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LetterBeacon
20-Sep-2017, 06:58
I've just bought a MPP MicroPress camera (see my Intrepid vs MPP MicroPress thread for more on that exciting story...) and I've just read that the early version didn't have the international standard back.

Apparently the older versions had a .2 inch/ 5.08mm register, and the later versions had the international standard of 4.8mm. I'm not entirely sure how to tell if I have the early or later models, so I guess I should try and measure the register to see which one I've got.

My question is - how do I measure the register of a large format camera's back?

Or... how can I tell if I have the early or later version of the MicroPress?

Any help would be much appreciated!

Bob Salomon
20-Sep-2017, 09:04
I've just bought a MPP MicroPress camera (see my Intrepid vs MPP MicroPress thread for more on that exciting story...) and I've just read that the early version didn't have the international standard back.

Apparently the older versions had a .2 inch/ 5.08mm register, and the later versions had the international standard of 4.8mm. I'm not entirely sure how to tell if I have the early or later models, so I guess I should try and measure the register to see which one I've got.

My question is - how do I measure the register of a large format camera's back?

Or... how can I tell if I have the early or later version of the MicroPress?

Any help would be much appreciated!
Why not just shoot a test subject and see if it is sharp?

LetterBeacon
20-Sep-2017, 10:06
Thanks for your reply. It's because I don't have the means to shoot with it just yet and if it doesn't have an international back on it, I'd like to return it for a camera that does.

xkaes
20-Sep-2017, 10:16
I'd check with the seller or manufacturer. If the manufacturer made an International back, I would think that there is a good chance that it is interchangeable with the back you have. In the process, you should be able to determine which back you have.

Bob Salomon
20-Sep-2017, 10:51
I'd check with the seller or manufacturer. If the manufacturer made an International back, I would think that there is a good chance that it is interchangeable with the back you have. In the process, you should be able to determine which back you have.

Since the manufacturer has been out of business since 1982 the OP would have a problem checking with them!

Jac@stafford.net
20-Sep-2017, 11:28
Apparently the older versions had a .2 inch/ 5.08mm register, and the later versions had the international standard of 4.8mm

The difference by your measures is 0.01" (.28mm) That's something a paper or common steel shim could fix.
How-to measure? I assume by register you mean film and ground glass distances.

remove the back if you can,
place a sheet of film in a holder,
insert film holder and remove slide,
place a straight edge across the removed back,
Measure.
Remove the film holder,
measure again.

The accepted difference/tolerance is .007" which is also the thickness of most sheet film.

Just read Leigh's post which reminds me that I was remiss in detailing the measuring technique. Leigh is a long time veteran machinist. I'm just a poor bloke with one good steel straight-edge and a Mitutoya SC-6C gauge. I take four measurements and average. I hope I'm okay doing that.

Leigh
20-Sep-2017, 11:53
Apparently the older versions had a .2 inch/ 5.08mm register, and the later versions had the international standard of 4.8mm.
The 0.028mm difference = 11 thousandths of an inch (0.011 inch).

There's considerably more slop than that in the fit and registration of the filmholder in the back of the camera.

- Leigh

Cor
21-Sep-2017, 00:16
The 0.028mm difference = 11 thousandths of an inch (0.011 inch).

There's considerably more slop than that in the fit and registration of the filmholder in the back of the camera.

- Leigh

Well to me 5.08-4.8=0.28 mm (disregarding these silly inches..:p)..) of that is insignificant or not in respect to the above mentioned slop I leave to you... In the end shooting a big ruler under a slight angle, lens wide open, focus on a clear number on that ruler and carefully judge the negative ( perhaps project it with an enlarger) will tell.

Oh and check this (https://books.google.nl/books?id=tYmblNt3wG8C&pg=PA146&lpg=PA146&dq=measure+depth+film+holder+lambrecht&source=bl&ots=FVfAHH89Fi&sig=qEVFbyqbrn_uYTK2_nauDnKgWtY&hl=en&sa=X&ved=0ahUKEwjksq7U3bXWAhWFYVAKHRFpB2sQ6AEIKDAA#v=onepage&q=measure%20depth%20film%20holder%20lambrecht&f=false) out, hope the link works..

best,

Cor

alexmuir
21-Sep-2017, 00:56
There was an MPP owners club with online resources. There was talk of it closing down a year or so ago, but it may be worth checking. Perhaps they had details of serial numbers of early/late versions. Try
mppusers.co.uk
Alex


Sent from my iPhone using Tapatalk Pro

hporter
21-Sep-2017, 04:01
I don't know if the information from this table is still available on the new club's site, but I copied this from the old site's webpage in 2009.

