D3 & DX format

[craig_shurmer]

Hi, hope this isn't a daft question, but if you attach a "full-frame" lens

(35mm/FX format) to the D3 body and then put the camera into DX mode, does it

then make the focal length of that lens x1.5 (eg 200mm becomes 300mm?. Thanks.

[ellis_vener_photography]

The optical focal length of the lens remains the same (in this case 200mm) which also means that the depth of field remains that of a 200mm at whichever aperture you set it to, but the angle of view that is recorded yes indeed, becomes that of a 300mm.

[ShunCheung]

Craig, the focal length for a lens will never change regardless of what type of camera you put behind it or how you crop the image. When you set the D3 in the DX mode or use a DX-format body, the angle of view you get from the same focal lenght narrows compared to the "full 35mm frame" FX format.

 

What Ellis is saying is that the angle of view for a 200mm lens in the DX mode is roughly the same as the angle of view for a 300mm lens in the FX mode/format.

[frank_skomial]

And the crop is almost the same as a crop that you can apply in post processing. Just cut out central portion of your picture, and you can narrow this way the angle of view to any lens length equivalent that you desire.

 

Let say, you cannot afford a 1000mm lens - then crop picture with whatever lens you have, to get that narrow view of that tele lens.

 

And that may ? or may not make sense to you?

[Hector Javkin]

It's not a daft question at all. If you are going to enlarge the image to the same extent whether you use the DX crop or not, then the DOF <b>will change</b>. The appropriate circle of confusion is different depending on whether we shoot fx or dx format. <a href="http://www.bobatkins.com/photography/technical/digitaldof.html">Here is a good article </a>on this by Bob Atkins.

[frank_skomial]

As always, generalizations are risky, as usually there is more to it than pleases your eyes...

 

When I joined photo.net, I expressed desire to purchase long lenses to get that stunning "compressed perspective", - my unfortunate use of words.

 

Then it was explained by a "101 class" scholar/teacher that perspective does not depend on the focal length of the lens, just the relative distance. ... and I did not need any long lens as I could achieve the same with a normal lens.

 

Foolishly, I did not listen to the professor and then I acquired more of the NAS.

 

When I see wild nature photographers with very long lenses, it makes me think that perhaps they did not listen to the professor either?

[Peter_in_PA]

Frank,

 

A nature photographer with a real long lens is probably trying to photograph something

quite far away, and not only probably listened to the professor, but just might BE the

professor...

[s_nathan]

I'm confused. Are you guys saying that the D3 accepts both FX and DX format lenses? Sorry

in advance if this is a dumb question.

[studor13]

Hector, I'm not sure if I understand you correctly but Bob Atkins says (as do most people) that if you are using the SAME lens from the SAME distance then the DOF does not change whether you are shooting FX or DX.

 

All that happens is that in DX mode the centre part of the image gets cropped.

[david_dorcich1]

"I'm confused. Are you guys saying that the D3 accepts both FX and DX format lenses? Sorry in advance if this is a dumb question."

 

The d3 has a full frame sensor. If you use a dx lens the camera can crop the sensor so it acts like a DX sensor, enabling the use of both types of lenses on the camera.

[s_nathan]

That explains why this camera is selling like hot cakes. Wow, it shoots only at 5 mp in DX

mode, but 11 fps.

[manitas]

Yes, it does,and also crops the sensor automatically to make up the difference in the image circle on DX lenses.

[ShunCheung]

Nikon uses the exact same lens mount for its DX lenses and non-DX lenses. Any lens that can be mounted onto the D3 can also be mounted onto any other Nikon DSLR ever made, since the first D1 from 1999 and the current D40.

 

You can certainly mount DX lenses onto the D3 and take pictures. If you choose to use the entire FX frame, you may get vignetting using DX lenses. If you select the DX crop mode on the D3 (and presumably future FX-format DSLRs), the D3 will behave like a DX-format camera and avoid the vignetting problem.

 

If you are coming from the Canon world, Canon is using a different approach and their EF-S short-mount lenses for small-sensor DSLRs cannot be used on their full-frame and 1.3x DSLRs, as those mirrors will hit the rear-end of the EF-S lenses.

[frank_skomial]

Peter,

 

You are right. That nature photographer listened to the professor, but did not follow the idea from "class 101" to use normal lens and crop to get the same (theoretically) result with normal lens as with telephoto lens, and got long lens anyhow.

 

The nature photographer was smarter than the professor, and did not let over education cloud his common practical sense.

[Hector Javkin]

Andy,

 

I guess it comes down to which of Bob's scenarios you're looking at. I was thinking of his second bulleted item. Below is my take on it:

 

If you stand in the same place with the same lens, take one shot in DX mode, the next shot with FX mode, and blow up both shots to the same size, the shot with the DX mode will have a smaller DOF. The cropped area would be enlarged more, and those areas not in exact focus would be more fuzzy.

[ajay_ukidve1]

Hector,

 

Yes the same lens say 50mm full frame will give 75mm focal length on a DX APS-C sensor. However remember that number of pixels will be less so the quality of the photo will suffer. If a 75 mm lens is now put on the FX sensor camera ie equivalent to 35mm then now the picture on the DX sensor ( 1.5 crop factor) with 50mm lens and the FX sensor with the 75 mm lens will be identical. However the pixel density and number of pixels will vary from FX to DX. Secondly the DOF will also vary.