Rare 645 back for Hasselblad

[Vlad Drakula]

Hi everyone, I’m new to Hasselblad cameras. I’ve got recently a 500cm body with a kinda strange back. The back has indicator 16 on the side where the crank is and also there is letter M. What’s interesting that the 645 frame is not centred according to the square frame of a back. Unfortunately I’ve already loaded the film in the camera and took few shots, so I can’t open the back and take a picture and tell the position of the 645 frame according to a square frame, but I drew two possible variations. My question is if I want to make a paper mask on the viewfinder for this 645 back, where should be the wide strip of the paper in the viewfinder, at the top or at the bottom?

 

[photoeil]

To find the answer, you will have to pull the protective slide out and make a picture of the filmframe (do it fast in subbed light to avoid some occasional flare), you will only lose one of the sixteen frames, but I think it's worth the sacrifice.
I couldn't find an answer in Ernest Wildi's 'The Hasselblad Manual' book, this makes me very curious!

 

[Richard700]

Try bringing the mag into a darkroom (or a changing bag) - pull out the slide and try by feel with your finger to determine where the hole is.

 

[rcs907x]

The frames are vertical, not horizontal. This way, 16 frames; not 12. Make sense?

 

[superwhite]

It must be landscape to get the extra frames and in the middle of the frame to avoid edge of lens issues.
The great thing about the P45 digital back on the V system is one could swap from landscape to portrait by revolving the back.
Unless you want to shoot everything landscape I’d flog that back to someone who does and get an A12 back then crop any way you want.
Happy cropping.

 

[f.hayek]

The frames are vertical, not horizontal. This way, 16 frames; not 12. Make sense?

I thought there were two versions of the 645 back, one horizontal (more common) and a vertical one (rare).

 

[superwhite]

The frames are vertical, not horizontal. This way, 16 frames; not 12. Make sense?

It must be landscape or you would only get 12 frames right?

 

[f.hayek]

From the sketch provided by the OP, appears to be the landscape version so 16 frames it is. The vertical oriented 6 x 4.5 back is the A12V and gives you 12 frames a roll. It's a pretty uncommon one to find. For the one the OP has, would have to look up what the 'M' signifies; not a moniker for the A16 back I've heard of. The A16S is for the 4 x 4 "superslide". Here's mine:
:

• Apple - iPhone 14 Pro Max
• iPhone 14 Pro Max back triple camera 2.22mm f/2.2
• 2.2 mm
• ƒ/2.2
• 1/60 sec
• Pattern
• Auto exposure
• ISO 1000

• Apple - iPhone 14 Pro Max
• iPhone 14 Pro Max back triple camera 2.22mm f/2.2
• 2.2 mm
• ƒ/2.2
• 1/60 sec
• Spot
• Auto exposure
• ISO 250

 

[jotloob]

Again , from Richard Nordins HB Compendium . For me the HB bible .
Have a look .

• iPhone 13 Pro back triple camera 5.7mm f/1.5
• 5.7 mm
• ƒ/1.5
• 1/128 sec
• Pattern
• ISO 32

 

[f.hayek]

But mysteriously, no "M"...

 

[jotloob]

Hi everyone, I’m new to Hasselblad cameras. I’ve got recently a 500cm body with a kinda strange back. The back has indicator 16 on the side where the crank is and also there is letter M. What’s interesting that the 645 frame is not centred according to the square frame of a back. Unfortunately I’ve already loaded the film in the camera and took few shots, so I can’t open the back and take a picture and tell the position of the 645 frame according to a square frame, but I drew two possible variations. My question is if I want to make a paper mask on the viewfinder for this 645 back, where should be the wide strip of the paper in the viewfinder, at the top or at the bottom?

Can you please show an image with the backs serial number . That might help to identify in more detail .