Filmwasters

Which Board? => Main Forum => Topic started by: Nigel on December 10, 2017, 11:31:45 AM

Title: What's this line?
Post by: Nigel on December 10, 2017, 11:31:45 AM
I've bought a Pentax 67, which I've only put one roll through but I'm really enjoying it so far. I developed the first roll yesterday, which is tri-x in HC-110 and there are a number of very faint lines on all the negatives.

I can only see them in the light areas of the negative, but they seem to run the length of the film. I guess the best way to see if it's the film is to shoot another roll, but I'm sure Kodak's quality control is pretty good. Anyone have any idea what they might be?
Title: Re: What's this line?
Post by: Pete_R on December 10, 2017, 12:19:17 PM
Do they line up with anything in the back of the camera?

Can you actually see the lines on the negative? Do they look like scratches?

I think I can see one or two more that you haven't marked about the same distance in from the left as the ones on the right are from the right edge.

Sorry that's not an answer.
Title: Re: What's this line?
Post by: Bryan on December 10, 2017, 01:13:16 PM
They look like scratch lines to me but that can either be a quality control problem for Kodak or your camera.  With movie cameras I clean the film gate constantly to avoid this because bits of emulsion can come off and scratch the film.  I will clean a movie camera after every 50 foot roll, you would be amazed at how much gunk can build up.  When you project 8mm movie film you will almost always see bits of emulsion on the edges of the frame.  Every now and then I clean my still cameras the same way I’d do my movie cameras.  That’s the only thing I don’t like about my Leica screw mount cameras, you can’t really get access to areas that need cleaning.  I clean both sides, the pressure plate and the gate, wherever film comes in contact. 

That batch of Ferrania P30 Alpha I got was riddeled with scratches but I could tell that was from the factory because I could see it on the ends of the film that weren’t dragged through the gate.  With 120 film it’s hard to tell because all of the film is dragged through the gate.  Kodak has had quality control problems lately like backing paper numbers showing up on the film. 
Title: Re: What's this line?
Post by: 02Pilot on December 10, 2017, 01:28:33 PM
I've had a few cameras that scratched the film. Usually it's just a rough surface. Use a cotton ball to find snags (rub it lightly over the area - if there's any sharp bits it will likely pull a little cotton off). Polish with 0000 steel wool and blow it clean.

Bryan, the screwmount Leicas come apart fairly easily, especially from the IIIc onward, as long as you don't have a self-timer. A few screws on the shell and the lens mount ring and it's off.
Title: Re: What's this line?
Post by: Bryan on December 10, 2017, 01:58:05 PM
Bryan, the screwmount Leicas come apart fairly easily, especially from the IIIc onward, as long as you don't have a self-timer. A few screws on the shell and the lens mount ring and it's off.

Thanks, I assume the slow speed knob comes off easily as well or do I need the remove that?
Title: Re: What's this line?
Post by: Nigel on December 10, 2017, 02:26:58 PM
Thanks guys.

I realised afterwards the way I'd posted the image could be misleading, the scratches run the length of the film not top to bottom.
At first, I thought it was the scanner but I can just about see a couple of them on the negative and they do run through the edge of the frame.

The inside of the camera is amazing there are seven rollers in the film transport, they all seem very smooth though.

I suppose the only way to test for sure is to run a different film through it.
Title: Re: What's this line?
Post by: Francois on December 10, 2017, 03:10:39 PM
Maybe you could check it out using an angled light. Reflect light on the film and see if you can see scratches. If the scratches are on the matte side, check the camera side. If they are on the shiny side, check the back.
Also, since the image is upside down in the camera, the sky is at the bottom of the film gate.
You can always align the negative with the camera to get a rough idea of where the problem lies.

Also, Kodak isn't what it used to be. I've had some tmax with impossible to remove AH layers. The results were negatives with blotchy blue spots that didn't come off after a four minute pre wash with multiple water changes and a 30 minute final rinse in my film washer!
Title: Re: What's this line?
Post by: Nigel on December 10, 2017, 03:13:19 PM
Thanks François,
I tried a little test by turning the film 180 deg in the scanner. The darker line switched sides on the image, so that must be scanner related. The pair of pale lines stayed in the same position so they're a mark on the film.  I can just see them on the emulsion side.  I'll try a different film and see what results I get.
Title: Re: What's this line?
Post by: 02Pilot on December 10, 2017, 03:38:19 PM
Bryan, the screwmount Leicas come apart fairly easily, especially from the IIIc onward, as long as you don't have a self-timer. A few screws on the shell and the lens mount ring and it's off.

Thanks, I assume the slow speed knob comes off easily as well or do I need the remove that?

Slow speed knob doesn't need to be removed on IIIc-up cameras. The earlier bodies have a screw under the knob that needs to come out to get the shell off. They attach differently (late ones screw off, early ones lift off). The later bodies are generally less fussy to disassemble.
Title: Re: What's this line?
Post by: hookstrapped on December 10, 2017, 06:54:41 PM
I was about to say that the thin dark (purplish?) line looks like a scanner registration issue, which can be fixed by cleaning the glass of the scanner bed at the top (where the scanning starts).

The other one, I dunno...
Title: Re: What's this line?
Post by: Francois on December 10, 2017, 08:32:28 PM
It's actually the dark line that is on the negative, not the pale white one.
The line is clear on the film and gets inverted by the scanner.

Pale lines are probably dust in the scanner head (which appear dark on a slide scan but get inverted too because it's a negative).
For those, often just locking the scan head, turning the scanner on its side and burping it like a baby will dislodge the dirt and make it fall more to the side (hopefully out of the sensor area).