Focusing Problems Nikkor 105mm f/2.5 non-cpu lens

Lonnie1212 · Jun 13, 2023

RAZKY said:
If her eye had been in sharp focus on the focusing screen when you released the shutter, it ought to have been in sharp focus on the sensor. How accurately have you adjusted your diopter? It doesn't sound like camera or lens error.

Okay maybe I should pay more attention to the diopter. I was at a photography class this weekend and was told to try shooting without wearing my glasses. Thank you

Lonnie1212 · Jun 13, 2023

smoke665 said:
Just a thought, but at the settings used, depending on the the distance your DOF would have been 4" or less. "but the burlap on the back of the chair is in focus" - if you look closely at the burlap you'll see there's only about a 4" section just under the front of the hair that's in sharp focus, coincidentally of the same plane as the hair in front of her face. If you look at the hair in front of the eye, it's also in sharp focus. I've had this problem before with auto focus locking on hair rather than the eye. When that happens I can sometimes use spot focus on an area free of hair and use my DOF to catch the eye, or switch to manual focus.

Another possibility, which AF mode were you Using? AF-C, AF-S, or AF-A?

There's always the possibility of a focus problem, I've only found that to be the case a couple times in my lifetime. If you have concerns here's the way to check it, there's a link in the article to download the focus chart. How to do a Camera Focus Test for Autofocus Issues

It is a manual focus lens. But I will check that setting when I get home tonight.

ac12 · Jun 13, 2023

Lonnie1212 said:
Okay maybe I should pay more attention to the diopter. I was at a photography class this weekend and was told to try shooting without wearing my glasses. Thank you

In the days of film I tried that. I got a diopter for my SLR.
BUT . . . without glasses, I essentially could not see anything outside the viewfinder. So BAD idea.
The only time I am without my glasses, is when it is raining. The rain on the glasses makes the vision through the glasses worse than without glasses.

I ALWAYS adjust the eyepiece diopter. It just bugs me when the viewfinder is not in focus, and I get a headache from my eyes "trying" to focus on an out of focus viewfinder.

wfooshee · Jun 14, 2023

RAZKY said:
According to the original post, the issue has nothing whatever to do with depth of field.

Yet he's obviously trying to achieve a shallow depth of field, so I made the point that experience with one lens may not lead to appropriate expectations with another lens. That's still a valid point.
The main point was the absolute impossibility of focusing accurately on the ground glass screen.

RAZKY · Jun 14, 2023

wfooshee said:
Yet he's obviously trying to achieve a shallow depth of field, so I made the point that experience with one lens may not lead to appropriate expectations with another lens. That's still a valid point.
The main point was the absolute impossibility of focusing accurately on the ground glass screen.

The post I read said the area he was trying to focus on wasn't sharp, and he wanted to know why. That is not a depth of field issue.
As for accurately focusing on a ground glass screen, anyone wishing to educate themselves might want to take a look at what the Nikon and Leica R Compendiums have to say - in particular the advantages of a plain screen with no distracting focusing aids.

Lonnie1212 · Jun 16, 2023

I would like to thank everyone for their help. I obviously need more experience with this lens. Everyone has offered a valid opinion. Last year I was having the exact same problems with the 105mm AF F/2 lens.