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Hello All

I have the opportunity to get a Maxwell screen. However, it seems to be designed for an Ebony. Could anyone tell me if there is any reason why the Maxwell screen (ultra bright - for an Ebony) would not retrofit on a Chamonix 045-u2.

Cheers


Ian

Hi Ian

interesting point

have a search around over on The Large Format Photography Forum, there is a wealth of stuff on there regarding focusing screens etc etc. I am sure that the mods on here will not mind me directing you to that resource as they will accept that not every aspect can be or has as yet been discussed on here

You might also care to send a mail to Hugo Zhang who is a member on there - Hugo is either the main man or one of the main participants with Chamonix and will definitely be able to help. That's if you are a member on there that is - if you are not, let me know and I'll forward it to Hugo

regards

andrew

HI Andrew

Thanks for your advice. I am a member of the other forum and had a look through their posts yesterday without much success. I decided to leave a posting similar to this message later in the evening. I've had one reply from that forum which suggested that is unlikely that the screen would fit.

I have also emailed Hugo and hope to get a difinitive answer.

Thanks again

Ian

ian

thx indeed

regards

andrew

Hi Ian, I have used an Ebony screen on a Shen Hao and am currently using a Beattie screen for a Sinar on an Arca and they fit fine.
I suggest that you measure the screen on your Cham (assuming you already have one) and ask the vendor to measure the screen for the Ebony, if they are the same or the Ebony is small enough to fit the back without being too small, then you should be fine. The focus distance will be the same I would think.
The only Caviat is that some Chams had a screen that seemed to have a been a combination of Focus screen/fresnel that (from what I can gather) had the Fresnel in front of the focus screen, meaning the focus point was not the surface of the screen facing the lens. I may have misunderstood this, especially as I can't imagine why someone would think it was a good idea!
Gari

Dav Thomas fitted a Maxwell screen to his Chamonix, and wrote a blog about how to do it. I think it did involve a bit of work, but this is the link.

http://www.peaklandscapes.com/blog.php?entry=10

Jenny

For the record you can also use an Ebony screen with a Linhof (so much brighter!) monorail, so it should be OK.

You need to know whether the Chamonix back was designed to have a fresnel under the focus screen or not.

The company made a huge error selling cameras for a while with a fresnel and a screen that was out of register, they'd not allowed for the thickness of the fresnel itself.

So not all Chamonix backs are equal, I know one British photographer (in Turkey) who had big problems shooting portraits at wider apertures and plenty of others posted similar tales on the Internationla LF website.

Ian

Hi All

Thought I should post an update in case anyone finds themselves in a similar situation in the future.

I have been in touch with Hugo Zhang who advised me that the Chamonix 45-n2 (latest version - Sept 2011) screen is comprised of ground glass, fresnel and protective cover (lens to viewer). After several emails with Bill Maxwell, I have tried the Maxwell screen (designed for Ebony), after removing all the Chamonix components (as advised by Bill) in my camera. The screen fits fine and is an improvement over the original. However, due to the differences in overall screen thickness between the original Chamonix (3 in total) and Maxwell (2 in total) the clampdown discs do not hold the glass cover securely. This is compounded by the fact that on the later (n2) versions of the camera these discs are modified like those shown in Dav Thomas' blog post (see pic 7 - http://www.peaklandscapes.com/blog.php?entry=10).


I would be grateful if anyone could tell me were I could get/buy some replacement clampdown discs, the same as those in Dav's blog post pre-modification (pic 1).

Alternatively could anyone recommend someone who repairs/services LF cameras (in the Northwest if possible) who could sort this out for me

Cheers

Ian