Why do my Medium-Format Negatives Seem Thicker and Less Clear?

[RLangham]

So I use Cinestill C-41 chemicals because they're cheap and they work well enough for me. I shoot both 35mm and 120 color film, in a variety of speeds and emulsions. Mostly with 120 I've used brand-new Ektar 100, @ box speed, and expired, but refrigerated Fuji HG400. The Fuji expired in 1998, and I don't know how long it's been at room temperature vs. refrigerated by the previous owner, so I rate it @ 100 ASA and get similar results to the Ektar 100.

I'm very fastidious about exposure, and I'm quite sure I'm exposing these within an average one stop of the correct EV for the rated speed. On 35mm I get very nice-looking negatives.
On 120, my negatives always come out much thicker with much less clear lowlights and edges--almost as if I weren't bleaching or fixing enough. The final images come out... okay, I guess? Maybe not quite up to the standards of my 35mm images.

Now, the Cinestill kit has both in one bottle as a blix solution, which is used for 8 minutes at 102F. / 39C. with the same agitation as the development stage. Is this a case where the emulsion itself is thicker and I have to blix longer? Or what's going on?

 

[BobD]

On 120, my negatives always come out much thicker ...

Thicker than what?

 

[RLangham]

Thicker than what?

Than a well-exposed and well-developed 35mm negative.

 

[Andrew O'Neill]

Never shot colour 120 so I have no clue... Most of the B/W I shoot...Acros, TMY, TMX, HP5, FP4, have fairly clear FB, some slightly more than others.

 

[RLangham]

Never shot colour 120 so I have no clue... Most of the B/W I shoot...Acros, TMY, TMX, HP5, FP4, have fairly clear FB, some slightly more than others.

Yes, my experience with B/W 120 over the years has been similar to my (much less extensive) experience with 35mm B/W. I've usually seen a transparent white to transparent grey backing... Color negative 120, in my experience, has the same orange-amber backing as any other modern C-41. It's just that the emulsion overlying that backing doesn't seem to get as bleached or something when I'm processing 120.

 

[Andrew O'Neill]

Yes, my experience with B/W 120 over the years has been similar to my (much less extensive) experience with 35mm B/W. I've usually seen a transparent white to transparent grey backing... Color negative 120, in my experience, has the same orange-amber backing as any other modern C-41. It's just that the emulsion overlying that backing doesn't seem to get as bleached or something when I'm processing 120.

Different beast, I guess. Sorry I couldn't be of more help... I bet PE would have an answer. Miss him...

 

[RLangham]

Different beast, I guess. Sorry I couldn't be of more help... I bet PE would have an answer. Miss him...

Departed? Or just off the forum?

 

[peter k.]

Departed.. sigh ..
https://www.photrio.com/forum/threa...rey-aka-pe-photo-engineer-feb-15-2020.173245/

 

[RLangham]

Departed.. sigh ..
https://www.photrio.com/forum/threa...rey-aka-pe-photo-engineer-feb-15-2020.173245/

Oh, and so recent! I'm sorry. I regret not having met him on the forum!

 

[MattKing]

Well...
120 film is on a different substrate than 135 film - it is thinner.
It also uses backing paper rather than anti-halation layers.
There may as well be a subjective component as the 120 negatives are bigger and lack the open perforations.
Someone with a transmission densitometer could provide a scientific measurement.

 

[RLangham]

Well...
120 film is on a different substrate than 135 film - it is thinner.
It also uses backing paper rather than anti-halation layers.
There may as well be a subjective component as the 120 negatives are bigger and lack the open perforations.
Someone with a transmission densitometer could provide a scientific measurement.

But does it lack antihalation layers? I thought that that was the orange-amber tint that all modern C-41 film has. As for the lack of sprocket holes and any subjectivity... no, I think I'm accustomed enough to both formats to compare them accurately, and these negatives are powerfully thick, lemme tell you. As for a densitometer reading, I imagine it would only confirm that these negs are dense compared to 35mm negatives exposed with the same degree of accuracy and processed identically in the same chemicals.

 

[MattKing]

The orange-amber tint comes from the built in correction mask which is in place to deal with the non-linear properties of the colour dyes that form the image - it has no anti-halation role.
I don't shoot Ektar 100, but my experience with 120 and 135 colour negative films - in recent years mostly Portra in 120 and Kodak amateur emulsions in 135 - is that when processed by regular labs the negatives look to be of similar density, once one allows for the different subjective influences.

 

[RLangham]

The orange-amber tint comes from the built in correction mask which is in place to deal with the non-linear properties of the colour dyes that form the image - it has no anti-halation role.
I don't shoot Ektar 100, but my experience with 120 and 135 colour negative films - in recent years mostly Portra in 120 and Kodak amateur emulsions in 135 - is that when processed by regular labs the negatives look to be of similar density, once one allows for the different subjective influences.

