Help Identify Sinar P2 Bearers

I hope somebody of Sinar historians can shine some light as I couldn't find any information in catalogs, forums, or even from Sinar themselves.

I have Sinar P2 4x5 camera and I've recently got 8x10 conversion kit with special front and rear bearers (or at least that's what I thought).
Later, I came across photos of the special bearers that looked quite different from mine. I've made a compilation of all three bearers (standard P2 for 4x5, probably special that I have, and special that matches photos from the catalogs) for each front and rear sets.

Rear:


Front:


I have marked the key differences (base width difference, shift wheel difference, height difference). They also have different scales.

From what I see the middle one (the special bearer that I have) looks like 4x5 version but beefier and with a bit more movements vs the bearer on the right is made for 8x10 first. When the right bearer is 'zeroed' the markers are pointing at 8x10 size while when I zero mine, it points at 4x5.

Doesn't anybody have an idea what kind of bearers do I have?

Thank you for helping me to resolve this mystery.

—V

I don't have any real experience with Sinar P components, and thought maybe someone else would speak up. Lacking that: from the Sinar catalogs, it seems likely that there are 3 kinds of function carriers:
1. regular 4x5
2. somewhat beefed up for 8x10
3. front for 8x10 with taller rise to center the front standard

I don't know if the shift wheel difference is indicative or not, they could have made a running change somewhere along the way. We can probably figure out the code numbers for each type from the catalogs, but I'm not sure it would be helpful as I don't think the numbers are marked on the pieces.

reddesert said:

I don't have any real experience with Sinar P components, and thought maybe someone else would speak up. Lacking that: from the Sinar catalogs, it seems likely that there are 3 kinds of function carriers:
1. regular 4x5
2. somewhat beefed up for 8x10
3. front for 8x10 with taller rise to center the front standard

I don't know if the shift wheel difference is indicative or not, they could have made a running change somewhere along the way. We can probably figure out the code numbers for each type from the catalogs, but I'm not sure it would be helpful as I don't think the numbers are marked on the pieces.

Click to expand...

According to Sinar Code catalogs, there were only two variants for P2: 4x5 standard (front 431.51 / rear 433.51) and special (front 431.52 comes with a frame, rear 433.52 is just the bearer).

EDIT: I think I figured out the mystery, the bearers in the middle are Sinar E (that have larger base for electronics) and they are still 4x5 non-special bearers.