is this a glass plate holder?

[Wayne]

Someone gave me what I thought was an ordinary a 5x7 holder, but when I got it home and pulled the darkslide I saw that it wasnt. Its old, wooden (even the darkslide grips are wood), and there is no hinge at the bottom. Actual image area is 5" x 6.75". It looks like it could hold something up to 1/8" thick.

I just noticed as I wrote this that the bottom (hinge) edge is apparently spring-loaded, and can be pushed out of the way is you were sliding something like glass into place. I think I just answered my own question but I'm still curious what you think.


Wayne

 

[Ryuji]

That sounds like a 5x7 plate holder. Glass plates of that size is usually 1/16 or 1/15 inch thick.

Plates can't be bent to insert to the holder, so the holders are equipped with a spring loaded edge.

 

[Wayne]

This jogged some dormant brain cells so I ran up to the attic and looked at a pile of 5x7 holders that used to belong to my dad. There are several plate holders in that pile too, with Kodak sheet film adapter inserts/sheaths so they be used for plates or film. The sheaths can be removed for use as a plate holder. Cool, I'm halfway to wet plates now.

 

[Ryuji]

You're very lucky. I've been using full plate camera (Seneca Competitor in full plate size) but I usually shoot it in 5x7 reducing holder. I want a nice 5x7 plate camera...

 

[Ole]

I want a nice 5x7 plate camera...

You're a day late!!! I'm sending one to another APUG member...

BTW, there are 5x7" (or 13x18cm, but in this case they're interchangable) plate holders that fit "modern" camera backs. They are rare, but turn up on ebay every now and then. I've got two 18x24cm ones which fit 8x10" cameras.

And then there are the Linhof Universal plate and film holders with pressure plate and "Auswerfer". Great holders; both for films and plates. But those 13x18cm ones can't take 5x7" film.

 

[Wayne]

You're very lucky.

Yes and no. I did catch the photography bug from my father, as well as a modest supply of hardware, but I also got his genes. Wanna trade? Some plate holders for head hair, anyone? But all I have is an 8x10 camera with reducing back to use these in.

I started to panic when I read Ole's post and realized I had never checked to see if these actually fit my 5x7 back-but they all do.

 

[Jim Jones]

That sounds like a 5x7 plate holder. Glass plates of that size is usually 1/16 or 1/15 inch thick.

Plates can't be bent to insert to the holder, so the holders are equipped with a spring loaded edge.

The 1951 ASA standard thickness for glass plates from 2.25 x 3.25 to 4.75 x 6.5 is from .048 to .053 inches.
From 5 x 7 to 8 x 10 it is .058 to .063 inches.
From 10 x 12 to 14 x 17 it is .080 to .095 inches.
From 16 x 20 to 20 x 24 it is .120 to .130 inches.
From 22 x 28 to 30 x 40 it is .190 to .2 inches.

 

[Ole]

Yes and no. I did catch the photography bug from my father, as well as a modest supply of hardware, but I also got his genes. Wanna trade? Some plate holders for head hair, anyone? But all I have is an 8x10 camera with reducing back to use these in.

I started to panic when I read Ole's post and realized I had never checked to see if these actually fit my 5x7 back-but they all do.

Sorry, I've got no head hair to spare.

I just remembered I have a big box of assorted Linhof "stuff" which includes among other things two adapters for using metal single-plate holders in modern cameras: One for 9x12cm plates in 4x5" cameras, one for 10x15cm in 5x7" cameras. So there's always another way to use plates!

I had no idea such things even existed until I found them in the box...

 

[Ryuji]

The 1951 ASA standard thickness for glass plates from 2.25 x 3.25 to 4.75 x 6.5 is from .048 to .053 inches.
From 5 x 7 to 8 x 10 it is .058 to .063 inches.

Sounds like I misremembered: "1/15 or 1/16 inch" (incorrect) for "1/17 or 1/16 inch" (correct). I'm actually a metric person. (Yes, I order 476 milliliters of Guiness.) In reality, my choice is limited to whatever available at the glass store... as I don't cut glasses myself.

 

[Wayne]

The 1951 ASA standard thickness for glass plates from 2.25 x 3.25 to 4.75 x 6.5 is from .048 to .053 inches.
From 5 x 7 to 8 x 10 it is .058 to .063 inches.
From 10 x 12 to 14 x 17 it is .080 to .095 inches.
From 16 x 20 to 20 x 24 it is .120 to .130 inches.
From 22 x 28 to 30 x 40 it is .190 to .2 inches.

So where does someone get glass of the "correct" thickness? My local glass shops only carry glass 2.0 mm or 3/32" or thicker, which is much thicker than the number given above for 5x7. However, it appears that my plate holders will easily take 3/32 or maybe even 1/4" glass and were clearly (IMO) designed to do so. Thinner glass would be quite loose in the holder.


Wayne

 

[Ryuji]

5x7 glass sold by MCS Industries as a replacement glass for their cheap plastic frame is 1.6mm thick. But don't tell this to anyone until I get a nice cheap 5x7 camera...

 

[Wayne]

I found 1/16 glass in some cheap frames I have laying around. I'm surprised, but after cutting a plate it seems to fit OK. I wasnt taking into account the spring band in the convertible holder and the ridges on the septum in the dedicated late holder, both of which take up the excess slop that I was anticipating.


Wayne