ciaran_mcmenemy

<p>there are developers with different characteristics. This will definitely be of use http://shop.silverprint.co.uk/Black-And-White-Film-Developer/catalogue/462/</p>

<p>I don't believe any films have true ISO. Tri-X is supposedly around 320, and Delta 3200 is around 1000... nothing to worry about, just develop it at the 3200 time. Think about it - why else would one 400 film have a different development time to another 400 film, with the same developer? <br> Since pushing film increases contrast, then pulling it will decrease contrast. I've never tried pulling, I think of it as a waste of speed. It does have benefits though; reduced grain and less base fog. <br> An old film will have lots of base fog. Example (from experience) I used a Kodachrome 50 (or 64?) and used/developed it as 200 or 400 speed film. The film is basically too dense to be scanned. That's because the development time was long enough to bring out the fog; if I had used it at 50/64 it would be much better. Pulling it would give the film more light from a scene, which would need less development time to bring it out. Less development time will mean less fog is brought out.<br> I follow the 1.5 rule, and so should you. Use 200 as 400? Multiply the stated development time by 1.5. In general, multiply or divide by 1.5 to the power of stops increase/decrease. E.g. 100 as 3200: say the 100 time is 6min. 6*1.5^5 = 45min. Long time! (100>200>400>800>1600>3200 is five stops) So I would increase the developer temperature to decrease the time, which will have effects too, I hear. For non-BW films just use the Tri-X time as a guide. Works well for me. <br> Consider a see-saw. Development time (D) is one end, exposure (E) is on the other. With the exposure being brief (pushing) the E end hits the ground and the D end points up - with little light received, you'll need to develop it longer to bring out sufficient silver (i.e. enough density). With a long exposure time (pulling), E points up and D hits the ground; there's so much light hitting the film that it won't take long to bring out the silver.<br> Lately I'm into BW reversal. What you do is, expose the film, develop it as you would, then bleach it - the developed silver is removed but the unexposed silver is left. After fogging, the film is developed again. All of the remaining silver can now be brought out. So, for example, if someone's jacket was light in real life, then a lot of silver on the film would be formed showing the jacket - that's dark on the film. After bleaching, there's a little bit of silver left for the jacket. It's then fogged and developed, so now the jacket is represented by clearness, not blackness. Try it!</p>

<p>If the film is wound tight then edge blackening is your only 'concern'. The backing on BW films (goes clear after processing) should stop light from going too far through. If you've ever opened a camera back too early, you'll know what I mean..</p>

<p>I always try to keep a wrapper handy, so I can keep the roll outta the light. I also put some black tape around both flanges (I think that's the word). Let's me re-use it later on and keeps out the light.</p>

<p>Thanks for the link! Development time +/- 5 seconds, how can you even pour it out in time?! E6 sounds like a lot of hard work; you get a low yield, short shelf-life, very high tolerances.. wow, two minutes for one stop is a big change in time.<br> Thanks for that list, are you using the T films outdoors with filters? You were using C-41 for that right? What made it different at 2 min? I will probably end up using chemicals, but for now I'll stick to Tetenal or some small-scale CDs///</p>

<p>ah thank you! you have REALLY helped me out here, Lorenzo.<br> 30 sec per stop it is then. I'm assuming it's -30sec for a pull?<br />I've bought some cinema film; Vision3 250D. What are you using?<br> Two minutes is short, are using ECN2?</p>

<p>Hi all, I want to know what the rule is for extended development of colour film.<br />I've read here and there to add 30 sec per stop, is this true? <br />I would be using C-41 starting at a time of 3:15. 100'F.<br> Searching for push process times on slide film is especially unhelpful - just a load of people saying they got the lab to do it. <br />I read you can push Provia by no more than two stops. That would mean 100F could become 400. 400 is my ideal speed (or 800..) <br />so I'm keen on the idea. Any thoughts? Or example pictures and what you think of the results.?<br /><br />Thanks <em>a lot!!!</em></p>

<p>why are you bleaching it, what does it do?</p>

<p>Ron Andrews has got it. In the dark, is the film all wound around a take up? If it's still in the can except for the leader, then pull out say 10cm (or less), snip it, and develop it. No need to fix it. If you see the writing e.g. KODAK PKR and no image (blank) then it's usable. <br /><br />If it's old, old film then it may well be fogged but have images on it. Hold it up to a light source and inspect.<br /><br /></p>

<p>assuming that you mixed the same dilutions in proportion (e.g. 10ml in 40ml // 20ml in 100ml = 1:4) then it's fine. </p>

