alexz
Well-known
My second manually processed B&W roll - I begun to notice a common issue in my two processed rolls after scanning them - the contrast appears to be somewhat "light", almost all the frames exhibit dead zone on the shadows side of the histogram in PS (Levels) - usually require to squeeze the left (shadows) lever of Levels by 10-18 units to the right towards the begnning of the histogram in order to stretch the contrast into darker tones. Almost all frames on both rolls show the bulk of the histogram shifted to the right (lighter tones).
I can hardly blame the scanner - it performed flawlessly for many years so far (nikon LS-40), no problems with it, but to my untrained to B&W processing eye the reason apparently lies in development - either under or over development, or probably agitation-related issue.
The film is Tri-X shot at nominal 400, developer: HC-110 (European), dill. B @ 20 degrees C for 6.5 minutes, first minute continuous agitation (slow flipping upside down and back), then 10 seconds at the end of each subsequent minute. After that (and prior to fixer) - filling up the tank with water at approx. the same temp. and letting it to sit for another 5 minutes with little agitation (10 seconds per minute).
So, if you see the histogram continuously shifted to the right (towards lighter tones) leaving the shadows empty (no pixels) up to about 10-18 points thoughout entire processed rolls - should it be under or over development ? Or probably excessive or, alternatively, non-suficient agitation ?
I can hardly blame the scanner - it performed flawlessly for many years so far (nikon LS-40), no problems with it, but to my untrained to B&W processing eye the reason apparently lies in development - either under or over development, or probably agitation-related issue.
The film is Tri-X shot at nominal 400, developer: HC-110 (European), dill. B @ 20 degrees C for 6.5 minutes, first minute continuous agitation (slow flipping upside down and back), then 10 seconds at the end of each subsequent minute. After that (and prior to fixer) - filling up the tank with water at approx. the same temp. and letting it to sit for another 5 minutes with little agitation (10 seconds per minute).
So, if you see the histogram continuously shifted to the right (towards lighter tones) leaving the shadows empty (no pixels) up to about 10-18 points thoughout entire processed rolls - should it be under or over development ? Or probably excessive or, alternatively, non-suficient agitation ?
Xmas
Veteran
If you have no shadow detail then you need more exposure.
Look at the emulsion side of the negative with the light source behind your head do you see a positive image?
Noel
Look at the emulsion side of the negative with the light source behind your head do you see a positive image?
Noel
Last edited:
alexz
Well-known
Thanks Noel, but that doesn't look like exposure problem, in particular bearing in mind I often use incident metering (and generally pretty much good with my exp. estimation).
While looking at the negs, I very rarely see solid bright areas (that are rendered to shadows), most of the neg. area in most frames is darker which may confirm the general "lightness" (or shell I say "thin") of the negatives.
While looking at the negs, I very rarely see solid bright areas (that are rendered to shadows), most of the neg. area in most frames is darker which may confirm the general "lightness" (or shell I say "thin") of the negatives.
pau3
Well-known
Hi,
it may be some exposure problem after all. The real speed of TriX is closer
to 250 than to 400, which means that if you shoot it at 400 you are loosing
some shadow detail. However, not much shadow details. On the other hand,
if you see a shift of all the histogram, probably that means that you haven't
reached enough density in the highlights, and then you should develope during
longer times. In fact, my developing times for TriX are way longer than those
in the boxes.
Pau
it may be some exposure problem after all. The real speed of TriX is closer
to 250 than to 400, which means that if you shoot it at 400 you are loosing
some shadow detail. However, not much shadow details. On the other hand,
if you see a shift of all the histogram, probably that means that you haven't
reached enough density in the highlights, and then you should develope during
longer times. In fact, my developing times for TriX are way longer than those
in the boxes.
Pau
Xmas
Veteran
Alexz
Did you try the positive image test, above?
Incident metering will leave uniform high light density but negative film needs some detail in shadows.
And yes you might need more dev time, e.g. is your thermometer calibrated.
I have to derate film and dev for longer, and still get thin negatives, but I cant advise on Tri-x.
Noel
Did you try the positive image test, above?
Incident metering will leave uniform high light density but negative film needs some detail in shadows.
And yes you might need more dev time, e.g. is your thermometer calibrated.
I have to derate film and dev for longer, and still get thin negatives, but I cant advise on Tri-x.
