I thought about posting some images in the gallery...

[photomc]

Sandy, have enjoyed your comments but have to ask - What is ES you refer to here? Sorry, just don't have a clue.

 

[scootermm]

I think he means Exposure Scale.

by the way... I was afraid you were going to say that Efke 25/50 would be better films.... damn those more expensive films

 

[sanking]

I think he means Exposure Scale.

by the way... I was afraid you were going to say that Efke 25/50 would be better films.... damn those more expensive films

That is right. ES means exposure scale. If a print is to have a full range of tones from deepest shadows to highest highlights the exposure scale must match rather closely the negative log DR (density range of the negative). Otherwise one of two things happens: 1) you will have to sacrifice tones at one end of the scale, i.e. either in the shadows or in the highlighs, or 2) the print will be flat.

VDB has an ES of 1.95 or slighly higher, so a negative tailored for it should have a log density range of 1.95. If the negative log DR is much more than 1.95 you will be unable to print both the shadows and highlights without dodging or burning, if much less than 1.95 the print will have an overall flat look. Overall flat is what you see quite often with VDB because developing film to a DR of 1.95 is way beyond what we normally do, even for other alternative processes such as carbon or straight palladium. In fact, as I mentioned earlier, in low contrast scenes it may be impossible, depending on the film.

Sandy

 

[scootermm]

Im in need of learning more about log, density, ES, et al. I had a meeting tonite for the Austin Alt Photo Group and spoke with Ed Buffaloe about alot of stuff (including the things that you are talking about Sandy - by the way he had wonderful things to say about you Sandy - much like the wealth of knowledge you so willing offer up - I look forward to meeting you in the future)
I would be out right lying if I said I had much knowledge or experience with the technicalities of all these sorts of things so will continue to be a sponge of read and experiment. All of my knowledge is quite new and fresh (havent been at this that long... and much less time than many here) most of my experience is based on visual observation, "this negative looks good and seems to visually have a good range of tones", "from my experience it will likely print well with van dyke browns" but nothing that is measurable or tangibly proved. so Ill have to delve into that sort of thing.
The main manner to measure whether Im reaching that 1.95 range is with a densitometer right sandy?

 

[donbga]

The only way I ever found to control contrast with VDB was to mix up a separate solution using ferric citrate and then combine this in varying proportions with the regular VDB solution. Don Bryant I believe has used this. It work, but changes the color of VDB from brown to a rust brown.

Sandy

Using Ferric Citrate does work and the color change doesn't bother me much. However there are limitations to the effectiveness of the use of FC in my experience. I would reccomend experimenting with it if you want to keep printing VDBs. Ferric Citrate can be difficult to find, I purchased mine from Tri-Ess which is now out of business. B&S and Art Craft don't carry this product and when I ordered from Tri-Ess it took them a couple of weeks to fill my order since they had none in house.

Actually I think your VDBs look pretty good. I think you are pretty close with your negative contrast. Since you are using 7x17 perhaps FP4 would be a good film to use. I've had great success with TMAX 400 processed in Pyro-Cat. I can make snappy VDB contact prints or enlarge onto silver gelatin with ease with this combination.

I would encourage you to continue to work with VDB befor jumping to Plt/Pld. You will learn a lot and save money.

I've also experimented with the bleach back technique as written by Wynn White and found that it doesn't provide repeatable results. It is very easy to over bleach and to produce prints that have too much contrast (using this technique on cyanotypes is also not very productive,IMO.) I would suggest using selenium toner - but very very dilute selenium toner. Perhaps 1:1000 dilution. This may give you some added snap to some of your marginal images.

Like many alt processes there can be many variations to achieve print nirvana!

Good luck,

Don

 

[donbga]

BTW, I meant to mention that the addition of gold chloride to the sensitiser may off set some of the color effects of the ferric citrate but it also shifts the color to a mauve colored brown (with or without the FC) which I like very much. The use of a gold additive also seems to smooth out the tonal scale (my subjective observation.) The use of gold will give a slight boost to the contrast but not much.

Don

 

[photomc]

Matt, not trying to speak for Sandy, but think a densitometer would be very helpfull in determining the ES, DR of the negative. Don't feel left out, I am still trying to figure this all out as well...just glad there are so many here to help us.

I would suggest using selenium toner - but very very dilute selenium toner. Perhaps 1:1000 dilution. This may give you some added snap to some of your marginal images.

Like many alt processes there can be many variations to achieve print nirvana!

Good luck,

Don

Interesting Don, I know Matt and I both have used very dilute selenium toner and we have been please with the results. Matt has also done some toning in Plt as well. I on the other hand, used LiPd to tone with (had it on hand for Ziatypes is the only reason I tried it...well that and suggestion by Mateo) and found the reults very pleasing. One thing I did find is the LiPd, and this may be true with other toners in citric acid, the print bleachs at first then takes on a more neutral tone, away from brown. If you check my personal gallery you can hopefully see what I am describing. The first two images were left to tone for 4-6 minutes before going into the thiosulfate, the third one though was the first one I tried and it bleached so much, thought is was ruined, but went ahead and pulled it after only a minute, into a water bath and then the thiosulfate. Have been able to reproduce this BTW..more than minute color shifts to more neutral tone, around a minute and it has the color you see in the third print.

Thanks for the information...

 

[roy]

Matt, not trying to speak for Sandy, but think a densitometer would be very helpfull in determining the ES, DR of the negative. Don't feel left out, I am still trying to figure this all out as well...just glad there are so many here to help us.QUOTE]

One of the things about this great forum is the way so much useful and helpful information is given in the quest to strive for better pictures. I have been drawn to Matt's growing portfolio of Van Dyke brown prints and look forward to any new image posted. This was acting as an incentive to me but I thought that the process had limitations as far as the contrast is concerned. I look forward to the continuing discussion on how to bring out this contrast as I think that as Matt has shown us, the process is capable of very fine results.

 

[donbga]

Mike,

Interesting Don, I know Matt and I both have used very dilute selenium toner and we have been please with the results. Matt has also done some toning in Plt as well. I on the other hand, used LiPd to tone with (had it on hand for Ziatypes is the only reason I tried it...well that and suggestion by Mateo) and found the reults very pleasing. One thing I did find is the LiPd, and this may be true with other toners in citric acid, the print bleachs at first then takes on a more neutral tone, away from brown. If you check my personal gallery you can hopefully see what I am describing. The first two images were left to tone for 4-6 minutes before going into the thiosulfate, the third one though was the first one I tried and it bleached so much, thought is was ruined, but went ahead and pulled it after only a minute, into a water bath and then the thiosulfate. Have been able to reproduce this BTW..more than minute color shifts to more neutral tone, around a minute and it has the color you see in the third print.

Thanks for the information...

Mike,

I did see your print scans and thought the results are interesting. I've used the LiPd with Kallitypes but not VDB. The problem is (if you want to call it a problem) is that there are so many variations one can try.

My toning of VDB with palladium have generally not please me since the color shift has been too neutral for me. I do need to test a palladium additive for self toning.

Don