Trying to locate a light leak in Makina 670

J

johnny.moped

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Hi,

please help me to locate this light leak in my Makina 670.
- It's always in the same position.
- It only appears on the last (10th) frame of the roll.
- Did check the bellows with a flashlight and they seem to be ok.
- The form might suggest that it hits the film when still "rolled" but the centered position is kind of strange.

thanks,

d.





(click for larger images)
 
It looks like a fracture
Sometimes I get such things when I'm putting film in spiral of the tank carelessly.
 
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Well, some gear has to be repositioned for winding on the trailer after the last exposure - but I don't see anything in the 67 which looks as if that could create a light leak. It could also be mechanical - crescent shaped "exposures" can be caused by bending.

Maybe it is a 670 peculiarity, or you are missing some part. Or it happens somewhere else - the lab in particular is suspect, as that is the end from which the film is wound onto the spiral or taped into the loop. Before you take apart the camera or mail it in for service, try a second lab, and try another film batch.
 
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I agree with Arvay..I get almost the exact same sort of marks when I am lazy/careless rolling film and especially when I am trying to remove the tape from the end of a roll. I clamp my fingers onto the film to get leverage to get a fingernail under the tape and I often get the same mark on the same frame... really :)
 
It's in the same place on two different exposures? Light leak.

Circular in nature? Probably near something round (I think.)
 
Thanks everybody for the answers.
I will do some checks with black and white film, lens cap on and a flashlight.
If there is any sort of light leak it should be visible on the film then.
actually I can't imagine that it's the labs fault. they are very professional and a fingernail or kink should be haptic present on the negative.

does anybody know where I can buy new seals?
 
sevo said:
Medium format base material often is polyester - kinks don't leave any traces there.
Click to expand...
Sure does on mine...arista edu leaves all sorts of marks unless i am very careful. Tri x is much more forgiving but it will still mark

Might be a light leak but my money is on processing somehow causing it.
 
It's becoming weird:
Yesterday I shot a roll of black and white film in total darkness (except the 9th frame) with the lens cap on and before and after every shot I illuminated every angle of the body and the bellows with a very strong flashlight.
The good news is: There is no obvious light leak in the bellows or anywhere else.
The (kind of) bad news is: I get the same strange pattern on the end of the film.
I developed the film myself and can assure that it wasn't kinked in any way and the pattern was visible right after I took it out of the developing-reel.

5369918570_7abc2929f6_z.jpg
 
johnny.moped said:
It's becoming weird:
Yesterday I shot a roll of black and white film in total darkness (except the 9th frame) with the lens cap on and before and after every shot I illuminated every angle of the body and the bellows with a very strong flashlight.
The good news is: There is no obvious light leak in the bellows or anywhere else.
The (kind of) bad news is: I get the same strange pattern on the end of the film.
I developed the film myself and can assure that it wasn't kinked in any way and the pattern was visible right after I took it out of the developing-reel.
Click to expand...

What sort of spiral are you using? 'Cos to me, this looks a LOT more like kinking than like a light leak.

Cheers,

R.
 
johnny.moped said:
.

I would agree with you, but the color negatives were developed in a lab (without any reels).
Click to expand...
Are you sure?

And even if you are, there's pulling the film off the backing paper.

I've NEVER seen a light leak like this, but I've seen LOTS of kinks. And they all look like this.

I'm not saying I'm right. I've been wrong often enough before. But even so...


Cheers,

R.
 
im not familiar with the loading of the makina, but could it not be something in the chamber or the back plate that when a full roll is in the end spool causes pressure on it?

as kinking film in the same spot when its a lab and yourself seems quite un likely, but if the kink is caused by something in the camera/chamber etc then that would seemingly make more sense.

just a postulation
 
Roger Hicks said:
Are you sure?
And even if you are, there's pulling the film off the backing paper.
Click to expand...

But that's the end of the film. The adhesive tape is on the beginning of the film.
And that would be to much of a coincidence: Two different types of film developed by two different labs/persons.

nimcod said:
im not familiar with the loading of the makina, but could it not be something in the chamber or the back plate that when a full roll is in the end spool causes pressure on it?

as kinking film in the same spot when its a lab and yourself seems quite un likely, but if the kink is caused by something in the camera/chamber etc then that would seemingly make more sense.

just a postulation
Click to expand...

I don't think it's a kink. One would be able to feel it as it must be still kinked when in developing.

The only thing that might be possible is that there might be a short leak when the winding mechanism switches from winding to the next frame to infinite winding.

this is really driving me crazy. :bang:
 
Sorry, that is defenetly a half moon/kink. Many old timers never expose the last frame of 120/220 film for this reason.

Regards,
Robert
 
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johnny.moped said:
But that's the end of the film. The adhesive tape is on the beginning of the film.
And that would be to much of a coincidence: Two different types of film developed by two different labs/persons.
Click to expand...

Either a big coincidence, or someone involved both times doing something wrong. How do you tape up the roll?

johnny.moped said:
I don't think it's a kink. One would be able to feel it as it must be still kinked when in developing.
Click to expand...

Film is tough. The only times I've had kinks that could still be felt after processing was when the film had been through something so violent as to strip gears, bend the pressure plate or crack a reel as well...
 
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Guys, I think you convinced me.
I had a look at the black and white negative again and I could feel the "kink".
So a light leak can be ruled out.

Now the big question is: what did cause this?

I think I can rule out processing as two films where processed by a lab and one by myself (and I am very sure, that I didn't kink it in any way - also I have never seen this before).
Also I just checked the backing paper of the film I developed yesterday and I saw this "kink" there too.

So it must be the camera.
Could it be that too much tension is causing this?
Or is it any part inside the chamber(s) that is pressing against it (though it would press against the backing paper and not the film)?

Here is a (bad iphone) pictures from inside the camera.

5371181860_47cbc21035_z.jpg




thanks again
 
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