View Full Version : Push/Pull non-intentional experiments
06-11-2011, 05:33 AM
I need to process an Adox CHS 100 pushed to Iso 400 and another pushed to Iso 200
I also need to process a Rollei retro 400s pulled to Iso 200
I am searching the www for solutions and have found that Adox Atomal 49 is recommended for push process which is good news for the ADOX but not for the Rollei, however I am unable to find push/pull process development times.
06-11-2011, 06:33 AM
Welcome to APUG.
On the Rollei 400 for the 1-stop of extra exposure you gave the film personally I wouldn't even change the development process. You will probably just have better detail in the shadows with little if any noticeable loss of detail in the highlights. Many people rate their films at 1/2 box speed for every shot they take.
The reason I say this is that pulling reduces the contrast changes between tones in the scene. When I print low contrast (under-developed/pulled) negs I am typically disappointed with the look; they look grey, lifeless, muddy, chalky.
06-11-2011, 07:56 AM
Thank you Mark
Your advice is much appreciated especially your descriptive experience of printing low contrast.
06-11-2011, 08:14 AM
You are welcome.
06-11-2011, 09:05 AM
Develop the pulled roll as normal, it will be dense but perfectly fine.
For the pushed rolls, you want a speed-increasing developer - there are a bunch you can google for, but I would suggest XTOL as maybe being a good start for the 1-stop push. The Adox films are generally absolutely no faster than rated and most people tend to be safe and overexpose them to retain shadow detail, so a two-stop push might be asking a lot.
One good option for two stops might (and this is a big might) be semi-stand development with Rodinal 1+50. You want a long development time to get the shadow detail (I would guess 30 minutes at 20C but that is a total guess) and minimal agitation (e.g. first 30s then 5s at the 1,2,5,10,15,25 minute points) so that the highlights don't get crazy-dense. If you agitate too often, the highlights will get away. If you agitate insufficiently, you can get bromide drag and therefore horrid vertical streaks on the negs.
If these shots matter, you will need to shoot some more of the same film at the same EI and do some tests. If the lighting was contrasty, you are going to find it difficult. If the lighting was horribly flat, you might actually get a really nice result!
Edit: MDC has a very few suggestions (http://www.digitaltruth.com/devchart.php?Film=Adox+CHS&Developer=&mdc=Search), seems to sort of agree on the Rodinal (shorter time, probably more agitation)
06-11-2011, 11:41 AM
Thank you polyglot
Very interesting advice on the agitation process, I have much to learn!
The pictures are a record of a friends "milestone" hence I am seeking the exact science to correct my shooting errors.
06-11-2011, 09:38 PM
Ah, sounds like you might want to do some experimenting first then - lucky that that particular film is cheap ;) Shoot a test roll of exposures just like the ones that matter (similar brightness range), cut it into 4 pieces and try 4 different developments on it, e.g. 24 minutes and 30 minutes, agitation every 2 minutes and every 5 minutes. Once you see where those 4 options get you in terms of shadow detail and highlight density, you'll hopefully know which way to proceed (you might decide on a different time and agitation scheme altogether!), do another test development of a whole roll (because that may behave differently than a quarter roll) at your chosen time & agitation scheme and if that's good, go ahead and soup the ones that matter.
The reason agitation affects the highlights with Rodinal so much is that when highly diluted, the developer exhausts at the highlights quite rapidly and slows developing there, while the shadows keep on developing. When you agitate, it brings fresh developer to the highlight regions and they start developing more rapidly again - the amount of highlight density is therefore mostly controlled by the number of agitations. A nice (usually) side-effect of this is the edge-effects you get, which is sort of like unsharp-mask: the highlight regions retard development in the edges of the shadow regions and vice versa, which means the edges look very sharp.
Assuming that you shot it in 35mm, if you use Rodinal, expect the result to be quite grainy.
06-11-2011, 10:26 PM
I am seeking the exact science to correct my shooting errors.
Two thoughts here.
1- In general, film is fairly forgiving. More so of overexposure than underexposure. With the underexposed rolls adding extra development (pushing) is prudent and reliable for making negatives more usable but, it won't create detail in the shadows that doesn't already exist. Also time is working against you. The fresher the latent image the better the detail will be. The developer you have, used today per the manufacturer's directions for a push, may do a better job than any specialized developer that takes you a few weeks to get. There is a fairly fresh thread about this effect, search "latent image".
2- In general, film follows the rules of physics very nicely. Problem is we don't always have control of or manage all the variables/rules well. You are far from being unique here, we have all done this. There are so many variables that I find that with a problem like this that it is best for me to only deal with what I know I did, using stuff I already know how to use.
What I'm saying here is that experimenting with stand development and new developers, different agitation, and other things may be interesting but it is no gaurentee. Adox, Ilford, Kodak, Rollei, et al know their products well. When in doubt following their recommendations, tempered with your own experience, is quite reliable.
06-12-2011, 06:17 AM
Experiment I shall! just glad I made a note of which film I underexposed when I did.
Thank you polyglot.
06-12-2011, 06:18 AM
Thank you Mark