enlarging paper under a grain focuser

dslater · Jun 10, 2007

This came up in another thread and I didn't want to hijack that thread so I decided to start a new one.

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.

You know, in the past, I too used a piece of enlarging paper under the focuser to account for the paper thickness. lately however, I have stopped doing this - I just don't think it's necessary - I focus my enlarger at f/5.6, then expose my paper at somewhere between f/11 to f/22. I have to believe that at these f-stops, the thickness of the enlarging paper is far less than the depth of focus of the enlarging lens. I certainly haven't noticed any lack of sharpness in my prints. I'd be interested in other opinions on this.

Dan

David A. Goldfarb · Jun 10, 2007

I don't see any good reason not to do it. Why introduce another potential source of error when it's so easily avoided? I just keep a folder with scrap sheets of all the different papers I use next to the enlarger for focusing.

Roger Hicks · Jun 10, 2007

Dear Dan,

I'm sure you're right.

Cheers,

R.

dslater · Jun 10, 2007

David A. Goldfarb said:
I don't see any good reason not to do it. Why introduce another potential source of error when it's so easily avoided? I just keep a folder with scrap sheets of all the different papers I use next to the enlarger for focusing.

Well - the reason boils down to this my darkroom is only 4.5' x 5.5' so space is at a premium - there is no space by my enlarger to keep such a folder .

Dan

k_jupiter · Jun 10, 2007

dslater said:
Well - the reason boils down to this my darkroom is only 4.5' x 5.5' so space is at a premium - there is no space by my enlarger to keep such a folder .

Dan

Dan,

Honestly. Do you know how stupid that sounds?

Use it, don't use it. It's a variable. I was taught by some great B&W printers, many whom have work in the permanent collection at MOMA. They all said use it.

I use it.

tim in san jose

Jim Jones · Jun 10, 2007

Omitting the paper under the focusing aid might typically cause image blur of .005mm or a little more. That's a small part of the blur we can usually see. Focusing errors can be cumulative, and perfectionists might well feel safer using the paper. Perfectionists should also check their focusing aid to see if it has any errors.

Neal · Jun 11, 2007

Dear Dan,

You are not alone. I can see a difference in the viewfinder of my focusing aid, but I can't see the difference in prints. I also suggest that you ignore rude comments as sometimes folks here allow their passion for the work to overcome their manners. I know of at least one very good printer, Ctein, who has stated that he does not feel it necessary to place the focuser on a sheet of paper.

Neal Wydra

Steve Smith · Jun 11, 2007

If I was a manufacturer of grain focusers, I would 'build in' the thickness of the paper into the base (for an average paper thickness). Has this not been done already?

Steve.

jstraw · Jun 11, 2007

Steve Smith said:
If I was a manufacturer of grain focusers, I would 'build in' the thickness of the paper into the base (for an average paper thickness). Has this not been done already?

Steve.

I'm glad they don't. Average? Bah. Of all the focusing errors that can accumulate...whether this one is significant or not, it's the simplest to correct.

Steve Roberts · Jun 11, 2007

Steve Smith said:
If I was a manufacturer of grain focusers, I would 'build in' the thickness of the paper into the base (for an average paper thickness). Has this not been done already?

Steve.

Sound engineering thinking there, Steve!

Steve

cao · Jun 11, 2007

Since enlargement is basically macrophotography, wouldn't depth of focus make the effect of paper thickness negligible. Does someone want to take on Ctein here?

David A. Goldfarb · Jun 11, 2007

dslater said:
Well - the reason boils down to this my darkroom is only 4.5' x 5.5' so space is at a premium - there is no space by my enlarger to keep such a folder .

Dan

If you can find the pictures of my dark/bathroom in the "Darkroom Portraits" thread, I think you'll see we're about even on that score. I just keep the folder with focus sheets, dodge and burn tools under the enlarging baseboard when I'm not using them, and I usually find a spot somewhere to keep them out when I do need them.

In any case, it's easy enough to find out if you need a focus sheet. Just focus without one, put the sheet under it, and see if you need to refocus. Why bother with a grain focuser?

Michel Hardy-Vallée · Jun 11, 2007

Two things:

1) It's really not that hard to keep around a small square of paper with the grain focuser and slip it underneath when focussing.

2) On the other hand, the Ctein principle for all things related to photography is "If you can't see it, it doesn't count." If you can't see it, then good for you.

schroeg · Jun 11, 2007

Tiring of having to remember the piece of paper - I trained my self to levitate the focuser with my mind (the exact thickness of the paper).

dslater · Jun 11, 2007

David A. Goldfarb said:
If you can find the pictures of my dark/bathroom in the "Darkroom Portraits" thread, I think you'll see we're about even on that score. I just keep the folder with focus sheets, dodge and burn tools under the enlarging baseboard when I'm not using them, and I usually find a spot somewhere to keep them out when I do need them.

In any case, it's easy enough to find out if you need a focus sheet. Just focus without one, put the sheet under it, and see if you need to refocus. Why bother with a grain focuser?

