Finding the balance between acutance and resolution in 35mm

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
After reading Edge of Darkness by the late Barry Thornton, I found that his approach to targeting "the appearance of sharpness" in the final print instead of chasing ever finer grain or higher resolution really resonated with me. To the point that I've done a bunch of experimenting with his metol-based 2-bath developer to see if I liked it better than my previous go-to for all 35mm films, Instant Mytol (basically XTOL stock). In my handful of semi-formal tests, I don't know whether I've actually seen a super noticeable increase in acutance, edge effects, or highlight compensation. But I also have yet to feel like I've confidently dialed in the proper time/temp/agitation for the BTTB. Meanwhile, I can't help but wonder if diluting my Mytol to 1+1 could get me that slight bit of extra grain and edge sharpness that I'm looking for without having to start refrigerating my BTTB

So I started writing down the plan to do a bit more intensive test that includes some side-by-side comparisons of prints made where the only thing changed was the developer (same camera, lens, scene, light, exposure, film, etc. etc.). And figured I might as well post it publicly in case it benefits someone down the line. At the end of the day, the appearance of the final print is what I will use to make my final decision between the two developers. I'll try to provide pictures to illustrate actual differences, but I find that even the best scan of a fiber print just doens't show the way it looks in person. So that part will have to remain kinda esoteric

First contestants will be HP5+, my most-used 35mm film.
 

Paul Howell

Subscriber
Joined
Dec 23, 2004
Messages
9,786
Location
Scottsdale Az
Format
Multi Format
If you are going down the Thornton way, just remember that a high acuance type developer is just one on many factors that he controls for, you may not see the difference if another factor cancelled out the benefit of a given developer.
 

Alan Johnson

Subscriber
Joined
Nov 16, 2004
Messages
3,294
Thank you for sharing. Here are Dr Henry's results for an earlier version of Tri-X developed in Beutler developer with continuous agitation. It's on p240, it may be needed to log in and borrow first.

Controls in black and white photography : Henry, Richard J. (Richard Joseph) : Free Download, Borrow, and Streaming : Internet Archive

270 p. : 28 cm
archive.org

BTTB may be similar (metol) but somewhat less with the newer film and lower pH. I daresay there may be some fringe effects from the acidic oxidation products of Xtol.
 
Last edited:

Harry Callahan

Member
Joined
Nov 15, 2017
Messages
555
Location
?
Format
Analog
Having not heard of Thornton - and after a quick search not having found an explanation of his philosophy - i may be entirely wrong on this, but let me stick my oar in:

If you want acutance and edge effect, the print has to have a certain factor of enlargement. If you do a postcard-size print of a LF negative you can have as much edge sharpness in the neg as you can get - but you wont be able to see it on the print.
Depending on the format and film (and developer) you need a minimum of enlargement factor to see edge sharpness - you`ll have to see the grain on the print.

A metol(-based) developer does reduce grain size. And does increase negative contrast. Hp5 already is pretty contrasty. If this 2-bath-developer can reduce negative contrast it may counteract the higher contrast metol usually does produce, but the grain should be smaller (which wouldn`t be that of a problem with Hp5 as it has a pretty big grain - but you wanted bigger grain as far as i understood).
Edge sharpness usually is achieved by stand or semi-stand developement. Depending on your standart developing procedure you may not see a big difference, as you already may be developing for acutance by doing stand or semi-stand.
 

Ian Grant

Subscriber
Joined
Aug 2, 2004
Messages
23,283
Location
West Midland
Format
Multi Format
It's some years since I tested various films and developers, 1986/7. I had been using FP4 in replenished ID-11, then Adox Borax MQ, again replenished, for nearly 20 years.
,
I was looking for a film/developer combination that gave me good acutance, fine grain, a good tonal range. I ended up using Agfa AP100 (later APX100) in Rodinal, my alternative was Tmax 100 in Rodinal, results werevery similar, the only major difference was I used AP/APX100 at box speed and Tmax 100 at half box speed, same development times.

For a faster35mm/120 film I preferred Tmax 400 at 200EI developed in Xtol (replenished). For a short spell after Agfa pulled out of the film market I was only shooting Tmax, however I switched back to Ilford while living abroad as Kodak B&W films were near impossible to find.

So since 2007 I've been using Delta 100 & 400 in 120 (I rarely use 35mm) and HP5 for 5x4, all processed in Pyrocat HD. I also shoot Fomapan 200 at 100EI agin developed on Pyrocat.

