Linhof missed focusing

[nobrains]

Hi,

I've recently got into shooting large format, bought a Linhof super Technika iv with a Schneider150mm lens.
I tried searching the web, but couldn't find anything related to it and so do I feel something strange as well, thought will post it here to check if I can find help.

When I focus, I miss the point of focus on the film and it tends to focus something at the back by a marginal small amount.
Initially it thought it was me, asked someone else to reconfirm the focus, tried a different lens and back 4x5 and 120 both as well, simillar problem.

Its a metal body, so can't even say something can be done there, only possiblilty could be ground glass.
I'm based in India, so can't send it over to the members or Linhof technicians who can service or check it.

Is there something I can do to cross check before I find someone to repair/service it?

Thanks,
Parvez

[pau3]

If it consistently focus at the back of your focus point, probably the ground glass is reversed: the frosted part is probably facing you instead of facing inwards the camera. Try to flip the ground glass, if possible.

[nobrains]

Thanks Pau for the reply, I did think that but nope it's in correct place and frosted part inside, that is what I'm surprised about, nothing I could find wrong so asked someone else to focus and shoot :)

[Bob Salomon]

Your gg spacing is off. There are 4 small set screws that adjust the focus plane position of the gg. They have to be reset.
It sounds like:
1 your camera originally had the fresnel under the gg and removed it.
Or
2 someone adjusted those screws incorrectly for some reason.
Or
3 you are missing the 4 small shims that sit on those screws.

[Tin Can]

Good to know Bob

German engineering

I will keep this in mind

[nobrains]

Thanks Bob, you always come for a rescue!

This camera was lying unused for 20+ years and no Fresnel for sure and I was the lucky one to open the fungus filled box!
I cleaned it but didn't play around with any screws, attached is the image of the ground glass.

210124

Is there something I can se using some defined measurements to reset it to normal or will it need someone with experience to set it up for me?
The problem is finding one locally!

Thanks,
Parvez

[Bob Salomon]

Thanks Bob, you always come for a rescue!

This camera was lying unused for 20+ years and no Fresnel for sure and I was the lucky one to open the fungus filled box!
I cleaned it but didn't play around with any screws, attached is the image of the ground glass.

210124

Is there something I can se using some defined measurements to reset it to normal or will it need someone with experience to set it up for me?
The problem is finding one locally!

Thanks,
Parvez
You should have an old camera like that get a professional CLA for best results. Any LInhof service center can help you,

[Conrad . Marvin]

If you measure the distance from the gg toward the lens the distance will be somewhere near 13/64 Inches or 5 mm. If not....

[nobrains]

I so wish there was a Linhof centre in India or a reputed technican or if I was around there Bob! :)

[nobrains]

If you measure the distance from the gg toward the lens the distance will be somewhere near 13/64 Inches or 5 mm. If not....

Thanks, I'll give it a try and been searching for a technican as well. Wish me luck!

[Bob Salomon]

Thanks, I'll give it a try and been searching for a technican as well. Wish me luck!

Indien / India
EASTERN PHOTOGRAPHIC CO.
203, Magnum House-II
Karampura Commercial Complex
New Delhi – 110015
Fon +91 11 25920156
Fax +91 11 25920157
info@easternphotographic.com
www.easternphotographic.com

[nobrains]

Indien / India
EASTERN PHOTOGRAPHIC CO.
203, Magnum House-II
Karampura Commercial Complex
New Delhi – 110015
Fon +91 11 25920156
Fax +91 11 25920157
info@easternphotographic.com
www.easternphotographic.com

Thanks Bob, I'll speak to them tomorrow, I know them and as far as I know they are resellers but not not sure about servicing.

[Bob Salomon]

Thanks Bob, I'll speak to them tomorrow, I know them and as far as I know they are resellers but not not sure about servicing.

They are the authorized Linhof distributor for India. The authorized distributor in each country is contractually required to be responsible for warranty service in their country. If they don’t do service they will know who does.

[Doremus Scudder]

An easy, fairly accurate test for ground-glass spacing and adjustment is as follows.

Set up a close-up shot of a ruler at an oblique angle to the camera. Use a longish lens shot wide-open for best results.
Focus on a mark at the middle of the ruler.
Make a negative and develop it. Check whether the mark you focused on is actually the sharpest mark on the ruler.
If the sharpest mark is farther away than the one you focused on, the ground glass needs to be shimmed away from the back a bit.
If the sharpest mark is closer than the one you focused on, the ground glass needs to be moved forward. This can be problematic if your camera doesn't have adjustment capability. Milling the back or similar might be necessary.

Shims can be made from any suitable thin gasket material or the like if needed. Your Linhof likely has adjustments for either direction.

Make small changes and test again. Repeat as needed till you have acceptable focus accuracy.

Best,

Doremus

[nobrains]

An easy, fairly accurate test for ground-glass spacing and adjustment is as follows.

Set up a close-up shot of a ruler at an oblique angle to the camera. Use a longish lens shot wide-open for best results.
Focus on a mark at the middle of the ruler.
Make a negative and develop it. Check whether the mark you focused on is actually the sharpest mark on the ruler.
If the sharpest mark is farther away than the one you focused on, the ground glass needs to be shimmed away from the back a bit.
If the sharpest mark is closer than the one you focused on, the ground glass needs to be moved forward. This can be problematic if your camera doesn't have adjustment capability. Milling the back or similar might be necessary.

