Goodbye remjet, hello AHU?!

[Tommy Aschenbach]

The AHU is a new layer in the emulsion under the cyan dye layer. It contains silver that is converted in the bleach and washed off in the fix. Bleach bypass will cause the AHU to be retained.

[Aapo Lettinen]

3 hours ago, Gautam Valluri said:

@Aapo Lettinen do you happen to have any example stills of what the "ghost reflections" look like on these chrome pressure-plates when shot without the remjet layer?

not having any Arri or Aaton material. I think I have some Krasnogorsk2 footage which has such reflection somewhere but don't remember where it is and would take too long to look for it. I think would be easier to just use b/w film and replicate the reflection by intentionally pointing the camera at bright lights directly

[Joerg Polzfusz]

Of course this will affect all gauges = also DS8, Single8, D8, 9.5mm, … . And I can’t think of any camera for these formats without a „silver“ pressure plate.

[Tyler Purcell]

5 hours ago, Joerg Polzfusz said:

And I can’t think of any camera for these formats without a „silver“ pressure plate.

16mm Bolex's do not have a polished silver plate in the Rex series, they are one of the only camera systems (besides super 8 of course) that will not in any way be effected. 

[Tyler Purcell]

7 hours ago, Tommy Aschenbach said:

The AHU is a new layer in the emulsion under the cyan dye layer. It contains silver that is converted in the bleach and washed off in the fix. Bleach bypass will cause the AHU to be retained.

Oh interesting, tats fascinating. Why would the AHU later contain silver? 

[dan kessler]

On 6/3/2025 at 2:49 PM, Tyler Purcell said:

We just want to come up with a generic and easy solution to modify the OG plates because machining new ones, where it may sound simple, the tolerances are challenging and costly due to the materials used. Removing the chrome and painting/polishing seems to be the best option thus far, but it's not working yet. 

On another thread you mentioned DLC coating as a viable solution.  Have you not tried it?  Does it work?

[Tyler Purcell]

3 hours ago, dan kessler said:

On another thread you mentioned DLC coating as a viable solution.  Have you not tried it?  Does it work?

Can't make it smooth enough, talked to an expert, not gonna work. 

Now we're researching paints that can be polished. 
 

[Simon Wyss]

6 hours ago, Tyler Purcell said:

Why would the AHU later contain silver? 

It is a colloidal silver layer in gelatine. Colloidal silver is black.

[Aapo Lettinen]

fomapan reversal has dark silver anti-halation layer too and similarly removed in first bleach

[Piotr Wołoszyk]

Perhaps coating is not a proper attitude. May be you need some metal alloy that is dark enough to prevent ghost reflections?

[Geffen Avraham]

will processing for this be just c41?

[Dirk DeJonghe]

ECN2 uses CD3 developing agent, C41 uses CD4, you would get an image but it would be off colour.

If the bleach bypass retains the silver in the image, then the AHU may interfere with proper scanning of the negative.

[Aapo Lettinen]

3 hours ago, Piotr Wołoszyk said:

Perhaps coating is not a proper attitude. May be you need some metal alloy that is dark enough to prevent ghost reflections?

that would probably need to be sintered alloy or some kind of carbon composite. both are more trouble than they are worth I think and probably not dimensionally accurate enough but not an expert on these materials.

anodizing can be made in different colours as well as chrome plating. but the issue as I understood was that porous surfaces don't have the proper friction in this use or wear too quickly?

I would just redesing the pressure plate part actually being behind the gate. changing the geometry of the surfaces would allow using different type of materials. someone would probably need to manually precision polish the final parts to proper tolerances but other than that I think it should be possible to make "good enough" replacement parts if abandoning the original design and making a new one which works better with the black materials available.

a composite carbon material could actually be somewhat usable solution. some older cameras like Cameflex have bakelite pressure plates and they work pretty fine though the wear faster than metal ones. If a composite black pressure plate could be made at reasonable price it would be possible to replace it regularly if it has been too worn, thus making it possible to use wider range of materials for this application

[Simon Wyss]

A piece of black velvet can always be glued on a pressure plate.

