Push/Pull processing if Scanning Negative

[McAir]

I am returning to 4x5 BW film after about 30 yrs. I will be scanning my negatives using Epson 850 Scanner and processing in Lightroom & Photoshop. My question is, given the capabilities of the software to alter contrast and burning and dodging in Lightroom, is there any benefit to push/pull exposure and negative development. Or is it best to just use the film rated ISO. I will be using mostly Illford HP5 or Delta 100.

[koraks]

Pushing and pulling are conceptually different (but share many similarities with) the use of a personally determined Exposure Index (IE), which again is different from expansion and contraction in Zone-system speak. I have a feeling you're convoluting both into some diffuse amalgam.

Pushing is often done because the film available won't allow for the shutter speeds necessary to prevent motion blur etc. Typical use case: concert photography. For pulling I don't really know a common equivalent; perhaps if people want to obtain a satisfactory blur on a waterfall or crashing waves but forgot to bring an ND filter. Pushing relies on stronger development to reach the same overall density range in the negative compared to a box-speed exposure + normal development; pulling relies on reduced development to achieve the same.

Expansion and contraction are technically similar to pushing and pulling, and some would argue they're the same thing, but conceptually I consider them different. Expansion and contraction aim to capture the scene brightness range into a convenient or optimal part of the negative's response curve, usually with an eye on desirable printing characteristics in the darkroom. The commonality with pushing and pulling is that over- or underexposure compared to box speed (or one's established EI; see below) is combined with reduced or increased development to obtain the desired negative contrast range and curve shape. Variations in agitation can also be employed to tailor the curve shape; this is a matter of some (and sometimes, heated) debate. Of course, expansion and/or contraction could also be done with an eye on scanning.

Establishing a personal exposure index for a given film and a given developer and development regime is yet another issue and generally relies on maintaining desired shadow detail combined with a desired contrast / gamma / steepness of the HD curve. This is where the term 'box speed' comes in and the endless bickering over film's either or not living up to their rated box speed.

Using the above to formulate an answer (and many 'correct' answers are possible, mind you):
* Pushing and pulling have nothing to do with scanning or printing per se, and I would consider them convenience options at exposure time resulting in some inconvenience limitations later on in the process.
* Expansion and contraction could very well be used for scanning, but as you noted, scanners generally handle a pretty admirable density range to begin with and in my experience, you can get away with more variation in negative densities than you can (at least with ease) in the darkroom. So in that sense, I wouldn't bother.
* Determining an EI for whatever film and development you use might be wise and especially relevant if you notice that you consistently end up with negatives lacking in shadow detail. Again, scanning saves your a&$ much of the time since a scanner will happily give you workable data even from eerily thin negatives, but there is a point where even a good scanner throws in the towel and spits out noise and garbage.

PS: welcome back to 4x5, I'm sure you'll enjoy.

PPS: consider darkroom printing, it's so much more fun than staring at a dreary grey box making humming noises.

PPPS: disregard any of the above you don't like; for every 1000 photographers, there are 1001 answers - all are absolutely, vehemently correct. Of course!

[Bruce Watson]

...is there any benefit to push/pull exposure and negative development? Or is it best to just use the film rated ISO? I will be using mostly Illford HP5 or Delta 100.

The name of the game is basically to get sufficient shadow detail and highlight detail, along with contrast index, onto the film so that you can print it relatively easily. By "print" I mean by whatever means you choose, from darkroom prints to digital prints.

If you are making photographs that will only be scanned, and you'll never make darkroom prints from them, you can optimize your negative for scanning. But if you're ever going to make darkroom prints from them, you'll almost certainly be better off optimizing for darkroom printing because a decent scanner can easily scan a negative optimized for the darkroom.

If you're going to optimize for scanning, you'll have to experiment to find where that "sweet spot" is for you and your process. That typically is slightly less Dmax than a negative for printing on a #2 silver paper. Why? Callier Effect. Density in B&W films is from metallic silver which is opaque. The light can't go through it, so it reflects off it and "bounces around" lighting up all the silver nearby. The end result of this is reduced highlight contrast.

So, how to get there? What worked for me was to properly expose the negative using my personal exposure index (which depends on your meter, lens/shutters, developer, developer agitation, etc.). Then I would adjust my "normal" development time to give me about a stop less density (which turned out to be optimal for me and my needs) for my highlights.

Notice that this is neither a push, nor a pull.

Will this work for you? IDK. Depends on how much work you're willing to put into it and how repeatable you want your results to be.

But if you don't really want to put that much work into it, I advise that you expose for box speed and develop a little less than you normally would. Depending on what you want, that might be enough.

[edit]

In the end: "Expose for the shadows and develop for the highlights" is still true, whether for darkroom printing or scanning and digital printing.

