How to use a grain focuser?

Removed Account · Jun 10, 2007

OK, I should know this by now... I have been using what is most accurately described as a focus magnifier, but have recently purchased a grain focuser, and I can't figure out how th damn thing works... The eyepiece goes in and out, but there is a little hexagon built in that is only in focus with the eyepiece in all the way. Whenever I look in it I get lots of reflections, but I can't see any detail. I kind of see a part of the image, I think, but yeah... I'm doing something wrong. Any ideas?

- Justin

phaedrus · Jun 10, 2007

You're halfway there. If you see the hexagon sharp with the eyepiece all the way in, leave it there. Focus on a part of the projected negative that has some density and some fine image structure, grass, twigs or hair would be good. While focissing, aim to see the hexagon and the grain structure sharp at the same time. That's vital, as you're focussing on an aerial image, not a ground glass. Don't forget to close the lens to it's optimum aperture afterwards.

Anscojohn · Jun 10, 2007

With the old Bausch and Lomb, you viewed the grain and a squiggly line in the optical system of the magnifier. You viewed directly in the magnifier, then moved your eye slightly from side to side. If the image of the grain and the object in the system moved in relation to each other when you moved your eye, (parallax) you focussed until there was no apparent movement.
Oh, and be sure you focus on a piece of paper the same thickness as your printing paper.
Anscojohn, Mount Vernon, Virginia USA

Removed Account · Jun 10, 2007

Hmmm... I can't see anything other than the hexagon... When I move the focuser I can see the image move, but I can't make out any sort of detail at all... I have had this issue with other grain focusers, so I am pretty sure it is not that this one is defective.

- Justin

digiconvert · Jun 10, 2007

cafeharrar said:
Hmmm... I can't see anything other than the hexagon...
- Justin

you're not alone - these things do help produce really well focussed images but actually getting your field of view correct is a problem.
For me thing got better when I realised that the image I was seeing was refl=ected from the mirror not the baseboard (it sounds SO obvious I know) . I try and nmake sure that the part of the image I look at is virtually central in the neg and look straight down at the image. It's fiddly but it sort of happens with practice. It's a bit like the first time you try and focus an image that's laterally inverted - after a while you wonder what the fuss was about but can't explain how to do it to another person.

keep trying - Cheers Chris

Bob F. · Jun 10, 2007

A couple of suggestions, which you may already do of course... Use the magnifier in the middle of the projected image: unless you have one of the adjustable-angle ones, it will only work close to the axis of the lens. If possible find a high-contrast edge or an area with obvious grain.

Focus as best you can without the magnifier first and continue to shift the focus a little so it goes through correct focus to just out of focus again. You now know roughly how far you need to turn the focus knob, and in which direction, to bring it back into focus. Now put the magnifier in place and use the focus knob to bring the image back into focus - slowly - it's easy to go past.

Good luck, Bob.

srs5694 · Jun 10, 2007

You might also want to start out using a high-grain negative (ISO 400 or faster film, say) in a small format (or more to the point, high magnification). That should give you obvious grain even in uniform areas, unlike something like 35mm Efke KB25, which can be close to grainless even under a grain focuser, particularly at small sizes.

jsfyfe · Jun 10, 2007

One of the tricks I learned from Fred Picker was to cut out and glue a piece of your normal enlarging paper on the bottom of the focuser. That way you don't have to mess around with putting a piece of paper under it each time. I used this solution for years and it worked great.

jstraw · Jun 10, 2007

jsfyfe said:
One of the tricks I learned from Fred Picker was to cut out and glue a piece of your normal enlarging paper on the bottom of the focuser. That way you don't have to mess around with putting a piece of paper under it each time. I used this solution for years and it worked great.

Since I use a variety of papers and can't see the sense in using a variety of grain focusers, I use a sheet of whatever I'm printing on as a focusing sheet. I have one sheet of each, labeled with a sharpie, within reach.

Removed Account · Jun 10, 2007

You might also want to start out using a high-grain negative (ISO 400 or faster film, say) in a small format (or more to the point, high magnification)

Hmm... T-Max 100 in 4x5 probably isn't that helpful for learning this... I'll dig up one of my Delta 3200 35mm negs to see if I can figure this out.

- Justin

vanspaendonck · Jun 10, 2007

Aping

One thing I don't like about grain focusers is that you have to keep your eye real close to the focuser and at the same time turn the focusing knob of the enlarger, which makes you feel like an ape dangling from a tree by one arm, at least with my Polaroid MP-4 enlarger. Anybody has a trick for this?

Jon Shiu · Jun 11, 2007

Hi, I was wondering what type of grain focuser has a hexagon? and what the hexagon looks like?

Jon

pentaxuser · Jun 11, 2007

vanspaendonck said:
One thing I don't like about grain focusers is that you have to keep your eye real close to the focuser and at the same time turn the focusing knob of the enlarger, which makes you feel like an ape dangling from a tree by one arm, at least with my Polaroid MP-4 enlarger. Anybody has a trick for this?

I know the problem. Paterson make a micro and macro finder for just such a problem. At larger enlargements your eye with the macro finder is higher and more in line with your focusing hand so less strain and "monkeying" around.

Actually the micro finder is a bit of a pain at any enlargement. I manage with mine with difficulty at times but if I was starting all over again I'd go for a macro finder to begin with.

pentaxuser

ic-racer · Jun 15, 2007

vanspaendonck said:
One thing I don't like about grain focusers is that you have to keep your eye real close to the focuser and at the same time turn the focusing knob of the enlarger, which makes you feel like an ape dangling from a tree by one arm, at least with my Polaroid MP-4 enlarger. Anybody has a trick for this?

Other than growing larger arms I know these methods:
1) "tall" grain focusers have been made
2) Manual extensions (flexible or geared) that hang down from the focusing control are available for some enlargers
3) Motorized focusing is available for some enlargers
4) On the D5500 the knob that raises the head is more within reach than the focusing knob and sometimes I fine-focus by moving the head up and down with that knob.
5) Some microscopes will 'fine focus' by moving the slide stage up and down, similarly I have seen 8x10 enlargers that can fine focus by moving the baseboard up and down. I have not seen this on any 4x5 enlargers, though.

Mick Fagan · Jun 16, 2007

Justin, I too have difficulty with Tmax 100 in 4x5" in finding grain.

What I do is find a line of a building or a piece of the image that has a high contrast edge where the image goes from black to white.

Basically you rock focus back and forth a smidge until you are pretty certain this is the finest you can see the line at.

Using FP4+ on 4x5" I find easier, but not much as it is quite fine grained. I find Tmax 100 in 4x5" is hellishly difficult to focus, there is no apparent grain to see at 8x10" and 12x16" enlargements.

I recently cropped a Tmax 100 4x5" neg enormously, enough to make a 36" print on the short side, I could see grain (or something resembling grain) easily then.

Mick.

fschifano · Jun 16, 2007

That's the truth about TMax 100. Even at 8x to 10x it can be difficult to find any grain under the focuser. This happens to me all the time even with 35mm negatives.

How to use a grain focuser?

Privacy & Transparency

Privacy & Transparency