[Lucas Xavier Simes]

6 hours ago, Geffen Avraham said:

will processing for this be just c41?

I would imagine yes. Because the whole idea of this is that more still photographers will buy motion picture film for bulk loading. Many already do that, so the only remaining barrier to entry I can imagine is just that most labs don't process ECN2. 

[Karim D. Ghantous]

Just for fun: quantum stabilised mirrors:

https://www.science20.com/news_releases/quantum_stabilized_atom_mirror_the_smoothest_surface_ever_created

[Uli Meyer]

13 hours ago, Lucas Xavier Simes said:

I would imagine yes. Because the whole idea of this is that more still photographers will buy motion picture film for bulk loading. Many already do that, so the only remaining barrier to entry I can imagine is just that most labs don't process ECN2. 

No, the process remains ECN2.

[Gautam Valluri]

2 hours ago, Uli Meyer said:

No, the process remains ECN2.

Is it still ECN2 if the remjet removal step is skipped?

21 hours ago, Dirk DeJonghe said:

ECN2 uses CD3 developing agent, C41 uses CD4, you would get an image but it would be off colour.

No wonder the Cinestill images were always a little "off" on their colours.

[Uli Meyer]

56 minutes ago, Gautam Valluri said:

Is it still ECN2 if the remjet removal step is skipped?

According to my contact at Kodak it is.

[Christian Flemm]

6 hours ago, Gautam Valluri said:

Is it still ECN2 if the remjet removal step is skipped?

As of yet the removal process isn't skipped. The new material runs in the same mag as the remjet material. It passes through the prebath and wash steps all the same - the only difference being that there is no remjet to remove.

Kodak print films also had remjet at one point (in this domain I have experience with EXR print film, which was also confectioned without remjet), so machines processing ECP-2E had at one point to also run through a remjet removal process. Once print films with remjet were phased out, the lips and hoses relevant to remjet removal bath were also removed from the processor.

Time will tell if the same thing happens with the ECN-2 process. But as far as I am concerned the process designation stays the same.

5 hours ago, Uli Meyer said:

According to my contact at Kodak it is.

Additionally, if we are talking technicalities, the process remains ECN-2 or ECP even if you run a skip bleach, so I cannot imagine the designation of the ECN-2 process changing at all.

[Uli Meyer]

5 minutes ago, Christian Flemm said:

It passes through the prebath and wash steps all the same - the only difference being that there is no remjet to remove.

I was told that less water is being used since there is no remjet layer that needs washing off.

[Christian Flemm]

5 minutes ago, Uli Meyer said:

I was told that less water is being used since there is no remjet layer that needs washing off.

I think this is true only if the material running through the magazine is entirely without remjet. The jets of water that help remove the remjet remain on all the same if there is remjet and remjet-free material running through the machine all at once in the same magazine.

In theory it would be possible to control for this variable by looking at the roll number if the sticker remains on the tin, or by snipping some film from the customer material and observing it with the naked eye (the base side of the remjet free material is brownish compared to the black color of the base side of the remjet material), but then it becomes a bottleneck in the workflow process, and a matter of enabling and disabling part of the processor to use less water.

[Christian Flemm]

I wasn't able to capture the clear difference between the old and new material with my phone, but this photograph nonetheless illustrates the difference in appearance of the remjet-free stuff to the old stuff.

 

 

[Matt Figler]

Do we expect labs to slowly stop processing Remjet films? I know there are TONS of shortends/recans/expired/new stock still out there. My fridge would be bummed if this is the case. 

[Uli Meyer]

1 hour ago, Christian Flemm said:

I wasn't able to capture the clear difference between the old and new material with my phone, but this photograph nonetheless illustrates the difference in appearance of the remjet-free stuff to the old stuff.

 

 

Interesting, thank you for sharing the photo! I'll be shooting a short film in a couple of weeks and was told that the material I will receive is still with the remjet layer. I think it might be a little while before the remjet stock gets phased out. While that happens, they'll probably be running a machine that can process it.