I don't care for the crop factor thing but everybody uses it...
18mm if it's really 18mm x 1.53 = 27.5
16mm if 16mm x 1.53 = 24.4
15mm if there was a zoom that started at 15mm x 1.53 = 22.9
OK I use a AF 28-70/3.5-4.5D Nikkor on my D800 and quite like the results. I needed something to replace an AF 35-70/2.8D Nikkor that while showing no impact damage was giving me images that smacked of decentering.
If image quality is high on the list I'd look into the AF-S DX Zoom-NIKKOR 17-55mm f/2.8G IF-ED. I have no experience with this lens so this is not a recommendation to buy but a recommendation in investigate. The B&H (USD) price new of $1,500.00 or the KEH.com (USD) Ex w/caps and hood of $754.00 might not fit the budget.
17mm if it's really 17mm x 1.53 = 26mm
55mm if it's really 15mm x 1.53 = 85mm
I'd be OK with that range.
I don't think putting an FX lens on a DX camera is such a straightforward idea. The best reasons would be you plan to buy and FX camera or you already own the FX lens or something on that line. Otherwise I would buy a better quality DX lens for a DX camera except when getting out to something in the 105~200mm range and beyond.
T-stops? This is pretty complicated. I wouldn't simplify it too much. If reflected light is being absorbed before it hits the sensor it doesn't matter. The purpose of T-stops is for cine where switching lenses and the next angle or crop requires exactly the same exposure. If one lens loose 1/2 stop and another 1/3 stop the difference the difference is 1/6 stop. I can't see that as being of any consequence to still photography.
I'm not packed with data but if T-stops were high on my list I would not be looking at zoom lenses. I would also use a hood more appropriate to the DX format (narrower) than the designated FX hood. Too much stray light. Trix are for kids, T-stops are for cinema photographers.
In general lenses for smaller formats are designed to be sharper, resolution, acutance, etc. In general, there are plenty of exceptions. An FX lens on a DX camera might please or be lacking as you'll enlarge the DX image 1.5 times to make the same size print as FX. If one always makes smaller prints or views smaller image on a display for DX as compared to FX then disregard the previous sentence.
I'd like to own an AF-S 16-85/3.5-5.6G ED DX VR but I never bought a DX lens as I knew my primary format would be 36x24. I'd still like one as I still own a D300s.
Dave Hartman
Where did 1.53x come from? 35.9/23.5=1.528. I compare the long edge of the sensor or film. It's best to leave the crop factor behind. I made a table for comparing 35mm to 4x5 inch when I bought my first 4x5 camera. After a few weeks I filed it and didn't find it again for a decade or more. The crop factor is like try to use a this language to that language book. It only makes sense if you are tourist. Yes, I just got up and drank my first cup of coffee. Why do you ask?
