I do quite a bit of lens testing and have recently been using Agfa APX25 - which is now impossible to find. Prior to that I had been using Tech Pan, but it's expensive, slow and a bit tricky to process so I'd like to find a more "conventional" film - plus a little extra speed wouldn't hurt!

Now APX25 is gone, what's the current highest resolution B&W film? I'm guessing Tmax 100 and/or Delta 100 would probably qualify. Kodak has some MTF and resolution data on their web site, but I can't find equivalent info on the Ilford site for Delta 100. From what I hear, Pan F+ has lower resolution than Delta 100 despite being a stop slower, but again I couldn't find any hard data on the Ilford site.

-- Bob Atkins (bobatkins@hotmail.com), May 17, 2001

Answers

None.... It's a German product called Gigabit film that claims to have 3x bigger resolution than than Techpan and a better tonality. Just got my order delivered. It is rumoured that it is actually a Agfa microfilm, prepared for 35mm and 4x5 with a special developer. See their site: http://www.gigabitfilm.de/

-- Marc Leest (mmm@n2photography.com), May 17, 2001.

We've had quite a few people singing the praises of Gigabit film on this BB, but none of them actually seem to have used it! It all seems to go quiet once someone's used the stuff, and it would be nice to hear about real experience with this 'wonder film'. Better yet, it would be nice to see some results from it.
Any chance in the near future Marc?

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 18, 2001.

The following resolutions were given to me by Ilford Germany:

Pan F Plus 150 l/mm FP4 Plus 110 l/mm HP5 Plus 100 l/mm 100 Delta Pro 160 l/mm Delta 400 Pro 145 l/mm Delta 3200 Pro 100 l/mm XP2 Super 110 l/mm SFX 200 80 l/mm

They apply to a contrast of 1:1000. Under practical conditions, expect to find half these values.

Ilford does not give these resolutions in technical documentation as they find they are not really useful for practical application.

I, too, cannot say I have tested Gigabitfilm yet, and I certainly won't for the time being, as it seems the film still has some problems. It is extremely sensitive to residues of surfactants (wetting agents) in the tank, and the comments from those who did test it are inconclusive. Whereas some say sharpness and tonal rendition are great, others state the either the negatives or the prints, or both, look real bad. So far, there has been one realistic test in a German B&W magazine that compared the film to Tech Pan and other high-resolution films, and it was the bottom line of this article that Gigabitfilm is far from being the revolution is resolution. To me, the examples of resolution test targets shot with Tech Pan and Gigabitfilm using the same Leica camera and lens showed no recognizable difference in resolution. Gigabitfilm is indeed Agfa Copex material, and all the proprietary stuff is in the developer. The film is developed to give really soft negatives. That, together with the fact that it's actually underexposed (so the author of the article claims) makes for the alleged overexposure tolerance.

If it's for resolution testing, you might be happy with a document film such as Cachet/Macophot Ort 25.

Regards, Thomas Wollstein (thomas_wollstein@web.de)

-- Thomas Wollstein (thomas_wollstein@web.de), May 18, 2001.

Thanks for the info. Gigabit film does seem interesting but unproven so far. I haven't found any tech specs on european ISO 25 films and they are difficult to get in the US.

Kodak claim 200 lp/mm at 1000:1 contrast for Tmax 100 in D-76, which I think is their highest number other than for Tech Pan (320 lp/mm).

-- Bob Atkins (bobatkins@hotmail.com), May 18, 2001.

Three years ago I ran comparison tests on a bunch of film/developer combinations, and found the following produced the "sharpest" negatives: 1)Kodak T-Max 100 in Rodinal(1+50), 2)I couldn't tell the difference between the next four, so listed them alphabetically: Agfapan 25/Rodinal, Ilford Delta 100/Rodinal, Ilford Pan F/Ilfosol, Kodak Tech Pan/Technidol, all followed closely by 3) Agfapan 100/Rodinal, Ilford XP2 super/C-41, Kodak T-Max 400/C-41, and finally: 4)T-Max 100/T-Max. Nothing else came close to these. More recently, I have been developing Tech Pan in Diafine and get the sharpest negatives I've ever seen. But it's tricky, and the excess contrast is still a problem.