<p>Thanks again Peter! so I should wait for it to turn green.. it's a little bit milky right now. I tried BW reversal on a colour film, and it didn't work. After bleaching, I could see some sort of fog (just not on the sprockets) under the negative images. I'm guessing it's the filters built into the film..?<br> Any idea how to accurately measure out 2g of some powdered chemical? I don't think scales are sensitive enough.</p>

<p>Oh, the bleach <em>can</em> damage it... I never squeegee! Is photoflo any good? <br />(C41 stabiliser is terrible when it comes to leaving clean negatives, there are streaks everywhere...)<br /><br />I was thinking of trying reversal on print film. The B&W reversal didn't work - I bleached/cleared it and I could see a negative image and a sort of fog underneath, but not on the sprocket area. .. So next time I will develop the black and white, expose it to light, then carry out the C41 process. Might be a cheap(er) way of doing slide film!<br> Can the clearing solution (sodium meta in my case) be reused? The PDF is unclear.<br> Thanks for your reply Chris. I wondered how toning works! What chemical(s) are used to tone the film itself? Is the element/molecule you replace silver with stable as well?</p>

<p>heh, welcome !! the negatives you get will turn out very well, don't worry too much. The blix time really gets bad, so keep that in mind. ends up being 20 minutes! </p>

<p>Hi!<br />From the offset, here's what I <em>think</em> d.r. is. If I'm wrong, point it out. Fix any stupidity :D<br />- see image - <br /><br />I want to see if I'm right or totally wrong. <br />Starting from the principle that negative film has a wider latitude than positive film, I think this is achieved by a roll-off in the response at both ends, for the former. By that I mean as a scene gets darker and darker, there will still be some response. This response gets less and less as the darkness increases, with the behaviour beginning to occur at some amount of stops <em>below </em>the chosen/indicated light level for 'grey' (in the middle of the band). Meaning: even though there is lots of shadow, there is still some silver, so you can represent varying shadows. <br />At the other end of the scale, as the scene gets brighter and brighter, the silver response doesn't quite reach the maximum. It might only be the sun that can be completely white, and this response may occur after some amount of stops <em>above</em> the chosen light level. Meaning: as things get brighter and brighter, the densities don't increase as much, so we can represent varying brightnesses. These two qualities have the effect of <em>compressing</em> the scene onto the film, meaning that very dark things are 'pushed' into the image while very bright things are 'pulled' into the image.<br> Now, for positives.. I think it works like this: at some point below the chosen exposure (just a couple a' stops), there is no exponential (or is it logarithmic?) roll-off. Instead, it hits the flat, in that anything above a threshold of darkness is completely black. No silver density. On the other side, the response hits the peak, meaning anything too bright is completely white. 100% silver. On top of that, there is a smaller range of stops between the thresholds, meaning that exposure should be careful, especially in contrasty scenes. I have no idea why positive film would work this way, however.<br> Example: metered 'correct' exposure for a subject is 1/125, with the aperture fixed. Their shadow would take 1/30 (2 stops under), the sky would take 1/1000 (3 stops over), the clouds would take 1/4000 (5 stops over), the shadow from the house nearby would take 1/8 (4 stops under). On negative film: everything is in view, with the clouds and house-shadow being somewhat detailed. On positive film, the person's shadow becomes nearly pure-black, the house-shadow is characterless, the sky is very bright, and the clouds are pure white, no detail. <br> Now, is that right, or am I re-inventing the wheel by making it square?</p><div></div>

<p>Some experiments for you to try: <br />push film, using temperature to decrease the time as well<br />develop a colour roll in B&W chemistry (just follow Tri-X times and apply them for the matching ISO. That's my rule)<br />here's the big one: develop <em>positives</em>. For this you will need bleach. Ask me all about it.</p>

