Jump to content
evikne

75mm Summilux back focusing

Recommended Posts

Advertisement (gone after registration)

I have recently purchased a used 75mm Summilux f/1.4 which has an issue with back focusing. I did some tests today, and from minimum focusing distance to about 1.5 meters, the focus is very good. Then the back focusing is more and more visible at longer distances. At 2 meters the focus is about 5 cm behind, and at 3 meters it back focuses maybe 30 cm. I can't see any difference at different apertures.

 

What is the best thing to do? Send it to Leica for an adjustment? Do they need the camera as well? (hope not). Or should I just find a way to live with it, e.g. try to remember how much nearer I have to focus at different distances?

 

I have planned to buy a Visoflex, but currently I can't afford it.

Edited by evikne

Share this post


Link to post
Share on other sites

I bought one with severe focus problems on the basis that it would go to Leica to be sorted (and code) which it did. It is now absolutely fine and I'm the only focus problem it has. So all I can say is that Leica fully sorted my copy out and did a great job. They shouldn't need your camera unless it has focus issues with other lenses.

Share this post


Link to post
Share on other sites

When focus is good at short distance and backfocus increases with distance then usually the viewfinder alignment at infinity is the culprit.

 

I would start checking alignment in the viewfinder with the lens at infinity. Take a test object at a distance of at least 1 km, preferably in good weather conditions.

There are two conditions possible:

- When the viewfinder is not at infinity while the lens is, you use the 2mm hex key to align infinity. Usually this solves the issue

- If this is not the case and the viewfinder is aligned with the lens at infinity, the lens needs to be calibrated by Leica

 

This test has worked for me over the last 10 years!

Sometimes the lens was at fault, but most times the viewfinder had drifted somewhat.

 

Maarten

Share this post


Link to post
Share on other sites

I would definitely have it fixed - it is a wonderful lens that is hard enough to focus without these issues ! Is there no good repair location in Norway ? If the viewfinder needs alignment with the lens they need both..

Edited by DickieT

Share this post


Link to post
Share on other sites

When focus is good at short distance and backfocus increases with distance then usually the viewfinder alignment at infinity is the culprit.

 

I would start checking alignment in the viewfinder with the lens at infinity. Take a test object at a distance of at least 1 km, preferably in good weather conditions.

There are two conditions possible:

- When the viewfinder is not at infinity while the lens is, you use the 2mm hex key to align infinity. Usually this solves the issue

- If this is not the case and the viewfinder is aligned with the lens at infinity, the lens needs to be calibrated by Leica

 

This test has worked for me over the last 10 years!

Sometimes the lens was at fault, but most times the viewfinder had drifted somewhat.

 

Maarten

 

Great advice - thank you !  

Share this post


Link to post
Share on other sites

When focus is good at short distance and backfocus increases with distance then usually the viewfinder alignment at infinity is the culprit.

 

I would start checking alignment in the viewfinder with the lens at infinity. Take a test object at a distance of at least 1 km, preferably in good weather conditions.

There are two conditions possible:

- When the viewfinder is not at infinity while the lens is, you use the 2mm hex key to align infinity. Usually this solves the issue

- If this is not the case and the viewfinder is aligned with the lens at infinity, the lens needs to be calibrated by Leica

 

This test has worked for me over the last 10 years!

Sometimes the lens was at fault, but most times the viewfinder had drifted somewhat.

 

Maarten

 

Thanks for the advice! I can make a test tomorrow when the daylight is back.

 

But I have other, newer lenses that focuses perfectly at all distances, so I don't think my viewfinder can be the problem.

Edited by evikne

Share this post


Link to post
Share on other sites

Advertisement (gone after registration)

When I bought the 75mm Summilux way back in the M8 days, it too was off focus.   In the USA, I sent DAG the lens and he fixed it perfectly and focus is still correct on my M10. 

Share this post


Link to post
Share on other sites

How much is a LUX 75mm in good condition?

I just acquired a late version of Lux 75 for $3,650 including original box.

Everything is mint condition as described, Only snag is the foam in the box needs to be discarded as it had chemically decomposed.

 

Starting to learn the ropes to use its strength.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue., Read more about our Privacy Policy