Noel
markinlondon
Elmar user
If the shadows have no detail it is underexposure. Underdevelopment will give low overall contrast. For that combo I've found 7 mins at 20C (according to my themometer) to give good at results at EI400 but 1/2 to 1 stop of extra exposure wouldn't have hurt at all. You agitate quite a bit more than me too.
I couldn't possibly comment on the real speed of Tri-x, that depends on so many variables.
I couldn't possibly comment on the real speed of Tri-x, that depends on so many variables.
alexz
Well-known
Thank you guys.
What I meant to say is that there is lack of deep shadows and the histogram of the scans approves that. Would that be exposure problem, that would hint for overexposure, but somehow I tend to believe this is not related to exposure.
What I need to understand is development processes - i.e. how it is handled, what may result under or overdevelopment, etc...
I was told once that at the beginning of the development, first highlights are developed, then followed by mid tones and towarsd then end of development time shadows are developed. If this is correct, what might be our conlcusion (development-wise) bearing in mind obtaining not dense enough shadows ? Will longer development dain more density in shadows ? Or, should I talk about shortening development time ? Or probably too intensive (or too lazy) agitation may lead to such result ?
P.S. Noel, sorry, I didn't understand what did you mean by positive testing. Can you pleas elaborate ?
Mark, what I meant in my original query - exactly the opposite issue - the shadows are too light stealing from overall contrast, I got almost no deep shadows on the entire roll - had to tweak Levels in PS (squeezing a bit from zero to the right) in order to gain an artificial contrast.
What I meant to say is that there is lack of deep shadows and the histogram of the scans approves that. Would that be exposure problem, that would hint for overexposure, but somehow I tend to believe this is not related to exposure.
What I need to understand is development processes - i.e. how it is handled, what may result under or overdevelopment, etc...
I was told once that at the beginning of the development, first highlights are developed, then followed by mid tones and towarsd then end of development time shadows are developed. If this is correct, what might be our conlcusion (development-wise) bearing in mind obtaining not dense enough shadows ? Will longer development dain more density in shadows ? Or, should I talk about shortening development time ? Or probably too intensive (or too lazy) agitation may lead to such result ?
P.S. Noel, sorry, I didn't understand what did you mean by positive testing. Can you pleas elaborate ?
Mark, what I meant in my original query - exactly the opposite issue - the shadows are too light stealing from overall contrast, I got almost no deep shadows on the entire roll - had to tweak Levels in PS (squeezing a bit from zero to the right) in order to gain an artificial contrast.
Last edited:
Xmas
Veteran
Alez
Hold negative with emulsion side the matt side facing you and a the light source behind if you rotate the negative if it is underexposed it will appear as a positive image, at the correct angle. That would indicate independent of your scanner histograms that it was underexposed.
If so you need to think about more exposure.
When I use chrome film I set my meter to the box speed and use incident method, 100% or near acceptable slides, I need +1.5 stops more for B&W...
Noel
Hold negative with emulsion side the matt side facing you and a the light source behind if you rotate the negative if it is underexposed it will appear as a positive image, at the correct angle. That would indicate independent of your scanner histograms that it was underexposed.
If so you need to think about more exposure.
When I use chrome film I set my meter to the box speed and use incident method, 100% or near acceptable slides, I need +1.5 stops more for B&W...
Noel
Kameran Kashani
Newbie
Hi Alex. If I were in your shoes, I'd make some test shots and experiment with different exposures and different agitation.
According to a note on the Digital Truth developing chart, you might want to try continuous agitation with Tri-X 400 and HC-110. (Check out http://www.digitaltruth.com/devchart.html.)
For the tests, I would include a chalkboard/whiteboard with the exposure info of each frame, plus something with a full tonal scale, then vary the exposures incrementally from way-under to way over. I'd also do this twice: one set of tests on frames 1-18 and a duplicate set of tests on frames 19-36.
In the darkroom or changing bag, cut the film in half. It doesn't have to be precisely in half... just get close. The middle two frames will be biffed, but if you have multiple frames of each test it won't matter. Load each half onto seperate reels and develop one reel in your usual way and the other reel using continuous agitation.
If neither of those tests solves the problem, I would re-do the same test exposures and experiment with longer development times.
Kameran
According to a note on the Digital Truth developing chart, you might want to try continuous agitation with Tri-X 400 and HC-110. (Check out http://www.digitaltruth.com/devchart.html.)
