Inexpensive two bath developers <i>besides</i> Diafine? Pat G.? Jay?

[discpad]

<p><i>

This is moved from the thread entitled <a href = "http://www.photo.net/

bboard/q-and-a-fetch-msg?msg_id=00F6pF&tag=" target = "_blank"><u>Diafine

air agitation</u></a></i>

</p><p>

OK, let me rephrase my original question above: I'm looking for a

foolproof 2-part developer for little or no agitation ("stand

development") of 120 roll film in 3" diameter x 36" tubes, i.e. each tube

holds about 4 liters. Also, I need it where timing is not critical, hence

my initial attraction to Diafine.

 

</p><p>

Additionally, I can compound it and give Lisa the concentrate parts in

30ml 35mm plastic canisters, i.e. "fill the tube(s) 2/3rd with warm water,

dump one of part A and one of part B and stir, then top off with water.

 

</p><p>

Since the Pyro developers are inexpensive enough to use single-shot (or

more accurately, with over a gallon of dev, one or two sessions then dump

), are there any 2-part devs that have the same non-critical timing as

Diafine? <b>Alternately</b>, would a dilute single part dev also work for

the non-critical time & temp requirement?

 

</p><p>

<b>Paging Pat Gainer and Jay De Fehr! :)</b>

 

Thanks in Advance! <br>

<a href = "http://users.snip.net/~joe/default.htm" target =

"_blank"><u>Dan Schwartz</u></a><br>

<b>Note:</b> All links open in a new window

</p>

[scott_walton2]

Divided D76 is great. Extremely fine grain, compensating, and I have used it with great results with Technical Pan as well as all other non t-grained films. 3 minutes Bath A, 3 minutes Bath B - fixer and wash. You can get it commercially or cheaply mix it yourself. It has the same keeping qualities as Diafine and can be used over and over. Not as high on the acutance but definitely extremely fine grain! The Divided D23 works best, for me, when I use t-grained films. Some people use the Diafine and state good results but I don't care for it as well as the DD76 as the negs with DD76 are thinner than I care.<div></div>

[don_mckeith]

I use the "teaspoonful two bath" with whatever I have in the house at the time--usually D-76, but it works with any developer I've tried it with.

 

I don't know if you caught Roger Hicks 15/50 method (a few posts down---about contrast),but this time of year where I live,most every roll I shoot is 15/50 on the same roll, so I have to do a little compensating.

 

http://www.ephotozine.com/techniques/viewtechnique.cfm?recid=70

[discpad]

Scott,

 

What are the two recipes at the top of your pix?

 

Thanks! Dan

[scott_walton2]

They are both Divided D76 but if you know you have an allergy to Metol... get itchy hands after developing (at least), use the one with Phenidone. Phenidone is more expensive but in the long run, you use a whole lot less per gallon. There will only be a slight increase in density so don't worry.

[discpad]

ARGGHHH!

 

I'm trying to convert the volumes in DD-23 at http://unblinkingeye.com/Articles/DD-23/dd-23.html from weights to volumes, for a 4 liter batch. For example, 40 grams of borax = 24cc, 400 grams sodium sulfite is 280cc; and 30 grams of Elon (metol) is ???

 

Have fun finding the specific gravity: It's not listed in any MSDS I found, including the six on the Kodak website! When I called Kodak's B&W line, the first guy was utterly confused; and the second guy was trying to convince me that specific gravity only applies to liquids!

 

So then, he puts me on hold and asks a "chemist:" He said that they don't recommend measuring chemicals by volume. Fine. WHAT IS THE NUMBER?!

 

"Thank you for calling Kodak!"

 

No wonder they are hemorraging cash...

[rowland_mowrey]

Dan;

 

I'm here as always. Never fear.

 

Now, you have gotten into what I have been trying to get across to you for about 2 years.

 

There is no such thing as specific gravity for a solid material.

 

The density of a solid can be measured, but only for a constant physical form, but the physical form varies from batch to batch. This variation is on the order of 20%. Therefore, I have absolutely no answer for you and the Kodak answer from a chemist was right.

 

Sorry.

 

Ron

[jordan_w.]

I'm with Ron. The "density" of a crystalline substance changes with crystal form. You can use volumetric measurements, but it would be best to "calibrate" each material you have (and not rely on published conversion equivalents).

[scott_walton2]

Dan, There is an easier way to convert... the teaspoon method and for B/W there isn't the need to be exact. Slightly rounded teaspoons. Enclosed is a converion chart I have used for about 25 years with great and predictable results.<div></div>

[kirk_keyes]

Solids do have specific gravities just like liquids do. My CRC handbook lists the sp. gr. for thousands of solid compounds. Ask a geologist about the any of the minerals they work with, and they all have specific gravities.

 

The problem here is that the sp.gr. listed are going to be based on individual crystals, and not the form that most of our chemicals come in, like powders or crytals of varying sizes...

 

What you want to ask for is called "bulk density". This is measured by pouring an amount into a fixed volume and then dividing by the weight. It is typically used for industrial chemicals and other materials. It takes into accound the vloume of air between the material being measured.

[discpad]

Scott, that table is **exactly** what I'm looking for!

 

By the way, did you know that a 35mm plastic canister holds 1.0 ounces? :)

[rowland_mowrey]

Kirk has given the correct 'extended' answer to this question.

 

I would like to add though that bulk density of solids still is not accurate from varying samples.

 

Ron

[patrick_gainer]

Not absolutely accurate is true enough. Absolutely not accurate is not true for many uses. Certain chemicals, among them Vitamin C powder, are very consistent. Before you buy a lab balance that weighs to the 0.1 milligram, do some experiments to find out how precise you must be. Some formulas that started out in avoirdupois, upon conversion to metric units, are afflicted by calculatoritis and listed to 0.001 gram. D-23, for many years, was approximated in newspaper photo labs by 1 oz metol and 1 lb sulfite to 1 gal water, IIRC. I could use 1/4 cup of sulfite and 2 tsp metol to a quart of water. The difference in results between that and 7.500 grams, 100.00 grams in 1000.0 ml is about as much as you might get by an error in measuring the temperature. D-23 is forgiving. So are most other concoctions used as divided developers.

[discpad]

Hooray for Pat!

 

When I first saw it, I was thinking of a body part I massage on my lady friend(!), but then I realized he was talking about significant digits... Something they pounded into us in freshman chemistry in engineering school.

 

I'll bet if that smart-ass E-K chemist actually looked at the original formula for D-23 from the 1920's, he'd probably notice it was accurate only to two significant digits... MAYBE three.

 

Look again at the formulas in Scott's posting above (at:

http://www.photo.net/bboard/big-image?bboard_upload_id=27926984 ), and you'll notice that, when you express them in scientific notation (which uncovers significant digit "calculatoritis"), you'll see they are only accurate to 2 significant digits.

 

For example, 750 ml of water is 7.5 x 10^2, and so forth.