Enlarger aperture settings question

Is there a web guide to their use, as our tutor in college just says leave on f8

Well, f:8 or so is probably optimal (usually 2-3 stops from wide open with most lenses, 1 stop from wide open with Apo lenses), but if you need more time for dodging and burning, there's no crime in setting the lens for f:11 or 16.

Smaller apertures produce greater diffraction, which will reduce sharpness, but they will also increase DOF, which could help if you have negative pop or if the enlarger is misaligned, or if you tilt the easel for perspective correction and don't have the option of compensating tilt at the lens or negative stage.

Im so sorry you have lost me on some of your terminology whats negative pop and how does tiltling the easel correct perspective and what is compensating tilt at the lense neg stage, im just a beginner

rgds
Dusty

Negative pop - negative is not flat in enlargers negative holder, for example edges of negative are flat but center is little up or down.

Compensating tilt - if your paper easel is not lying flat, if you raise one side of paper easel up for correction of perspective control (for example if you photographed tall building from ground). Than you have option on enlargers lens holder to tilt lens to compensate paper easel tilting. Of course, you have to use enlarger with that option.



You should get some books for photography technique, from your post I belive you are beginner. Of course you can ask here, but with book you will have reference at any time, even if you don't have access to computer at particular moment.

If you use a glassless negative carrier and the negative heats up, the shape of the negative can become distorted. That's "negative pop."

Tilting the easel--Imagine that you are photographing a building facade straight on with the camera pointing up. The straight lines will converge at the top. If you had a view camera, and you wanted to have the lines appear square, you might raise the lens with the camera level to get the whole building in the frame with the corners square. If you don't have a view camera, there are two options. One is to level the camera, shoot with a wide lens, and crop--this would be the equivalent of using front rise on the view camera. The other is to tilt the easel in the darkroom, and this would let you get one plane square on the print--so it works for a straightforward building facade, but not for a complex scene with buildings at varying distances from the lens.

If you tilt the easel, though, you need more DOF to get the whole image in focus, so you can either stop down the lens, or if you have an enlarger with a tilting lens or neg stage, you can use the Scheimpflug principle to get the image in focus, like using tilt on a view camera. The principle is that the lens plane, the film plane, and the image plane all meet in a line (unless they are parallel). So if you tilt the easel, and you can also tilt the neg or the lens, you can make all three planes meet in a line, and bring the image into focus without having to stop down the lens.

Can you suggest such a publication that may be of help

rgds
dusty

Sorry, I can't recommend you books. When I used those literature it was literature from my country, written on one of south Slovak languages, so that will not be of any help to you. And I didn't used literature written on English, so I don't know what to reccomend to you. We have here, on forum, one great man, great knowledge, and ready to help, Les Mclean, check his book Creative Black & White Photography. Ansel Adams wrote trilogy, The Camera, The Negative, The Print, I have heard that is good too. In fact I will try to get Les and Adams books myself. But, I don't know if those books are for advanced photographers only or cover begginers questions too. You will have to ask someone else for books recommendation, sorry.

Indeed, the Adams trilogy and Les McLean's books would both be excellent choices. A little more advanced, but worth looking at as well would be Ctein's book _Post-Exposure_ (2nd ed.).

Thankyou so much for the insight and help and guidance very much appreciated

rgds
Dusty

Thankyou verymuch for taking the time

rgds
Dusty

I usually print with the lens (an El-Nikor 150, or 105 depending on the negative) stopped down to f16. The reason is the time it gives me to dodge or burn or both. Most of the negatives I enlarge work out to require exposures of between 15 and 25 seconds or so (a VERY broad generality!!) I must say I haven't been disappointed in the degree of sharpness such an exposure offers, but perhaps I should experiment with f8 just to see if I can discern a difference.

I stop WAY down, usually to anywhere between f11-16. I find that I need the time to dodge and burn. I'm still not happy with my printing skills (very novice), but I'm glad your here asking questons too.

Print away!


Joe

I usually print between 11 and 16.5. Am always playing with the paper plane. Also always focus stopped to almost all the way. There is plenty of lattitude for focus past 11.
If you need to reduce light for burning and dodging install a dimmer switch in line before the lamp head then test and mark it for reduced volumes of light.