For the tests, I would include a chalkboard/whiteboard with the exposure info of each frame, plus something with a full tonal scale, then vary the exposures incrementally from way-under to way over. I'd also do this twice: one set of tests on frames 1-18 and a duplicate set of tests on frames 19-36.
In the darkroom or changing bag, cut the film in half. It doesn't have to be precisely in half... just get close. The middle two frames will be biffed, but if you have multiple frames of each test it won't matter. Load each half onto seperate reels and develop one reel in your usual way and the other reel using continuous agitation.
If neither of those tests solves the problem, I would re-do the same test exposures and experiment with longer development times.
Kameran
bmattock
Veteran
ChrisN
Striving
A related recent thread: http://www.rangefinderforum.com/forums/showthread.php?t=42457
40oz
...
there is a difference between a lack of shadow detail and a lack of black shadows from a scan. Pretty much all of my scans of Tri-X demand adjustment of contrast. I'm not bothered by it because I still get all the shadow detail and highlights. It's more of an indication of how the film and scanner interact than any indication of the film process.
Do you have a sample you can post? Preferably a straight scan that has simply been resized.
If you consider scanning to the be end use of your films, you might consider adding some time to your development process to increase contrast by say, 20% and see how it scans. The bottom line is that no matter what anyone else says, the only "correct" exposure and development is that which makes you happy. You might find you need to adjust exposure and/or development, or that the process you are already using is as good as it is going to get.
Do you have a sample you can post? Preferably a straight scan that has simply been resized.
If you consider scanning to the be end use of your films, you might consider adding some time to your development process to increase contrast by say, 20% and see how it scans. The bottom line is that no matter what anyone else says, the only "correct" exposure and development is that which makes you happy. You might find you need to adjust exposure and/or development, or that the process you are already using is as good as it is going to get.
alexz
Well-known
40oz said:
That something that may indeed be needed to take into consideration indeed
The scans show no problem with details in shadows - the problem is that these shadows appear to be lighter then I would expect making an impact in overall frame contrast (lowering one). The histogram (Levels menu in PS) confirms that by means of showing no pixels amount in the darkest end and in most cases the total bulk of the histogram appears to be shifted towards highlights (to the right of the histogram). To cope with that, I have to sqeeze the dark-side histogram slider (in Levels) to the right a bit by 10-18 points in order to stretch shadow into darker appearence to gain some contrast.
I'm preparing a few examples of straight scans to post here (resized of course)...thanks..
alexz
Well-known
Here are two images -straight scan, no any further processing except of resize.
Checking histogram reveals no pixels in dark shadows, though some clipping on highlights. The highlights may be clipped correctly due to extremely wide contrast range in the scene. Highlights clipping isn't typical - I don't think this is some precedence...but shadows lack of contrast are....
Please let me know what you think...I may add some more examples if needed
Checking histogram reveals no pixels in dark shadows, though some clipping on highlights. The highlights may be clipped correctly due to extremely wide contrast range in the scene. Highlights clipping isn't typical - I don't think this is some precedence...but shadows lack of contrast are....
Please let me know what you think...I may add some more examples if needed
Attachments
vicmortelmans
Well-known
alexz said:
Can you do a raw scan as well? After all, these images have been post-processed by your scanner software, so it can very well be that the scanner software messes up your images, by applying wrong post-processing.
Groeten,
Vic
vicmortelmans
Well-known
alexz said:
I looked at the article "assessing negatives", and based on the information you provided, I think your negative classifies as 'overexposed - underdeveloped'.
The fact that you don't get enough shadow detail seems contradictory to the overexposure, but there may be another explaination for that. Because of the underdevelopment, the negative contrast is low, and maybe the scanner can't handle this.
Groeten,
Vic
alexz
Well-known
Thanks.
Well, raw scan can hardly be achievable (IMHO, I wish Id be wrong) - all I set for scanning was Neg (Mono) and Grayscale. Since it is grayscale, I suppose scanner's software should apply any color-related processing, neither I manually tailor curves or levels prior to full-res. scan.
The underdevelopment - sounds reasonable to me, especially once to be handled by scanner, however not sure about overexposure (perhaps some particular frames, but not in general). Right now I tend to think the issue is related to development-scanning link, i.e. the need to tweak the development for particular scanner characteristics (i.e. to somewhat extend the development to achieve more dense shadows to that my scanner would treat them properly and fit the entire contrast range into its physically achievable scale).