Now that you say that, when I had my 120 processed by a lab (it seems like ages ago but it was only about two years), it did look very similar to 35mm color film in terms of thickness and density. Do you think their machines automatically process 120 a little differently than 35mm, to compensate for whatever differing characteristics they have?

Because hand-processing it like I do, I do everything the same between the two formats. The same agitation regime (ten seconds agitation out of every sixty), the development time calculated the same way (to compensate for depletion), the same blixing time (8:00) with the same agitation, in the same tank. The only difference is the type and size of film.

Perhaps next time I'll try blixing for ten minutes...

 

[kevs]

You could try clearing the 120 negs in a 10% solution of potassium ferricyanide for ten mins, wash, fix in a regular fresh B&W fixer, then wash and dry as you would B&W film. That will remove any remnant silver from your negs and you can compare them with untreated film.

 

[RLangham]

You could try clearing the 120 negs in a 10% solution of potassium ferricyanide for ten mins, wash, fix in a regular fresh B&W fixer, then wash and dry as you would B&W film. That will remove any remnant silver from your negs and you can compare them with untreated film.

"Wash and dry as I would B&W film..." Like, when you say wash, do you mean with soap? Or with stabilizer? I... I may cut corners in that area, if I'm being honest.

I don't know that it's a problem worth buying chemicals (especially scary-sounding ones) over. I'm trying to scan my latest batch of 6x9's right now and they seem fine despite the density.

 

[Lachlan Young]

Do you think their machines automatically process 120 a little differently than 35mm, to compensate for whatever differing characteristics they have?

No, they're running exactly the same process for all formats - and usually more consistently than most hand processing too. The main differences you are seeing may be to do with absolute temperature control, agitation patterns (remember that 3m 15s is not a long time) and separate bleach and fix baths. Excess density could be any of too much development time, temperature too high/ rising over development time, too much agitation or as others have noted, insufficient silver removal because of the shortcomings (exhaustion?) of the of blix in your kit rather than separate bleach and fix in full-fat C-41.

 

[RLangham]

No, they're running exactly the same process for all formats - and usually more consistently than most hand processing too. The main differences you are seeing may be to do with absolute temperature control, agitation patterns (remember that 3m 15s is not a long time) and separate bleach and fix baths. Excess density could be any of too much development time, temperature too high/ rising over development time, too much agitation or as others have noted, insufficient silver removal because of the shortcomings (exhaustion?) of the of blix in your kit rather than separate bleach and fix in full-fat C-41.

When you say 3m 15s, my Cinestill kit actually starts at 3m 30s... I don't think agitation is the problem given that I'm pretty conscientious about that specific aspect, and that I've observed the same result both at the very first usage of the chemicals, and when the developer is running almost depleted, with development times in excess of six minutes.

Here's the thing, though. Whether I'm being totally consistent or not, and I tend to think I'm doing a middling job of consistency, this result is itself consistent. I've always had dense, semi-opaque 120 color negatives and clear, pretty 35mm color negatives. The sample sizes are pretty large and any variation in the process should be represented in both samples, given that I don't do a bunch of 35mm and then a bunch of 120 or vice versa, but interspersed throughout the life of the chemicals. It's been the same through probably four batches of Cinestill chems at this point.

 

[kevs]

"Wash and dry as I would B&W film..." Like, when you say wash, do you mean with soap? Or with stabilizer? I... I may cut corners in that area, if I'm being honest.

I don't know that it's a problem worth buying chemicals (especially scary-sounding ones) over. I'm trying to scan my latest batch of 6x9's right now and they seem fine despite the density.

Just to clarify; by "wash and dry" I meant use water to remove the fixer from the film, rinse with wetting agent and dry it. I'd forgotten about the stabiliser but I guess you should use it if that's your usual process. It's a while since I processed any C-41 film and I never used stabilizers when I did.

Potassium ferricyanide (aka pot ferri or potassium hexacyanoferrate) may sound scary but it's not unusually poisonous and perfectly safe to use. It's used as a rehalogenising bleach in most B&W toning kits and is easy to buy from photo chemical outlets. The idea here is to turn the remnant silver in colour negs back into silver halide with pot ferri then use fixer to remove that silver halide.

I wouldn't wash film with soap.Your stabiliser might contain a wetting agent but I wouldn't know for certain.

 

[Lachlan Young]

When you say 3m 15s, my Cinestill kit actually starts at 3m 30s... I don't think agitation is the problem given that I'm pretty conscientious about that specific aspect, and that I've observed the same result both at the very first usage of the chemicals, and when the developer is running almost depleted, with development times in excess of six minutes.

