Dear Mr Tai,

I know you very experienced in ultra high resolution films including Kodak's Technical Pan.

Up until now I have been using Kodak's Technidol to process it. However I saw that you recommend a combination of Rodinal and Sodium Sulfite.

Is this mix better than Technidol? If so in what way? Lower grain? Higher resolution? Better (i.e. lower) contrast?

Also what exactly is the recipe? And where can I get Sodium Sulphite?

Thank you in advance...

-- Sol Campbell (solcam31@hotmail.com), October 20, 2000

Answers

If I may add.....

Rodinal 1:100 6'/68F EI 12

Ethol TEC 1:15 6'/68F EI 40-50

C-41 developer, 9'/68F EI 12

Those will all work ok and don't require the finicky agitation scheme of Technidol in order to get good evenness.

The addition of a little sodium sulfite (10g/L) _may_ give a little more speed than plain old Rodinal; it does with faster films but I've never tried it with TP.

You can buy sodium sulfite via any camera shop that stocks Kodak and Edwal chemicals and would be willing to order you some if they don't have it; otherwise it's available from Calumet, B&H, Photographers Formulary etc.

If you try it for TP and don't like it or it doesn't do anything you haven't wasted your money; you can make HCA by dissolving a level tabelspoon of sodium sulfite (about 20g) in a quart of water; use as you would any other hypo-clear wash aid.

-- John Hicks (jbh@magicnet.net), October 20, 2000.

If I may add to John's list, Divided D-76 works great and I get an effective EI of 80! Cheers

-- Scott Walton (scotlynn@shore.net), October 20, 2000.

John:

I tried Rodinal 1:200, 8 minutes at 76F. The negatives were thin at EI 25. I will now try 1:100.

I order I lot from B&H. So I will look at their web site and see if I can find sodium sulfite.

Scott:

The EI of 80 is great, but won't grain suffer? I might as well then use T-Max 100 in XTol. That in my opinion is the second best combo for grain. Better in my opinion than Agfapan 25.

Thanks to the both of you.

-- Sol Campbell (solcam31@hotmail.com), October 20, 2000.

I just checked B&H's web site and this Sodium Sulfite stuff sells for $180!!! And it is only available in 100 lbs bags! So it will cost an arm and leg to ship as well! And B&H does not carry it but it takes them 2-4 weeks to get it!

It is made by Kodak.

So is there cheaper way to try this stuff?

Thanks!

-- Sol Campbell (solcam31@hotmail.com), October 20, 2000.

> 100 lbs bags

The smallest size sold by Kodak is one-pound bottles; I found it as KOSSLB 1463538 $8.50 listed under Bulk Chemicals, and it's shown as special-order. They sure didn't make it easy to find.

A quick look at Photographers Formulary (www.photoformulary.com) turns up this: 0-1340 Sodium Sulfite 1 lb 4.95.

Also at Calumet (www.calumetphoto.com) Kodak sodium sulfite item # KP02074 $7.50.

Sodium sulfite is sodium sulfite, brand doesn't matter. It can also be obtained from some pool-supply dealers, but there's not much point in buying a huge quantity even if it's cheap because it's hygroscopic.

Also note that sodium sulf_ite_ is different than _ide_ or _bisulfite_.

-- John Hicks (jbh@magicnet.net), October 20, 2000.

For reasonable bulk chemicals, see: http://www.colba.net/~fotochem/index.htm For instance, they price Sodium Sulfite at $4/lb.

-- Alec (alecj@bellsouth.net), October 21, 2000.

B&H sells Sodium Sulfite in small quantities packed by Photographer's Formulary. It may not appear in the catalogue, but I've seen it on the shelf. Just ask. I've found that even the online catalogue at B&H, which I thought was linked to their stock database, doesn't really list everything they have in the store.

-- David Goldfarb (dgoldfarb@barnard.edu), October 21, 2000.

I'll chime with my tech pan formula. Rate at 80 and develop in diafine. Develope in the "B" solution for 45-60 seconds. 45 seconds will print with a 2-21/2 filter(condesers). 60 seconds will print on 2 with a diffusion enlarger.

Advantages;

Diafine works with all films, also outstanding for T-max 100.

Time in the solutions other than the "b" for tech pan is not critical

No need to adjust for temperature as long as it is between 70 and 85 F

Agitation is not critical. In other words, the only way you can screw up the negatives is to either miss the exposure or leave the top off the developing tank when you turn on the light(Did that earlier this week and lost a roll of grandchildren pictures-I've only been doing darkroom work for 50 years.)

A batch lasts for up to a year with replenishment from unused stock solutions.

Disavantages

No +/- N development.

No other disavantages.

KISS!

-- Gene Crumpler (nikonguy@worldnet.tt.net), October 21, 2000.

Hi Sol, my ISP has being down for some time. In subminiature B&W photography circle, Technidol is not popular, many submini photographers prefer to use 1:100 Rodinal (one part Rodinal in 100 part of weak sodium suphite solution, which contain 56g of sodium sulphite in 1000 cc of water. Techpan in technidol gives flatter negatives as compare with Rodinal. Rodinal gives sharper looking pictures. Personally I like to use Agfa Rodinal Special, another of version or Rodinal developer which contains hydroquinon.

In 1:100 dilution, the Rodinal Special appears to be weaker than regular Rodinal, and appears to gives finer grain.. Rodinal Special is sold only in Canada/EU, not in USA, probably because it contains allergy inducing substance

-- martin tai (martin.tai@capcanada.com), October 31, 2000.

Ethol TEC is also excellent with Tech Pan. According to Ethol's web site, TEC is the developer of choice for the Leica Institute, FWIW.

-- Gene Crumpler (nikonguy@worldnet.att.net), November 08, 2000.

I guess it's time for my standard TechPan answer. Rate at 50 ASA, develop in HC-110, Dilution F (1:19) for 6 minutes at 68B:F.

-- Pete Schermerhorn (PeteScherm@aol.com), November 08, 2000.