Shims can be made from any suitable thin gasket material or the like if needed. Your Linhof likely has adjustments for either direction.

Make small changes and test again. Repeat as needed till you have acceptable focus accuracy.

Best,

Doremus

Thanks Doremus, honestly I didn't want to waste more of my film so was trying ways and finding possibilities.
Though it does sound like a way to do it, instead of film, maybe I'll break open one of the film holders and put a paper instead of film and try focusing it on the ground glass and here. I remember this was the way it was done on a TLR, but not sure if it will work for large format.

Hi Bob, I did speak to Eastern photographic company. Like I said they are resellers, he did say the same. He did add to it saying, if you have major issues then we can send it to Europe for servicing, locally they had some technician but now no one.

Will find someone and update.

Thanks,
Parvez

[Bob Salomon]

Thanks Doremus, honestly I didn't want to waste more of my film so was trying ways and finding possibilities.
Though it does sound like a way to do it, instead of film, maybe I'll break open one of the film holders and put a paper instead of film and try focusing it on the ground glass and here. I remember this was the way it was done on a TLR, but not sure if it will work for large format.

Hi Bob, I did speak to Eastern photographic company. Like I said they are resellers, he did say the same. He did add to it saying, if you have major issues then we can send it to Europe for servicing, locally they had some technician but now no one.

Will find someone and update.

Thanks,
Parvez

Too bad!

[Tin Can]

You say you will break out a film holder...now?

What have you been using? Exactly, by name, age and design?

Some film holders, some roll film devices, and some plate holders DO vary, in a critical way.





Thanks Doremus, honestly I didn't want to waste more of my film so was trying ways and finding possibilities.
Though it does sound like a way to do it, instead of film, maybe I'll break open one of the film holders and put a paper instead of film and try focusing it on the ground glass and here. I remember this was the way it was done on a TLR, but not sure if it will work for large format.

Hi Bob, I did speak to Eastern photographic company. Like I said they are resellers, he did say the same. He did add to it saying, if you have major issues then we can send it to Europe for servicing, locally they had some technician but now no one.

Will find someone and update.

Thanks,
Parvez

[nobrains]

I tried this on different film holders, 4x5 - Fidelity these are like new and works well on friends Sinar, tried Linhof film holder as well.
For 120 film, tried it on Linhof Super Rollex 6x7 and Horseman 6x9.

All of these have similar results, so initially had thought it was me! :)

Thanks,
Parvez

[Tin Can]

Did this camera come without film holders, perhaps somebody 'customized' it to their strange holder...

[nobrains]

Did this camera come without film holders, perhaps somebody 'customized' it to their strange holder...

Nope, this didn't come with any holders, but I'd doubt about the customised part as the earlier owner had got this from Linhof Germany when he went there in 60's and had Linhof 9x12 holders only and he might have hardly used this camera.

Thanks.

[Embdude]

Are you using the rangefinder to focus? as there are 3 ways to focus on the Super Technika IV we need to know which ones you have tried. It has rangefinder focus, focus scale focus and ground glass focusing.

[Bob Salomon]

Are you using the rangefinder to focus? as there are 3 ways to focus on the Super Technika IV we need to know which ones you have tried. It has rangefinder focus, focus scale focus and ground glass focusing.

Only if you have the proper cam by serial number of the lens on top and the body on the bottom and you have the correct distance scale and the infinity stops are correctly positioned. Otherwise you only have gg focusing, provided that the gg is properly installed.

[nobrains]

Focusing only using ground glass, no cams calibration done and no infinity adjusted for lenses.

[Embdude]

Then I would agree with what was said previously about a missing fresnel making up the difference...

[Cor]

I recall that in Ralph Lambrechts excellent book "Way beyond monochrome"a method is discribed which shows how to check the depth of the loaded fim holder and the groundglass. Something with a straigth metal ruler and a tooth pick attached to it..

Best,

Cor

[Embdude]

It is possible it is caused by the lens.. focus shift can occur (moves the focus plane slightly further away) when you focus wide open but shoot stopped down...

[Embdude]

It is possible it is caused by the lens.. focus shift can occur when you focus wide open but shoot stopped down...

https://photographylife.com/what-is-focus-shift

[LabRat]

One of my Tek III lenses had a factory custom washer/spacer between board and shutter (precisely machined)... If missing, no way lens focus distance would line up to the RF and body distance markings...

Factory stuff...

Steve K

[nobrains]

Just to close this, I did order a new ground glass as this was too aged and dull. The newer Linhof ground glass is much clear and brighter than the one I'd (since 1961).
The focusing on this GG is much better and was able to get sharp images now!
The mystry still remains, if it was me or the camera as it was showing sharp images on GG but were not sharp before.

Thanks for all your inputs, the problem is now solved :)

[Tin Can]

Good to know!

[Phaedros]

You can measure this. It takes a nice depth gauge though as you will go for 100/s of a millimeter...

Take off the rotating back of your Linhof and carefully measure how deep the gg is set. I Measure every corner and take multiple readings to adjust for stupid. Then add a film holder with a donor-sheet of film inside, remove the darkslide and measure onto the emulsion. Compare and adjust your gg accordingly.

On LF repro cameras that would shoot from the top down you were recommended to use a vacuum film holder to keep the negative from sagging through gravity... shows how critical even a bit of distance is.