Is this focus shift?

[KIKO]

Advertisement (gone after registration)

Hi, I have an m9, been using it with either the 50 1.1 nokton and the 50 summicron. But I can use only one, because if I use the other I have to go back to the Allen key adjustment. So can't get the right focus with both without recalibrate with the Allen method. Is this normal?

When calibrated the nokton gets sharp results and spot on, but then mount the summicron and its has back/front focus. I can recalibrate with the Allen for the summicron and spot on, but if I mount then the nokton is way out of focus, I have read so much about issues like this, some says sometimes can't get both lenses to be spot on, what you guys think?

[BerndReini]

What happens when you stop down? If you focus either lens wide open, take a picture that is in focus, then stop it down, and take more pictures at different apertures, they should all still be in focus. If not, then this particular lens exhibits focus shift.

 

If neither lens shows focus shift, then one of the lenses is simply off. Use a Leica lens of a longer focal length (maybe a 75mm or a 90mm) to confirm, which lens is off. If the third lens focuses at the same adjustment as one of the others, then that lens needs to be adjusted. If it is the sum micron that needs to be fixed, then send it to Leica and they will fix it. Leica New Jersey shimmed my 50lux aspherical, and it is perfect now.

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[250swb]

I have read so much about issues like this, some says sometimes can't get both lenses to be spot on, what you guys think?

 

If you have read so much you should know that you shouldn't try to calibrate the focus of the body for a particular lens, doing so is a fundamental mistake made by home repairers or bad camera technicians.

 

It is impossible anyway because as you have found if you adjust the body for one lens other lenses will appear to be out of adjustment. As it sounds like you have screwed everything up and now have no datum point it would be best to send your body off for adjustment together with your Summicron. An experienced technician at Leica will then calibrate the body to meet set parameters, and they will calibrate the lens to meet set parameters, when they are put together the lens and body will then be in perfect harmony. Leica will not do what you have been doing and try to make the body match the lens, or make the lens match the body.

 

Steve

[jaapv]

Fiddling with the Allen key adjusts the rangefinder on the body.(The infinity adjustment, to be precise, but it will change the closeup adjustment slightly as well) If one lens focuses correctly and the other not it means one of the lenses is out of adjustment. Unfortunately you have been fiddling with it, so it is now virtually impossible to tell what is correctly calibrated and what not. Take the set to any competent camera repair shop that handles Leica and have them adjust lenses and camera to the correct standard.

Focus shift is something quite different. Some fast lenses will focus correctly wide open and as one stops the aperture down the plane of focus will shift, until at say f 5.6 the DOF catches up and it will be in focus again. This is a lens property and no amount of adjusting the camera will change that.If you try to do so you only destroy the focusing accuracy of the whole system.

Hi, I have an m9, been using it with either the 50 1.1 nokton and the 50 summicron. But I can use only one, because if I use the other I have to go back to the Allen key adjustment. So can't get the right focus with both without recalibrate with the Allen method. Is this normal?

When calibrated the nokton gets sharp results and spot on, but then mount the summicron and its has back/front focus. I can recalibrate with the Allen for the summicron and spot on, but if I mount then the nokton is way out of focus, I have read so much about issues like this, some says sometimes can't get both lenses to be spot on, what you guys think?

Edited January 3, 2015 by jaapv

[jaapv]

The problem is that Leica will not adjust a Voigtlander lens, so the OP either needs to have his Summicron checked and his camera body readjusted to the correct standard and try to find somebody to adjust his Nokton (the most likely culprit) or forget about that lens.

So it is off to DAG, Will van Manen, or similar.

 

If you have read so much you should know that you shouldn't try to calibrate the focus of the body for a particular lens, doing so is a fundamental mistake made by home repairers or bad camera technicians.

