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Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 2
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 12, 2009 - 10:18 am: | 
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I recently acquired a Corfield Periflex 2 with Corfield Lumax 1:2.8/45 lens, which one would expect to have the correct registration with the camera body.
However, focussing (on an object a few feet away) via the mirror/screen assembly gives a lens position where the distance markings on the lens read further than the real,measured, distance to the object. Consistently with this, when moving the test distance out towards 'infinity', the lens adjustment runs out of travel before correct focus is achieved on the ranging screen.
On running a film through the camera, I found that the results confirmed the above behaviour, in that with the lens set to the infinity mark (where there is anyway no further travel possible), objects in the foreground were in better focus than more distant objects. So any inconsistency between the registrations of the focussing screen and the film plane would not appear to be be the issue, or at least not the main issue.
There is no discernible distortion in the camera body, the glass film pressure plate is clean, smooth and correctly positioned, and the lens screws neatly home into its mounting ring.
Thus I am driven to the inference that there must be a maladjustment in the Lumax lens assembly, although visually it appears to be 'un-molested', and its operation is smooth and backlash-free.
I would be grateful if anybody has any knowledge to offer or link to - it might be generic to many types of detachable lens, not just the Lumax.  |
Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 3
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 22, 2009 - 07:11 am: |
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Update: I got hold of another lens (Jupiter 8 50mm f2) to try with the camera. With this, the focussing agrees with distances as measured with a tape measure. This confirms that the problem lies with the original Lumax lens - I have to assume that it had been mis-assembled, probably during servicing by or on behalf of a previous owner. So the Lumax has to join the list of items awaiting attention ...  |
Fredster
Tinkerer
Username: Fredster
Post Number: 19
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 22, 2009 - 10:28 am: |
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Never heard of this camera, so I looked it up - wow, what a neat setup. Thanks for bringing this to my attention. |
Contax_crisis
Tinkerer
Username: Contax_crisis
Post Number: 21
Registered: 08-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 12, 2009 - 11:39 am: |
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It's a fantastic little camera Johnny, albeit a little slow in use. Here's the one I use:
http://www.luxcamera.co.uk/pages/Antiqua/Corfield/Periflex.htm
The wide angle scale makes it useful for zone focussing instead of periscope focussing.
A wonderful Swedish guy sold me a Canon f1.2 lens which I started using with the Periflex for close-up and portraiture work. With an undamaged periscope alignment system, it can focus down to the breadth of a hair!
Sorry to hear of your problem with the Lumax lens. It's a decent lens too. If the lens is running out of travel, then you may need to open up the grub screws and play around with the lens, using a ground glass or semi-translucent tape tacked on the film chamber and the camera mounted on a tripod to work out if you're hitting the ball park focussing zone. |
Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 6
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 13, 2009 - 09:02 am: |
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Contax_crisis that's a beautiful combination that you use, and thanks for the tips. :-)
Since my last posting, I had the luck to get hold of a (later model) Corfield f1.9 Lumax that was very inexpensive because the metalwork is battered and the glass a bit discoloured, yet it is functionally OK, registers correctly, and has the added convenience of being able to focus at f1.9 then stop down quickly to the preselected exposure stop without having to then look at the aperture control.
I will of course keep the f1.2 Lumax as it is the original model for the year of the camera, in the 'queue' of my 'to-do' projects. |
Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 7
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 13, 2009 - 09:22 am: |
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Oops: in the last sentence of the previous posting I meant to write 'f2.8 Lumax' (not 'f1.2 Lumax') |
Contax_crisis
Tinkerer
Username: Contax_crisis
Post Number: 26
Registered: 08-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 13, 2009 - 11:56 am: |
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Johnny,
That f1.9 50mm Lumax has been eluding me for years...! I like the 50mm lenses; trying to source a 35mm optical disc for the viewfinder isn't easy. The Lumax 90mm lens is a very short lens for its length, although by 135mm, the camera starts to look funny peculiar!
You may find that Exakta lenses, can be coupled via a M39 adapter to Exakta mount; these lenses will focus perfectly for infinity on the Periflex and expand the range of lenses to select from. It's quite a fantastic idea; using the LTM/M39 mount, which can also take on M42 type Pentax screw mount lenses and focus any and everything with the built-in periscope!
Do beware of the Jupiter 35mm f2.8 LTM lens however; the rear lens bulb will collide with the periscope; as will a number of Voigtlander [VM] mount lenses, such as the 12mm/15mm Heliars. |
Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 8
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 13, 2009 - 01:02 pm: |
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Contax_crisis,
Thanks again for the useful information. I watched the very recent bidding 'wars' for 90mm and 135mm LUMAX-es on ebay, but decided I didn't want one badly enough - it got quite 'hot' in the final seconds! |
Contax_crisis
Tinkerer
Username: Contax_crisis
Post Number: 28
Registered: 08-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 14, 2009 - 12:31 pm: |
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Hi Jonny,
That's correct ~ unfortunately the Periflex has a historical/collector's market interest, rather than photographers.
This is the main reason for pursuing the alternative lens mounting options. It is a really fun camera the the little periscope finder!
Hope you enjoy shooting with yours too. The Alden/Watson type bulk film loaders are fantastic for spooling short exposure rolls to prevent the spacing becoming too uneven towards the end of the roll; this is inherent in the camera's design, so short exposure rolls of 12-24 exposures work best. |
Johnnyh
Tinkerer
Username: Johnnyh
Post Number: 9
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 16, 2009 - 07:16 am: |
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Hi Contax_crisis,
Thanks, and I normally use the shortest that I can get hold of anyway when testing a new acquisition as I'm impatient to finish the film! Oh - bit of a swerve off-topic - I recently dug a 12-exposure cassette out of the cupboard, 10 years after its use-by date, and it was quite OK :-) |
