame and is excellent: http://www.photo.net/reviews/nikon-18-35mm-g-review/<br>

But obviously it doesn't cover 45mm.</p>

<p>In the last 3, 4 years, Nikon has introduced a bunch of affordable FX lenses to match up with the D600 and D6100. They tend to be f1.8 (instead of f1.4) for fixed and f4 or f3.5-4.5 for zooms. Optically they are very good, but those are slower lenses and are not necessarily built like a tank. The result is that they are also lighter, perfect for landscape photography.</p>

[wade_thompson1]

<p>good write up</p>