 

It is impossible anyway because as you have found if you adjust the body for one lens other lenses will appear to be out of adjustment. As it sounds like you have screwed everything up and now have no datum point it would be best to send your body off for adjustment together with your Summicron. An experienced technician at Leica will then calibrate the body to meet set parameters, and they will calibrate the lens to meet set parameters, when they are put together the lens and body will then be in perfect harmony. Leica will not do what you have been doing and try to make the body match the lens, or make the lens match the body.

 

Steve

Edited January 3, 2015 by jaapv

[Lenshacker]

Calibrate the M9 for the Summicron, it has an "indexed Cam".

 

Most likely the Nokton is back-focusing when the M9 is in good calibration. If it is, there is a very easy fix: build up the RF cam of the lens. I use one strip of copper tape, available on Ebay.

 

nokton_coppercam

 

So- set the camera for the Summicron, take a test shot of a ruler or something similar. If it is back-focusing, build up the RF cam. If it is front-focusing- You could send to DAG, the optics need to be moved closer or the Cam needs to be polished down.

 

The original question: this problem is not focus shift. This problem is often the result of manufacturers optimizing their own lenses for their cameras, and making assumptions about how film sits in their camera. I found that both my 50/1.1 Nokton and 35/1.2 Nokton required one layer of copper tape for correct focus on the M9 used wide-open. About 0.04mm.

Edited January 3, 2015 by Lenshacker

[KIKO]

Advertisement (gone after registration)

i thinks it is the nokton that has the problem with the summicron i get perfect focus at short, medium and long distances, but with the nokton is a real mess, i think that the problem is with the nokton. perfect focus at all distances with the cron, but as soon as i mount the nokton its out of focus at all distances, back focusing. i can adjust it back for the nokton and it works ok at short and medium distances, but at long it back focuses, so definitely it is the nokton

[KIKO]

Calibrate the M9 for the Summicron, it has an "indexed Cam".

 

Most likely the Nokton is back-focusing when the M9 is in good calibration. If it is, there is a very easy fix: build up the RF cam of the lens. I use one strip of copper tape, available on Ebay.

 

nokton_coppercam

 

So- set the camera for the Summicron, take a test shot of a ruler or something similar. If it is back-focusing, build up the RF cam. If it is front-focusing- You could send to DAG, the optics need to be moved closer or the Cam needs to be polished down.

 

The original question: this problem is not focus shift. This problem is often the result of manufacturers optimizing their own lenses for their cameras, and making assumptions about how film sits in their camera. I found that both my 50/1.1 Nokton and 35/1.2 Nokton required one layer of copper tape for correct focus on the M9 used wide-open. About 0.04mm.

 

this actually sounds like a great idea, i was tired of going back and forward and ended up letting it with the cron, i will try this ! thanks man ! i´´ll let you know if it works

[RvN]

Don't know copper tape. Sounds like an interesting solution. But isn't there a chance that it will leave residu/scrapes in the cam when using it for a longer time?

[Lenshacker]

I've been using copper tape for 15 years or so to build up RF cams, first required for a 13.5cm F4.5 Culminar. It is softer than the RF pickup of the camera. I've never seen the adhesive come lose. This is a 3M product made for shielding electronics. I usually run the side of a screwdriver over it to flatten out on the Cam.

[mmradman]

I've been using copper tape for 15 years or so to build up RF cams, first required for a 13.5cm F4.5 Culminar. It is softer than the RF pickup of the camera. I've never seen the adhesive come lose. This is a 3M product made for shielding electronics. I usually run the side of a screwdriver over it to flatten out on the Cam.

 

There are many copper tapes on eBay, can you please provide link to the one you use, thanks.

[Lenshacker]

It has been a long time since I got my roll...

 

this looks like it, thickness is what counts. I run the side of a small screwdriver over the take on the cam to smooth it out.

 

3M 1181 EMI Copper Foil Shielding Tape 1 2 in x 18yd | eBay

[mmradman]

It has been a long time since I got my roll...

 

this looks like it, thickness is what counts. I run the side of a small screwdriver over the take on the cam to smooth it out.

