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false_Aesthetic
18-Dec-2007, 14:06
Heya,


What does one gain when changing the dilution of Xtol from straight to 1:1, 1:2 and 1:3?
Is it simply acutance?

Second, I heard somewhere that Xtol 1:3 is unstable for some reason. Is this true? I've forgotten who/where I heard this.

Third: Is there an info article on semi-stand developing somewhere.



Oh yeah, I usually shoot fp4+ and develop it in Xtol 1:1.


Thanks

T.

Ted Felton
18-Dec-2007, 14:26
When Kodak first came out with Xtol they listed times for 1:3 dilution. However, when using a small tank for 35mm, such as a Nikkor SS tank that uses only 8 oz., there wasn't enough developer for the film. Film developed this way had on it what Kodak called "donuts" which were little circles with a hole in the middle. I found this out because I was having this problem, sent Kodak some developed film, and one of their engineers called (on the phone) and explained the problem. The solution was to use either 1:2 or 1:1. I chose 1:1. Soon afterwards they eliminated the 1:3 dilution from their data.

Ted

Bruce Watson
18-Dec-2007, 14:56
What does one gain when changing the dilution of Xtol from straight to 1:1, 1:2 and 1:3? Is it simply acutance?

Mostly what you get is the dilution of the sulfites. This results in a small increase in perceived sharpness and a small increase in graininess, all other things being equal (film, temperature, time, agitation, etc.).

Of course, you also gain development time because of the dilution, but I'm assuming that you aren't asking about that.


Second, I heard somewhere that Xtol 1:3 is unstable for some reason. Is this true? I've forgotten who/where I heard this.

I've been using XTOL 1:3 for years. I mix stock solution using distilled water, then dilute at run time with distilled water. Never had a problem.

The problems XTOL has had in the past seem to be attributable to packaging problems and mixing with water containing too many impurities (I seem to recall something about too much iron in the water, but can't remember what that was exactly). People mixing with distilled water report few problems apparently.

Kirk Gittings
18-Dec-2007, 16:07
Bruce I am in the process of switching to Xtol. How are you processing and


Mostly what you get is the dilution of the sulfites. This results in a small increase in perceived sharpness and a small increase in graininess, all other things being equal (film, temperature, time, agitation, etc.).

Since you scan film (what film? how large do you print?) do you find the grain a drawback for scanning?

Henry Ambrose
18-Dec-2007, 16:47
I second what Bruce wrote and carrying it a bit further --

There is no problem with Xtol 1:3 if you will simply use enough developer. Don't scrimp. You need 100ml MINIMUM for each 80 sq. inches of film. I use a bit more. Minimum means the least you can get away with -- but why court problems? Always, always use enough stock developer.

Xtol at 1:3 is just wonderful with most any film you can pick.
Wonderful in small tanks and wonderful with hangers in large tanks and Jobos if you'll just be sure to use enough stock developer.

For best quality control keep it in dose size bottles. If you typically use 250ml each session buy a bunch of 250ml glass bottles and keep your Xtol there ready for one shot use. Don't store half full bottles for long. Keep air away from your stored Xtol. It'll last a long, long time and give consistent predictable results.

tgtaylor
18-Dec-2007, 16:59
I have just started using Xtol (I'm about 100ml of finishing the 2d 5L batch) and have been developing Fuji Acros at 1:3 by hand inversion in a Jobo 2500 tank. Fuji says to agitate continousle for the first minute and then 5 seconds each minute thereafter. I've been following that religiously for the last 10L of Xtol with a total developing time of 14.5 minutes or 30 seconds beyond the time in Digitaltruth. The extra time is to compensate for filling the tank. No problems on 120 and 4x5. What about letting the film stand longer than 60 sec between agitations? Has anyone tried that yet that would care to share their experience?

Helen Bach
18-Dec-2007, 17:17
I use Xtol 1+3 for most things. As already mentioned you need to pay attention to minimum quantities.

The German Kodak site still has the data sheet with the 1+3 times. http://www.kodak.fr/AT/plugins/acrobat/de/professional/xtolEntwickler.pdf

Best,
Helen

Brad Rippe
18-Dec-2007, 17:21
I also just started using Xtol with Fuji Acros 100 in quickloads. At 1:1, 68 degrees, I'm at around 9 min in trays. The other day I tried some Tri-X 320 with the same dilution, slightly shorter development time, and the film came out beautifully. I'll try it again, but I'm not quite ready to switch from HC110.
-Brad

Bruce Watson
18-Dec-2007, 17:35
Bruce I am in the process of switching to Xtol. How are you processing and since you scan film (what film? how large do you print?) do you find the grain a drawback for scanning?

I'm processing with a Jobo CPP-2, 3010 tank. I'm using XTOL 1:3, 20C indicated (I think it's a little off, maybe 20.5C or so). I've printed up to 12x enlargement (about 150 cm in the print along the 5" dimension of the film).

I've been using Tri-X. I was about to start the trials (EI, normal development time, all that) to bring up 400Tmax when Kodak announced TMY-2, so I'm delaying that until I can work with the new emulsion.

As to the grain itself. It's a sort of nebulous question. What I found was that the grain seems about the same size as I was getting with HC-110H, but it's a little more nicely formed. Local contrast on that level (loupe level) is a tiny bit better with the HC-110H, but that's a moot point for me since I can't control the HC-110H with continuous agitation -- just too active a developer (meaning, development times have to be too short). My point being that I don't feel like I lost anything at all by going to XTOL, and in fact gained 2/3 stop of real film speed. I'd make the switch just for that ;) The environmental aspects of XTOL are a really big plus as well.

