I'm a newbie in dslr, very confuse with the DX format of nikon. Let say i gt a D40 and i mount a 35mm on it. what is focus length im getting? isit a eye view just like a 50mm on a D3X?
Thanks! But what about a fx 50mm on d40? What will the focal length be?
I'm a newbie in dslr, very confuse with the DX format of nikon. Let say i gt a D40 and i mount a 35mm on it. what is focus length im getting? isit a eye view just like a 50mm on a D3X?
Thanks! But what about a fx 50mm on d40? What will the focal length be?
Just for your info, the same 1.5 crop applies to DX lenses as well. Also, if a DX lens is used on an FX camera, the image will be cropped as well.
Not quite. But you'll get vignetting.
FX lenses:
- on FF cameras : effective focal length will be the actual focal length
- on DX/crop cameras : effective focal length = actual x 1.5
(FX lenses can be used on both FF and DX cameras)
DX lenses:
- on FF cameras : effective focal length will be the actual focal length (but there will be severe VIGNETTING)
- on DX/crop cameras : effective focal length = actual x 1.5
(DX lenses are suitable for DX cameras only, not meant for FF cameras)
hope this helps..
to be precise, a lens does not provide a perspective. The perspective is what you get based on your position relative to the objects in your frame.please get it right and stop that none sense!!! a lens with 50mm focal length will ALWAYS have 50mm focal length regardless if you mount it on a DX or FX camera! what happens when you mount a lens on a camera body with different sensor sizes is a varying part of the image circle is cropped out. A FX camera will crop a bigger picture than a DX sensor. so the angle of the view of field changes which gives the appearance that the focal length changes. However, the perspective of the lens does not change! so a 35mm on a DX sensor still does not provide the same perspective as a 52mm on a FX sensor.
the difference between a DX and FX lens is the size of the image circle. A FX lens produces a bigger image circle, a DX lens a smaller.
Not quite. But you'll get vignetting.
FX lenses:
- on FF cameras : effective focal length will be the actual focal length
- on DX/crop cameras : effective focal length = actual x 1.5
(FX lenses can be used on both FF and DX cameras)
DX lenses:
- on FF cameras : effective focal length will be the actual focal length (but there will be severe VIGNETTING)
- on DX/crop cameras : effective focal length = actual x 1.5
(DX lenses are suitable for DX cameras only, not meant for FF cameras)
hope this helps..
yes sorry about that, the perspective is indeed dependent on the distance between camera and object. Essentially you gotta step backwards if you increase the focal length and you want to maintain the size of the subject in the frame. so the focal length influences the distance to the subject. it further influence how much of the background is included, the longer the focal length the less background is included which creates the compression effect in a telelens. if you use a wide angle lens then more background is included and the scene is stretched. in other words with a 35mm on a DX body you still need to be closer to your object than with a 50mm on a FX body. Therefore the frame shot on the FX body has a feel that is more compressed than the frame from the DX body.to be precise, a lens does not provide a perspective. The perspective is what you get based on your position relative to the objects in your frame.
but yes, I will certainly agree with your point that the focal length of a lens does not change, regardless of what camera body (FX or DX) it is mounted to.
To be fair, some ppl did use terms like 'effective focal length', which though technically still not accurate, sorta gets the point across
Hi Michael, I agree with your post except for the last part about the diff between DX and FX.
If the distance remains unchanged, the 2 formats give essentially the same perspective to the image. So neither is more "compressed" than the other.
For example I am seated across the dining table from my 2 friends. I first shoot with DX + 35mm lens, then FX + 50mm lens. Since I haven't moved between shots, they would look very similar in terms of perspective. DOF difference, but not perspective difference.
so far have not done an actual side-by-side comparison, but I think you have a point there.Except for background... The 50mm and the 35mm will create a subtly different background perspective and this won't change because APS-C doesn't actually change the focal length, it just crops.
Oops sorry, I was talking about the DX crop mode, should have been more specific.