First time poster, short time reader :-)

I've recently got into large format photography, and have embarked on a testing binge over the last week or so.

I don't have a densitometer (who does?), and don't have the time to alter my Minolta Spot into one, so I purchased a gray scale card from the local camera store (named, strangely enough, 'The Camera Store' :-) ).

I mounted the gray scale (and the color scale, just for fun) on a gray card, and metered (at 400 ISO) on the gray card. I took a single picture.

I then took an unexposed negative, and developed it at roughly 73F for about 9 minutes (standard dev time is 68F/9.5m). I also developed one oother negative for the same amount of time, at the same temperature.

I took the negative of the gray card, and focused the enlarger such that the exposed image would match the gray scale card so I could do comparisons. I then placed the blank negative into a carrier, and determined that dMax is about 13 seconds at f/11 at the set height of 60. I then took the first exposed sheet of film, exposed it the same way, and developed the print. After the print dried, I compared it to the gray scale card, and found that I was off three graduations, which from reading the card is 0.3 in density, or 1 full stop.

I then took two more shots with a full stop more exposure (200 ISO), and proceeded to develop one of the negative the same as above, and the other with about 30% development. The first negative with 1 stop more eexposure didn't show much difference. The second negative, with about 30% more development, was 1/3 stop closer to the gray scale.

After making the print (and not changing anything), I only gained 1/3 stop more exposure.

Now I'm a bit stumped. I would have thought that 1 stop more exposure should have pretty much nailed the gray scale card, and the second + developed negative would have shown some signs of expansion, but no such luck.

After thinking about this for a while last night, I remembered that the film developer (IFOSOL-S) is probably getting a bit old, and the airspace in the original container was getting pretty big. Am I looking at aging of the developer? Would that cause what I've seen?

I'm heading to the store at lunch today to buy a fresh batch of developer, and I'm going to try again. If anyone has any other suggestions other than getting new film, I'd love to hear them.

Thanks!

-- Ken Miller (andawyr@my-deja.com), July 24, 2001

Answers

If I was in your shoes, I would really be confused...

I would start by using fresh chemicals for my tests, you will never get any constant results by using old developer, especially if you are not really sure about its activity levels. You should start by doing a film sensitivity test also. The compesation for the raise in the dev. temperature you have mentionde was not enough. If the normal dev. time is 9,5 minutes for 68 degrees farheneit, then you should develop for far less than 9 min. at 73 degrees.

-- George Papantoniou (papanton@hol.gr), July 24, 2001.

I'm not sure what you mean by a film sensitivity test; could you elaborate?

My thoughts are that I should get new developer, and work with room temperature everything, and go from there. I don't want to get into altering the temperature of the chemicals, since you're always going to be fighting it. I have a heated floor in my house, and the temperature of that is very constant - I just sit the solutions on that, so temperature should not be a problem.

I forgot to mention that I'm using home-made tubes for development. Not sure if that leads to altered development times or not...(and the water bath is at room temperature).

Thanks for your suggestions!

-- Ken Miller (andawyr@my-deja.com), July 24, 2001.

The film sensitivity test determines your true film speed for your equipment. Once that is determined, then you expose your film to the 18% gray card, devlope the film, make a print, if it matches the gray card that is your development time (N time). If not, development time needs to be adjusted. Without a densitometer it can be done but it is real time consuming. With a densitometer it's a very simple procedure.

-- william nagel (wdnagel@home.com), July 24, 2001.

Buy a copy of Ansel Adam's book, The Negative. It has step by step instructions to do what you need in Appendix A. Your problem is trying to match a print to the grey card. What you should be trying to do is get the negative to a density of .1 over blank film. That is how you find your film speed. Keep developer temperature constant. The lowest density will not change that much with changes in time. Once you figure out your exposure index (EI), then you adjust development time to put the highlights were you want. The grey scale won't help as much as a step wedge would.

-- Dave Mueller (dmueller@bellatlantic.net), July 24, 2001.

Maybe this is where I'm getting confused.

