Karim Ghantous Posted December 15, 2021 Share Posted December 15, 2021 I have seen a few examples online of pulled negative film, both colour and b&w. However, I am not sure where to look for examples of pulled slide film. The reason I ask is that I've been wondering about low contrast positive films, and it seems that none exist. By low contrast I mean a film that needs to be scanned, or duplicated, to bring back the contrast. At this point my interest is academic. But it might have commercial applications at some point. Link to comment Share on other sites More sharing options...
AJG Posted December 16, 2021 Share Posted December 16, 2021 Kodak used to make ECO in 16 mm, which was a deliberately low contrast reversal film when color negative film was still a lot more grainy than comparable speed reversal films. If you had bright lighting (ECO was ASA 25 for tungsten light, ASA 16 for daylight with an 85 B filter) it was a good film and when printed on release film stock looked quite good. The extra contrast from printing brought it up to normal contrast in release prints. I'm pretty sure that it hasn't been made for decades and I certainly wouldn't search eBay for outdated rolls, since you probably couldn't get it processed now, even if through some miracle it would still look OK. 1 Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted December 16, 2021 Share Posted December 16, 2021 If all you're trying to do is lighten the shadows in a dupe, then that's better done by post processing or 'flashing' a digital copy. The flashing route is more tricky, since the level of flashing (fogging) exposure needs some trial-and-error adjustment. Easier to combine two copy exposures (normal and +2 stops for example) using layers and masks. But it might have commercial applications at some point. How? Surely nobody needs to shoot slide film to get greyed shadows or low contrast. Link to comment Share on other sites More sharing options...
Karim Ghantous Posted December 17, 2021 Author Share Posted December 17, 2021 If all you're trying to do is lighten the shadows in a dupe, then that's better done by post processing or 'flashing' a digital copy. Easier to combine two copy exposures (normal and +2 stops for example) using layers and masks. AFAIK, flashing does reduce noise in shadows but it doesn't reveal any more detail. However, on to your point about multiple exposures. There's an app that automates HDR between sets of frames, which is definitely something to consider. I forgot what it's called. That certainly could work in almost all cases (i.e. when the subject is not moving). Doing that manually is just regressive, though, and I will not be going there. Link to comment Share on other sites More sharing options...
JDMvW Posted December 17, 2021 Share Posted December 17, 2021 low contrast positive films, and it seems that none exist. They used to, but that day is, I think, gone forever. To increase contrast, for example in aerial images, I used to copy Kodachrome to Kodachrome - talk about "snap"! :rolleyes: Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted December 17, 2021 Share Posted December 17, 2021 That certainly could work in almost all cases (i.e. when the subject is not moving). It's still not clear what you're wanting to acheive. A slide for copying isn't a moving subject, so you're wanting to get a lower contrast/higher dynamic range out of slide film while shooting a real-world subject? A flashing exposure will certainly do that. It won't give lower noise though, and I'm not sure where that idea is coming from. But really? Just forget slide film if you want a high dynamic range and control over contrast. There's a whole world of digital cameras to choose from that'll give you exactly that. Link to comment Share on other sites More sharing options...
glen_h Posted December 17, 2021 Share Posted December 17, 2021 I have seen a few examples online of pulled negative film, both colour and b&w. However, I am not sure where to look for examples of pulled slide film. The reason I ask is that I've been wondering about low contrast positive films, and it seems that none exist. By low contrast I mean a film that needs to be scanned, or duplicated, to bring back the contrast. At this point my interest is academic. But it might have commercial applications at some point. If you are going to scan or duplicate, might as well use negative film. C41 films (color, and B&W) have a gamma of about 0.5. That was mostly needed when they were used with simple cameras, over a wide variety of exposure situations. It almost requires a printing exposure meter, but then again, they required one for color balance. The more usual gamma for B&W films of about 0.7, makes it easy enough to print with test strips, though a simple printing exposure meter is nice. Slide films normally have a gamma a little less than -1, as that is what people like to see. -- glen Link to comment Share on other sites More sharing options...
glen_h Posted December 17, 2021 Share Posted December 17, 2021 They used to, but that day is, I think, gone forever. [ATTACH=full]1411758[/ATTACH] To increase contrast, for example in aerial images, I used to copy Kodachrome to Kodachrome - talk about "snap"! :rolleyes: Seems that this is the later version, probably also gone: https://www.tate.org.uk/file/kodak-edupe-duplicating-film-technical-data-dying-technologies-project Looking at the graph, it is gamma close to -1. -- glen Link to comment Share on other sites More sharing options...
