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50% Bleach Bypass Still Test


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We're planning on using Bleach Bypass this summer on a S16 shoot so I wanted to do a cheap & easy 35mm still test.

 

Shot on 35mm Fuji Superia400, got a friend to process it & went for 50% bypass - But something went wrong & as such I'm sure whether to trust the results of the frames that seem unharmed.

 

 

So I ask you chaps, do the 2 attached pictures marked as 'Good' seem correct for 50% BB?

 

I had a look at the oft referred to article from American Cinematographer & I think it's all cool. In any case I'm going do more testing obviously and hopefully test it on 16mm too (8683 or 7229).

 

Attached also are two of the damaged pics from the end of the roll (any idea what happened?)

 

Thanks alot.

 

- Colum.

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post-39587-1271928285.jpg

post-39587-1271928357.jpg

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Doesn't really matter what happens with the stills... you're not shooting your movie on stills film, which is entierly different processing in the end, not to mention that you're not shooting 35mm, so you're not going to see how it'll really be looking. You need to test this out on 16mm film using the lab you're planning on using with the stock you're planing on shooting, else you're really just running in the dark.

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I disagree. I had unintentional bleach-bypassing done on some film once, and the results were very similar in appearance to what you'd get with ECN-2.

 

 

The two processes, C-41 and ECN-2 are almost identical, chemically, after the developer step. ECN-2 is lower-contrast, and uses a different color developing agent, but both processes have a color developer, bleach, fixer, wash, and stabilizer. In fact, the secondaries (everything but developer) are interchangeable.

 

 

For more precise results though, I believe the ASC magazine still has an online artilce from the late '90s that shows the effects of a lot of the various silver retension techniques.

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You need to test this out on 16mm film using the lab you're planning on using with the stock you're planing on shooting, else you're really just running in the dark.

At the moment looks like it's the best I can do, don't think the production will pay for any 16 tests, regardless of whether I advice it or not.

 

 

For more precise results though, I believe the ASC magazine still has an online artilce from the late '90s that shows the effects of a lot of the various silver retension techniques.

I had a look at it, and I reckon the results make sense.

 

Karl, any idea what happened in mess-ed up picture, processing-wise?

 

 

Thanks guys.

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Without an ability to do a proper test @ the facility that you'll use, you should really consider, as mentioned, doing the look in post. You can do it at the Telecine stage, or what would be best, would be to wait until everything is edited and do a nice correction of the finished piece (recommended for best matching)

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I recommend you do it digitally if you're only doing 50% BB.

 

The problem with not running a secondary (non-developer) step to completion is that they are designed to run to completion.

 

 

In other words, if you dicker with the time and temperature and make it too low, or slow down the processor, it will run to completion at the very edges of the film first, and may still be incomplete near the middle of the film.

 

 

Depending on how your stills were processed (by slowing down the bleach temperature or speeding up the machine) this could also result for what looks like a half-bleached frame.

 

 

Even with 35mm, you can get consistency issues with this sort of thing. . .

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You really should consider doing this look in post.

 

Without an ability to do a proper test @ the facility that you'll use, you should really consider, as mentioned, doing the look in post. You can do it at the Telecine stage, or what would be best, would be to wait until everything is edited and do a nice correction of the finished piece (recommended for best matching)

 

Part of me would certainly prefer to take the extra money from the BB (0.04p per foot) & use it in drip or lighting gear.

 

Part of me says that because of the strange weather we tend to have here in Ireland the post route might be best to try to match scenes (Sun splitting the stones in the morning & overcast weather in the afternoon are far too common) & would also just give the wiggle room necessary.

 

Sad thing is that by in terms of budgets for Irish shorts & esp. student films, the budget is huge - But still not big enough to do the necessary tests.

 

I recommend you do it digitally if you're only doing 50% BB.

 

...

 

In other words, if you dicker with the time and temperature and make it too low, or slow down the processor, it will run to completion at the very edges of the film first, and may still be incomplete near the middle of the film.

 

 

Depending on how your stills were processed (by slowing down the bleach temperature or speeding up the machine) this could also result for what looks like a half-bleached frame.

Wasnt sure about the 50% BB, kinda what the tests were for. If, and it's a big if now we were going to go ahead with the BB, I'd probably end up going with the skip.

 

That's very interesting about the processing - makes sense looking at the dodgy frame.

 

 

Thanks again.

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Guest Stephen Murphy

Colum,

 

I've shot plenty of bleach bypassed footage over the years both S16mm and S35mm and I'd always recommend

going with a chemical bleach over a digital "bleach bypass". They don't look the same and the beauty (and peril) of the chemical approach is that you cant entirely predict what the results will be and thats a very good thing you need to embrace that. As advised you need to shoot tests on the motion picture stock you're planning on using with the lab/lenses/diffusion you're planning on using. The inconsistent Irish weather shouldn't be a factor in your decision to chemically or digitally bleach - you cant match extreme weather conditions regardless of your post path - and just because you go for a chemical BB doesn't preclude the use of a DI or Telecine grade as a finishing tool at a later point in the production.

 

S

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Karl is right.

 

The bleach stage of the process should normally run to completion, so the machine is designed to complete the bleaching at some point well before the film passes into the next bath (wash). That allows for day-to-day variations in the bleach solution. It doesn't matter if the bleaching is completed half way through or 95% of the way through. The chemistry isn't controlled quite so precisely as the developer, and so the end-point may be reached differently on different days, or with different stock types, or gauges. Also ther eis the issue of turbulation and faster processing near the perfs, that Karl describes. Not a problem for complete bleaching, potentially a serious problem for partial bleaching.

 

Which is all well and good until you test a "partial bleach". What you get one day may well be different from what you get the next, or on a different emulsion type or gauge. The "test" isn't a reliable predictor of your end result.

 

So whether you prefer the look of the chemical effect or the digital effect, you won't have the control you need if you go for chemical "partial" bleaching.

 

Spend your 4 cents a foot on lighting instead - as you know you really want to.

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Colum,

 

I've shot plenty of bleach bypassed footage over the years both S16mm and S35mm and I'd always recommend

going with a chemical bleach over a digital "bleach bypass". They don't look the same and the beauty (and peril) of the chemical approach is that you cant entirely predict what the results will be and thats a very good thing you need to embrace that.

I really do think that I need to explain to the director (whose idea the BB initially was) the unpredictable nature of the process, even as a way of putting the case for money for (proper) testing - as well as seeing what can be done in post.

 

 

Karl is right. ...

 

Which is all well and good until you test a "partial bleach". What you get one day may well be different from what you get the next, or on a different emulsion type or gauge. The "test" isn't a reliable predictor of your end result. ...

 

Spend your 4 cents a foot on lighting instead - as you know you really want to.

 

Dominic, thank you for such a concise explanation.

 

 

& thanks to all for your helpful advice.

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