So much for mechanical cameras

[Alan Edward Klein]

Maybe the light from each shot taken eventually faded the area on the backplate where the sprocket holes are located. (Assuming this camera doesn't block that portion)

 

[Don_ih]

Maybe the light from each shot taken eventually faded the area on the backplate where the sprocket holes are located. (Assuming this camera doesn't block that portion)

No light reaches there.

 

[Pioneer]

Ahhh!! Another neat photography myth bites the dust.

 

[awty]

It is. The most film sprocket holes could do is wear a stripe into the pressure plate, since the edges of the holes could be a little abrasive. You wouldn't see rectangles in that instance - just a line. But that would be pretty much impossible - the greatest points of pressure are where the plate presses the film against the rails (between the sprocket holes and the shutter curtain). The rectangles are from the film sitting in the camera - probably getting a bit moldy.

Somebody just left the last roll in the camera for a few years. The pressure plate only uses a a gram or two of pressure to hold the film, any more and it will scratch the film. Would require tons of pressure to make an indentation with film, if at all.
I've seen the exact same thing, just wipe it away as it would create friction on the film.

 

[reddesert]

Winogrand's last M4 is a historical artifact and museum piece, not a camera any of us own or have inspected, or should be wiping alcohol on. The likely source of the markings is the film base reacting with and pressing on the finish of the pressure plate, not the film base actually denting metal.

However, I haven't seen old moldy film make a mark on the pressure plate. I have seen it react with and put corrosion on the film rails. It is more likely for the emulsion side to get moldy or react, than for the base side, which is just plastic. So I'm willing to believe that the camera was worn from use, not storage. Stephen Gandy's page shows that the camera has a lot of other wear from heavy use, and that the owner after Winogrand was actively using it, not storing it. And Gandy physically inspected the camera, which we have not.

Some cameras are much more regular about aligning the sprocket holes with the film always in the same place, so that even as the film is advanced the sprocket holes always come into the same place with respect to the frame, as likely happened here. For a long time I had just two 35mm cameras in use and I could tell which camera a negative strip came from by the frame spacing (they were a Nikon F and a Canonet, and of course the F was more regular, but that isn't a knock on the Canonet, the F was built to a more solid standard and weighed like it).

I also do not know if all 35mm cameras have the sprocket holes detented to a specific position with respect to the frame. Obviously many do, but there may be some where it depends on where you start the film.

 

[MattKing]

I was thinking about this thread while loading my Retina IIIc in preparation for a walk with the camera. The Retina has the same sort of smooth pressure plate. My camera was bought used, so it is only a guess that it hasn't seen nearly as much film as Gary Winogrand's M4 ( ) but if held at the right angle to the light it too distinctly shows a faint wear image on the surface of the pressure plate - essentially a difference of reflectance that allows you to see where the image area is and to differentiate that from the area where the sprockets are. I can't see any image of individual sprockets, but I can clearly tell where the film rails are in relation to the pressure plate.
It will be hard to show that in a photograph, but I'll try after I finish the roll, and post the result here.

 

[Don_ih]

So I'm willing to believe that the camera was worn from use, not storage

Which is nice, but it's not possible for use to leave sprocket hole outlines. Use implies the sprocket holes continually brushing the pressure plate, wiping away any impression left there from sitting around between exposures - if such a thing even happens in that case.

Don't forget there could be more in there than just the back of the film - like anything that got on the fingers of the user. Hamburger grease from one of Garry's lunches could have contributed to making an imprint on the pressure plate.

 

[RalphLambrecht]

Almost every box camera I've ever picked up worked.

same here. One of my Hasselblad 501cs just decided to jam;ordered the Hasselblad tool to unjam it;hope that works.

 

[SodaAnt]

same here. One of my Hasselblad 501cs just decided to jam;ordered the Hasselblad tool to unjam it;hope that works.

There’s nothing magic about the unjam tool. It’s just screwdriver with a circular guard to prevent it from slipping off the screw head and damaging the camera body or lens.

 

[Steven Lee]

@SodaAnt What do you mean? That circular guard is the magic

 

[SodaAnt]

@SodaAnt What do you mean? That circular guard is the magic

Yes, it is that! I’ve got one of them, but fortunately I’ve never needed to use it.

 

[Sirius Glass]

@SodaAnt What do you mean? That circular guard is the magic

Yes, that saves messing up the surfaces when the tool is needed. It does not weigh much and takes up very little space.

 

[Alan Edward Klein]

Which is nice, but it's not possible for use to leave sprocket hole outlines. Use implies the sprocket holes continually brushing the pressure plate, wiping away any impression left there from sitting around between exposures - if such a thing even happens in that case.

Don't forget there could be more in there than just the back of the film - like anything that got on the fingers of the user. Hamburger grease from one of Garry's lunches could have contributed to making an imprint on the pressure plate.

Vinegar in the ketchup for the hamburger acted like an acid and engraved the sprocket holes on the plate.