 

3M 1181 EMI Copper Foil Shielding Tape 1 2 in x 18yd | eBay

 

Thanks for the link.

 

Curious, thickness of copper layer is very thin just a fraction of millimetre (66microns) but enough to build up on the cam, your pictures show thin layer of copper sticking snugly to the cam.

 

Can you explain how do you eliminate or reduce all or most of 1.2mm thickness of the adhesive while enabling copper to stick, I would imagine copper tape and adhesive combined would be excessively thick to fix the cam.

[Lenshacker]

It is not 1.2mm thickness on the adhesive, it is 1.2mils. A mil is 0.001 inch. It's about 0.025mm. After thinning by running the side of the jeweler's screwdriver over it, about 0.04mm or so between the adhesive and copper. My thinnest shims are 0.02mm, used on the pre-war Zeiss Sonnars. Kitchen Aluminum foil is about 0.07mm, at least what I have measured with the calipers comes up to that.

[CNagappa]

On 1/3/2015 at 5:26 AM, Lenshacker said:

Calibrate the M9 for the Summicron, it has an "indexed Cam".

 

Most likely the Nokton is back-focusing when the M9 is in good calibration. If it is, there is a very easy fix: build up the RF cam of the lens. I use one strip of copper tape, available on Ebay.

 

Thank you for the tip @Lenshacker

I noticed the slight back-focus issue on my brand new Voigtlander Nokton Classic 40mm F1.4 on my Leica M-E. I got the copper foil tape (2.6mil = 66 micron) and applied it to the RF cam. Voila, back focus problem solved! It's almost perfect now.

Here's a pic. I admit it looks a bit crudely done, but the top surface is pretty flat and the foil is pretty secure.

(Incidently, I also filed about 0.5mm off the shoulder of the tab pointed to in the arrow. Now brings up 35mm frame lines in my M-E.)

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Jeff S]

12 hours ago, CNagappa said:

Thank you for the tip @Lenshacker

I noticed the slight back-focus issue on my brand new Voigtlander Nokton Classic 40mm F1.4 on my Leica M-E. I got the copper foil tape (2.6mil = 66 micron) and applied it to the RF cam. Voila, back focus problem solved! It's almost perfect now.

Here's a pic. I admit it looks a bit crudely done, but the top surface is pretty flat and the foil is pretty secure.

(Incidently, I also filed about 0.5mm off the shoulder of the tab pointed to in the arrow. Now brings up 35mm frame lines in my M-E.)

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

His last forum post was from May, 2015, so unlikely to receive your gratitude.

Jeff

[CNagappa]

6 hours ago, Jeff S said:

His last forum post was from May, 2015, so unlikely to receive your gratitude.

Jeff

Thank you, Jeff.

(BTW, that was my first post.)

[Jeff S]

42 minutes ago, CNagappa said:

Thank you, Jeff.

(BTW, that was my first post.)

Welcome to the forum.

Jeff

[gsfx]

Am 25.4.2021 um 04:44 schrieb CNagappa:

Thank you for the tip @Lenshacker

I noticed the slight back-focus issue on my brand new Voigtlander Nokton Classic 40mm F1.4 on my Leica M-E. I got the copper foil tape (2.6mil = 66 micron) and applied it to the RF cam. Voila, back focus problem solved! It's almost perfect now.

Here's a pic. I admit it looks a bit crudely done, but the top surface is pretty flat and the foil is pretty secure.

(Incidently, I also filed about 0.5mm off the shoulder of the tab pointed to in the arrow. Now brings up 35mm frame lines in my M-E.)

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Hello,

I am Frederik from Germany and I have a question. Unfortunately I cannot send you a private message in this forum?

Best regards

Frederik

[Advertisement]

Hallo,

Look here: Leica M

[jaapv]

Given that lenshacker last visited in 2015 it is unlikely that a PM will be read.