After a long time and a lot of test shots, I now think that I have perfected the process. I’ve tried it with both E-6 and C-41 films with good results on both. First, I’ll start off with the boring bit and then get to the results.

Here is the recipe. I purposefully made it so that it could all be done at the single temp of 102F as used by every C-41 kit I’ve ever seen. Note that temperature control is more critical in this and that some kind of warming method will be needed for the long first developer time.

NOTE: It is trivial to re-reel the wet film with stainless steel reels. With plastic reels it would seem impossible; however, several tips online has said that you can easily (apparently more easily than stainless) re-reel the film by sticking both the reel and film in a water filled bucket so that they are submerged. If you’re stuck with plastic reels, you can try this method but I haven’t tested it for myself.

Mix HC-110 A working solution (1+15)

Heat both HC-110 and C-41 chemicals to 102F (you might also want a bottle of water for rinsing)

Rinse/preheat the tank for 2 minutes

Develop for 6:30 in HC-110. Agitate 10s initially, and then 4x every 30s after. Experimenting with less aggressive agitation could lead to less blown highlights, but additional time might be required for full shadow development. Less agitation might also add some color casts. Develop for 7:30 for C-41 films for “box speed” results (otherwise you’ll need to over expose by 1.5 stops for best results)

Rinse several times in order to stop development

Remove film from tank, fog over daylight colored light pad. Do not fog over tungsten lights or outside using the sun. Fog for 2 or 3 minutes, ensuring to cover both the front and back of the film

Put film back in tank

Rinse/preheat tank again for 2 minutes

C-41 develop for slightly longer. For my kit it says 3:30, so I did it for 4:00 for VERY fresh developer (ie, this was the second roll I used with it). If you’ve processed more than 4 rolls, extend to 4:15. If you’ve processed more than kit capacity go for 4:30 or even up to 5:00.

Blix for almost twice as long as instructed. For my kit it says 6:00, so I blix for 10:00. If using a two bath kit, extend both bleach and fix times. See troubleshooting to figure out if you need more blix

Rinse as normal. I recommend inspecting the film before stabilizing in case more blix is required.

Troubleshooting and FAQ:

Can I use a different B/W developer? - Yes, however not all developers are ideal. Before HC-110 I used a generic F-76+ developer and had problems reaching the native box speed, even with greatly extended development times and higher concentrations. HC-110 solution A is ideal because it’s high contrast like slide film works best with, and it’s also incredibly active, meaning you can develop the film very quickly. Previously 18 minutes and beyond was required just to reach half of the native ISO. HC-110 also does not seem to produce any color shifts by early development of the color couplers.

My film came out but it looks faded and blacks aren’t deep - This is caused by a moderate to major lack of C-41 development. Ensure that your C-41 chemicals are still good

My film came out missing an entire color region, or there is only one color present - I’ve had this happen only twice and both times I chalk it up to my C-41 developer getting contaminated somehow.

There is a lot of grain and weird reddish coloring in the highlights - This is caused by lack of blix. If there is any grain AT ALL in the highlights of the film where it should be clear (like the exposed leader) then this indicates lack of blix. When not enough blix is applied it tends to affect only certain portions of the film, so that some frames will be correct and others not. There is no harm in putting the roll back into the blix if you see this. Note that massive under development in the B/W developer phase can also cause this, where the exposed leader is only gray rather than white.

Can I use stand development to decrease contrast/safely develop badly shot film? - I’ve tried this a few times. Do NOT under any circumstances use it for the C-41 development part. The result is really massive color shifts, fog, and lack of certain colors. For the B/W development part, it should be possible. Keep in mind though that you still need a very active developer and potentially raised temperatures. I tried doing stand development with the less active F-76+ stuff, and over 1 hour it barely even touched the film. Also for C-41 film, it’s exposure latitude even when processed like this is much more forgiving than E-6 film. As long as the C-41 film isn’t massively over exposed it should still produce something. I’ve used this with film that was suppose to be pushed 2 stops (ie, 400 ISO shot at 1600 ISO) and processed it this way with very good results.

I tried a different film and it looks weird - That’s part of the fun. Each film, be it C-41 or E-6, has it’s own unique character in this process. Sometimes the results aren’t great, but it’s almost always unique.

All my highlights are blown and the shadows are faded - If the unexposed portions of film are dark black, then you did not develop in B/W developer long enough. If the unexposed portions of film are not dark black, then you either did not fog for long enough, or you didn’t do C-41 development long enough, or your C-41 developer can be contaminated… or of course you could’ve shot it at the wrong ISO in the camera.