I have read Edge of Darkness, I thought it rather obsessive

Ian
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
It's interesting that Thornton seems to have eventually settled on staining/tanning developers (DiXactol and its variants seem quite similar to a kind of proto-Pyrocat HD). I'm sort of getting interested in that as well, but... I'm interested in seeing if BTTB can work for my goals too. It's potentially a lot less hazardous and more convenient than pyro/catechol stuff.

At any rate, I am shooting my first side-by-side test rolls right now and will share results when I have them.
 

John Wiegerink

Subscriber
Joined
May 29, 2009
Messages
3,706
Location
Lake Station, MI
Format
Multi Format
I think BTTB will work very well for what you're trying to get. I liked it when I tried it and it's simple/foolproof to use. That said, I think I find Pyrocat-HDC or HD gives me slight compensation when I need it, excellent resolution and very good acutance with most of the films I use. I just tried it with some Foma 200 35mm at EI125 and I must say I'm very, very impressed with the resulting negatives.
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
snusmumriken said:
Most sources that I've read say the opposite, that metol alone gives low contrast negatives.
Click to expand...

Your understanding mirrors my own. Metol alone shouldn't do much of anything to grain size. A simple Metol-based developer (such as D23) uses sodium sulfite with the Metol, both to create an alkaline environment that activates the Metol, and as a grain reducer, so perhaps that's what Harry meant?

I believe Thornton started with D23, split it into two baths, and then carefully lowered the sulfite specifically in an attempt to have less solvent action on the grain, and therefore higher acutance.
 

snusmumriken

Subscriber
Joined
Jul 22, 2021
Messages
2,546
Location
Salisbury, UK
Format
35mm
BHuij said:
I believe Thornton started with D23, split it into two baths, and then carefully lowered the sulfite specifically in an attempt to have less solvent action on the grain, and therefore higher acutance.
Click to expand...
It doesn’t really matter, but I think he more likely started with the Leitz 2-bath formula.

I don’t think you have mentioned what kind of photos you have in mind? Are we talking landscapes where every blade of grass needs to be crisp?
 

snusmumriken

Subscriber
Joined
Jul 22, 2021
Messages
2,546
Location
Salisbury, UK
Format
35mm
BHuij said:
Yes, this whole project has specifically been for making exceptionally sharp-looking prints of nature photos.
Click to expand...
I won’t say it can’t be done with HP5+ and some chemical magic, but if you want small sharp details and are committed to 35mm (as I am too), I think Delta 100 (and a tripod and a still day) would get you there more quickly.
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
snusmumriken said:
I won’t say it can’t be done with HP5+ and some chemical magic, but if you want small sharp details and are committed to 35mm (as I am too), I think Delta 100 (and a tripod and a still day) would get you there more quickly.
Click to expand...

I use Delta 100, FP4+, and HP5+ extensively in 35mm. I realize the slower ones are going to be higher resolution To this point I've had good results with Instant Mytol. But Delta 100 in Mytol is extremely high resolution without necessarily being high acutance.
 

snusmumriken

Subscriber
Joined
Jul 22, 2021
Messages
2,546
Location
Salisbury, UK
Format
35mm

Hmm, ok, I see what you mean. I will follow with interest, but I suspect you will ultimately have to be satisfied with being dissatisfied!
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
Okay, I've made some progress here. I found a scene I wanted to photograph that really benefits from high acutance. I shot it on two frames of HP5+ with the same lens, focus, aperture, and shutter speed, with both exposures happening within 30 seconds of each other. Finished both rolls, including some boring "calibration" frames. One roll got developed in Mytol 1+1, and one got developed in BTTB.

I have contact sheets (which are already pretty enlightening) done on RC paper at grade 2. I also have made uncropped full-frame straight prints on 8x10 fiber paper from both frames, selenium toned, etc. The way I normally make my prints.

Print #1. Contrast and exposure optimized via test strips for the Mytol version of the photo
Print #2. Exact same exposure and treatment, but using the BTTB negative
Print #3. Contrast and exposure optimized for the BTTB negative

Comparing 1 and 2 should provide some useful information about differences in the effective film speed and tone curve between the two developers. Looking at 1 and 3 side-by-side is more useful for a subjective "which one gives me more pleasing final results when printed to the best of my ability" type comparison.