Karim Ghantous Posted December 18, 2021 Author Share Posted December 18, 2021 It's still not clear what you're wanting to acheive. Slide film is 'human readable'. Negative film has more DR. It would be nice to somehow have the best of both worlds - to a point. Let's not get nuts, here. A flashing exposure will certainly do that. It won't give lower noise though, and I'm not sure where that idea is coming from. https://www.robdraperacs.com/2011/11/varicon-creativity-and-dynamic-range/ Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted December 19, 2021 Share Posted December 19, 2021 (edited) Slide film is 'human readable'. Negative film has more DR. It would be nice to somehow have the best of both worlds - to a point. Let's not get nuts, here. Using Varicon in Digital Cinematography. (text & video post) - Rob Draper, ACS - Director of Photography OK. Let's get right back to basics. The real world presents the eye with a brightness range of hundreds-to-thousands to one. A ratio that can't possibly be accurately reproduced on a reflective surface, and only with great difficulty using a self-luminous or transmissive device. Therefore the brightness range must be greatly compressed for reflective reproduction, and somewhat attenuated for transmissive reproduction. Over-attenuate that brightness range - i.e lower the contrast too much - and the result just looks dull and dingy. So what you're suggesting, effectively, is to put the ~100:1 brightness range of a print onto a bit of transparent film. That will just result in a very flat and dull looking slide. WRT noise. The base noise of the medium (film or digital) isn't altered at all by a flashing exposure or any other fogging device. How can it be? But what actually happens is that the maximum 'black' recorded is turned into a dark grey that sits above the base noise. Not the same thing as reducing the base noise at all. In addition, with film the 'noise' (in the form of grain or dye-clouds) is distributed fairly evenly across the entire dynamic range; and is actually most visually intrusive in mid-tones where the eye is most sensitive to it. So no, technically a flashing exposure does not reduce noise, and in the case of film does absolutely nothing to make it less visually apparent. All it affects is the visibility of shadow detail. Edited December 19, 2021 by rodeo_joe|1 Link to comment Share on other sites More sharing options...
glen_h Posted December 19, 2021 Share Posted December 19, 2021 (snip) Therefore the brightness range must be greatly compressed for reflective reproduction, and somewhat attenuated for transmissive reproduction. Over-attenuate that brightness range - i.e lower the contrast too much - and the result just looks dull and dingy. So what you're suggesting, effectively, is to put the ~100:1 brightness range of a print onto a bit of transparent film. That will just result in a very flat and dull looking slide. (snip) Yes. I don't know if any psychologists study this, but it seems to be true. Though it seems that I like mine slightly lower contrast than others. About 30 years ago I learned about VPS, and especially that I could use it for ordinary shooting, and not worry about keeping it cold. For me, Kodacolor is too contrasty. I suspect I like my slides just a little lower, but not as low as the OP needs. It seems that he wants two things. One is a positive image for its "human readability", but also the dynamic range of negative films. If it is only used for scanning, then the low contrast is fine. Negative films get that by having a low contrast, assuming that will be changed in printing. If there was an unmasked negative film, it might be able to be processed in reversal chemistry for a low contrast slide. Just a reminder, the reason for masking in C41 films. The dyes aren't perfect: they tend to absorb more than they should on the shorter wavelength side. https://imaging.kodakalaris.com/sites/default/files/files/products/e4050_portra_400.pdf And even more, since this happens both in the negative and print, the error is multiplied. By using colored couplers that have the same absorption as the unwanted part of the dye spectrum, the difference between the dye and the colored coupler is (mostly) in the desired range. However, in the case of scanning one can correct such errors in the digital data. That can be done for either negatives or slides. I suspect there isn't enough reason to convince someone to produce a new low contrast slide film. 1 -- glen Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted December 19, 2021 Share Posted December 19, 2021 (edited) I suspect there isn't enough reason to convince someone to produce a new low contrast slide film. I also suspect that there are very few organic chemists with photographic dyestuff experience left around that want to waste their time working up a new film type for a very niche market. That, and even fewer film manufacturers willing to pay them for the necessary R&D time. And as you say; once the film is scanned you can adjust the colour digitally to almost any result imaginable. Edited December 19, 2021 by rodeo_joe|1 Link to comment Share on other sites More sharing options...
Karim Ghantous Posted December 20, 2021 Author Share Posted December 20, 2021 I also suspect that there are very few organic chemists with photographic dyestuff experience left around that want to waste their time working up a new film type for a very niche market. That, and even fewer film manufacturers willing to pay them for the necessary R&D time. I agree with both you and Glen. A special low contrast film stock is not warranted. My question is simply asking about pulled E6 film. I'll eventually give it a go anyway, and I'll see what happens. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted December 20, 2021 Share Posted December 20, 2021 The pull is only applied to the 1st developer, which is effectively a negative. Therefore the darker parts of the positive - i. e. the shadows - will be darker and lacking in detail, while the highlights will be greyed over unless the film is overexposed. The colour will be less saturated. This is very similar to the difference seen between using a coated and an uncoated lens. Overall, you might get one stop more 'dynamic range', but nowhere near to the 11 or 12 stops you could achieve shooting RAW with a decent digital camera. Why not just use the best tool for the job? Link to comment Share on other sites More sharing options...
glen_h Posted December 20, 2021 Share Posted December 20, 2021 It is well known that pushing films increases contrast. It isn't so obvious that means that pulling will decrease contrast. High contrast films have all the grains close to the same size, and low contrast a variety of different sizes. Exposure and development don't change those. It is often said that slide films push better than negative films. That is sort-of true, but mostly because they have less latitude in the first place, due to their higher contrast. Also, I suspect, because we already expect them to have high contrast and low latitude. As well as I know, from what I have heard over the years, slide films don't pull well. (Mostly from people who accidentally use the wrong ISO value.) I suppose you can try it. Another popular development method is stand, where you use a very weak developer for a very long time. (An hour seems usual.) I have never heard of stand used for slide film, though. 1 -- glen Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now