FX Lenses on D7500

was_a_guru

Senior Member
I have a Nikon DSLR with two kit lenses (18-55 f/3.5-5.6 & 70-300 f/4.5-6.3). I also have two Nikon Series E lenses that were used on a Nikon FM film camera. Both of those have a lower maximum f stop (35mm f/2.5, 50mmf/1.8) and might be good for low light situations. I wanted to see if these would work on my D7500. I realize I would have to focus manually, set aperture manually (both of those on the lens), and also meter manually for setting shutter speed (on the camera).

So I experimented. With my camera on a tripod took four shots (all at same distance from subject):
1. With my 18-55mm lens set at ~35mm, in A mode - f/5.6, 1/160, ISO 800
2. With my 18-55mm lens set at ~50mm, in A mode - f/5.6, 1/160, ISO 800
3. With the Series E 35mm lens, in M mode - manually set f/5.6, 1/160, camera set ISO 800
4. With the Series E 50mm lens, in M mode - manually set f/5.6, 1/160, camera set ISO 800
(#2 & 3 only worked in M mode.)

I had expected that since the Series E lenses were basically FX lenses that the prime 35mm lens would act like a focal length of ~50mm and the prime 50mm lens would act like a focal length of 75mm on a DX camera.

BUT the object size and angle of view of the picture taken with the Prime 35mm lens was identical to that of the 18-55mm lens @35mm. And the same for the pictures of the Prime 50mm and the 18-55 @50mm. Shouldn't the pictures taken with the prime lenses have shown a different sized image (telephoto-ish) comparatively to the DX images respectively?
 

480sparky

Senior Member
Once again, "Crop Factor Multiplier Confusion" rears it's ugly head.

Here's the truth of the matter: Focal length is focal length. NOTHING about it changes between FX and DX. 35mm is 35mm. 50mm is 50mm. 200mm is 200mm. Format (FX/DX) does not affect focal length one tiny bit.
 
Once again, "Crop Factor Multiplier Confusion" rears it's ugly head.

Here's the truth of the matter: Focal length is focal length. NOTHING about it changes between FX and DX. 35mm is 35mm. 50mm is 50mm. 200mm is 200mm. Format (FX/DX) does not affect focal length one tiny bit.

The difference comes in when you try to compare that 35mm lens on the DX camera and the FX camera. the apparent focal length would be different at that time.
 

nickt

Senior Member
A dx sensor is smaller than an FX sensor. The dx sensor does not capture the entire image that is cast onto the film plane. That smaller captured area ends up getting enlarged to a standard size, hence the apparent zoom or crop factor. So on a dx camera it makes no difference if you use a dx or fx lens. Compare this to a 35mm negative, get the 35mm negative printed at 5x7. Then take that negative and trim 1/8" off each side. Print the resulting cropped negative again at 5x7. That's the DX concept. I guessed at the 1/8" but you should get the idea: Less image captured, but its enlarged to fit the same paper size that you printed the full size negative on.

Now for the lens... Either fx or dx lens will work on dx. The difference is the dx lens is a cheaper design. They 'cut corners', figuratively and literally. The outer edges of the cast image won't be captured by the smaller sensor so the dx lens can be designed cheaper and lighter. The image that spills beyond the sensor does not have to be good. But put that dx lens on an fx sensor and you might get an image with distortion at the edges and corners. Or maybe vignetting. Or you may get away with it and not see any noticeable problems.
 

Marcel

Happily retired
Staff member
Super Mod
Your prime lenses (if they are AI-S) should meter with your camera, but I think only in A mode. But you have to put the lens aperture at it's smallest aperture (read larger number) and go in the menu to let the camera know what is the largest aperture of that lens.
 

480sparky

Senior Member
The difference comes in when you try to compare that 35mm lens on the DX camera and the FX camera. the apparent focal length would be different at that time.

Once again, the focal length DOES NOT CHANGE. A 35mm DX lens is 35mm. A 35mm FX lens is 35mm.

What changes is apparent FIELD OF VIEW between a 35mm lens on a DX body and a 35mm on an FX body.
 

Pocono_ACE

Senior Member
Your prime lenses (if they are AI-S) should meter with your camera, but I think only in A mode. But you have to put the lens aperture at it's smallest aperture (read larger number) and go in the menu to let the camera know what is the largest aperture of that lens.

Not sure this is true. I've been thinking of getting a D7500 lately, and was very unhappy to learn that it will not perform autoexposure (even "A" mode) with non-CPU lenses. This is apparently true of all the new Nikons -- even the top of the line. My 9-year-old D90 will do it, but none of the new cameras will. What happened to Nikon's famed backward compatibility? And more to the point, what am I supposed to do with my 1990s-vintage 80-200 f2.8? It's a fabulous lens, but its functionality is severely limited if I put it on a new camera. Very frustrating!
 

Marcel

Happily retired
Staff member
Super Mod
Not sure this is true. I've been thinking of getting a D7500 lately, and was very unhappy to learn that it will not perform autoexposure (even "A" mode) with non-CPU lenses. This is apparently true of all the new Nikons -- even the top of the line. My 9-year-old D90 will do it, but none of the new cameras will. What happened to Nikon's famed backward compatibility? And more to the point, what am I supposed to do with my 1990s-vintage 80-200 f2.8? It's a fabulous lens, but its functionality is severely limited if I put it on a new camera. Very frustrating!

You probably are right about the 7500. But the 500 and 7200 still support these great oldies. Of course the Df will take all of them.
 

Pocono_ACE

Senior Member
You probably are right about the 7500. But the 500 and 7200 still support these great oldies. Of course the Df will take all of them.

