Choosing B&W film to optimize scanning results

[Raghu Kuvempunagar]

I have yet to see a good discussion on the origin of grain aliasing that goes beyond vague generalities but is reasonably rigorous and also reasonably accessible to me. Can anyone point to a good discussion of the origin of grain aliasing.
...

Not sure if this meets your criterion, but is an interesting read:
http://www.normankoren.com/Tutorials/MTF8.html

 

[Oren Grad]

As a complement to Norman Koren's discussion, see also this...

https://theonlinephotographer.typepad.com/the_online_photographer/2011/03/gigabyte-film-scans.html

...including the comment exchange by Chalres Rozier and Ctein, starting here:

https://theonlinephotographer.typep...0c#comment-6a00df351e888f8834014e5fa24e5d970c

 

[Alan Edward Klein]

For whatever it's worth, here are two scans on my V850 of 4x5 film Tmax100 and Tmax 400. You can definitely see the grain in the sky with the 400. Whether that's grain, aliasing, or whatever, I don't know.

When the pictures open, you can click on them to zoom in to see the skies better.
4x5 Tmax 100 https://www.flickr.com/photos/alanklein2000/49843392888/in/album-72157714124881023/
4x5 Tmax 400 https://www.flickr.com/photos/alanklein2000/50009699402/in/album-72157714124881023/

 

[Michael Mutmansky]

I shoot 6x17 scan and print (cause i dont have a 5x7 or larger enlarger). you are talking 24 inches on the height if I read you post right, so a 10x enlargement. for B&W most 100/125 speed films and slower will work as well as tmax 400. if you are having a lab develop, then I would suggest doing it yourself if you are as worried about results as you seem to be. for me, the best developer FOR SCANNING has been pyro-M. it really helps with the grain. even tri-x 120 shots enlarged 10x dont show grain or mushiness which seems to worry you. also, the scanner is gonna make or break your results. I used to scan my 6x17 film on a nikon 9000 and stitch in photoshop, but after getting a flextight scanner i can now do it on 1 pass. slide film will scan your size no problem. I have scanned and printed at the sizes you are talking about and they look great. but be careful no to over sharpen you scans!

all things being equal, the scanner will be the deciding factor for you. a flatbed will not work for what you are looking to do. if its really important, get a drum scan, be done and stop worrying about it. otherwise, its a compromise.

i have shot a total of 1 roll of xp2 and it didnt work for me. I would look at delta 100, tmax 100, acros or panF

john

John,

I don't see me doing 10x enlargements very often at all, but I want to make decisions that will allow that to occur. I think that if I go there, I will likely get a drum scan for those unless I have a good path to do a really good quality high-res sacan myself.
I figured that a tanning developer may come into play for this throgh the recommendations... I know that this will have a lower grain appearance while maintinaing the optical density, so that is an option I will leave open. I used to use Pyrocat HD in the past for the pt/pd negatives to build the contrast needed in the negatives, but I found that approach to be somewhat unpredictable so I dropped it in favor of the PQ Universal because it proved much more consistent.

Ultimately, I want to be making decisions that give me the best options in the future with the negatives. That means exposing properly, developing optimally, and choosing the most amenable films. I'm targeting 100 Delta primarily and I guess 400 Delta as well for B&W. In color, I'l probably be keeping some Provia 100Fand some Ektar 100 in the bag.

 

[Adrian Bacon]

That's a great question. The answer is that I am not aware of any serious references (and by serious here I mean 'peer reviewed').

The field of hybrid photography is relatively new and needs solid quantitative foundations that essentially do not exist currently. In my limited, but growing, personal experience, I'm finding that truisms such as 'just expose and develop optimising for a grade 2 condenser enlarger print and your scans will be FINE" just don't always hold true. A scanner CCD sensor is a fundamentally different device than the pair (condenser enlarger, grade 2 paper) and a direct translation doesn't even begin to address a question of optimality.

I think it would be interesting to put together a working group, team up and do methodical experimentation to this end.

If you're going to digitize negative film, in my experience, it's best to scan it so that you get the maximum number of discrete tonal values out of the sensor (i.e. bunch the raw scan as far over to the highlight side as far as possible without clipping anything), then from there, apply the gamma correction to linearize it back out, then invert it. This is assuming you have the raw sensor values. The more discrete tonal values you have, the better it looks, and negative film is unusually well suited to scanning with the way digital sensors work.

 

[Adrian Bacon]

The classical definition of grain aliasing is the accentuation of the film grain in a scan because the scanning sampling pattern overlays on the grain in a manner that can introduce a higher visual impact of the grain (thus, the grain looks, uh, "grainier") than it is in the actual film.

In my experience, the vast majority of what many claim to be grain aliasing is actually artifacts being introduced as part of the post processing step to get a positive image. If you have the actual raw negative scan, much of what people claim as grain aliasing just isn't there in the raw pre-processed image. Unfortunately, much of what is posted online as examples is post processed images compressed as jpegs. Look at the raw sensor values and see if it's there. That's the only way to judge things.

That being said, most film scanners don't have an optical system that even comes close to the native sensor resolution, so the whole concept of grain aliasing with those scanners is moot.

 

[Adrian Bacon]

Factors that impact this are the size of the grain, the sampling frequency of the scanner, the size of the scanner sampling "dot", the spacing of these "dots", whether there is a gap between the dots (or if they overlap), and a bunch of other factors related to the optical performance of the scanner and also the nature of the film grains. Plus, throw in the moon cycle and whether Mercury is rising for good measure...

