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View Full Version : What's a good grain magnifier?



brian steinberger
2-Oct-2005, 21:47
Can anyone recommend a really good, and easy to purchase used grain magnifier. i just purchased a micro-sight one that is 20x. But I cannot view sharpness in the corners on the image. I'd like to be able to do so. Thanks

John Cook
3-Oct-2005, 03:54
I have earned my living in many labs (with many grain magnifiers) over the years. For my money, this has always been the easiest to use, although not always the most costly:

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=4641&is=REG&addedTroughType=categoryNavigation

Every ten years or so, the brand name changes. But the basic silhouette and 25 power remain constant.

I can’t imagine why your present magnifier doesn’t do corners. But here is a general caveat on buying used magnifiers:

All grain magnifiers utilize “first surface” mirrors, which have the silvered coating on the front of the glass instead of the back.

Coating the front of the glass prevents double images. But the coating is extremely soft and nearly impossible to clean without damaging it. The mirror needs to be kept covered when not in use.

Many experienced lab technicians, never mind all the twits on eBay, have never heard of first surface mirrors and often attack these units with Windex and paper towels, destroying the mirror, before putting them up for sale.

My best advice would be that if you can afford $100 for a box of sheet film, you should make an effort to find $50 for a NEW magnifier.

Remember me mentioning the elderly Swedish cabinetmaker from my childhood who once wisely said, “My son, cheap tools are like cheap women”.

ronald moravec
3-Oct-2005, 05:42
The best Peak if you can find one. The long mirror lets you see the corners so you can use it to allign enlargers to perfection too.

The old 25x model works in the center only which is good enough if you already know how your lenses and rest of the enlarging set up works.

The 25x one started life a Scoponet, but was rebranded once or twice. Get a new one so you know it has a good mirror and has not been knocked around and out of adjustment. The 25x is better for large format, as the Peak is only 10x and sometimes it is hard to see grain in large format small prints,but again it is no good in the corners.

paulr
3-Oct-2005, 10:47
If you get an old peak that's in good shape except for the miror, you can jus get a new 1st surface miror for it.

this place sells them: http://www.fsmirrors.com/

and there used to be a place in florida that sold all kinds of optical and darkroom doodads that had them for a reasonable price.

I love the peak. It's the only one I'm comfortable with because it allows you to check focus and overall optical performance over the whole image. You can use it to see the performance falloff of your lenses at different apertures, and to keep constant tabs on your enlarger alignment. It's bright and accurate enough to let you focus at your working aperture, which is one thing that makes these tests possible.

Calamity Jane
3-Oct-2005, 11:03
John wrote "cheap tools are like cheap women"

I RESENT THAT REMARK!

As a cheap woman, I can tell you that "cheap women" are LOTS of fun ;)

John Cook
3-Oct-2005, 12:09
Jane, another relevant quote, this time from Bob Hope:

“All this talk about sex and violence on TV. Sex and violence, violence and sex. At my age, it’s all the same thing.”

Or, as Dolly Parton once remarked, “You have no idea how much it costs to make me look this cheap”.

lee\c
4-Oct-2005, 18:28
I have the scoponet and the peak grain enlargers and now I have a Hocus Focus that I like a lot. Realativly cheap when compared to the Peak.

leec

Reece Vogel
5-Oct-2005, 04:23
Well I guess I'm not going to answer your question the way it was asked but if you are handy and watch for deals, you can put one together for very little.

A company called ElectroPhysics, I think, used to make a fantastic grain focuser. . They show up on Ebay from time to time but can be thrashed.. But the principle is great: A CCD without a lens is built into a probe that is placed on the easel and a highly magnified image of the grain is sent to a black and white monitor. These were great for murals where the traditional focus devices are useless. And they also made it easy to tell a sharp lens from a dog. As a device for evaluating optics and film characteristics, this unit was very handy beyond it's intended purpose. If you have never paid attention to diffraction when stopping down, this device will wake you up.

Problem: They were $1200. When you could buy one.

Solution: Build a better one for $100.

I have made my own with parts from Ebay. The original did not function in the corners either. So I bought a few worse for wear Omega top of the line grain focusers ($14) removed the standard optics and replaced them with a tiny color wireless CCD (lens removed) and calibrated it manually. I strapped the 9 volt battery to the side of the unit and with the optic sight/CCD mount rotating on axis, it can be taken out to the edge of the easel. The CCD transmits to a small B&W monitor (or color). Any TV will do if it has an input jack. The CCD and Transmitter kit can be had for $25 on Ebay if you get the right auction (and there are tons). It would be nice to make a custom unit to hold the CCD, battery and front surface mirror one of these days. But in the meantime this works just as well.

You won't want to use anything else.