Focus problem

[Deadbear77]

So I've been using a bunch of different minolta and off brand md/mc mount lens on my nex 5n.

If noticed that some if not most of my zoom and fixed lens have problems focusing to infinity.

I've tried 3 different adapters from 3 different company's.

Do you think it's the camera?

 

[Bugleone]

You do get differences between various lenses, even those of the same manufacturer, and also diferences in adaptors.......

However, if you have the same problems regardless of lens/adaptor, then suspect 'error between teh ears of the operator'.....

.......the NEX is not likely to be wrong and is, anyway, easily checked. Manual focus is NOT as straightforward for all users and definately requires (and improves with) practice. Are you sure it's a focus fault?.....not slight camera movement as this can look like slight poor focus.

 

[Deadbear77]

After looking at it more it looks as if most of my lens focus at the almost to infinity. All the way is blurred but slightly turned is not. I think I just need to stop down a bit more. I think I'm expecting too much.

 

[Bugleone]

Well a few other things come to mind;.....what are you using as an 'infinity target'..? A large aperture is normally MUCH better for focusing and determining focus faults,..that said, most lenses give a sharper image when stopped down two stops....

 

[Deadbear77]

Actually I use the moon as an infinity target to test my lenses at night just to make sure that they're working correct
I also have the EVF viewfinder that I use with it

 

[Deadbear77]

This lens focuses at the infinity point perfectly

 

[Luckypenguin]

All the way is blurred but slightly turned is not.

So it's not that your lenses can't focus to infinity, but that they can focus beyond it. Just about every lens adapter that I have used was constructed slightly too short. With the construction tolerances of the cheaper adapters being what they are, this ensures that you'll never have an issue where you can't focus a lens to infinity but it does mean that you can't just rotate the focus ring all the way out to infinity when shooting a distant target.

 

[Deadbear77]

Ok. That makes me feel better, on another note. I just purchased a vivitar 28/210 and it does not focus at all for me. The lens seems in almost brand new shape as it came with box and papers and all that. Just can't get a single shot in focus.

 

[Dioptrick]

Ok. That makes me feel better, on another note. I just purchased a vivitar 28/210 and it does not focus at all for me. The lens seems in almost brand new shape as it came with box and papers and all that. Just can't get a single shot in focus.

Yep, Nic was spot on with the infinity focus problem. With adapted legacies we can't always use the end stop of the barrel movement as an infinity guide especially at wide open apertures.

The Vivitar 28/210 is obviously at fault since all your other legacies work on our camera.

Give us more info...
1) It doesn't focus only at infinity, or all the time at every distance?
2) Does the focusing problem exist at all focal lengths, or only at the extreme wide or tele setting?
3) Have you looked through the open ended lens and checked if the glass is clean and clear?

 

[Deadbear77]

Ok now I'm an idiot. The 28/210 was slightly threaded wrong on the adapter causing a tilt.

Wow what a rookie.

Thanks guys.