If you use a camera and macro lens set up, many cameras have an antialiasing filter in front of the sensor that makes grain aliasing a moot point. Frankly, I wouldn't ever use any bayer CFA camera that didn't have one as it introduces all kinds of other issues when you take that anti-aliasing filter out of the optical path.

 

[alanrockwood]

Thanks for the links Raghu and Oren. (I had already seen some, but not all of them, but it's appreciated nevertheless.)

 

[hsandler]

I am surprised that no one mentioned Acros as a fine-grained film. In my limited experience, Acros at box speed in Xtol or D76 produces grain a bit finer than Delta 100 at similar exposure and development. Also, I find the shadows don’t need to be boosted by a curve with Acros, as I usually have to do with Delta: Acros looks about right with a linear scan. Xtol 1:1 is a bit finer grained than D76 1:1, but having experienced sudden death of Xtol, I now stick to D76. I have used XP2 a bit. It’s good for high key images, especially when overexposed at ISO 200, but it has a different look as the “grain” is in the shadows. It doesn’t tolerate underexposure much at all. I scan with an Epson V750at 2400ppi or photograph 35mm negs with a 16MP digital camera and macro lens.

 

[alanrockwood]

It seems to me that, all things considered, from a technical standpoint Acros might be the world's best conventional black and white film. Too bad it's expensive, but I guess you get what you pay for, assuming one actually needs the best. (By the way "best" here does not mean best at doing a single thing, but best over all.)

 

[yeolde]

John,
Ultimately, I want to be making decisions that give me the best options in the future with the negatives.

Michael, hello! I scan on the eversmart Supreme with 5600 ppi. I recently scanned some XP2 and can recommend. There is special know-how how to reduce grain, and prepare the neg to the scanning (and enlarging)
Would you be so kind to post the real size fragments of your image. I want to see your situation to be compared with mine

 

[Michael Mutmansky]

I am surprised that no one mentioned Acros as a fine-grained film. In my limited experience, Acros at box speed in Xtol or D76 produces grain a bit finer than Delta 100 at similar exposure and development. Also, I find the shadows don’t need to be boosted by a curve with Acros, as I usually have to do with Delta: Acros looks about right with a linear scan. Xtol 1:1 is a bit finer grained than D76 1:1, but having experienced sudden death of Xtol, I now stick to D76. I have used XP2 a bit. It’s good for high key images, especially when overexposed at ISO 200, but it has a different look as the “grain” is in the shadows. It doesn’t tolerate underexposure much at all. I scan with an Epson V750at 2400ppi or photograph 35mm negs with a 16MP digital camera and macro lens.

It seems to me that, all things considered, from a technical standpoint Acros might be the world's best conventional black and white film. Too bad it's expensive, but I guess you get what you pay for, assuming one actually needs the best. (By the way "best" here does not mean best at doing a single thing, but best over all.)

I used to only use Acros when shooting 4x5, in part because it was available in the QL packs so I could keep it in my bag and swap from color to B&W very easily. It's a great film for sure, or at least it was. I haven't used it in the current form, but I can't imaging it has changed much if at all.

The cost is a bit silly, though. Maybe they are pricing it where it must be to keep the line profitable, but it drives away customers with the premium; over 50% higher in cost than a lot of other b&w films. My other thought is that they no longer offer a 400 speed film so I'd have to go to Delta for that anyway. Or maybe TMAX, of course... I'd probably prefer to keep to a single brand, although I suppose that isn't really all that important or necessary.

 

[yeolde]

Also from the handling point i very like Ilford film base (way handier than kodak)

 

[PhilBurton]

Tmax 100 and Tmax 400. Both scan well and were made for scanning. Use Xtol if the lab provides. Tmax uses T grain. Other developers are very good too Use the 100 for long shots on a tripod. If you absolutely need the speed, then shoot Tmax 400. I use an outside lab.
See my FLickr for samples of 4x5 and other formats.
Tmax 400 35mm and 4x5, sorry no MF. https://www.flickr.com/search/?sort=date-taken-desc&safe_search=1&tags=tmax400&user_id=55760757@N05&view_all=1
Tmax 100 6x7 and 4x5 https://www.flickr.com/search/?sort=date-taken-desc&safe_search=1&tags=tmax100&user_id=55760757@N05&view_all=1

And Tri-X? Not as good for future photographs meant to be scanned? And I have some old Pan-X and Plus-X I also need to scan. Comments?

 

[StevieRose]

Hi Oren--Greetings from a fellow TOP buddy! I haven't been over here in a long time but have recently started lurking again. In regard to your question, while there are likely some films that scan better than others (mentioned above) I think if your goal is a hybrid workflow it comes down more to creating a negative that contains as many of the tonal values present in the scene as possible--so creating a "flat" negative. The reason is that you can always add contrast in post processing (with curves, etc.), but, you cannot re-create tones in post that aren't there in the negative. To do this I try to "overexpose" and "under develop" by around 15-20% with traditional BW films. I will shoot HP5+ or Tri-x at an EI of 200-250 and then decrease the development time a bit. Also, in this regard, I have found that HP5+ works out well--many people prefer Tri-X to it because HP5 develops generally with flatter contrast and Tri-X with more contrast punch. However, for scanning the flatness is an advantage. Another route to consider is to use Diafine (or another 2 bath developer) if your intention is scanning. It does a great job of preserving highlights and shadows without much fuss. Of course you lose the ability to control contrast with the Zone System with Diafine, but, Diafine kind of does that for you. Tim Layton wrote a good blog post about this: https://www.timlaytonfineart.com/blog/2015/3/diafine-a-black-and-white-developer.
Take care
Steve Rosenblum
Ann Arbor, Michigan