DX or FX

meddyliol

Suspended / Banned
Messages
74
Name
Brian
Edit My Images
No
My Nikon D90 has ( I believe) a DX format sensor. From what I've read that means that my zoom lens (one of which is a 18-55) is actually equal to 27-82.5. I have no idea how this is assuming that I am correct. Is this a good thing or a bad thing? I have a feeling that I might be opening a can of worms with this question but I am trying to learn.

Thanks

Brian
 
Neither good nor bad - just a way of comparing lenses between formats.

You'll soon begin to notice that lenses made just for DX tend to correspond to focal lengths of FX lenses - eg FX 'walkaround' zooms being 24-70mm whereas the DX kit lenses are usually 18-55mm.

It only really matters when you put an FX lens on a DX body - the focal length will be a bit odd e.g. a zoom starting at 24mm may not be wide enough for many DX users.
 
Just forget about it and move on. Unless you buy an FX body in the future, it really doesn't make any difference to anything.
 
An FX should give better pictures then a DX due to electronic parameters.
A DX crop is like using a FX then cutting only the middle out so its like a digital zoom.
A 35mm on a DX gives you a field of view like a 50mm lens on an FX but the depth is still like a 35mm on a FX (think about the fuss that parking cameras have caused by using the using the wrong lens and compressing the background).

For most people the DX & FX makes little difference
 
Good - If you want more reach

Bad - If you want really wide angle

I don't think that's actually the case. I think I'm right in saying that the difference at the wide end between APS-C and FF is something like 1mm at least for mainstream lenses that us ordinary folk may want to buy and I think that APS-C might have that 1mm advantage... either way, I don't see the wide end as a deciding factor.

OP. I honestly don't think it'll matter all that much unless you want to take pictures of black cats at midnight and/or make very large prints and for hand held shooting I think that (for me) the sweet spot is more towards APS-C (DX) or Micro Four Thirds than to FX.
 
Last edited:
I don't think that's actually the case. I think I'm right in saying that the difference at the wide end between APS-C and FF is something like 1mm at least for mainstream lenses that us ordinary folk may want to buy and I think that APS-C might have that 1mm advantage... either way, I don't see the wide end as a deciding factor.

Well its pretty simple, a crop sensor adds reach to the image, at 14mm lens becomes a 21mm on a Nikon DX camera, 14mm and 21mm is quite a big different in the viewfinder...not rocket science :P
 
Well its pretty simple, a crop sensor adds reach to the image, at 14mm lens becomes a 21mm on a Nikon DX camera, 14mm and 21mm is quite a big different in the viewfinder...not rocket science :p

No, it isn't rocket science :D

My point was concerning the wider end of the field of view and whilst the widest non fish eye FX zoom lens, I think, is the Sigma 12-24mm (I owned one and it's a cracking lens) I think that Sigma also make a DX 8-16mm and 8 x 1.5 = 12mm which would mean it's the same old same old :D FoV wise. There may well be wider lenses out there but they may be few and far between and very possibly expensive too and my thinking was that for mass market lenses there probably isn't much in it between DX and FX FoV wise if you want to go wide.
 
Last edited:
Well its pretty simple, a crop sensor adds reach to the image, at 14mm lens becomes a 21mm on a Nikon DX camera, 14mm and 21mm is quite a big different in the viewfinder...not rocket science :p
No it isn't rocket science, but nowadays a 10-20 or similar is easily and cheaply available for crop cameras, same as a 16-35 for full frame.
Which was the point of the post.

Of course you can go wider in both formats too, the bottom line is, you'd need to have a fairly specific requirement to not be able to find a wide enough lens.

Clearly cross posted
 
Ignore that crop factor / multiplier thing. Just remember one thing: a 'standard' focal length for your camera is around 30mm. Anything shorter than that is going into 'wide angle' territory, and anything longer is going into 'telephoto' territory. Here's how I'd categorize it:
  • Ultra-wide angle: <17mm
  • Wide angle: 17-25mm
  • Standard: 25-35mm
  • Short telephoto: 35-50mm
  • Medium telephoto: 50-70mm
  • Telephoto: 70-140mm
  • Super telephoto: >140mm
That's somewhat subjective, and very arbitrary.
 
The biggest difference difference between fx and dx is fx lenses cost a shed load more and yes fx bodies and generally better in low light but the difference in image quality is getting smaller and smaller. I dare say a new dx body like the d7100 will give a d700 a good run. It all comes down to cost and what you shoot. Many wildlife photographers opt to use crop bodies for the extra reach
 
Back
Top