Frequently Asked Questions III

Selected questions and answers, based on the collective wit and wisdom of contributors to the original Black & White Photography Forum. Be sure to visit our Community and participate in current discussions. Our thanks to all who have contributed!

Dichoric Head Variable Contrast Filtration Settings

When using variable contrast paper and a Superchromega enlarger what filtration settings are equivalent to multigrade filters?
Not exactly sure where my husband found it, but be got an Ilford Multigrade Filter to Dichroic Filter Conversion Factors chart off the Web. He searched either Ilford's homepage: or through Alta Vista under filter conversions. (Mary Christenberry-Lott) I use Ilford papers, and the sheet that comes packaged with the paper has conversion tables for a variety of enlargers. (Bob Derenthal)
I would suggest that when you have made the Technology leap from graded papers to multigrade, in combination with a dichroic or variable-filtration enlarger, that you altogether Forget about paper grades. Use your magenta and yellow as part of your new `paintbrush' selection. Of course you will keep notes, for repeatability, but don't let the Old grading system in any way get in the way of exploring and creating photographic art. (Mike World)


Guide Number Guidance

Can someone explain guide numbers?
The flash guide number for a given ISO is the *flash* distance multiplied by the f-stop. It can be converted from one ISO to another by the formula GN2=GN1(sqrt(ISO2/ISO1)). The guide number is more accurate for handle and shoe mount flashes. Studio flashes have trouble with it because of the variety of reflectors that are too different from a point source. When using guide numbers for photomacrography calculations, measure distance from the back of the hot shoe. (Amilcar de Oliveira)
Guide Number is an indication of the "light output" of a flash :The bigger the number, more "light output" the flash will have (and usually the more expensive it will be). Practically it means that the bigger the GN, the farther to object can be for the same f-numnber, or that you can use a smaller f-number for the same flash-object distance.This is only a physical (qualitative) explanation of what it means. The "quantitative explanation" is in Amilcar's answer. It is worth to point out that the formula (shown in Amilcar's answer), involves the term "distance". This distance is the "flash-object-camera" distance divided by two. This means that if you are working with the flash mounted in your camera is just the flash-object distance, but if you are working with the flash detached from the camera you will have to add both distances (flash to object and object to camera) and divide it by two. Have in mind that the GN is specified for "A" film speed (usually 100ASA) and you will need the formula written by Amilcar to find the GN for a different ASA number. If you really want to play with the maths, I recomend you to try to work out the chart that most flashes bring on their back. You will be able to do so with these formulas. Hope this helps. (Marcelo Prillo)

Incorporated Developer Papers

I use Ilford Multigrade RC papers (III Rapid, Deluxe &IV) for all of my B&W
printing and have always been curious about something. Some have developer
incorporated into them, and some don't. Yet all have the same one minute
development times. What is the difference?
The developer inc papers go to a point & thats it. They are better for machine processors. The non-dev inc, Deluxe in Ilford RC, will keep developing longer, allowing more control and are considered by Ilford to be archival and usable for the finest prints for gallery work. If it is to be archivally processed the Ilford gang says\ use the Deluxe, not the Dev inc stuff. Try your deluxe at one minute, and then a few at longer times & see how your very fine detail & d-max may change a bit. (Dan Smith)


The Best Archival Washer?

I would like to hear from anyone who has Used the Nova Washer, made in England. They have out a model ( Academy) that let's you put in wash aid in one or two of the slots. It was recommended in an article in Photo techniques. Another model I am considering is the ECOWash from Cachet that was Designed by Oriental. I have the Patterson with the Plunger Action and I'm starting to go nuts with it as it's hard to control and the prints pop up. I'm doing high output and find that the continued adjustment needed by the Patterson is costing too much time and noise fatigue caused by the pulse action that agitates the prints.
I used Patterson washers many years ago and they were junk then. Sounds like they haven't changed.I use the narrow, 5 slot Nova Washmaster and love it. I'm sure their larger models are also good, I just didn't have the room for a wide model. Any of the major name brands will probably do the job, though this new Nova model with slots for hypo clear really sounds attractive. Good luck in your selection! (Fred Greenspan)
I just got a Cachet Ecowasher because it uses much less water than other models. I'm not yet sure that I did the right thing. The dividers are smooth, so that prints can stick to them. The instructions say that it is OK because fixer will diffuse through the paper, but I am skeptical. Testing will tell. If necessary I will replace the dividers with ones cut from fluorescent light diffusers, which should work. Incidentally, the assembly instructions are terrible. (Morton Klotz)