My film is mostly black, or it looks under exposed - If the exposed (ie, leader on 35mm) portions of film are not clear, then you have a major lack of B/W development. If it is clear, then it is a moderate lack of B/W development, or inaccurate metering in the camera. (note that when shooting slide, it’s typical to meter for shadows and not highlights)

My highlights are completely clear, but shadows are very dark - Part of this is the fun of slide film, but this can also indicate too much C-41 development. There is a balance to be struck between dark blacks and reasonable contrast. The more time you develop in C-41, the darker shadows will get and the deeper colors will turn.. but you’ll have more contrast because the highlights will be more or less unaffected. If you greatly reduce the C-41 development time, contrast is pushed way down, but color saturation is also much weaker.

Can I push or pull with this process? - Of course! I don’t have reliable times, but a 1 stop push appears to be around 8 minutes with HC-110 A. If you are looking to do extreme pushes of 2 or more stops, it can be helpful to pull in the C-41 process. If you pull (shorten development time) in C-41, then dark shadows can survive and not get completely blocked. Of course this has effects on color rendition, dMax, and can cause some (mostly correctable) color shifts. Note that if you push (extend development time) in C-41 development, then you need to push in B/W development even more, because pushing in C-41 effectively decreases the perceived speed of the film since shadow detail etc gets so dark, and contrast also can be drastically increased.

I followed everything you said, but ended up with a blue tint over everything - This is normal and varies depending on film. On some film it is a red tint. The tint appears to be incredibly minor (ie, you can only really see it when scanning) if the C-41 developer is fresh, and it seems to get worse as the C-41 developer is used to capacity. The blue tint is incredibly simple to correct out though, and there are otherwise no crazy color crossing with E-6 film like you see with traditional negative X-Pro. If the blue tint is not subtle, you may have also not done enough C-41 development. I’ve found “by the box” C-41 development to give some slightly more noticeable blue tint, but with extended times it goes away quickly. If you extend C-41 development a lot, then the blue tint eventually goes away completely, but also contrast can get pushed to insane amounts, so it’s a balancing act.

Does this contaminate my C-41 developer, how many rolls can I process with one kit? - I have no idea to be honest. I’ve done normal C-41 processing after several rounds of this process with no problem. However, I have noticed that the kit capacity should really not be exceeded when using this process if you can help it. It introduces more and more color tints, and blix times especially will need to be extended potentially to 12 minutes or more since this process is much more blix intensive.

Is there some special way I should shoot with this process? - Just shoot it like slide film. The exposure latitude is about the same or only slightly reduced, so avoid really contrasty scenes if you want both shadows and highlights to have detail. Also keep in mind that it’s safer to under expose slide film than over expose. A lot of shadow detail can be brought out of an under exposed slide with a good scanner.. but there is no highlight detail to recover. It’s the opposite of color negative.

Why would you want to do this? - I hate needing to have a second batch of color chemicals mixed and going bad when I want to develop slide film without crazy colors like in X-Pro. I also like that the B/W developer can be used one-shot. But also I think the color changes are interesting. With C-41 film it can give a unique color pallette, while with E-6 film it gives fairly predictable colors. This process isn’t like X-Pro when used with E-6 film, so it won’t give you crazy color crossing where red is purple etc.. but it does change the strength of certain colors, and at least for Provia 100F, I think it makes things look similar to Kodachrome. For Velvia it seems to emphasize blue colors rather than green colors, etc. Also, unlike X-Pro, there is very little grain, about the amount (or maybe just slightly more) of grain you’d expect from slide film.

What can I expect from using C-41 film with this like Portra? - Orange base, color shifts, medium amount of contrast (usually), blown highlights, good looking shadows, and slightly finer grain than normal. Each stock of film tends to respond differently to this process. Superia 400 introduces some insane color shifts that can be very unflattering to skin tones, though can provide a dreamy look during golden hour lighting. Lomo color 400 (rebranded Gold 400 iirc) responds with somewhat normal colors, but with weak blue highlights but strong blue shadows, and other colors are very saturated and punchy

Ok, now we know the technical bits, lets move on to what the results actually look like. Each stock of film has it’s own personality in this process. I personally like Provia’s look the best so that’s where I’ll start

E-6 Provia 100F (120)

I processed this with newly mixed C-41 developer and the colors were worth it! This looks completely fine when held up to a slightly warm lightpad, but looks ever so slightly blue when held against a daylight lightpad. I also shot this on a cloudy day, which apparently results in a slight blue tint for Provia when processed normally. I took these using my Yashica Mat 124G, my favorite camera of all time for portraits.

Despite being a fairly cloudy day, I absolutely love the color of these. I did have to do some curve adjustment as they looked a quite blue to begin with, but I expect if I had my lightpad set to something near tungsten during scanning it would’ve looked almost as great with no correction at all. I especially love how the colors seem to pop, and how much contrast it has without blowing any important highlights. Absolutely perfect processing in my opinion. I think standard E-6 processing with Provia is a bit drab with less saturation. This process ramps up saturation without making things garrish like Velvia can sometimes be.

