Hi all,

I have just set up my first ever darkroom. I actually developed my first b&w film around two months ago ! but you know how it is - something else far more important always comes along. Anyhow, I am having problems getting a border around the edge of my prints and can't figure out how to do it the same each time. I have a Rollei colour enlarger with a 50mm Minolta lens and a 370x450mm masking easel. I've tried all sorts but I'm wondering if there is a definitive way of doing this or whether it's just a matter of practice makes perfect.

Thanks in advance,

Rowland.

-- Rowland Walsingham (rowland.walsingham@digital.com), April 15, 1998

Answers

I'm not sure exactly what type of border you are talking about but I presume it is the black border that you see in many photographs produced by enlarging the opening of your negative carrier larger than the image. Is this what you mean? How are making them now?

-- Andy Laycock (agl@intergate.bc.ca), April 15, 1998.

An even white border should be easy with a two-bladed easel. Lift the blades, slide the paper against the back stop, and lower the blades. You have to change the setting of the blades for each paper size.

A black border running all the way to the edge of the paper is pretty easy, using one of three methods:

1. Take a piece of black card larger than your photo paper. Cover the photo paper, leaving one edge uncovered. Expose that edge. Repeat for the other three sides.

2. Use a negative carrier with a hole larger than your negative format.

3. Use a piece of black card the required size of your picture. Use this to mask the picture, then expose the borders.

Any unevenness can be trimmed away afterwards.

My favourite is to have a white border, with a thin black line running exactly around the picture (fairly easy), or slighty outside it (slightly harder).

To get the black border exactly around the picture: expose the print in the easel with a white border, then cover the print with the black card, leaving an even gap between the card and the easel blades. This does need care. It may be helpful to swing a red filter in the path of the lens and turn the safelight off.

To get the black border outside the picture area: as the previous paragraph, but reset the easel with a wider border. This is awkward, especially for a batch of same-size prints, and is much simpler to either use two easels, or to use a black card with the appropriate size hole for the first exposure.

-- Alan Gibson (gibson.al@mail.dec.com), April 16, 1998.

Thanks for your responses. I ran off another couple of prints last night and concentrated on trying to get the easel set up for the size of paper that I'm currently using (5x7 I think).

It is the white border that I'm after (initialy). It seems quite fiddley ! What worries me is that my easel is not completely "on" the base of the enlarger. Is there such a thing as depth of field when considering focusing an image through an enlarging lense onto a sheet of paper ? - This probably constitutes another totally separate thread.

Kind regards, Rowland.

P.S. Alan, do you work for Digital Equipment ?????? only my old mail address used to be "@mail.dec.com".

-- Rowland Walsingham (rowland.walsingham@digital.com), April 16, 1998.

Using a large (?) two-blade easel for small prints means that one corner of the easel will be more-or-less under the centre of the lens, so it might be overhanging the baseboard. If the baseboard is on a table, try rigging up blocks of wood or something to support the easel. Better still, get a smaller easel or make larger prints!

For such small prints, I would just take a sheet of card, and cut an aperture, say 4.5 x 6.5 inches.

The depth of field of an enlarger is:

t = (2 x V x C) / D

where t is the total "up-or-down" movement of the paper allowed, V is the len-to-paper distance, C is the permissable circle of confusion on the paper, and D is the aperture of the lens. t, V, C and D should be in compatible units, such as millimetres.

For a 50mm lens at f/11, approximatel V=226 and D=14. A reasonable value for C is 0.2mm, so t = 6mm. So a misplacement of the easel up or down by 3mm should not be noticeable. However, this tolerance may already be "used up" by curvature of the lens field, non-flat negative, etc.

Yes, I do work for Digital. On Exchange, I am "Alan Gibson @EOL".

-- Alan Gibson (gibson.al@mail.dec.com), April 16, 1998.

Thanks again. That solves that one. I reckon the piece of card trick is gonna be my best bet. I have got what I consider to be large paper, that was the reason I bought the largest easel that would fit on my baseboard - I reckoned I would be kicking myself when I suddenly decided I wanted to move up from 5 X 7 to the bigger stuff. Good news about the depth of field too. that means that a little bend in the paper wwon't matter either :-)

Regards,

Rowland.

-- Rowland Walsingham (rowland.walsingham@digital.com), April 16, 1998.

It may seem strange, but large prints are easier than small ones (within limits). There is more room below the lens to do burning & dodging, exposure times aren't stupidly short, depth of field (on the paper) is greater, and viewing distances tend to be greater, so minor problems are less noticable.

The first time you do a 12x16, your socks will blow off! Have fun.

-- Alan Gibson (gibson.al@mail.dec.com), April 16, 1998.