Hi Loren. I've covered all this here:
Originally Posted by Loren Sattler
It's a long thread. You could get most of the basics by looking at the first page and the last.
That ND material sounds promising. What enlarger are you using?
This looks like something I could work with and it's reasonably priced:
That looks like it would work.
This one would give you 3 stops of neutral density: http://www.bhphotovideo.com/c/produc...l_Density.html
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
You will enjoy having 2 or more stops of Neutral Density. If you have Color Printing filters, you could always add equal parts CMY to make ND.
I personally use a 2-stop ND No. 96 Wratten gelatin filter when making small prints. It's only 2x2, and I simply drop it down inside the lens cone, right on top of the back of the enlarging lens. I would rather have 3 or 4 stops because still I have short exposure times.
If you have a camera-grade ND filter, you could put it in the optical path. I've gathered from random threads the feeling that "filters in front of the enlarging lens are not that bad".
While you're at it... do you have a "voltage regulator"? These units hold the voltage steady despite fluctuations of the incoming line voltage. Shouldn't be too expensive, and it can help rule out exposure variations caused by voltage spikes/drops that can happen between two prints that should look the same.
As Bill suggests voltage regulator is a great suggestion and will insulate you against line variation.
Another choice would be a "variac", a variable transformer. This takes in 120V from the wall plug and allows you to choose whatever voltage you want with a knob. A variac rated for 75W shouldn't be too expensive, and is probably available from Digikey or Mouser, both of which are highly reliable electronics distributors. I use a variac for the heating mat under my developing trays, it allows me to maintain chems at 70F in the winter in my otherwise-underheated darkroom.
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Originally Posted by kbrede
I am also using a Beseler 23CII.
As for the ND sheets, either density should work. The 3 stop material is probably more useful, but with the 1 stop sheet, you can cut multiple pieces and gang them for more density.
I rarely print smaller than 8 x 10. I might need the ND filter if I printed smaller than 5 x 7.
Over time you will probably expose your negatives with more density and solve the problem, or you will discover that your bulb is too bright for some reason causing the issue. Good luck.
Is the condenser at the correct height? There should be a scale on the RH side of the assembly.
A motorcyclist is the only one who understands why a dog rides with it's head out the window.
"I had an idea once, it died of loneliness"--George
Originally Posted by John Koehrer
Yep, the condenser is at the right height.
I've used a 23c with correct 75w bulb and Ilford WT VC. Exposures typically f/11 and 15s. 120 film, under the lens filters, 80mm optic, 6x8 in prints.
From what I understand, lowering the voltage on a bulb will change the color temp of the light.
I do not know what that will do for VC paper. It may throw off the grades, so a #2 may print differently at full vs. reduced voltage.
Since they do not make photo bulbs lower than 75 watts (that I know of), another option is to use a regular WHITE incandescent bulb of a lower wattage, say 40 watts or even 25 watts.
I say this is not the best option because a regular bulb may not have an even coating of white to evenly diffuse the light. You also have to watch where the printing on the bulb is, vs the light path. If the printing is on the top end, and that is the path of light to the lens, you need to remove the printing from the bulb. I was considering this option myself, since a 75w bulb in my Durst M600 gives me a somewhat short exposure time of about 10 sec.