50mm 1.8D looks "normal" on my D7000?

Hello all!

I've recently picked up a 50mm 1.8D to get a pseudo medium-tele for low light on my D7000. However, it seems like I'm at a normal field of view when focused close to infinity and appears much like my 35mm 1.8G. I only get the "true" field of view when focused on very close things.

Is this expected behavior due to focus breathing?

First off, welcome to the board, kirbfucius. As for your question, I'm not quite sure what you're referring to. Do you mean the field of view changes more than you would have expected when adjusting focusing? I've the 1.8G and I don't remember seeing much of a change, I wonder if the D is significantly different or ?

Thank you for the welcome!

Yes, the field of view changes pretty significantly, relatively speaking. Certainly more than I was expecting, and more than I realized when I tested it in the store. It looks like it's just due to the focus breathing so there's not much I can do about it. The G version focuses internally so it doesn't have the issue.

I also have the 35 1.8G. On my crop sensor, it gives me a 52.5mm field of view whether I focus closely or further away. That makes sense considering on my crop sensor the 35 is essentially a 52mm. The only telephoto benefit I get for the 50mm 1.8D is when focusing within about 10 feet (2m). Even then it's pretty minimal unless it's closer than three feet.

kirbfucius said:

Hello all!

I've recently picked up a 50mm 1.8D to get a pseudo medium-tele for low light on my D7000. However, it seems like I'm at a normal field of view when focused close to infinity and appears much like my 35mm 1.8G. I only get the "true" field of view when focused on very close things.

Is this expected behavior due to focus breathing?

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I'm sorry but I don't understand what you mean by "field of view". Do you mean "depth of field", where the focus point is very shallow and the front and back focus are out of focus?

Marcel said:

I'm sorry but I don't understand what you mean by "field of view". Do you mean "depth of field", where the focus point is very shallow and the front and back focus are out of focus?

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He's referring to the "field of view" changes when focusing. Or what they call "breathing".

As Dave mentioned, it's the breathing that's giving me an issue. On my camera I should see what a full frame camera sees at 75mm. However, after 3 feet I start losing the telephoto effect. Beyond 20 feet I'm seeing the same 50mm that I would on a full frame. That's all well and good, except I already get that from my 35mm prime.

Dave_W said:

He's referring to the "field of view" changes when focusing. Or what they call "breathing".

Click to expand...

I thought breathing was focal length change when you move closer and was only applicable to certain zoom lenses...

Marcel said:

I thought breathing was focal length change when you move closer and was only applicable to certain zoom lenses...

Click to expand...

The breathing of a lens is typically not a big problem unless you're doing focus stacking because with each change in focus you have a slightly larger or smaller field of view. For perfect focus stacking you not only have to change the focus but you also have to move the lens ever so slightly one way or the other in order to make each image exactly the same.

So I did a comparison of my 50mm to the 35mm on side-by-side shots. It is getting a bit closer (as it should), but not enough to me to make it worth owning both. I'll probably sell the 50mm and look into an 85mm.

I think this is where the confusion comes in; and I might be wrong. The crop factor relates to the sensor not to the lens. The 50mm lens mounted on your D7000 or on a D800 (FF) are identical. Since the sensor on the D7000 is smaller the viewer or what the lens see is cropped image (factor 1.5 of FF).

So your 35mm does see moderate wide angle but it would be like you cropping the FF by 1.5 but printing both the same size like an 8x10. If you would crop the FF 35mm to same dimension as the one that came from the d7000 they would be identical.

Even though the same rules applied from film at 35mm; so if you had a 28mm wide angle and took an image of a group of people edge to edge as we know that the two end people would be distorted. Follow me so far. But if I cropped those two end people out that what I would see with my D7000 at the same distance say 10 foot.

Now using the same rules we used in the old days my normal lens was a 35mm as 50mm (even though normal) I needed to get back or push a wall out to take images of friends and family. Some of us old timers remember we went an bought a 35mm lens.

So 28 or 35 mm good for groups and scenics, 50 mm "normal" lets say a full length to 3/4 portrait. The 75-85 mm for head and shoulders and the 135 to 200mm for full face.

It just us with cropped sensors will have to move farther back then we did when we had 35 mm film.

My 2¢

​Lou Cioccio