Focusing Problem

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harriet&borris
Posts: 4
Joined: April 7th, 2019, 3:01 pm

Focusing Problem

Post by harriet&borris » April 7th, 2019, 3:30 pm

Hi, I have just bought a Micro-Press 5x4, it has xenon 1.4 Lens. When I use the rear glass and hood, the only way I can focus is by having the front slide and bellows reversed totally in the rear position to infinity. It does not matter if the subject is 5 cm or 100m, everything os blurred if it is not at infinity. I would be much appreciated if someone could advise me or tell me if I am doing something wrong, I am a bit confused and cannot see how the camera could be faulty

Many Thanks

Andy

IanG
Posts: 82
Joined: December 23rd, 2016, 11:31 am

Re: Focusing Problem

Post by IanG » April 9th, 2019, 1:17 pm

My question is what lens do you actually have, the Xenon lenses were not designed for Large Format. Sounds like you have a short focal length Xenon designed for something like a Retina or similar 35mm camera. So let us know what lens you have.

You need a 150mm or 135mm Xenar usually in a Compur shutter for an MPP, or an equivalent FL LF lens like a Schneider Symmar, Nikon, Fui etc.

Ian

harriet&borris
Posts: 4
Joined: April 7th, 2019, 3:01 pm

Re: Focusing Problem

Post by harriet&borris » April 10th, 2019, 6:18 am

Hi Ian

Thank you for your reply, and my apologies I typed the wrong description, the lens is Xenar. The full description of the lens is:
Schneider - Kraeuznach. Xenar 1: 4,7 / 135 *3676829
Having read previous posts and people mentioning the need to reset the infinity, but for me everything just go's very blurry, the more the bellows are extended.

Thank you

Andy

IanG
Posts: 82
Joined: December 23rd, 2016, 11:31 am

Re: Focusing Problem

Post by IanG » April 10th, 2019, 9:31 am

With a 135mm f4.7 Xenar Infinity focus is when the front standard is approx 1½" from the body, that's with the focus rail locked. Or another measurement is when the lens aperture is approx 135mm fom the film plane.

As it happens there was a MicrTechnical MKIII on my darkroom bench with a 135mm Xenar, however I just realised the body isn't as deep as a MicroPress so checked with a Pacemaker Speed Graphic the front of the lens board is 1½" from the body at Infinity with a 135mm lens.

Ian

harriet&borris
Posts: 4
Joined: April 7th, 2019, 3:01 pm

Re: Focusing Problem

Post by harriet&borris » April 11th, 2019, 4:35 pm

Thank you for your reply, that makes sense to me. At about 1½" from the body it focus's perfectly, but if I zoom and extend the bellows to any subject from there, all focus is lost. I cant see anything wrong with the camera or the lens but surely I should be able to focus onto something.

Thanks

Andy

IanG
Posts: 82
Joined: December 23rd, 2016, 11:31 am

Re: Focusing Problem

Post by IanG » April 11th, 2019, 6:43 pm

You can't zoom an LF lens :D

With a 135mm lens the difference in lens position between Infinity focus and about 3 foot is less than 1cm at a rough estimate (I've just tried it). Think about a manual focus lens on a 35mm or 120 camera the helical focus only moves the lens element a few mm between Infinity and maybe 12" focus.

I don't know where you are in the UK but if not too far from North Worcestershire you can pop over and I'll run you through using an LF camera.

Ian

harriet&borris
Posts: 4
Joined: April 7th, 2019, 3:01 pm

Re: Focusing Problem

Post by harriet&borris » April 13th, 2019, 2:01 pm

Hi, Thank you for reply. I understand now, tried a few times this morning, forward or back focuses on subject perfectly. My mistake was I thought you could zoom onto a subject.
Many thanks for your help, would have like to call in but I am down on the coast in west sussex, so a bit far.
Much appreciated

Andy

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