Hmm, you got me thinking. I went to the NikonUSA website and looked up the technical specs for both the Df and the D850. Both had this entry under "Metering Method":

Color Matrix Metering available with non-CPU lenses if user provides lens data

I also see no lens restrictions under "Exposure Modes." So does this mean that if I supplied the lens data to the D850 it would offer Color Matrix Metering in all exposure modes? Ugh, I really hadn't planned on spending over $3000 for my next camera.

What I really don't get is why Nikon would drop a capability its "prosumer" camera (the D90 ten years ago and the D7500 now) used to possess. Was there an engineering reason, or was it just to push the customer up the food chain? That would be a real crap move on their part.


 

RocketCowboy

Senior Member
What I really don't get is why Nikon would drop a capability its "prosumer" camera (the D90 ten years ago and the D7500 now) used to possess. Was there an engineering reason, or was it just to push the customer up the food chain? That would be a real crap move on their part.

Why did Nikon drop dual card slots and the option for a battery grip from the D7500, when the previous versions of this "prosumer" body had those capabilities? Absolutely to create feature distinction between models so that there was a feature driver towards higher-end (i.e. more expensive) models. If you have old glass from the 90's, you aren't spending enough money with Nikon and buying into the refresh cycle. So, they catch up on that lost revenue by driving you into a higher camera body when the time comes.
 

Danno

Senior Member


What I really don't get is why Nikon would drop a capability its "prosumer" camera (the D90 ten years ago and the D7500 now) used to possess. Was there an engineering reason, or was it just to push the customer up the food chain? That would be a real crap move on their part.



I felt the same way when the 7500 came out. I stuck with my 7200. It will work with the older glass and for what I shoot it works well. I have a D700 and D7200 and they both work well for me. Maybe an 850 one day to replace the 700, but I am good for now. If I were upgrading in crop sensors it would be the 500 but I am really happy with my D7200.
 

Marcel

Happily retired
Staff member
Super Mod
Hmm, you got me thinking. I went to the NikonUSA website and looked up the technical specs for both the Df and the D850. Both had this entry under "Metering Method":

Color Matrix Metering available with non-CPU lenses if user provides lens data

I also see no lens restrictions under "Exposure Modes." So does this mean that if I supplied the lens data to the D850 it would offer Color Matrix Metering in all exposure modes? Ugh, I really hadn't planned on spending over $3000 for my next camera.

What I really don't get is why Nikon would drop a capability its "prosumer" camera (the D90 ten years ago and the D7500 now) used to possess. Was there an engineering reason, or was it just to push the customer up the food chain? That would be a real crap move on their part.


Yes, that is how it works. There is a menu for adding different non-CPU lenses, if I remember correctly you can enter 5 or 6. You enter the focal lenght AND the maximum aperture. This is how the camera can now know what the aperture is actually used in order to provide metering. When the camera doesn't know the aperture, it can't meter.
But with digital, this is not that important since you can view the shot and histogram and then correct if you have to. Manual exposure is not rocket science.
 

Bikerbrent

Senior Member
There is a very easy solution to the D7500 issue. Skip the crippled D7500 and get a D7200. My ancient 80-200 f2.8 works great on my D7200.
 

nzswift

Senior Member
Just go to the CPU part of menu system and add your older Nikon lenses focal length and maximum aperture. I think you van save up to ten lenses.
 

Pocono_ACE

Senior Member
Just go to the CPU part of menu system and add your older Nikon lenses focal length and maximum aperture. I think you van save up to ten lenses.

I wish this were true, but I found this on the D7500 Tech Specs page:



  • [h=4]Compatible Lenses[/h] AF NIKKOR lenses, including type G, E, and D lenses (some restrictions apply to PC lenses) and AI-P NIKKOR lenses and non- CPU AI lenses (M mode only)



How does this square with your comment above?
 

Pocono_ACE

Senior Member
There is a very easy solution to the D7500 issue. Skip the crippled D7500 and get a D7200. My ancient 80-200 f2.8 works great on my D7200.

It's a compelling suggestion, as the D7200 can be bought CHEAP these days. I guess I was thinking I wanted that Bluetooth/SnapBridge feature on the D7500, although I've read that SnapBridge has had its problems. It would be nice, while traveling, to be able to upload a photo to Facebook on the spot. It's probably not a deal-breaker for me, however.
 

Johnbennet88

New member
It's a compelling suggestion, as the D7200 can be bought CHEAP these days. I guess I was thinking I wanted that Bluetooth/SnapBridge feature on the D7500, although I've read that SnapBridge has had its problems. It would be nice, while traveling, to be able to upload a photo to Facebook on the spot. It's probably not a deal-breaker for me, however.
Well I personally own Nikon D7500 and extra features are really helpful, at least to me, because I want to have that flexibility, uploading picture as soon as I take it etc. Of course everything has its ups and downs.
As for the OP question, a lot of people get confused about it, there are many terms in photography area and not all are clear what they mean from the start. What helped me LEARN and become better photographer is reading some guides on google such as https://lensespro.org/best-lenses-for-nikon-d7500/, they explain a little bit about FX, lens compatibility etc so I think they will help you.
 

carguy

Senior Member
I felt the same way when the 7500 came out. I stuck with my 7200. It will work with the older glass and for what I shoot it works well. I have a D700 and D7200 and they both work well for me. Maybe an 850 one day to replace the 700, but I am good for now. If I were upgrading in crop sensors it would be the 500 but I am really happy with my D7200.

Same. I kept my D7100 as well. The D7500 is a neutered D7200 basically. My guess is to drive more traffic to the D500 body.
 
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