[/edit]

[Greg]

VIEWCAMERA magazine once published an article on the advantages of using Diafine to process negatives that were to be scanned. If someone has an index of the articles that appeared in the magazine, could you please post the issue that this article appeared in?

[Michael R]

VIEWCAMERA magazine once published an article on the advantages of using Diafine to process negatives that were to be scanned. If someone has an index of the articles that appeared in the magazine, could you please post the issue that this article appeared in?

I don’t have any of the magazines anymore but if I remember correctly one of the main points in the article was that two-bath and/or divided developers tend to have a straightening effect on characteristic curves. Some time ago I did a series of tests/sentitometry on various divided developer processes (not Diafine-type) and found this to indeed be the case. I don’t remember much else about the article though. There might have been stuff about image structure etc.

[SergeyT]

I never bother with push or pull for B&W film.
I will probably drive a lot of people mad here by saying that I use one and same developer and times for developing all B&W films that I expose (my "normal" development).
Here is why:
* Dynamic range of scanner's hardware well exceeds the range of densities that are possible with B&W films
* For everything that is within the scanner's hardware range the response curve more or less linear.
* Therefore, the scanning part could be kept out of equation
What matters is how the film is exposed:
* Insufficient exposure will naturally result in blocked shadows.
* Brutal overexposure will compress the highlights. To what degree - hard to say , but is something to keep in mind and to avoid unless intended.
In other words, exposure settings is what to care about the most.

[McAir]

First of all, I want to thank those that have responded. I realize and appreciate the time and thought some of these responses took, and think it speaks to the character of this group. There is some very insightful information that I think is valuable as I return to 4x5.

Among my film development consideration was a comment I remember that Bruce Barnbaum made about placing shadows in zone III. In short, because of zone III being essentially part of toe of the curve, it would be better to expose in zone IV and print down to zone III, thus retaining texture in the shadow rather than just tone. So, I was thinking of exposing Illford HP5 at 320 or even 200 and develop accordingly. This would I think result in a somewhat flat negative that, after a scan, could easily be modified in Lightroom. I could be way off here, but this was my thought process. Even a rating of 320 vs 400 with normal development might preserve highlights without over blocking shadows. I know testing would be in order but I'm just looking for a good starting point.

Again, thank you all for your comments. Really looking forward to getting back into large format. I have a trip coming up soon to the Hocking Hills of Ohio and the Badlands of SD in October. So, my new journey will begin.

[Alan Klein]

First of all, I want to thank those that have responded. I realize and appreciate the time and thought some of these responses took, and think it speaks to the character of this group. There is some very insightful information that I think is valuable as I return to 4x5.

Among my film development consideration was a comment I remember that Bruce Barnbaum made about placing shadows in zone III. In short, because of zone III being essentially part of toe of the curve, it would be better to expose in zone IV and print down to zone III, thus retaining texture in the shadow rather than just tone. So, I was thinking of exposing Illford HP5 at 320 or even 200 and develop accordingly. This would I think result in a somewhat flat negative that, after a scan, could easily be modified in Lightroom. I could be way off here, but this was my thought process. Even a rating of 320 vs 400 with normal development might preserve highlights without over blocking shadows. I know testing would be in order but I'm just looking for a good starting point.

Again, thank you all for your comments. Really looking forward to getting back into large format. I have a trip coming up soon to the Hocking Hills of Ohio and the Badlands of SD in October. So, my new journey will begin.

You might want to check out Mat Marash a large format photographer who's shot Hocking Hills a lot - he lives in Ohio. He's great for beginners.
https://video.search.yahoo.com/searc...9&action=click

[j enea]

many good points mentioned above and I agree with with many points. when I went from predominantly dark room enlarging/printing to scanning (seems we are always having a drought in California so I do my part)I found, in my totally amateur and trial by error way, that metering played an important, or maybe the most important part, then development came next. yeh, very similar to normal shooting developing schemes, but I changed how I do things from experience.

Sergey mentioned many key points that I found are similar to my thinking. when I dark room print I still spot meter for zone 3 and use standard zone system style development. but for scanning I found I got and get better results using and incident meter and doing a reduced agitation in pyro-m for development. keeps highlights in check, which for me is the bane of scanning, gives me, depending on the film, enough shadow detail to scan and print a nice photo. i can go on, but you get the drift. large format is much easier to scan and get good results, depending on your scanner than smaller formats, even though I really prefer to shoot MF for simplicity (also I never print scanned images over 16x20, except for some 6x17 shots)

john

[McAir]

Well, some of my initial return to 4x5 have been somewhat encouraging. I shot HP5 rated at 320 and reduced development by about 10% (~8min), Illford DD-X 1:4. Still refining my metering style using my Zone VI modified Pentax spot meter. Negatives were scanned using the Epson 850 flatbed. I was pleasantly surprised of the quality of scans and after post processing in Lightroom and PS, I feel the results were satisfactory, at least at this early juncture. Would love to hear your thoughts.