Tray Bien

Looking for a tray made of stainless steel for iniviual development of single 4X5 inch sheet film. Unable to locate a source here in Germany. Does anybody know where to get one?
B&H Photo in New York City at 1-800-947-6628 sells stainless steel trays and ships internationally. I don't know if they have the 4x5 size but you could ask. (Ted E. Felton)


Extra Texture

Was reciently at a gallery and while speaking with the photographer and commenting on how unique some of his prints were. He explained that he used texture screens to gain certin effects. Has anyone seen or used these? I asked where he got his, and he could not remember as he has had them for 30+ years.
I've seen these screens in photo shops that carry decent inventories of used
equipment. One shop, I recall, was Fred's Camera in Beloit, WI but I would think
you could order screens from one of the mail-order giants. I have never used these screens, although some of the textures (burlap, canvas, reeds) seemed interesting and the halftone screens might be useful in printing for newsletters/brochures etc. (Dave Strandberg)
You can do your own. Take any translucent or tansparent material and lay it over the paper when you make your print. (Ted Felton)
Texturefects is a texture screen manufacturer. Their address is 498 N. Mcpherson, Fourt Bragg, CA. 95437 1-800-477-4741 I use a 16x20 overlay texture screen called Cracquelure. They are pricy but work well. You can adjust the amount of texture effect by giving part of the exposure with out the texture screen and part of the exposure with the screen. (Jay langham)
Called Textureefects and they were quite nice. They have about 10 different styles. Pricy to say the least, $150.00 for 1-16/20. I am sure they are very nice and of excelent quality, but I think I will keep looking. (John Carolan)
Texture screens can be purchased from Porters. They have 2 sets of 4 screens @ $11.95 per set. (Dick Malone)


ISO 400 Films: Which One?

I have limited experience with B&W negatives and would like to select an ISO 400 emulsion to work with. I shoot with Pentax 645 and rely on a local pro lab for film processing and printing. I have tried Ilford HP5 Plus and Fuji Neopan and am thinking of exploring Tri-X and perhaps T-max and Delta. I Would greatly appreciate comments on how these emulsions compare in tonality, sharpness and grain (up to16x20 enlargements), particularly with the Xtol developer.
I have had very good luck using T-Max 400 (120 size) on a 6x6 format for making 16 x20 and 20x 24 inch prints. They are virtually grainless and have nice contrast. A little overdevelopment certainly helps increase your constrast. I have been using T-Max 400 consistently for the last 5-6 years with great satisfaction. (Rick Athearn)
I am spending this lifetime learning to use Tri-X perhaps in the next one I will try T-Max. ;) (Dell Elzey)
I agree with Rick that TMax 400 developed in TMax developer gives exceptional results. (Chuck Baker)
Pick one-any one- and work with it for 6 months to a year. Then see if it does what you want. If not, where does it fall short? If it falls short, try another since now you will have a basis for comparison. If you are working with your lab on a consistent basis, they will be glad to give feedback as to what they feel works best and help you fine tune things.(Dan Smith)


Rodinol Reviews

Is Agfa Rodinol any good? How can I get the best results with it?
I have used Rodinal for 30 years. It is an old standby developer created in the l930s.I find that if I extend development time 2 minutes more than recommended on the label, I get the density that I want from my negatives. I also downrate my ISO onfilm. For example, I shoot Verichrome Pan at ISO 100 (instead of 125) and over develop it about 2 minutes. You get a nice consistent #3 contrast out of it. The other problem with Rodinal is that it does tend to swell the grain. If you develop at l to 50 that lessens grain size. (Rick Athearn Photography )
I've used it with varying success. With TMax 400 I ended up with negs I found too grainy for my taste. With TMax 100 in 4x5, it was nice, but not any advantage over my usual ID11, so I didn't change. For Tech Pan, diluted 1:100, I get good results. (Dan Smith)
Rodinal is a classic developer. At its recommended development times, and at 1:25 dilution, it gives full ISA ratings, with sharpness, edge effect and superb tonal rendition. If you are expecting fine grain you will be disappointed, but there are more important factors. Don't use it with films over 100ASA, and , preferably, use it with Agfapan 100 or Agfapan 25. The results are outstanding! If you use it with 400 ASA material you will get noticeable grain in flat, mid-grey areas - e.g. blue sky. Use it for its strengths - if you need fine grain, or rely on programmed/auto metering, use a different brew. Dilution at 1:50 gives heavier grain and flatter contrast. (Richard Ogden)

I use it all the time with HP5 and TriX (35mm and 120) for very tight and sharp grain. Works great when the enlargements are going to be about 6X or under. (William Bell)


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