Wood collection (and some thoughts on testing failure)

[Alastair Moore]

I shot this (actually four of them) this evening to try and do some testing of my film (Foma 100) and developer (D-76). The testing was a bit of a fail - essentially I can hardly see any difference between the four negatives I exposed and developed. I quite probably didn't leave enough of a time gap between each negative (I only left 30 seconds between each sheet) to get a better idea of what more or less developing time does to negatives. That plus the light could quite easily have changed a little between exposures although I was pretty quick between each sheet. I am, at least, happy with the exposure on this shot.

Of course, my scanner (or scanning technique) could easily be at fault. I'm still not 100% happy how negatives are scanning in.

I'm now out of D76 and have a pack of Xtol to mix and try out so will probably do a similar (but improved!) test tomorrow and see how I get on. I'll try something like 15-20% difference between each negative and I'm going to try and shoot something with a wider subject brightness range too. I guess with the fairly narrow subject brightness range on the image above, the likelihood of seeing anything significantly different in those negatives is unlikely, perhaps? But there was essentially two minutes difference in developing time between the first and last negative and really there is very little difference between the two.

If anyone has any thoughts, advice, suggestions, or anything else to offer, it'd be appreciated!

[Walter Glover]

Phil Davis's BTZS system is the only method worthy of consideration. I still have a spare copy of his book that you can borrow if you want.

Was this done in the JOBO or by hand agitation?

[Lachlan717]

Phil Davis's [sic] BTZS system is the only method worthy of consideration.

The only method?

Come on, Walter; that's a little bit of an exaggeration, isn't it?

I would suggest getting in touch with Fred Newman and getting some of his pre-exposed film (about $50 +p&h). Google this to get more details. I doubt that he offers Foma, but you can send him film for him to expose.

If you do go down this route (BTZS and/or Newman), you will need a Densitometer. Let me know if you do, as I have one that I can lend to you (it's a hand held Radiologists' one. You will need a light table/light box, though).

If you don't want to go to the trouble of doing this level of testing, and I would strongly argue that few of us need to, make sure that you get images with a high dynamic range. The critical component, IMO, is contraction. You need to be able to know how to reduce Dev time to protect your highlights. Working with 15% reduced Dev time is a pretty good starting point, once you have done a normal Dev time.

If you want to have a chat about this, ping me a PM with your phone number and I'll give you a call.

[Alastair Moore]

Cheers for the feedback chaps.

Walter, I was using the BTZS tubes for continuous agitation. I reduced the developing time that Foma (and various sources on the internet) suggested a little to take into account continuous agitation.

I've been interested in the BTZS method and actually bought the eBook for a read but it did feel like I was going to need a lot of equipment and software to get the process set up. The thing is when I look at my negatives, they look to my eyes to be reasonably correct so it could well be my scanning process isn't quite right. I did some scanning last night using VueScan, Epson Scan and a trial version of Silverfast. They all gave completely different results. Epson Scan was a little too dark, Silverfast was a bit too bright and VueScan was far too bright and contrasty. I'm hoping when we've finished our darkroom and start doing some wet printing, much of these issues might go away. Stupid digital processes!

Lachlan, I dropped Fred an email regarding his testing service so I think I'm going to give that a go, for $50 it's probably worth it for my TMax sheets anyway. Foma is cheap enough so I'm happy to do this by trial and error. I'll drop you a PM shortly though, would be good to have a chat!

[Maris]

This is how I work when I have to use a new film or developer and I'm in a hurry for workable insights. First I find a "standard" front lit scene with some sky, clouds, some ground, grass and trees, dark shadows, white paint in sunlight, etc etc. The key thing is to have a wide range of subject luminances in the subject for a film/developer test. By a stroke of good fortune there is a scene like that every mid-morning near where I live. And it is very consistent all year round because I'm not far off the Tropic of Capricorn.

I expose 4 sheets of 4x5 film in my camera with a 5 step exposure sequence across each one done by pushing in the darkslide a little bit between clicks. I go from a notional two stops under to two stops over. Because my darkroom is close by I immediately develop all four sheets at different developing times. Typical times are 3, 6, 9, and 12 minutes; no pussyfooting around with small increments. Within an hour I know the correct exposure for the scene. All I have to do then is set the discovered EI number on my light meter so that my usual metering strategy delivers the exposure reading I already know is correct. And this test procedure also gives me the right development time. I don't have to hit the exact EI or developing time. Interpolation is plenty close enough. Developing times that are too short and too long also give me useful information about N+ and N- zone system tweaks.

Certainly this is not a laboratory standard test but it is quick and the arithmetic-free directness of it inspires confidence. By the way my results for Fomapan 100 4x5 indicate EI = 50 and N development in Xtol (replenished) is 6m 30s at 24 Celcius.

[Lachlan717]

The thing is when I look at my negatives, they look to my eyes to be reasonably correct so it could well be my scanning process isn't quite right. I did some scanning last night using VueScan, Epson Scan and a trial version of Silverfast. They all gave completely different results. Epson Scan was a little too dark, Silverfast was a bit too bright and VueScan was far too bright and contrasty. I'm hoping when we've finished our darkroom and start doing some wet printing, much of these issues might go away. Stupid digital processes!

I actually think that it's a bloody good image! It's just not a subject that (I think) needs a lot of contraction. There just doesn't seem to be a great deal of dynamic range in the subject.

Perhaps head to the beach on a bright day and shoot a scene that has some rocks in it. Meter for the shadows amongst the rocks, set this a Zone II and fire at Zone V. Hopefully, there is some cloud around (or some foam and/or sun reflecting off the water) that will fall in to Zone IX or X.

This is where dropping 15% will show more impact!!

This video of AA working on a beach will give you an idea of what I mean, as he is using N- development:

http://www.youtube.com/watch?v=am54LMSwz9E

The relevant part is about 6 minutes in.

[sharperstill]

I agree with the above. You need a better selection of lighter tones in your subject to make a judgement by eye.
It looks like you shot a fairly contracted scale to begin with.
Shoot the same scene with a bit of black cardboard, an 18% grey card, and a bit of white cardboard thrown in.

Jon

[Alastair Moore]

One last question (for now!).

Is the subject brightness range the number of stops between the metered values - ie. I meter my shadows at 4 seconds, for example, and my highlights at 1/60th of a second giving an 8 stop range.

Or, as I meter my shadows at 4 seconds but because I want to put that into Z3, I would use 1 second for my exposure. So the range in this case would be 6 stops.

I'm assuming the former as that is my actual brightness range but just want to clarify!

[Lachlan717]

8 stops (i.e. the former). Shadows in Zone III, highlights peaking into Zone X

I'd be looking at N-1, possibly N-2, in this case. I would also consider putting some of the shadows in either Zone II 1/2, or even Zone II to protect the highlights if there is significant/desired areas of Zone X.

[Alastair Moore]

Ok, I ran some more tests today with a wider brightness range - dark shadows, bright window. I ran 4 sheets through D76 at 3:30, 6:30, 9:30 and 12:30. I'm yet to scan them in (they're currently drying) but even looking at the negatives you can see significant differences between them and the sheet developed for 3:30, you can see quite a bit of detail in the window. So it'll be interesting to have a proper look at them when they've dried. Will post updates here when I get chance!