I am new to the forum and I did a search but did not find the answer to my question. What is the "normal" lens for a DX camera? According to the diagonal measurement it is 28.4mm . The closest prime lens makes to that is a 35mm which would make it slightly telephoto. Most literature I find states that 30mm would be "close". Any insight would be greatly appreciated.Thanks, Hayden
"Normal" lens for DX Nikons
- Thread starter HaydenB
- Start date
Nikon AF-S NIKKOR 28mm f/1.8G | Nikon Wide-Angle LensesIf that focal length appeals to you, give it a try. It is light, and sharp.
Horoscope Fish
Senior Member
Nikon makes a 28mm f/1.8 but it's an FX lens and several hundred dollars.
I suggest you use the 35mm f/1.8G and call it good. You won't notice the 7mm difference.
I suggest you use the 35mm f/1.8G and call it good. You won't notice the 7mm difference.
I'm confused. What the hell is a normal lense? When I do portraits. The lense I would choose would be my 70-200mm. So would this be my normal lense for portraits?
When I'm walking around and want to bring the camera along I choose my 24-70mm. So would this be my normal walk around lense? What would you all consider to be normal? Me? There is no normal. It's the lense I use for any given circumstance.
When I'm walking around and want to bring the camera along I choose my 24-70mm. So would this be my normal walk around lense? What would you all consider to be normal? Me? There is no normal. It's the lense I use for any given circumstance.
I am old school. Nikon was always the leader in providing the best camera equipment for forensic use. In the 35mm film days the 28mm was the accepted wide angle lens and the 50 was the "normal" lens for shooting crime scenes with little or no distortion. I would not have expected Nikon not to supply the technically correct appropriate lens for the same work. Rather than "just make it work" we were a little more precise than that. A 35mm DX lens will "work" but it is not technically correct, nor is a 28mm FX wide angle lens on a DX camera. Perhaps Nikon believes the D300 is a not a Semi-Pro camera and requires a FX to be a "Pro". But even the FX diagonal is 43.18 and they consider the 50mm lens the normal lens for full frame. Sorry to ramble, just talking out loud.
Horoscope Fish
Senior Member
A "normal" lens is one with a focal length that duplicates, as closely as possible, what the unaided eye sees; equal field of view, zero magnification.
As opposed to wide-angle, or telephoto lenses, that expand or contact that field of view, respectively.
.....
The 28mm 1.8g is as close to 28.4mm as you will find. The Fx or Dx doesn't matter, it's still a 28mm lens.
vindex1963
Senior Member
30mm Sigma f/1.4 is close to normal 50mm on DX and it's outstanding glass.
30X1.5 crop factor =45mm
30X1.5 crop factor =45mm
Ric, there is a major difference between a 28mm on a FX and DX camera. Yes it is still a 28mm lens but on the FX it is a wide angle and on the DX it is a "normal" lens. So to be clear, what I am hearing from this forum, is that a 28mm lens is as close as you can get to be technically correct the "normal" lens for a DX camera?
vindex1963
Senior Member
30mm would be closer 35mm more so.
30X1.5=45 35mmX1.5=52.5
30X1.5=45 35mmX1.5=52.5
Very true, but 35mm film has 43mm diagonal, which is the correct formula, but 50mm lenses were always assumed "normal".
But certainly yes, in these ball parks.
Lots of DX users hear about some importance of classical 50 mm (or 105mm) lenses, and automatically assume this has the same meaning for DX. DX users instead need to divide FX numbers by 1.5 (then 50/1.5 = 33mm, and 105/1.5 = 70mm). In this ball park.
Last edited:
WayneF, I understand "being in the ball park" but I was looking for a technically correct answer. 
And the 50mm lens as a "normal" lens for the 35mm was always confusing as different manufactures used 49, 50, 52 and 55mm as their "normal" lenses. I was told way back when that the difference was dependent on the actual distance of the back lens glass to the surface of the film. It seems Nikon and others do not advertize anymore what they consider is a "normal" lens with the various cameras. And I think the definition of "normal" has changed from what you actually see compare to what the camera sees to the "normal" lens that comes with the camera, or also known as the "kit" lens. The 50mm lens was the "kit" lens of it's time with the 35mm cameras.
And the 50mm lens as a "normal" lens for the 35mm was always confusing as different manufactures used 49, 50, 52 and 55mm as their "normal" lenses. I was told way back when that the difference was dependent on the actual distance of the back lens glass to the surface of the film. It seems Nikon and others do not advertize anymore what they consider is a "normal" lens with the various cameras. And I think the definition of "normal" has changed from what you actually see compare to what the camera sees to the "normal" lens that comes with the camera, or also known as the "kit" lens. The 50mm lens was the "kit" lens of it's time with the 35mm cameras.WayneF, I understand "being in the ball park" but I was looking for a technically correct answer.
As you pointed out, I don't think there is any one technically "correct" answer.
The concept of a normal lens is not related to frame size, except to the extent it tries to match the same frame size viewing width that the human eye perceives to see. But human eyes can only focus sharply in a very tiny center spot (that spot we actually look at). We do have peripheral vision that can detect light and movement at wider angles, but what that dimension is - is pretty vague. If you "look at" the edge of your monitor screen, you cannot read text in the center of the screen - but you are sure that you can see it.
But someone claimed if the focal length were about same as the diagonal, then this match to the eye is reasonably close - meaning the camera picture matches what we thought we saw when standing there. But 50mm was already the assumed "kit lens" for 35mm film much earlier, and it stuck.
The horizontal view of a 50mm lens on FX is 39.6 degrees (which is not far from 43mm diagonal). But I think most of us would imagine we see wider, maybe 90 degrees, even if we really cannot "see" stuff clearly at half of that 40 degree width. My own guess and perception is that 40 degrees is not much stretch to "see" if we move our eyes, but not our heads.
But, we are trying to precisely dimension something in mm, which is in fact quite vague and undefined. And also of course, we might choose for our picture to show a scene much wider (wide angle) or more narrow (telephoto), than what our eyes normally saw there. Nevertheless, a "normal" lens does turn out to be quite handy for many pictures.
Here is a chart of FX viewing angle for common focal lengths
http://en.wikipedia.org/wiki/Angle_of_view#Common_lens_angles_of_view
Last edited:
Horoscope Fish
Senior Member
HoroscopeFish, yes apparently this is true. But in every technical book that I have seen indicates the 50mm lens is referred as the "normal" lens for 35mm. Even in Charles Scott's Evidence Photography book printed in 1938, 1942, and 1969 indicates the 50mm lens is the "normal" lens used by the forensic photographer to show the object or scene "normally" or otherwise , as we see it with our eyes. While that is not totally true it was the accepted rule for displaying evidence photographs in court. Concept rather than measurement makes more sense.
Horoscope Fish
Senior Member
A 50mm lens on a film camera just happens to be the measurement, in mm, that most closely matches the perspective of the human eye. It's also a nice, round number which people tend to prefer and that may be part of the reason a "Normal" lens is *not* 51.638mm EXACTLY, and nothing else.
50mm: Close enough.
Actually, the odds of it being a little different than 50.00 mm are extremely high. The marked focal length is only a nominal round number, and then only when focused at infinity.
This is an old Nikon F lens, from back in the day when Nikon actually told us stuff.
