I am not an expert so I have no my own knowledge, but from discussion here on Photrio I understand, that it is a real problem and can be seen on films of other manufacturers too.
Somewhere in the archives of Photrio there is a post of a highly respected former forum member and former Kodak employee Photo Engineer wherein he reveals that Kodak suffered from emulsion cracks while they were developing (as in engineering) TMAX films. From what I can remember his description of the problem was very similar to the Foma 200 cracks.
Obviously Kodak managed to remedy the problem.
It has been shown that t-grains with a large diameter can be stressed in film when the film turns around rollers in cameras during winding. This cracking effect causes fog. This may be one limitation in the design of high speed t-grain films.
Also, the higher the efficiency of a coupler, the more dense a dye speck becomes. This can tend to increase the appearance of granularity. This is another of the obstacles placed in front of the engineer.
Higher speed films are more sensitive to the X-ray units used in airports and other terminals. With more X-ray checks and higher energy devices, this also increases problems faced by film manufacturers.
As you can see, this involves a series of tradeoffs.
Another spectrum of problems are faced when desiging slow speed high definition films.
PE
Seriously, t-grains all lie flat and parallel to the plane of the film support. Surprise, surprise.
The real problem is preventing them from cracking as they go around the rollers in 120 film cameras. The turn is too sharp for some grains and will cause cracking and fog. Kodak has eliminated this, but IDK if others have except for Fuji and Ilford.
PE
Denise, the early t-grain emulsions were so fragile that when the film was wound around the tiny 120 camera rollers the grains cracked. Emulsifiers and blenders can crack even large K-grains if run fast enough and that is why the Kodak PEPA has no blades so it mixes well without cracking. Yeah, we had a lot of problems "cracking" that problem. We no longer used prop mixers either due to the high speeds needed to make the more modern emulsions.
The foam certainly is reduced by filtration, but I am talking about foam present during the addition of silver nitrate. That causes bubbles on the surface in which a 2D model of pptn. takes place forming odd crystals when you don't want them and it also exposes the forming grain to the atmosphere over a large surface area. These are not the bubbles that may be present during coating.
PE
I have looked at it again and again and I feel that the defects are too sharp and well defined to be bromide drag. I remember now where I saw something similar to this. When the first t-grain coatings were made in 120 format, they had similar defects due to the sharp curvature of the 120 back rollers in some cameras. The coating formula had to be revised to allow more flex in the gelatin so that grains were not cracked by turning the sharp corners.
Bromide drag is often used for similar effects by developer and pH as I mentioned here earlier. It can also be regular and symmetrical, but it is rarely, if ever, sharply defined.
PE
I hope not — there is speculation that Ferrania’s new 120 films are using Foma’s backing paper.The problem might also be related to inconsistencies in the backing paper that Foma is using.
I have found these mentions by Photo Engineer regarding the fragility of tabular grains
I hope not — there is speculation that Ferrania’s new 120 films are using Foma’s backing paper.
Maybe make a look at these threads:
"Old" Rodinal = pinholes?
Hello! Recently I've gotten pinholes on almost every film I've developed. Just two or three holes, but still. I use different films, but have shot mostly Adox CHM400 Pro and CHM 125 Pro (HP5 and FP4) lately. I use Rodinal 1+50 for all my processing. The Rodinal bottle is soon empty...www.photrio.com
Stop Using Stop? - Pinhole Frustrations
I know there are are a few threads on this, but I coudn't find exactly what I was after by doing a search. Pinholes are starting to frustrate me more. I have always used acid stop bath. Last week I developed a 120 roll of Retro 400 and about five of the frames contained pinholes, mostly very...www.photrio.com
I've had no issues with Foma 200 in 35mm form. However, I've had no luck with it in 120 form. I've a couple of 120 rolls left but won't be replacing them and will move to Kentmere, Foma just isn't working for me.
Thanks for that, I had seen one of those threads before and that was what prompted me to try an alkaline fixer for the last roll I developed but I still got black spots. I've always used a pre-bath and water stop. I started with Caffenol but for my last two rolls have used Microphen but every time I have got black spots. Fixers have been Tetenal Superfix Plus for all but the last roll which used Eco Zonefix. Film has been batches 013456-3 exp 12/2024 and 013456 2 exp 09/2024.
Likewise! I have a bulk roll of Foma 200 35mm and it's fine, but I can't say the same for Foma 200 120. I've tried about four different rolls over a long time period and they were all bad. Hmmm, must be why I never, ever win anything on my lottery tickets? I'm just unlucky I guess.I've had no issues with Foma 200 in 35mm form. However, I've had no luck with it in 120 form. I've a couple of 120 rolls left but won't be replacing them and will move to Kentmere, Foma just isn't working for me.
The backing paper seems to do just fine on the other Foma films. I would t worry about this too much.
That's good to know. I'm not going to rush out and buy some or change my main films, but I surely will give it a try. Who knows, I might just like it. I really like Foma 100 at EI 100-125 for its tones and grain structure, but black specks are just too much to overlook.I know a sample size of one isn't statistically relavant, but my first roll of P30 in 120 had no issues I didn't cause myself (some under exposed frames because I didn't have a meter, so was guessing exposure.)
The backing paper seems to do just fine on the other Foma films. I would t worry about this too much.
Unless, of course, the problems are similar to the problems that Kodak had with wrapper offset - an interaction between particular emulsions, ink and the paper.
@albireo not to derail this Fomapan-focused thread, but what didn't you like about XT-3? I am curious because I found Xtol and D76 to be extremely similar with all films I used them with. I may even go as far as saying that they can be identical with some dilution+exposure experimentation. And XT-3 is supposed to be identical to Xtol.
Steven, it's minor effects for sure. And as you say, I'm sure most differences could be ironed out with some experimentation. However - this is what I'm seeing currently (with both Fomapan 200 and Kentmere 400)
The advantage I'm seeing with XT-3 is slightly better shadow detail than with D23 given same EI. Not that fussed about a 1/3 or 2/3rd stop increase, as I tend to do photography only in good available light.
- grain looks different. Much finer with XT-3 for sure. But I don't particularly like extra fine grain. I like the well defined grain I see with D23/D76. XT-3 seems to 'smudge' detail (for the lack of a better term)? I use Rodinal all the time, and find D23/D76 to give finer grain than Rodinal but really good detail as well. For some reason, XT-3 looks a little less detailed than D76 or D23?
- I have slightly more difficulty controlling the highlights with XT-3 than with D76, and much more difficulty that with D23.
So overall I don't see a clear advantage of XT-3 1+1 over D23/D76 1+1 for my use. Perhaps I should try XT-3 in 1+3 configuration.
Try D-23 1:9 and add 0.5g/liter of lye (handle lye carefully, it's highly alkaline and will burn eyes, hands, and skin badly). You will get ultrasharp negs with good highlight compensation.
Thank you!
Same camera
Same camera! Same batch! It MUST be something that manifests in development. If you have some Rodinal, can you shoot a roll and stand process it (1:100 for an hour) and see if you get spots?
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