I have a step wedge (Kodak grayscale printed on a piece of thin cardboard, each graduation is .1 density change). Where I'm running into problems is how to actually test a negative for .1 density without a densitometer?

I thought that trying to reproduce the steps of the grayscale on the print, using dMax would land me on the my effective film speed, based on how far off I was on the graduations. My initial test showed that I was off by three steps, which means I should have treated the film as ISO 200 instead of ISO 400 (whites were light gray, and the overall gray card was too dark). My next exposure at 200, however, didn't give me the result I was planning on, although the gray card *was* closer to the real thing.

I have Adams's books, and most of his analysis seems to depend on having access to a densitometer.

I'm currently reading BTZS (1999 Editiion) and the tecniques listed therin rely on a stepped negative, which I also don't have access to.

Oh well, nobody every said getting this right was going to be easy. Well, one fellow did, but only if you had a densitometer :-)

-- Ken Miller (andawyr@my-deja.com), July 24, 2001.

I don't have a step-wedge, just a gray scale.

Brain cramp, sorry about that.

So what you're saying is that really, I'm fighting an upward battle trying to calibrate my system using a gray scale, yes?

-- Ken Miller (andawyr@my-deja.com), July 24, 2001.

Not to muddy the waters further, but I'd ditch the dmax exposure procedure. The film base has significant density so the empty carrier method will give you an error. IMHO, you have to be careful trying to get absolute dmax of paper because dmax is hard to achieve and won't give you the best prints. Anyway, what you want is a negative density of 0.1 over b+f for an exposure 4 stops below your 18% gray card. That's actually quite easy to see. It's just slightly more than a detectable density when the neg is laid on a piece of white paper. A just barely detectable density is about .05 or a bit less and is quite hard to see. You need an unexposed area right next to it for comparison, maybe the unexposed edge of the film where the holder retains it. A question to stir the pot- Should an 18% gray subject reproduce as an 18% gray area of the print?

-- Conrad Hoffman (choffman@rpa.net), July 24, 2001.

get new developer before confusing yourself any more! In my experience Ilfosol S goes off very rapidly.

-- Nigel Smith (nlandgl@unite.com.au), July 24, 2001.

Ah, it just keeps getting more interesting.

Further reading on Usenet yielded using a meter and a light board to read the negatives (unexposed developed,and a series exposed for Zone I at different apertures). Find the one that reads rougly 1/3 stop more dense than the unexposed sheet, and bingo, there's your 0.1 density negative.

As for Ifosol-S, I didn't realize it goes off that fast.

What developer would you recommend with HP5+? I've also used D-76 - do you have any other suggestions?

Thanks.

-- Ken Miller (andawyr@my-deja.com), July 24, 2001.

I switched to Ilford Plus (LC29) which seems (i.e. does) to last a lot longer the Ilfosol. It's also a liquid. I got caught out with some Ilfosol once, luckily it was nothing important! I haven't done any back-to-back comparisions between the two, however I have with LC29 and DD-X and with an 8X loupe on 8x10 enlargements from FP4+ I could pick a difference, but not viewed 'normally'. I still use DD-X for Delta films, one day I'll try a test for those in LC29! I have used LC29 for HP5+ but have no grounds of comparision, other than to say it works :)

-- Nigel Smith (nlandgl@unite.com.au), July 24, 2001.

Another book plug. Get a copy of Fred Picker's "Zone VI Workshop" if you are into testing for the optimum results in B&W prints. Then find a copy of his book "The Fine Print". Ignore the plugs for his products, because he is out of the mail order business. Calumet handles the line now. The Zone VI enlager is teh BEST for B&W work!

It seems rather pedantic but the guy is right and if you follow his instructions, you will have a lot of trouble making a bad negative.

He swears by HC110 & Tri X but that was written 20 yrs ago.

Try the T Max or Delta films in T Max dev or the new Ilford DDX(I think) soup.

Cheers

-- RICHARD ILOMAKI (richardjx@hotmail.com), July 25, 2001.