Strange spots on some film negatives

[Mozg31337]

Hello everyone,

I have noticed a large number of small random spots on b&w Fujifilm Neopan 400CN 120 film which was developed using C41 process. A few months ago I have developed my first 400CN film and noticed this problem. Initially I thought that the washing was terrible and blamed it on that. However, a few days ago I have developed 4 films in the same tank (two 400CN b&w and two colour films) and the spots appeared on ly on the 400CN films and not on the colour films. I am controlling temperature at 38 degrees with my Anova sous vide gadget and the temperature is verified with a manual old school mercury thermometer. I am using constant manual rotation during development and fixing.

I have scanned a few negatives to show the spots. The small spots are there all over the b&w negatives and more visible on the light parts of the negative. The colour scans show the Fujifilm Pro 400N without such spots even though the films were developed at the same time in the same tank.

Has anyone experienced these issues? What could cause it?

Many thanks

 

[Rudeofus]

Do you by any chance use a BLIX kit with 120 format roll film? Do you go directly from CD to BLIX?

If your answer is "yes" to both above questions, then try to use a stop bath and a brief wash between CD and BLIX.

 

[Mozg31337]

Hi Rudeofus. I have used the Tetenal C-41 kit with BLIX for both developments. The first one that I've done (scans are not included here) was done with Blix directly after the CD. however, the second one I've done recently (scanned images in the thread) I have used a quick 1 minute wash after the CD, without using the stop bath.

 

[Rudeofus]

C-41 process is difficult with regard to timing, because CD step is very short. Remember that 15" extra development are equivalent to a full stop push! Therefore I recommend you practice and optimize the process between "pouring out of CD" and "fill in stop bath". This is pretty much the only time critical step in the whole process chain, and this transition from CD to stop should go as smoothly and as swiftly as possible. Make sure you have either a wide mouthed bottle, or a beaker for CD so you can pour out CD quickly, and have stop bath ready when its time has come.

 

[bvy]

C-41 process is difficult with regard to timing, because CD step is very short. Remember that 15" extra development are equivalent to a full stop push!

It's 30 seconds per one stop push, actually, but still, you have to work efficiently.

To the OP, if you're developing more than two 35mm rolls or one 120 roll in the same tank, you're likely going to be dealing with pour times that are too long to insure even development. An alternative is to drop the reels into the developer and remove them using a lift rod, but you have to do this in the dark, of course. Were the rolls most affected the ones that were on top in the tank?

You can also try adding a couple prewashes of water at 100F to promote even development. This will also help temper the film and tank for the developer.

 

[Mozg31337]

I will try to do a stop bath before the BLIX and also, from what I've read it helps to preserve the BLIX too. I have timed the emptying / filling the tanks and it typically takes 25-30 seconds to empty and fill a full 1.5L tank that is designed for 8x35mm rolls. When I've developed the last time I had put 2 x 120 rolls onto a single spool. I've used the sticky tape at the end of the roll to attach both rolls together. One of the problem rolls was at the top of the tank, the other one was at the bottom. The previous development of the Neopan 400CN that I've done was done one roll at a time in a small tank designed for 2x35mm or 1x120 films. The full/empty times are around 15 seconds if that.

However, I am not sure that the spots are caused by the timing. Two out of four films that were developed in the same tank at the same time do not have these spots. Thus, I am wondering if this is a problem with the film itself or perhaps the chemicals?

Has anyone developed the NeoPan 400CN before? Any issues with it?

Thanks

 

[bvy]

I will try to do a stop bath before the BLIX and also, from what I've read it helps to preserve the BLIX too. I have timed the emptying / filling the tanks and it typically takes 25-30 seconds to empty and fill a full 1.5L tank that is designed for 8x35mm rolls. When I've developed the last time I had put 2 x 120 rolls onto a single spool. I've used the sticky tape at the end of the roll to attach both rolls together. One of the problem rolls was at the top of the tank, the other one was at the bottom. The previous development of the Neopan 400CN that I've done was done one roll at a time in a small tank designed for 2x35mm or 1x120 films. The full/empty times are around 15 seconds if that.

