Enlarger aids ??

[Calamity Jane]

#1 - Wanting a more precise way to ensure proper focus when printing at the enlarger, I have been reading about "grain focusers".

I have never used one but there seems to be an inherent source of inaccuracy with these; if the distance from the mirror to the "viewing screen" (or whatever they use) is not EXACTLY the same as the distance from the mirror to the paper, they will NOT give precise focus. I also can not see any easy way to PROVE that these distances ARE exactly the same - everything ends up subjective.

It would seem a more accurate method of focus would be to look directly at the image projected on the paper-plane (with magnification), although admittedly it is not as convenient.

Do these things actually work as well as people think? How do you veryify the accuracy of the focuser?

#2 - I'm also thinking about an exposure meter for the enlarger. I have never used one but my appetite for 8x10 paper seems to have gone UP considerable since moving to LF! ;-)

They aren't very expensive and it would seem like a good way to reduce the number of tests strips required.

Any comments?

[Nick_3536]

You check if the grain focuser works by making a print-). They work just fine. Some are easier to use. I actually find them hard to use with 4x5 because the amount of grain is so small. It's even worse with a diffusion head.

The meter thing depends on you. I use one for colour and it's a dream. I almost never use it for B&W. It just doesn't fit my mindset. For me test strips really aren't an issue. Test prints can be. The test strip gets you into the ball park but until I see the whole thing it's hard to judge exactly what needs doing.

[Ernest Purdum]

You are right about the degree of accuracy required, but that should not be a problem to achieve with modern manufacturing methods. It's the same thing as making sure that a groundglass is in exactly the same plane as film. Actually, I think the chances of difficulty are much less with the grain focuser.



There are some frequent problems in enlarger focusing. Unless the film and paper are exactly parallel, and the lens axis perpendicular to them, there is no way that all of the image can be in focus. The same is true if either the film or the paper is other than totally flat.

[Mark Sampson]

A grain focuser (they do work) is easier to use with a high-res, low-mag image if you look for an edge- a transition between light and dark in the projected image.

[John Kasaian]

Very good points!

I find mine to be a neccesity.

It helps alot to focus on a sacraficial sheet of paper rather than on the easel, since the thickness of the paper you're using needs to be taken into account.

FWIW I have a Bestwell Optical Magnasight.

One thing I remember being told was that if you accidently drop a grain focuser they'll become worthless as they can get knocked out of whack quite easily and are realistically unrepairable. For this reason I wouldn't buy a used one(or a really expensive one)

Of course you can make contact prints and circumvent the whole enlarger thingy!

[Ralph Barker]

I, too, use a grain focuser (a Peak), and have had no problems with accuracy. I do, however, check composition and focus on the easel with a sheet of photo paper the same thickness as that I'm using for the print under the grain focuser.

As to the meter question, I had developed a technique for using a conventional meter that had a right-angle head. It helped, but didn't provide what I really wanted. A year or so ago I bought a ZoneMaster II enlarging meter from R. H. Designs (http://www.rhdesigns.co.uk), and have been quite pleased. You meter highlight and shadow (with the safelight turned off and no filter in place), and it gives you both the contrast grade and the exposure time. These measurements, along with any additional measurements are displayed on a string of LEDs that represent the Zone scale - pretty nifty. It stores the response curves of up to 8 different papers, which can be called up as needed, has a test strip mode, and also has a densitometer mode that are useful. R. H. Designs also has other meter models, along with timers that can be integrated, depending on the type of enlarger being used. They aren't inexpensive, but I feel I've saved more in paper cost than I spent on the meter.

[Jim Ewins]

Hello Jane, I too place a piece of paper in the easel. In using the grain scope, I think that the idea is to find the sharpest focus at the distance of the scope platform by racking back & forth, as I do most of the time by inspection with my glasses off (nose to paper). As to misalignment causing misfocus, the concept of circle of confusion applies. How else could one tilt the easel and focus on the average and get a sharp print? As usual, experiment. Jim

[Pat Kearns]

Jane, the focusing aids do work well and come in a low magnification and high magnification. I usually place a piece of printing paper of the same thickness and put the aid where there is and edge line and focus on the grain there. The high magnification can sometimes be pretty bright and may take your pupil sometime to dilate to the darkness again. That is the only bad thing I can say about them. I sure with your knack with building things, you of all people, can make one out of a soft drink bottle.

[J. P. Mose]

I second the motion for a ZoneMaster II enlarging meter from R. H. Designs (http://www.rhdesigns.co.uk)! It takes some practice but works great once you get used to it.
I also use a grain focuser for all enlargements with the correct paper thickness underneath.

[Calamity Jane]

Of course I put a sheet of the same thickness paper in place to focus on! Don't all "anal retentive types" do that? ;-) (Sorry fellers!)

"I sure with your knack with building things, you of all people, can make one out of a soft drink bottle."

Pat: Thanks for your vote of confidence! ;-)