170111

Pete Oakley
21-Sep-2017, 04:56
MPP's own brand 4x5 film holders are not that hard to find in the UK and these are the non standard register as far as I can remember. As you haven't said what country you're in this might not be much help.
Pete.

Jim Jones
21-Sep-2017, 07:01
. . . how can I tell if I have the early or later version of the MicroPress?

Any help would be much appreciated!

According to the 2005-2006 McKeon's camera the perhaps scarce initial 1950 MPP Press Camera was adapted from the metal bodied MPP technical camera. It was superseded in 1951 by the MPP Micro-Press with serial numbers starting with 3000. Its body was leather covered mahogany and the rangefinder was built into the top of the body. It included a focal plane shutter with instantaneous speeds of 30-1000.

LetterBeacon
21-Sep-2017, 07:05
Thank you everyone for your replies!

I've asked on the MPP forum, but for some reason my posts aren't turning up on their forum - perhaps I need to be approved by a moderator first.

Thanks for the table - that's still in the members area on the MPP Club site - I just need to work out if mine is the early or late version I guess!

LetterBeacon
21-Sep-2017, 07:06
MPP's own brand 4x5 film holders are not that hard to find in the UK and these are the non standard register as far as I can remember. As you haven't said what country you're in this might not be much help.
Pete.

I'm in the UK, so I might be able to find them. Trouble is, MPP seemed to use their own standard and then adopted the International Standard later, so not all 4x5 MPP holders are guaranteed to be be the non-international standard.

Jac@stafford.net
21-Sep-2017, 07:13
Just measure and if necessary shim to international standards. It is that simple.
.

Ivan J. Eberle
21-Sep-2017, 10:57
For a lot of 4x5 uses, due to a working aperture of f/22 or f/32, the spec and perfect focus may not prove so critical. I expect that's why some folks responding to this thread are dismissive of a few thousandths of an inch. OTOH, with any new camera, and especially if you're trying to do something like use an Aero Ektar or other portraiture lens wide open (like trying to calibrate a split image rangefinder) it surely can be critical. Also, anytime you have a problem with attaining sharpness with a new camera, you'll want to eliminate all the variables, and this is certainly one of those several things to double check.

There are several machinist's tools that are useful (quite nearly essential) if you're working with old cameras. A dial indicator one of these, a digital caliper is another.

Bunches of film holders in circulation are of an earlier era, many used ones something like 30-75 years old. so it's a good idea to not just examine them for light leaks but to see if they're worn out or otherwise trashed. Fortunately, measuring them is relatively easy.

When I was checking for flatness/warpage of film holders and backs, a cheap dial indicator on a standard "magnetic" base (weighted) is what I used since I happened to have them already. The set-up can be found for something like $30 USD at Harbor Freight Tools. For measuring individual film holders, a polished granite countertop would be an ideal surface, but any smooth counter-top should be sufficiently flat. Measure the difference from the front surface of the holder to the film pocket at several spots across each to get a sense of whether the holder is warped--the clean, polished granite surface makes it easy.
Note that the actual film-plane register is a published specification; it takes into account the thickness of the film emulsion.

Jim Jones
21-Sep-2017, 13:26
. . . Note that the actual film-plane register is a published specification; it takes into account the thickness of the film emulsion.

That dimension (the "T" dimension) is measured from the face of the film holder to the back of the slot in which the film slides. For 4x5 film holders, this distance is 0.197" +/- 0.007". It ignores the thickness of the film as it should in a standard for film holders. The minimum dimension of the slot (the "H" dimension) is 0.012". Curvature of film can exceed these dimensions. Even if the film is perfectly flat, there is enough slack within these specs to affect image sharpness with fast lenses. Anyone concerned with the critical distance between lens and film surface should research the matter according to their own needs rather than rely on what others may use.

Jac@stafford.net
21-Sep-2017, 13:49
If we wish to get anal about this look to aerial film cameras which use a a perfect glass plate with fiducial markings that presses against the film.

You cannot do this at home and if you tried it would be in vain. If you succeed to make perfect focus nobody would notice.

Bob Salomon
21-Sep-2017, 15:05
If we wish to get anal about this look to aerial film cameras which use a a perfect glass plate with fiducial markings that presses against the film.

You cannot do this at home and if you tried it would be in vain. If you succeed to make perfect focus nobody would notice.

Some aerial cameras. But virtually all photogrammetric cameras use the glass plate and fiducial crosses.