Bonus photo from my half-frame Pen EES-2:

E-6 Velvia 100 (120)

I did this on a slightly more cloudy day somewhere in Detroit, and again with my Mat 124G. This was with much less fresh C-41 developer (slightly past kit capacity) and it shows. I expect we’ll see something more exciting when I do a batch of this with fresh developer. I also didn’t have as much time to prepare for my shops since we were basically in the location thanks to the patience of a security guard, so I was relying more on the slightly inaccurate meter of my Mat 124G and a prayer. The ones close to over exposure actually turned out looking best with this. This film definitely had a blue tint to it, but with a very warm tungsten light could be passable and potentially used as slides.

As you can see the colors are definitely just not there like they should be in Velvia in most of the shots, but there was at least 1 that looked like what you’d expect. I’ve done this process (though not )

E-6 Ektachrome 320 (35mm)

This was my first time shooting with this film so I wasn’t really sure what to expect.I got this as “retrochrome” from Film Photography Project and was advertised as being frozen since creation, so I just shot it at box speed and hoped for the best. I shot this film with my Leica M6 with a classic character Rokkor 40mm f/2 lens on a cloudy day. This film actually caused me to increase my blix recommendation time to 10 minutes. I was using exhausted blix (past capacity) and did it for 10 minutes and the rest of the tank was clear, but this film still had some silver grains in the highlights. If using exhausted blix, I’d say do 12 minutes minimum if using this film. Overall the results were a bit of a mess. The colors were muted and aged looking, and there was some slight color crossings. It worked for some subjects, but it wouldn’t be something I’d shoot every day. For what I was using it for (Detroit and Heidelberg) it actually complimented things pretty well, but I’ll use with caution in the future. This is also very old film that is supposedly government surplus. This may also have had a quality effect. Looking at some E-6 processed reference photos of this stuff, I’m really not that far off either though. Also this processed caused a considerable blue tint on the film, more so than is common with Velvia or Provia. It was simple to correct, but would not be suitable for projection.

I’d say, compared to E-6:

Some slight color crossing, especially in the green and yellow spectrum

Slightly more grainy

Significantly worse exposure latitude than Velvia or Provia. This film really seemed to have a sweet spot that I missed 90% of the time.



C-41 Superia 400 (35mm)

This was the first C-41 film I tried after figuring out the final process. It has always been an unpredictable process with C-41 film, but the color crossing in this one was especially… unique. C-41 film does of course always have the orange mask, so highlights are orange rather than clear. This is easy to correct, but of course makes it completely unsuitable for projection. These pictures were taken on a mix of a sunny day and near sunset.

The following were taken using an earlier version of the process (all the same but 8 minutes of B/W development) with my Pen EES-2 camera:

And the following were taken using the final version on my M6 with Jupiter 50mm f/1.5 lens:

The colors are definitely other worldly and in some cases quite dreamy. I love this for golden hour and sunset stuff, but the color crossing is a bit less subtle in open daylight. You have to be careful using this for skin tones, because it can definitely make skin look quite blotchy and unhealthy for some reason. In the two pictures of my wife (the redhead) you can see I gave up trying to keep the colors realistic and just went with the color pallette this film naturally gives me. When trying to correct things to be more natural it made skin tones look really bad. When color correcting this film in this process, everything is up for a bit of interpretation anyway.

C-41 Lomo Color 400 (35mm, rebranded Kodak Gold 400)

On this one, the colors are much more natural but very punchy. This roll was mostly under exposed (it was suppose to be pushed 2 stops) but had some surprisingly good results despite that with this process. Honestly this might be my new way of pushing C-41 film with some slight modifications.

E-6 Rollei CR200 / Lomography X-Pro 200 (120)

(This was added after the initial post)

This one came out with a really thick teal cast, and came out incredibly curly. Definitely not the typical slide experience, but if you correct out the cast, it’s not too bad. I honestly have never processed this film in standard E-6 chemicals, so I’ll just give the results I got:

AR-5 FPP Color IR (35mm)

(This was added after the initial post)

This one came out looking great. The only problem is that lens has no focus mark that corrects for IR light, and so things aren’t nearly as sharp as they should be. Regardless, these slides came out looking great. I’m not sure if it’s the film with a red filter, or the process or what, but the results definitely lean to the greener side. It is still more grainy than I’d like. I’ve heard you actually get less grain with this stuff when processing normally in C-41 as a negative, and more grain with E-6.

Conclusion

For E-6 film this is definitely a doable substitute to traditional processing. I prefer only keeping one set of chemicals and using every one-shot if possible, and this process allows for both. You do have to be careful to not use exhausted chemicals and such, but overall it’s a less finicky process than traditional E-6. The only complication is that fogging must be done manually. This isn’t a problem with steel reels, but is near impossible with plastic reels. I bet some smart person out there knows how to make a chemical fogging agent, but I’ve failed to find it in my searching on google. Also I’m not sure how much I trust chemical fogs, since that is yet another chemical to go bad, so I’ll personally never use it. If anyone does find out though, definitely message me on reddit and I’ll include something here about it: u/earlzdotnet