However, I am not sure that the spots are caused by the timing. Two out of four films that were developed in the same tank at the same time do not have these spots. Thus, I am wondering if this is a problem with the film itself or perhaps the chemicals?

Has anyone developed the NeoPan 400CN before? Any issues with it?

25 to 30 seconds is way too long when you consider it's about 15% of the total development time.

I've not developed Neopan 400CN, but I have developed Ilford XP2 which is also a chromogenic black and white film. I found it to be especially sensitive to long (and even not so long) pour times. I posted an example recently. I have to wonder if these films don't develop "faster" than color negative films -- that is, in terms of how soon an image appears after being exposed to developer.

 

[Mozg31337]

Bvy, I agree that 25-30 seconds liquid change is not ideal and this is really the quickest I can do with my current setup. I've got 2l collapsible plastic canisters with pretty wide necks and I use a funnel to dump the chemistry back to the canisters. I think if I attempt to do it quicker, I will have spills and stains all over my kitchen. Having said this, I do compensate for longer times by starting the process about 10 seconds shorter of the recommended time. So, for the brand new mix of Tetenal C41 with the recommended dev time of 3:15 I have started pouring the developer at around 3:05.

By the way, what should I use for stop bath? I am planning to develop a few rolls next week using the suggestions from the thread.

Also, I have read a lot of nice things about using the Kodak C41 chemistry with a separate bleach and fixer. Could someone please point me in the right direction on what chemicals should I be buying and the instructions on mixing, keeping and processing at home? There tend to be too much information on the Kodak C41 processing and I don't really know where to begin.

Cheers

 

[bvy]

The pour times aren't a problem insofar as they affect getting the exact development time right; they're a problem in that for a large percentage of the development time, you can't control how the film and developer are in contact. Pouring faster isn't the answer since that's regulated by the design of your tank. Trying reducing your load (two 35's or one 120) and see if that helps.

For stop bath, I use one part distilled white table vinegar (from the grocery store) to four parts water.

See here for a complete "shopping list" of Kodak C-41 chemicals that includes a separate bleach and fix. Let me know if you have any questions.

List of Color Chemicals and Where To Get Them

 

[Mozg31337]

Thanks, I will give it a bash at some point in a near future!

 

[pentaxuser]

Are the spots to which you refer the mottling effect that only seem apparent in the sky area? I can see two almost pure white spots not in the sky area but only in the last of the two B&W negatives. However I don't think these are what you are referring to, are they?

Is there any chance that the mottling is a scanning artefact?

A lot of good advice about the process but can the contributors explain the link between the advice and the elimination of the effect to which the OP refers. What in essence is it about the C41 colour negatives that prevents the OP's current procedure from affecting the colour negs in the same way as the chromogenic B&W negatives?

Thanks

pentaxuser

 

[Mozg31337]

Hi Pentaxusers,

the spots that I am referring to are little grey specs of random shape that appear all over the b&w negatives. They are most visible in the lighter part of the image, like the sky, but some darker parts also have them. For example, in the image film-120mm-2017-08-2-002.jpg you can spot them all over the mountains. These are visible on the negative under a loupe and they are not scanning artefacts. I've not experienced anything like that with any other b&w or colour film, apart from the 120 NeoPan 400CN. I have developed a roll of 35mm Ilford XP2 before and not had any spots. From what I've read the NeoPan 400CN is a very similar film to XP2 and is also produced by Ilford for Fujifilm but with modifications. I have a few more 120 rolls of NeoPan 400CN and I was hoping I can develop them without having the spots.

Does it worth giving another wash to see if the spots go away?

Cheers

 

[pentaxuser]

I tried clicking on your example in post 12 but Photrio won't show me it. Maybe the link jpg shows the problem more clearly but all I can see is the mottling effect in the lighter areas of the two original B&W negatives. I can see nothing on the colour negs. If you saw nothing on an XP2 film and you can be sure that nothing about your process has changed then it suggests that the problem is with the Neopan film. Unless someone can give a good reason why your process only produces problems with the Fuji chromogenic film the logic leads to there being a problem with the film.

If it were XP2 I'd suggest contacting Ilford but as it is a Fuji film which may be produced by Ilford I have no idea how you contact Fuji.

pentaxuser