Saunders LPL Negative Carrier Dimensions

[Reinhold]

Hmmm...

It would be a shame to design a carrier like a Dogwood Sandwich: Jam every feature you can think of into it.
Kind of sounds like Patrick's glass carrier.

Question #1: What is the thickness of a standard production LPL Carrier, NOT including the indexing bars on the underside of the carrier?
Question #2: What is the thickness of indexing bars on the underside of the carrier?
Question #3: What is the maximum clearance between the baseplate and the lamphouse? This may not be so easy to measure accurately.
Question #4: Do all LPL's have the same clearance?

Thanks for the input, folks
Reinhold

[George Nova Scotia]

Question #1: What is the thickness of a standard production LPL Carrier, NOT including the indexing bars on the underside of the carrier?
A: 4.2mm glassless, 6.6 double glass 4x4 (includes index - which is 1.1mm)

Question #2: What is the thickness of indexing bars on the underside of the carrier?
A: 2mm

Question #3: What is the maximum clearance between the baseplate and the lamphouse? This may not be so easy to measure accurately.
A: with the lever up approx 7.3mm. with the negative stage plate removed 13.5mm. With masking negative stage plate ??

Question #4: Do all LPL's have the same clearance?
A: Sorry I only have the one model....

[Reinhold]

Thanks George.

Good data, any variants out there?

Reinhold

[Reinhold]

It seems that "engineers" at LPL designed a one-trick pony making it tough to produce low cost alternative negative carriers.

LPL's use of non-standard (metric?) aluminum sheet to make 4.2mm thin carriers is one obstacle.
The other obstacle is choking the maximum lift of the lamphouse to a mere 7~8mm.

The thinnest carriers I can economically make are about 6.5mm (1/4") thick (plus 2mm for indexing pins).
This means that the lamphouse would have to raise a minimum of 8.6mm above the base plate.

If the folks using LPL enlargers can devise a simple way to open the lamphouse to about 3/8" (about 10mm)...
... I could supply a simple, robust negative carrier for common formats for about $40.

To see examples of my workmanship, go here: http://re-inventedphotoequip.com/Sit...0Carriers.html

Reinhold

[Patrick Robert James]

Reinhold, I would be really interested in a glass carrier, with anti-newton glass on top and coated glass on the bottom, that would allow enlargement of the entire 4x5 negative. I think many other people would too. I don't know why the Saunders carrier crops as much as it does.

[Michael R 1974]

Reinhold, I would be really interested in a glass carrier, with anti-newton glass on top and coated glass on the bottom, that would allow enlargement of the entire 4x5 negative. I think many other people would too. I don't know why the Saunders carrier crops as much as it does.

It actually isn't that hard to make this yourself, and this way you can customize it to your own needs. I did a 4x5 and a 35mm for my LPL 4550. I started with glassless LPL carriers sourced from KHB - which they machined out to oversize. I installed coated optical glass from Schneider. Some careful measuring and shimming to make sure it is precise, but overall not very difficult. The machining by KHB was quite reasonable. High quality optical glass, custom cut is the expensive part.

[Patrick Robert James]

It actually isn't that hard to make this yourself, and this way you can customize it to your own needs. I did a 4x5 and a 35mm for my LPL 4550. I started with glassless LPL carriers sourced from KHB - which they machined out to oversize. I installed coated optical glass from Schneider. Some careful measuring and shimming to make sure it is precise, but overall not very difficult. The machining by KHB was quite reasonable. High quality optical glass, custom cut is the expensive part.

Where did you get the Schneider glass Michael?

[Michael R 1974]

Hi Patrick, I got it from Schneider Optics (the U.S. arm). If you are interested I can PM you the contact info. In fact I will need to contact them anyway because I need another piece of 4x5 glass.

For the 35mm carrier, I went all out with their MRC glass. They cut some rectangles for me out of B+W 007 MRC camera filters! You can't get better optical quality than that! One of the nice things about the MRC coating is how hard it is. Makes it extremely easy to clean and maintain.

For 4x5, MRC glass is not an option. Schneider Kreuznach does not currently put the MRC coating on glass large enough to make a 4x5 rectangle, and the Kreuznach office will not take custom orders for it. Probably just as well, since a 4x5 piece of MRC-coated glass would be well over $500. However, Schneider does offer coated optical filter glass in custom sizes from their film/cinema filter division. That's what I'm using.

[Patrick Robert James]

Michael, I would love to know how you made a glass carrier for 35mm for the Saunders. I would love to have one dedicated to 35. Wouldn't mind the contact info either....

[Michael R 1974]

Patrick - I started with the LPL 35mm glass carrier from KHB (which only has a top glass), asked them to mill out the bottom opening to the same size as the top, and include some spare top glass mounting tabs and screws. This was done for a nominal fee. The supplied tabs and screws make installing the top glass very easy.

For the bottom, I drilled two holes on each side of the opening (you could easily have KHB do the drilling for you) in the bottom plate and used some brass plate stock from the local hobby shop (you could use aluminum or whatever else as long as it is rigid without flex) to make some supports for the bottom glass. These supports are below the bottom plate (screwed in). The bottom glass sits on those. Some careful shimming is required (again I used brass stock from the hobby shop, but extremely thin sheets) to ensure the top of the bottom glass is perfectly flush with the surface of the bottom plate of the negative carrier. Some trial and error is involved there but it is not difficult.

For both the top and bottom glass I used the cut down B+W MRC filter glass from Schneider (2mm thick). Note in retrospect using that fancy glass for the top glass is more or less superfluous and a waste of money. You'd be better off just getting some plain or anti-Netwon ring glass from Focal Point (or even using the glass that comes with the LPL carrier). A variety of options work for the top glass.

This probably reads more complicated than it actually is. I'm not a machinist, and this was a fairly simple project. Mine ended up being more complicated only because I made it with pin registration functionality for masking, but even that was not very difficult - it just required some more planning and thought before getting started.

It ain't pretty looking (prototypes usually aren't, although building a second one would be much prettier), but it is precise and works perfectly.