Arista.edu Ultra 200 Emulsion Flaking Off

[bob_camarena]

I just processed two rolls of 120 Arista.edu Ultra 200 film in D-76 and, on

several frames there are irregular, somewhat jagged spots about the size of a

pin-head where the emulsion has flaked off (only one spot per frame on about 2

frames/roll.

 

I'm assuming this occurred during processing but I suppose it could have flaked

off before I shot it.

 

I usually shoot 35mm Ilford so I don't know if this is common with 120 film, is

the result of faulty technique or is a problem with the film. I did store the

film in the freezer for awhile in it's original, sealed packaging but it thawed

overnight before I loaded it. My 35mm film has been frozen as well without any

problems.

 

The last time I shot 120, I used Ilford film and didn't have this problem. It

also seems like the film base of the Arista is a bit thinner than the Arista.

 

Any thoughts?

[david_dorcich1]

What stop did you use?

[bob_camarena]

Are you asking what stop bath I used? If so, I'm not sure since I processed it at my community college darkroom. All I know is that wasn't just a water stop bath.

[david_dorcich1]

Its possible that is it "pin holing" from a reaction between the stop bath and the developer in the film. Could you post an image of one of the frames?

 

If it is an acetic acid stop bath there is the possibility that that is your problem.

[skygzr]

I had a variety of quality control problems with the Arista Ultra and Ultra.edu films. Pinholes and the like. I know other folks love them but I didn't use them for that reason.

 

BTW the 35mm versions are quite usable and I've never had problems with them.

[bob_camarena]

Wouldn't a pinhole be symmetrical? Here's a scan of the negative but it's not the best. Since my scanner isn't set up for medium format, I had to scan only part of the negative using the mask intended for color slides. Note that the flaw measures about 1mm in its longest dimension and there is no emulsion at all.<div></div>

[cj_bas]

David, isn't acetic acid the most common type of stop bath? (I don't know, I really am asking.) Would you recommend just using a water stop bath?

[frank.schifano]

Is the emulsion really flaked off, or is it simply a clear spot? If the emulsion is truly detached from the support, you should be able to see it under magnification and feel it with a fingertip. First thing I'd look for in this case would be some sort of mechanical problem, probably not camera related. I do not believe this to be a stop bath problem. I've been using an acetic acid stop for years and don't have one iota of evidence that it causes "pinholes."

[cj_bas]

I have heard, from other sources, of this film having p;roblems with pinholes. I'm wondering if it was a matter of the film not being properly coated with the emulsion in the manufacturing process. If that's the case, there is nothing that can be done to correct it in development.

[bob_camarena]

In answer to Frank's question, the emulsion has actually flaked off. Unless I'm convinced differently, I think I'm going to return to using Ilford film. The price difference is minimal when compared to the lost time and ruined images.

[beerbrain_ronny_perry]

If you are using a wat-air..or other turbulence type film washer, and you crank it up to much ,it will tear the emulsion.

[bob_camarena]

I don't think washer turbulence was a problem it was a very gentle washer.

[terence_spross1]

Examine a sample piece of unprocessed film under a microscope looking for imperfections in coating. This is easier to do with 35mm - a sample piece is readily available on every leader.

 

Many people might classify this as pinholes even though it isn't.

Also, could it be this emulsion is much softer and therefore much more subject to damage in the wash?