Since I scan and never print in the darkroom I optimized my film for my scanner and workflow. So my Dmax is somewhat less than it would be for darkroom work. I target a Zone VIII of around 1.0, or in Zone System terms, about N-1. Since graininess is directly related to density, this farther decreases graininess. The benefit is in the decrease of Callier Effect. What I see in my scan files is an increase in local contrast in the highlight (dense) areas. This means less work in Photoshop (actually, none) to bring local contrast in line from top to bottom. Before I optimized for scanning I would do some work to decompress the highlights, now I don't have to. The scans are really surprisingly linear.

What does all this mean to the final print? Well, I've been printing with Epson printers, Cone PiezoTone inks, and the StudioPrint RIP. I have to say that I can't see the grain in the print in a 10x enlargement (say a 50 x 40 inch print). Without a loupe on the print that is. Even under a loupe the smoothness is surprising. It's just smooth tone. At 12x I can just begin to see the start of graininess in clouds.

So I'd say I'm pretty happy with XTOL. Not that I recommend my methods to everyone - I think people should find workflows with which they are comfortable, learn them well, then concentrate on their art. But this sure works for me.

false_Aesthetic
18-Dec-2007, 19:44
Bruce, that is EXACTLY what i want to hear!!!

Kirk Gittings
18-Dec-2007, 20:33
Bruce interesting, my vintage TRI-X negatives all dev. in HC-110 have visible grain at 16x20, with a prosumer flatbed kind of mushy vague grain, with a drum or pro flatbed at sharp-grain almost identical to a traditional silver print at that size from the same negatives!?

Bruce Watson
19-Dec-2007, 08:48
Bruce interesting, my vintage TRI-X negatives all dev. in HC-110 have visible grain at 16x20, with a prosumer flatbed kind of mushy vague grain, with a drum or pro flatbed at sharp-grain almost identical to a traditional silver print at that size from the same negatives!?

<disclaimer>
I'm just a engineer / photographer who has done a lot of reading and too much subjective testing. I don't have access to the type of lab that would let me really investigate this stuff, so I haven't. Also, for the purposes of this discussion I'm just going to use "grain clump" when I really should say "grain clump and/or dye cloud." Anyone reading can extrapolate from B&W to color if they want to.
</disclaimer>

Well, this is why I said it's sort of nebulous. For one thing, when you scan film you can't actually image the grain. Grain clumps look to me to be almost fractal in nature. IOW, it would take a good many pixels to allow you to see the actual shape of the grain. For the sake of argument lets call it 10 pixels per grain clump. Now I read somewhere (don't remember where or even when) that film grain clumps range fairly widely in size, more than an order of magnitude. So for film with an RMS graininess of say 10 microns, grain clump sizes could be as small as say 2 microns and as big as say 18 microns. To get 10 pixels from a 2 micron grain clump you are going to need a spot size of less than 0.2 microns. Without doing the math I'd guess around 0.1 micron. That's about 30x smaller than the smallest aperture on the best commercially available drum scanner. IOW, that's a microscope.

All I'm saying is, even the best drum scanner isn't imaging actual film grain clumps. The laws of physics are too hard to violate.

So what they do instead is they create a perfectly square pixel (decidedly not-fractal in shape) that has a single color space value (say hue, saturation, and luminosity). You loose film grain and replace it with "digital grain" for lack of a better term.

On top of this, the distribution of film grain clumps in the emulsion is stochastic. All film scanners, CCD or PMT, are deterministic. That is, they create a virtual grid and create pixels by sampling the film through the holes of this grid. So if a film grain clump is centered in a grid hole you get a good idea of what it's HSL value is. If instead, which is the more normal case, the grain clump straddles two or more holes in the grid, the pixels still show what the scanner sees, but the resulting pixels contain a mixture of the HSL value for the grain clump and for the non-grain clump part of the film that the scanner sees through this particular hole. This is in part what causes scanned images to be somewhat soft and is the reason some people like to apply some "capture sharpening" to a fresh scan file.

I'm not even going to talk about lighting differences between flat bed scanners and drum scanners, and the effects thereof. Too painful.

But wait, there's more. You get the inverse effect happening when you print with an inkjet printer (or a lightjet, chromira, lambda, etc.). Here you are trying to create your pixel on paper using a number of ink droplets (laser or LED spots, etc.). The printer / driver does this using a dither algorithm which takes into account the HSL values for surrounding pixels, this done to improve gamut, smoothness, sharpness, whatever the particular dither pattern is optimized for. This is what I think of as "printer softness" and is one of the main reasons for people to apply "output sharpening" before printing.

The reason any of this works at all is that it takes a large number of film grain clumps to record actual image detail information. One can think of this detail information has being at a considerably lower resolution than the film grain. For example, one can think of capturing the majority of the image detail information with a scanner resolution of, say, around 2000 spi (actual number will vary widely from film to film, process to process, scene to scene, exposure to exposure, etc.) while one must go considerably higher to capture the actual film grain (say, 50,000 spi). Most people scan in the range of 4000 spi which lets them capture practically all of the image detail and coincidentally tends to be the maximum of many scanners.

All of this stuff probably adds together in some interesting ways. Visually I suspect that it's partly responsible for why inkjet prints can look smoother and less grainy than darkroom prints of the same enlargement.

Then there's that phrase "vintage Tri-X." Tri-X 30 years ago was a grainy film. Now, not so much. I've got access to a 20 x 16 Adams print, made with a 10x8 camera and Super-XX film. Visibly grainy and only a 2x enlargement.
So a lot depends on the film used and how it was exposed and processed.

And finally there's personal taste. What's too grainy for one person is another person's perfectly smooth.

In the end all we are left with is prints. And all we can do is work to improve our workflows so that we can make the best prints we can.