Questions re vandyke processing

[Craig Griffiths]

I have just recommenced working with the Vandyke process and contact printing either 8x10 or 8x20. I have scoured the forum for information and have used what I have been able to glean. While I have been reasonably happy with the results to date I have a couple of questions that hopefully someone can answer.

The first relates to negative contrast and the need for a more contrasty negative to be produced. What confuses me is why you need a more contrasty negative than normal silver processing. If I use a Stouffer 21 step wedge I can get about 8-9 clearly distinguishable steps when a print is made on Ilford Multigrade filtered for grade 2. The same step wedge will show 20 steps when printing with Vandyke (although this varies from 18 to 21 depending on paper). My understanding would be that the Ilford paper has a higher contrast than the Vandyke. If this is the case, wouldn’t the Ilford paper need the higher negative contrast?

The second relates to whether single or double coating with the solution is best (if there is such a thing), or whether that is something best determined for myself by trial and error.

The final question relates to the height of light source above the paper. Currently this is approximately 15 cms, but I have read where others have a substantially lower distance between light source and paper (8cm is not uncommon). Is this dependant on the light source (fluorescent tubes in my case) or is it just a matter of a closer light source meaning a faster printing time.

Long term I hope to move to some of the other alternative processes, but I am happy with Vandyke and Cyanotype at the moment, and want to get a better understanding and consistent output with both before trying something new.

Thanks

[R Shaffer]

Ciao Craig,

I do mostly kallitype, but some Vandyke. The more steps you get the longer the scale of the paper. I'm pretty pathetic at the sensitometry stuff, but consider that the Vandyke is getting tones through the densest part of step wedge. So your negative needs lots of density ( or contrast ) to do the same.

I have tried double coating a few times with kallitype & pd to try and get my Dmax higher. Mostly I get an inconsistent coating. I have had better luck with acidifying the paper in a 2% oxilic acid soak or using a better paper. I know some people swear by double coating, so I'll probably give it a try again some time. But it's worth the trying it out.

I started with my BLB bulbs at 6in ( 15cm ) and have kept dropping them down to speed up exposure. I'm down to around 2in ( 5cm ) now and don't see any evidence of uneven exposure. I have T8 bulbs at 1 1/2" centers, so your bulb spacing may effect this. My cheap BLB bulbs have lost intensity over time, strange??

Love the alt processes, way fun.

[Brian Ellis]

van dyke brown has a larger potential tonal range than silver paper, which is one of its beauties. To take advantage of that range you need you need a negative with higher contrast than normal. To take an extreme case, if you have a very flat negative, one with only a couple shades of gray and no shadows or highlights, then that's all the van dyke paper will print even though it has the potential to print much more. So you make a higher contrast negative to take advantage of the longer range of the paper.

The reason why silver paper doesn't need that much density is that it would go to waste. With its narrower potential tonal range you'll never get 21 distinct steps from a 21 step wedge with silver paper (as you can with van dyke) no matter what your negative looks like.

It's easy (and informative) to see this by doing a simple test that takes about 15 minutes. Just make three test strips of a 21 step wedge on variable contrast paper. With the first strip use a very low contrast filter on your enlarger or a low contrast setting on your enlarger head if you use a color head or a variable contrast head. Make another strip with a very high contrast setting and make another one or two in the middle of the two extremes. Write the settings you used on the back of each strip.

After you print the strips you'll see that all three settings produce essentially the same number of distinct steps. The only difference is which steps you can distinguish and which are pure black and pure white. The strip made with the low contrast filter will show distinct steps at the lower end of the step wedge (i.e. will give you good shadow separation in a print) with little separation in the middle of the wedge and none at all in the denser end (i.e. the highlights in the print). The strip made with the high contrast filter will do the opposite, and the strip made with the in-between setting will show good separation in the middle area with little to none as you get towards either end of the wedge. In other words, all silver paper has roughly the same tonal range and it's quite limited compared to van dyke. The differences between different brands and types of silver paper isn't in their tonal range - they all have about the same. The difference is in how the comparatively limited range is distributed as among the shadows, midtones, and highlights.

I never tried double coating so I don't know about that part of your question. I had enough trouble with one coating.

[Craig Griffiths]

Thanks for the replies.

So Brian, I take it then that the important part is to ensure that there is a full range of tones from black to white to get the best out of van dyke. If that is the case I have at least got something right.

[Brian Ellis]

Thanks for the replies.

So Brian, I take it then that the important part is to ensure that there is a full range of tones from black to white to get the best out of van dyke. If that is the case I have at least got something right.

Right

[Paul Metcalf]

Have you read this? http://www.alternativephotography.co...s_vandyke.html

[Craig Griffiths]

yes I have amongst heaps of other documents, but thanks for pointing it out.

I am happy with what I have produced to date but was getting a bit confused with the need for increased contrast with the process. I just misinterpreted what it actually meant. As far as double coating is concerned I havent tried it as yet, but I will be over the next couple of days.

[tenderobject]

hi guys! i just started on vandyke printing as well.. not that successful though.. i have a few questions. since the sheet film (efke 25) i used was souped in parodinal. that does affect density as well? would there be a good developer for vandyke printing or other altprocess/printing? or should i always consider to shoot and develop for high density. thanks!

thanks also to OP!

[sanking]

hi guys! i just started on vandyke printing as well.. not that successful though.. i have a few questions. since the sheet film (efke 25) i used was souped in parodinal. that does affect density as well? would there be a good developer for vandyke printing or other altprocess/printing? or should i always consider to shoot and develop for high density. thanks!

thanks also to OP!

You should not over expose negatives that are intended for vandyke. Expose normally, but develop for a much longer time than would be considered normal for silver printing to give you a very contrasty negative with a high density range (difference between Dmin and Dmax). I would recommend that your development time be at least twice as long as you would use for silver printing.

Sandy King

[tenderobject]

You should not over expose negatives that are intended for vandyke. Expose normally, but develop for a much longer time than would be considered normal for silver printing to give you a very contrasty negative with a high density range (difference between Dmin and Dmax). I would recommend that your development time be at least twice as long as you would use for silver printing.

Sandy King

thanks a lot sandy!!! i wanna try your pyro next time. would this be best for alt printing? read a lot of good things about pyro!

back to topic. so, then i will expose my film normally then overdevelop (twice the developing time for use in silver printing) the film to achive more density in the negative, developer is not much of an issue here right? how about grains and other usual stuff you get when you overdeveloped your negative. would the details suffer as well (just like in 35mm and mediumformat)

not sure about dmin and dmax though.. if my negative is overdeveloped can i still use it for silver printing? or atleast a normal scan.. i want to try other alt-process though i don't know if overdeveloping would help me achieve a good print on any other alt-process. hope i'm making sense here. thanks again for the help!