Once everything is dry and flat, I'll scan in high resolution and post for posterity.
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
Long overdue posting of the scanned prints. These were scanned at 600 DPI and had white and black points set in Lightroom.

I decided not to scan or post Print #2 - it was pretty light and a bit flat compared to BTTB, so it seems I developed it to a slightly lower contrast index than the Mytol roll. It also clearly had greater overall density. Both rolls preserved plenty of shadow detail, though I printed some of it down to black in Print #1 as I prefer that interpretation for this photo.

Without further ado,

Print #1 - from a roll of HP5+ developed in Mytol 1:1
Canon FTb, Canon FD 50mm f/3.5 Macro, f/11, mirror lockup and self timer used to eliminate camera shake. Didn't note shutter speed; I suspect somewhere around 1/30. On a tripod of course. Uncropped print made on 8x10 Ilford MG FB Classic (Glossy), diffusion enlarger, Grade 1.5, selenium toned.


Print #3 - from a roll of HP5+ developed in BTTB
Canon AE-1, Canon FD 50mm f/3.5 Macro. Identical exposure and printing procedures (though at Grade 2 instead of 1.5). I believe the lens must have been a millimeter or so closer to the subject at time of exposure, as the focus reference was the same (the veins of the left-central leaf), but the right-central leaf went out of focus. Likely due to differences in the relative location of the tripod plate on the camera body and the lens mount. Also please ignore the light leak. I just replaced the seals on that AE-1 and apparently missed a spot.


Obviously the test was executed imperfectly, and as such, I have decided not to submit my results to any scientific journals this time around

But close-in crops from my scanned 8x10 prints show pretty conclusively for my standards that I'm not getting a noticeable (any?) improvement in acutance using BTTB over Instant Mytol. I see none of the purported edge effects despite minimizing agitation with the BTTB. I do believe I saw a bit of compensating effect in the highlights, but nothing that made me want to standardize on this over Instant Mytol. The BTTB has noticeably more grain, but Mytol 1:1 gives a non-zero amount of grain with HP5+ that I think is probably enough for my tastes.

Comparison here:


I suspect sometime this year I'm going to test Pyrocat HDC against Mytol. They're pretty different animals. But for the next little while, I am going to work on some right-brained development in my photography and leave the laboratory tools alone. This is supposed to be an artistic endeavor, after all.
 
Last edited:

John Wiegerink

Subscriber
Joined
May 29, 2009
Messages
3,706
Location
Lake Station, MI
Format
Multi Format
The BTTB scan certainly has a lot more shadow detail so it might look to have slightly less "snap" than the Mytol scan.
 

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
23,716
Location
Europe
Format
Multi Format
To be honest, when it comes to optimizing acutance, I think the subject matter chosen is a little unfortunate. Ice crystals and snow tend to render rather fuzzily much of the time, unless you dial back exposure so that the ice ends up a little less far up the curve.

Try some leafless trees against a bright sky.
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format

Good advice for when I test Pyrocat HDC. Even with sub-optimal experimentation, I think I've seen enough from the BTTB to decide it's not for me. Besides what I already posted, I had a bear of a time finding the right balance between not enough and too much agitation. Had more than one roll with blown highlights, and more than one roll with mottled, uneven development.
 

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
23,716
Location
Europe
Format
Multi Format
I'm quite happy with Pyrocat when it comes to acutance. And in other regards as well, btw. As of late I've been developing most of my 35mm film in Pyrocat HD 1+1+100 with an agitation cycle every 3 minutes. A little grain helps, too. Try HP5+ this way.
 
OP
OP

BHuij

Member
Joined
Oct 12, 2016
Messages
888
Location
Utah
Format
Multi Format
Yeah honestly, I think my original (somewhat unstated) goal of getting thrillingly high-definition 11x14 enlargements from 35mm negatives is probably just pushing the boundaries of the format a little too hard. At the very least, if I can't get it with Delta 100, a prime lens at its sweet spot, and Mytol, then I really ought to just be going to medium format or large format for prints of that size.

Looking at 8x10s (and smaller prints) I have made from 35mm negatives, I'm generally extremely happy with the acutance and overall appearance of my results, even with films like HP5+ that aren't resolution kings.

Pyrocat HDC has some other interesting features. I'm still interested in edge effects, and I'm very interested in the way the color of the staining might help tease out a bit more shadow separation. So when I test it, I'll be watching for those two things more than anything else.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…