I took a look - I've got you beat here - my darkroom is a converted bar in my basement - when I say 4.5x5.5 - that's the total space. There's room for my plywood sink down one wall - a beseler enlarger in a corner and just enough room for me to sit on front of the enlarger and turn left for the sink. I'd post a pic if you wouldn't object to a digital picture on an analog darkroom - or would that have to go on the hybird photo site

In any case my decision not to use the paper is not a deliberate one. If I have a print I am making to be eventually mounted and presented to someone, then I would definitely use the paper - but for my work prints - most of which never go anywhere, I don't bother unless a piece happens to be handy.

Shmoo · Jun 11, 2007

Steve Smith said:
If I was a manufacturer of grain focusers, I would 'build in' the thickness of the paper into the base (for an average paper thickness). Has this not been done already?

Steve.

I'll bet there'd be some argument as to which paper to standardize on...single weight, double weight, Ilford/other paper...easier to keep a spare sheet of paper around...now where'd that folder go??????

S

Steve Smith · Jun 11, 2007

Shmoo said:
I'll bet there'd be some argument as to which paper to standardize on...single weight, double weight, Ilford/other paper...easier to keep a spare sheet of paper around...now where'd that folder go??????

There already seems to be plenty of argument about it!

I have never placed paper under my focuser and I don't think I have suffered loss of sharpness because of it. However, I think I will try a couple of prints though, with and without paper, to see if I notice any difference.

I always thought that there was a nominal extra height built in to compensate for the paper. I think I read it on the internet so it must be true!

Steve.

k_jupiter · Jun 11, 2007

Neal said:
Dear Dan,

You are not alone. I can see a difference in the viewfinder of my focusing aid, but I can't see the difference in prints. I also suggest that you ignore rude comments as sometimes folks here allow their passion for the work to overcome their manners. I know of at least one very good printer, Ctein, who has stated that he does not feel it necessary to place the focuser on a sheet of paper.

Neal Wydra

Dearest Neal,

I have extremely good manners. I just call people when they post things that are truly lame. I expect to be called on the same. And that was lame.

I have read Ctein's book. You take from it what you think is right, the rest you discard. Just like any source. Dan here should do the same. Free advice is worth exactly what you paid for it.

Eliminate variables. If the thickness of a DW sheet of paper makes no difference to you in focusing, don't use it. If using a triplet instead of a four lens enlarging lens works as good as the other, save money. If you can't tell the diff between a print on RC vs double weight fiber, use the damned RC. If you don't see the diff when you don't match up safelights to paper types, use one safelight. If developing at 75F gives the same results as 68F, don't buy the thermometer. And so on and so on... But don't come looking for advice if all you are looking for is for someone to tell you you're correct.

My apologies for anyone I might have offended. Even the Lame one.

tim in san jose

Ole · Jun 11, 2007

My darkroom isn't large, but there always seems to be plenty of scrap paper floating around. I just pick one which feels about the same as the paper I'll be printing on, and figure that it's going to be close enough.

On rare occasions (large lith prints from dense negatives, for example) I print with wide open lens, and it really does make a difference.

Richard Kelham · Jun 11, 2007

As others have said, why introduce a possible error by *not* using paper under the focus finder? But even odder is the OP's comment about printing at f22! Ye gods why? Do you like sitting in the dark twiddling your thumbs?

Decent enlarger lenses are designed to be used stopped down 1 or 2 stops at the most.

dslater · Jun 11, 2007

Richard Kelham said:
As others have said, why introduce a possible error by *not* using paper under the focus finder? But even odder is the OP's comment about printing at f22! Ye gods why? Do you like sitting in the dark twiddling your thumbs?

Decent enlarger lenses are designed to be used stopped down 1 or 2 stops at the most.

Hmm - I'm making 8x10 prints from 4x5 negs on Beseler with a condenser head - only < 2x enlargement. I admit I don't often go all the way to f/22 - but I have had the thin neg where I needed to do that to get print times in the 20+ second range. I usually work at f/11 or f/16.
Dan

pnance · Jun 12, 2007

Since I usually compose of the back of an old print (of the same paper type I intend to use) I just plop the focus checker on it and don't worry about keeping a small piece of paper around.

Richard Kelham · Jun 13, 2007

dslater said:
Hmm - I'm making 8x10 prints from 4x5 negs on Beseler with a condenser head - only < 2x enlargement. I admit I don't often go all the way to f/22 - but I have had the thin neg where I needed to do that to get print times in the 20+ second range. I usually work at f/11 or f/16.
Dan

Under those rather particular circumstances the fact that the focus finder is a few thou out probably doesn't matter nor will you notice the diffraction!

But I still maintain that under normal conditions enlargements from 5x upwards it does begin to make a difference.

Richard

rst · Jun 13, 2007

Since it is easier for me to get the right framing on a white area of dark grey, I have that sheet of paper anyway. So why should I take it away for focusing

Regards
-- Ruediger

Daniel_OB · Jun 13, 2007

Everything has its tolerances, and should have. Positioning enlarger's head so accurate that paper thickness is tolerance, should be fine. If you see the grain is crisp, so what else you wish.
I sometimes use a shim sometimes just forget to use it. When I look at photographs just cannot say I used the shim or not. However nothing is wrong to use a paper below the focuser.

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