I consider developing next roll (similar one to the previous two) about 15-20% longer then these I made and see how my scanner will handle them...
BTW, Massive Dev. chart suggests 7.5 min of developing for my conditions, I did 6.5min instead. Next roll I'll do 7.5 minutes to check out the outcome..
Well, raw scan can hardly be achievable (IMHO, I wish Id be wrong) - all I set for scanning was Neg (Mono) and Grayscale. Since it is grayscale, I suppose scanner's software should apply any color-related processing, neither I manually tailor curves or levels prior to full-res. scan.
The underdevelopment - sounds reasonable to me, especially once to be handled by scanner, however not sure about overexposure (perhaps some particular frames, but not in general). Right now I tend to think the issue is related to development-scanning link, i.e. the need to tweak the development for particular scanner characteristics (i.e. to somewhat extend the development to achieve more dense shadows to that my scanner would treat them properly and fit the entire contrast range into its physically achievable scale).
I consider developing next roll (similar one to the previous two) about 15-20% longer then these I made and see how my scanner will handle them...
BTW, Massive Dev. chart suggests 7.5 min of developing for my conditions, I did 6.5min instead. Next roll I'll do 7.5 minutes to check out the outcome..
40oz
...
the scans look fine to my eyes. I don't think you have a problem with development or exposure. I think it's just a factor of the scanner not rendering the shadows as black in the final image file. That's what I use photoshop for. It's rare that it isn't needed. I just used Image->Adjustment->Auto Contrast on one of yours, and it looks great.
I wouldn't worry about it, but I'm not you. I've only rarely had a negative that used the whole histogram, and the resulting image wasn't anything worth sharing, as far as I'm concerned.
I wouldn't worry about it, but I'm not you. I've only rarely had a negative that used the whole histogram, and the resulting image wasn't anything worth sharing, as far as I'm concerned.
John Bragg
Well-known
Hi, Alex.
I think the way to achieve your aim with this developer, is to use a higher dilution and far less agitation. The shadows are showing less contrast than you would ideally like, and the highlights are showing proportionately more development.... HC-110 is a very active developer and high rates of agitation will cause just the effect you describe. Many long time users of HC-110 make it at half the strenghth of dilution B, or as it is known unofficial dilution "H". If you then start at twice the development time for dilution B as a starting point, and reduce the amount of agitation given, the development will procede as normal in shadow areas, whilst being more restrained in the highlights. Used in this manner HC-110 is far more user friendly and can be tweaked to your liking a lot easier.
1:19 dilution from the European strength dev will give Dilution H. I would then run a test roll at 13 minutes, with agitation 30 secs initial, then 2 inversions at the start of each following minute. Bracket your exposures between EI 200 and 400 and see which film speed gives the best scan. My bet is somewhere about EI 200 or 250. Once you nail the shadows, then you can refine the length of development to give the highlight contrast you want. Blown highlights need a reduction in time and flat highlights need more development. Either way within about three rolls you should establish both your "PERSONAL" exposure index and development time.
Regards, John.
I think the way to achieve your aim with this developer, is to use a higher dilution and far less agitation. The shadows are showing less contrast than you would ideally like, and the highlights are showing proportionately more development.... HC-110 is a very active developer and high rates of agitation will cause just the effect you describe. Many long time users of HC-110 make it at half the strenghth of dilution B, or as it is known unofficial dilution "H". If you then start at twice the development time for dilution B as a starting point, and reduce the amount of agitation given, the development will procede as normal in shadow areas, whilst being more restrained in the highlights. Used in this manner HC-110 is far more user friendly and can be tweaked to your liking a lot easier.
1:19 dilution from the European strength dev will give Dilution H. I would then run a test roll at 13 minutes, with agitation 30 secs initial, then 2 inversions at the start of each following minute. Bracket your exposures between EI 200 and 400 and see which film speed gives the best scan. My bet is somewhere about EI 200 or 250. Once you nail the shadows, then you can refine the length of development to give the highlight contrast you want. Blown highlights need a reduction in time and flat highlights need more development. Either way within about three rolls you should establish both your "PERSONAL" exposure index and development time.
Regards, John.
Last edited:
vicmortelmans
Well-known
40oz said:
As a matter of fact, they do indeed, certainly concerning shadow detail.
You can see the detail in the black hair of the child and you can also see the wood structure in the side of the desk, two shadow area's that would have been without detail in case of underexposure.
Groeten,
Vic