<p>When you are using mixtures and times,<strong> think of the imbalance relative to the overall amount</strong>. For example, say there are two cases in which you add 5ml too much developer: <br />1) a Rodinal 1+100, 375ml total solution. 375/101 = 3.71287ml per unit. That means you should add 3.7ml Rodinal, with the overall strength being 3.7/375 * 100 = 0.99%. With the extra 5ml, that's 8.7/380 * 100 = 2.29%. More than double the strength!<br />2) an Ilfosol 1+14, 375ml total solution. 375/15 = 25ml per unit. That means you should add 25ml, with the overall strength being 6.66..%. With the extra 5ml: 30/380 * 100 = 7.89%. The strength only increased by a factor of 1.18, so you won't notice any big differences. In fast, I NEVER measure 25ml exactly, I just estimate it. <br /><br />The above is also the reason I prefer I-3. The dilution is a balance between the amount of rolls you can get out of the whole solution, and the ease of mixing/reliability. D76 is easy to mix, with such high dilution, but it doesn't last more than a few rolls, which is why I don't like it. As for Rodinal, you would have to measure carefully or the strength could be a lot different.<br /> If there is a bit of strength difference, just develop it 30 sec longer or 30 sec less. Or change the temp by a fraction of a degree or two. You get the idea.<br /> To push film, follow this rule: initial time * 1.5^n, where n is the amount of stops increased. so, for example if film is pushed from 400 to 3200 (done it before, of course), that's a three-stop increase. Say that 400 is developed at 12 min, then 12 * 1.5^3 = 40 1/2 min. That's a while, right?<br /> Thankfully you can increase the temperature to speed up the process. http://www.digitaltruth.com/devchart.php?doc=timetemp<br />with a temp of 26'C, the time becomes ~22min. Increase it to 32'C and it becomes ~12 min. Of course a temperature like that will mean the emulsion can get wiped off. To use a temperature like that, pre-wet the tank with water at the right temp (do it twice), and when you stop, add progressively cooler water to the tank. This has two benefits: The emulsion is cooled down again, reducing risk of damage, and reticulation is prevented.</p>

That's the C41 kit, I haven't tried E6. I used the stick with the blix as that stuff is very, very messy. Be careful with stabiliser or the formalin will pickle you

Huh??? When I bought the (sadly now discontinued) 1L kit, it was 3:15 at 100F initially, with 30 sec added for every four films (ie two sets). It says in the little booklet in the box. As for agitation, I settled on first 10 sec, then 4 every 30 sec. Works fine. I got over 16 (was planning at least 22) but I contaminated the CD with blix mistakenly.

<p>I know this sounds pointless, but from an experimental point of view; say you have a negative (or positive) and you used halogenising bleach (without fixer) on it, until the image disappeared. If you were to re-expose it to light and re-develop it, would there be any major changes?</p>

<p>maybe this sounds silly, but if you don't fix film is it possible for it to develop little holes? I tried skipping the fixer on a test frame, and later noticed it had damage. Not sure why! Does hypo just remove the unused silver, or does it 'stabilise' the used silver and make it last longer, in some way?<br> Thanks Chris. PoFerro sounds dangerous, I'm surprised to read it's not. It's useful to know how to halogenising chemistry! What's your dilution?</p>

<p>hi! thanks for your response! can you guide me to these 'push tables'? I just can't find any certain information. I want to know how much I increase the development time by for every stop. It's very vague here... a few people have said add 30sec/stop, others have said add30%/stop. Huh??? If I'm pushing two stops, then 3:15 becomes 4:15 in the first case, but 5:30 for the second case.<br /> Hmm, is that Colorplus? I lot of the film I see is at 200, but I want 400.<br />I'd like to buy a can of Vision3 film and use it up!</p>

<p>ah, baking soda. thanks!<br> I really gotta know, can it be pushed? I'm lookint at 50 ISO, would like to use it at 400.<br />I know about the exposure latitude allowing you to underexpose and brighten in post-processing, but I'd like to achieve it chemically</p>

<p>ah, thanks for the info. what would happen if you didn't fix after traditional re-development? is there the possibility that the image will get darker?<br> What's the advantage of dichromate instead of permanganate?</p>

<p>Hi! Apologies if there is some iteration of this thread.<br> I'm thinking of buying 'short ends' since you can get great value on them. How do they look when processed in C41? Is dye stability and issue, and can the film be pushed?<br /><br />I'm familiar with remjet, having done Kodachrome a few times. For Koda I would pre-wet it and use 'agitation' and drain until the water is clear. After fixing I would use a scourer (soft side!) to get rid of remaining remjet. <br />I read something about using mild vinegar solution (I think that's what it was) as pre-wash to get rid of remjet. I would try that, and also use cones & coffee filters when replacing C41 chemistry, for the Vision3 film... </p>

<p>Black and white barely degrades if it's old. Unless it's something like Selochrome, then it'll be workable. I used Tri-X that expired in the 80s, it was fine. No idea how it was stored... <br> how hot does it get where that building is? as long as it's not like an oven, you'll be okay. <br> that pulling film idea is smart, I never thought of it that way. I can see a reason for it now!</p>