Cleaning LF Lens

SoulfulRecover · Jul 12, 2016

I noticed that the inner glass elements have some dust specs on them and I would like to clean them. I see that there are two notches on the front of the lens and I am assuming I can use those to twist the front element off. Is that all there is to it? I don't want to force it or break anything.

480sparky · Jul 12, 2016

If you have a spanner wrench, you can certainly try it. Who knows how much force will be needed?

SoulfulRecover · Jul 12, 2016

I do/did somewhere. As long as one of the techs from my old work didn't steal it out of my box.

480sparky · Jul 12, 2016

Sticking up like it does, you may be able to use a butter knife.

tirediron · Jul 12, 2016

Actually since you've got the room, I would make my own "wrench". Take a piece of appropriate sheet metal (the largest that will still fit in the notches), and then file out openings so that it rests inside the lens opening and overhangs the outside (taking care to make sure it's well clear of the optical elements), and make the whole thing about 6" long and 3" high. This will let you get a good grip without exerting ridiculous leverage on anything and the notches in your wrench will help to prevent it from "jumping" off the lens and damaging anything.

cgw · Jul 13, 2016

Dust specks in a LF lens? Curb the OCD and just shoot it unless they're degrading your images--which I suspect they're not. A sticky shutter is one thing but minor dust?

compur · Jul 13, 2016

On most lenses of this type the whole front and rear lens groups twist off (from the shutter) as a unit.

I would do that and blow out any dust.

Going any further (i.e., separating individual elements) on an old lens is risky.

SoulfulRecover · Jul 13, 2016

cgw said:
Dust specks in a LF lens? Curb the OCD and just shoot it unless they're degrading your images--which I suspect they're not. A sticky shutter is one thing but minor dust?

Maybe I am being OCD about it? Ive only shot 3 images with this lens so far (waiting on 4 from the lab currently) and I figured if it really is as easy as unscrewing the front and back of the lens, why not give it a clean. Looking through it wide open it just seems like it could use it. Maybe not? I don't really know.

The 3 images I have gotten back had a couple spots on them which to me seemed like dust specs but it could have been from the scanner easily.

Ill see if I can take a photo through the lens this evening that will show the dust.

compur · Jul 13, 2016

Specks inside a lens don't cause specks on a negative.

480sparky · Jul 13, 2016

Neither does specks on the body of the camera. But that doesn't mean you can't clean it off.

SoulfulRecover · Jul 14, 2016

more there than what I could photograph but:

unpopular · Jul 14, 2016

You can, sure, but it won't make *any* difference other than cosmetic.

That's fine, if that's important to you, but heck, plenty of old lenses out there had bubbles.

SoulfulRecover · Jul 14, 2016

Can you explain why it wont make a difference? genuinely curious, not trying to debate or anything.

480sparky · Jul 14, 2016

SoulfulRecover said:
Can you explain why it wont make a difference? genuinely curious, not trying to debate or anything.

'Cuz they are so out of focus they cannot be seen.

Front Element Scratches

unpopular · Jul 15, 2016

Yep. If you focus on infinity and put your index finger in front of the lens. Was the sharpness of far objects affected?

Now imagine that with something the size of a speck sitting inside the lens. They can show up in bokeh, like little dimples with a brighter halo within the bokeh ball, but IMO that sort of thing just adds some character.