Why is nothing standard in dark room equipment?

[MattKing]

The D2 made a 6x7 carrier, 6x8 carrier, 6x9 carrier, and a 2.25x3.25 which were all different frames, I have them all

You are missing a few .
See KHB's listings for all the different types of negative carriers: http://www.khbphotografix.com/omega/Enlargers/D2.htm

 

[rwreich]

FWIW...

The D2 made a 6x7 carrier, 6x8 carrier, 6x9 carrier, and a 2.25x3.25 which were all different frames, I have them all.

A sheet of 2.25x3.25 film FALLS THROUGH the hole of the roll film holders. It took a while to find an official 2.25x3.25 Carrier, but they definitely are a separate thing.

Also keep in mind that not all photographers keep their film in STRIPS, some use individual frames, so the cutout had to have enough area to hold the frame without it falling through. This means cutting into the frame enough to avoid that, so, you lose a bit of it.

Furthermore many 35mm and other cameras' viewfinders don't actually show the full frame, there's a crop factor, so when people shoot, they might not realize there's more outside their viewable frame, so when they took their film to a printing lab to print, they would get back framed images closer to their original shot, not wider.

Those are just a few things that might help understand why they chose to cut into the frame a little bit.

I have the same enlarger and carriers (I have 645 and not 6x8, though). It's standard enough for me.

 

[StoneNYC]

You are missing a few .
See KHB's listings for all the different types of negative carriers: http://www.khbphotografix.com/omega/Enlargers/D2.htm

Haha! I meant all the "medium" format ones, except the official 127 carrier, but I hacked a slide carrier which happens to have the same size hole. I have an 8mm and 16mm/110, 35mm, 127, 6x6/6x7/6x8/6x9/3.25x2.25, 4x5 (and then the Salzman 8x10 glass carrier and 5x7 adjustable carrier... Still need the 8x10 adjustable one, I would trade for one of be 8x10 glass carriers since I have 2 of those.

I don't have ALL of them, but logical formats I have come across/shot.

I MAY have a 70mm carrier but I can't remember as the D2 isn't set up at the moment, and really I need one in better shape anyway, mine is a mess. But the 8x10 is the main priority.

I digress.

Point was there's a few reasons the frames are the size they are. And also equipment design and such (manufacturing) didn't have 3D printers etc, so things were designed probably for reasons we don't even think of now in terms of production.

 

[MattKing]

Haha! I meant all the "medium" format ones

Including both the glass-less and Rapid Shift glass ones?

I wouldn't be the least bit surprised to learn that Omega made different 6x9/2.25" x 3.25" carriers at different times during the D2's history, due to the coming on stream of different roll film cameras with different film gate sizes.

I wonder if the Kodak 620 cameras like the Medalist and the Monitor had distinctly different 2.25" x 3.25" film gate sizes, as compared to the 120 film competitors?