-- Bill Mitchell (bmitch@home.com), May 18, 2001.

There are a few high resolution microfilm available:

Fuji super HR at 800 lpmm

Agfa Rapid Copex

These films are no easy to get, as they are sold in quantity of 20 bulk roll box

People who used the Super HR have high praise for it.

-- martin tai (martin.tai@capcanada.com), May 19, 2001.

Fuji Super HR is very slow, EI 6 only

Another Fuji film, Fuji HR is faster.

-- martin tai (martin.tai@capcanada.com), May 19, 2001.

I believe on a practical level TMX and Delta 100 are pretty much equivalent. By "practical level" I mean that most likely other factors such as mechanical tolerances, focusing accuracy etc will make a far greater difference in results than any difference in RP between the two films.

I think Delta 100 may have a little higher acutance, but that's just my impression in pictorial usage; I haven't tried to test that in any way.

-- John Hicks (jbh@magicnet.net), May 19, 2001.

Assuming Delta 100 and/or Tmax 100 are the highest resolution "normal" (i.e. easy to find and process) films, what would be the developer in which they would yield the best resolution?

The Ilford site suggests Ilfotec HC (which I think is the same as Kodak HC-110) for maximum sharpness, while the Kodak site gives resolution and MTF data for D-76 (I assume they'd pick whichever developer gave the best results). Elsewhere on the Ilford site however, they cite Infosol-S, ID11 and Microphen as givening higher sharpness than HC. I know sharpness does not equal resolution in a technical sense, but I'm still a bit uncertain as to what Ilford are saying here.

I note that Ilford don't recommend DD-X and Kodak don't give film resolution info for development in Tmax developer, so I assume these tabular grain developers don't yield the highest resolution (though they may give less grain and better tonal properties?).

Any comments?

-- Bob Atkins (bobatkins@hotmail.com), May 21, 2001.

Kodak kodlith is very good for testing, although it is a bit slow. Postive aspect is it is orthochromic, so one can develop by inspection and stop development at the point of maximum. This comes in a 36 roll, but forgot the name. I had kodlith in a 100 foot roll.

-- Gene Crumpler (nikonguy@att.net), May 21, 2001.

Both Microphen and DD-X are P/Q developers, which give a bit more graininess (and a little more speed) than P/Q developers such as D-76 and ID-11. Microphen and DD-X give higher acutance but it's at the expense of fineness of detail.

D-76 and ID-11 are, of course, old standards. I'd simply use either of them at 1:1. If you'd like to see if a lesser amount of sulfite affects the results, dilute them 1:3 and use about 1.5X the 1:1 development time. I think there's sort of a tradeoff between sulfite concentration and contact time in that if you reduce the concentration but have longer contact time results are pretty much the same.

I've read in a few places that Microdol-X 1:3 and Perceptol at a similarly-high dilution will give the highest RP, probably at the expense of acutance and speed, but I haven't messed with either of them in so long I have no idea.

-- John Hicks (jbh@magicnet.net), May 21, 2001.

The advise given by John Hicks,in my opinion,is good advise. John seems tho have tried every film/developer combination going & has been kind enough to offer his findings to one & all. In another respect you could be chasing the Holy Grail as perfection using 35mm will be difficult if not impossible to obtain. We 35mm users can never expect to achieve the quality obtainable with 4x5 or medium format; using 3 backs for expansion & contraction. I have found that Delta 100 developed in ID11 to be as good as I can achieve; but your results for many reasons; could differ from mine or anyone elses. Pick one of the easy to find respected films & try it in your choice of developer & try every combination of film speed, developer time & dilution that you can before moving to a different film or developer. Hope this helps, Melvin

-- Mellvin Bramley (bramley@nanaimo.ark.com), May 21, 2001.

Oops..an error. D-76 and ID-11 are, of course, metol-hydroquinone (MQ) developers.

-- John Hicks (jbh@magicnet.net), May 22, 2001.

APX 25 is still available in Australia. Would you like me to get you some

-- William Buckingham (wbuckingham@bigpond.com), June 09, 2001.