Here's the thing, though. Whether I'm being totally consistent or not, and I tend to think I'm doing a middling job of consistency, this result is itself consistent. I've always had dense, semi-opaque 120 color negatives and clear, pretty 35mm color negatives. The sample sizes are pretty large and any variation in the process should be represented in both samples, given that I don't do a bunch of 35mm and then a bunch of 120 or vice versa, but interspersed throughout the life of the chemicals. It's been the same through probably four batches of Cinestill chems at this point.

What sort of tank are you using? And what quantity of chemistry are you using for 135 vis-a-vis 120?

 

[RLangham]

What sort of tank are you using? And what quantity of chemistry are you using for 135 vis-a-vis 120?

I'm using a recently-made Yankee Clipper II, which is, to my mind, the same thing as the original Yankee Clipper I see in antique stores sometime. It has amounts printed on the lid in ounces... among other things, it says 9 oz. for 35mm and 15 oz. for 120.

 

[RLangham]

I suppose you should use a stabilizer if you usually do that. It's a while since I processed any C-41 film and I never used stabilizers when I did.

Potassium ferricyanide (aka pot ferri or potassium hexacyanoferrate) may sound scary but it's not unusually poisonous and perfectly safe to use. It's used as a rehalogenising bleach in most B&W toning kits and is easy to buy from photo chemical outlets. The idea here is to turn the remnant silver in colour negs back into silver halide with pot ferri then use fixer to remove that silver halide.

I wouldn't wash film with soap.Your stabiliser might contain a wetting agent but I wouldn't know for certain.

I don't normally use soap, but I have in the past because someone told me to. I normally use a warm water rinse (into a bucket, the contents of which I dispose of safely, not down the drain), the stabilizer and then another water rinse.

 

[kevs]

I don't normally use soap, but I have in the past because someone told me to. I normally use a warm water rinse (into a bucket, the contents of which I dispose of safely, not down the drain), the stabilizer and then another water rinse.

Hi RLangham, I've just re-written my reply but you'd already replied. The updated version is:

"Just to clarify; by "wash and dry" I meant use water to remove the fixer from the film, rinse with wetting agent and dry it. I'd forgotten about the stabiliser but I guess you should use it if that's your usual process. It's a while since I processed any C-41 film and I never used stabilizers when I did."

Aside: I've used liquid soap a few times when I've had no wetting agent handy or when the wetting agent provided by my college was contaminated with fixer. It doesn't seem to have caused any problems but I wouldn't use it unless I needed to.

 

[RLangham]

Hi RLangham, I've just re-written my reply but you'd already replied. The updated version is:

"Just to clarify; by "wash and dry" I meant use water to remove the fixer from the film, rinse with wetting agent and dry it. I'd forgotten about the stabiliser but I guess you should use it if that's your usual process. It's a while since I processed any C-41 film and I never used stabilizers when I did."

Aside: I've used liquid soap a few times when I've had no wetting agent handy or when the wetting agent provided by my college was contaminated with fixer. It doesn't seem to have caused any problems but I wouldn't use it unless I needed to.

Ah, well, that clarifies things. I've never had wetting agent. Liquid soap doesn't do much for me in this regard--there are still marks from the hard water when the film is dry. So I end up using nothing and getting the same result. I need to get some wetting agent but I always forget to, because it would solve that problem at least.

 

[MattKing]

Whatever you do, you need to use stabilizer at the very last stage.
It contains a biocide that helps prevent bacterial damage, which colour negative film is susceptible to.
If you use anything - including a water rinse - after the stabilizer, you will defeat the biocide, and your negatives may deteriorate.
Black and white negatives contain a fair amount of silver, which is a natural biocide.
Most stabilizers also include a wetting agent.
If you are seeing significantly different results between the 135 and 120 results, it tells me that it is probably a problem with the process chemicals themselves.
Try extending the blix times, if you cannot access the much better separate bleach and fix chemicals.

 

[RLangham]

Whatever you do, you need to use stabilizer at the very last stage.
It contains a biocide that helps prevent bacterial damage, which colour negative film is susceptible to.
If you use anything - including a water rinse - after the stabilizer, you will defeat the biocide, and your negatives may deteriorate.
Black and white negatives contain a fair amount of silver, which is a natural biocide.
Most stabilizers also include a wetting agent.
If you are seeing significantly different results between the 135 and 120 results, it tells me that it is probably a problem with the process chemicals themselves.
Try extending the blix times, if you cannot access the much better separate bleach and fix chemicals.

I don't keep my negatives beyond the time it takes to scan or enlarge them, so I don't know that it matters, but I use it most of the time. I will say that my stabilizer doesn't seem to have a wetting agent, as the water leaves marks whether I use it or not.