New to Chromogenics - A Question About Pushability

Hi,

 

I am planning to shoot Kodak B&W 400 (the consumer - "process

anywhere" film) at ISO 800. With a one stop push in development, will

I still be able to get the fine grain and satisfactory tonal range

that's touted by Kodak and other users of this film? Thanks!

 

JW

In my opinion C-41 process films don't push very well. The film is really a 200 ISO film (if you want best results) that is fairly decent at 400. You'll need to use a pro lab if you want them to really push process. Most neighborhood 1-Hour labs won't do it, or don't know how. If you really need the speed Tri-X in Diafine is hard to beat, and gives a good negative at ISO 1200.

I've never push processed these films myself, but there are a couple of threads on this site which address the subject:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=005Jjv

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003g3Q

 

Do a search on "push process c41" and you should see a few more.

 

I don't know, but I thought the example of the XP2 Super @1600 was rather good...

I have never attempted to push Kodak B&W 400.<p>I have taken XP2 Super into a lab for a two stop push to 1600...it was a <b>total waste of time and money</b>. The grain was huge, ugly, mushy...<p>XP2 Super is, for me, one of the best films on the market <b>but I find that pushed or not it totally falls apart at any speed over 400</b>. <p>99 percent of the time I shoot my XP2 Super at 250. Using good optics and technique I find that at that speed it has a wonderful glow that can come across in prints (made from a 35mm neg) of up to 11x16 in size.

Don't bother pushing it. Try rating it at 800, and have it developed normally. If you like the result fine, if not -then find a conventional BW film.

 

I agree that those 400 chromogenic films currently on the market performs better when rated around 200-250.

The idea that you can rate these films at any ASA you like and get then developed normally is a misunderstanding. They have a wide latitude, and this is what people are seeing when they over or under rate them. An image is still possible from the result, but there are upsides and downsides. The grain gets smaller when you over expose them, at say 200 ASA, but the sharpness suffers. At 800 ASA on the other hand the grain gets bigger, but its not 'nice' grain, like from Tri-X.

 

But, when you have them properly push processed three things happen. The grain gets bigger, the sharpness suffers, and the mid tones turn to mud the more you push them. 800 ASA is OK, the tonal range is very reasonable, and they are sharpish, but push any more and its an ugly sight.

If you read the fine print in the fact sheets/data sheets for these C-41 B&W films, they tell you that the 400 speed rating is based on a "practical" evaluation of film speed (marketing BS) and not true ISO foot speed. Experience of many on this forum confirms that best results are usually achieved at a speed of about 200. But when extra film speed is needed to get the image, then speeds up to 800 can be used, but the quality (grain, etc) of the negatives will not be as good.

Virtually all modern C-41 films push a stop easily with only a moderate increase in grain and contrast. Anybody who tells you differently needs to stop giving advice on matters they don't know about and would likely claim Provia and NPZ can't be pushed either.

 

I agree that that film speed ratings for the chromogenics are a bit optimistic when stated at EI 400 and they do best around EI 250. Still, they have good lattitude and quality results should be expected when shot at EI 640-800 and pushed a stop. Pushing two stops however is not what I'd recommend. One stop however should only result in a moderate increase in grain.

 

Note that if you are scanning, or using a digital based Frontier type lab, you'll be better off using Superia/Press 800 and desaturating.

A one stop push to is likely to increase contrast, which may be a good thing with chromogenic monochromes which tend to be low contrast films.

 

The tricky bit will be finding a lab that can actually accomodate your processing request. Some minilabs are capable of doing it, but the operators don't know how to make it work.

C-41 B&W films can be exposed at a wide range of film speeds without changing the normal processing. Let's not confuse the issue of extending development time with just changing the ISO film speed rating.

 

Obviously this is different than conventional B&W film, because there is no such thing as "normal" processing except what is normal for each individual photographer.

1 stop push should be fine, the major problem being the lossin shadow detail (density in the neg) which tends to grain up the shadows, especially in prints from Frontiers, which are the recommended printers for these kind of films. So I would not expose it at 800 but 500-640 and give it one stop push.

I remember trying to push XP-1 some years ago ... pictures of Halley's Comet. My results were that the final images were no better than those that had been given normal development, both films having been exposed at the same (probably 800 or 1600ASA) rating. The difference was in the level of backgroung fog, which increased dramatically on the film that had been given the extended development, so these negs were more difficult to print.

Thanks to everyone who contributed. I rated the film at ISO 640 and had the lab push it one stop. Results: amazingly fine grain (even with the one stop push), excellent tonal range, and good sharpness. Suited my needs perfectly. Thanks again!

 

JW

<center><a href="http://www.photo.net/photo/1044037"><img src="http://www.photo.net/photodb/image-display?photo_id=1044037&size=md"></a></center>

 

<p>This has been taken on XP2, pushed 3 stops and overexposed by one stop (my camera was set at 1600). This was on an overcast day, so the scene contrast was very low. A one stop push should be a piece of cake. I'd set my camera at 640.