PDA

View Full Version : keeping the paper flat....



dave4242
10-Nov-2017, 16:21
hey all,
i seem to be having an issue with keeping my ilford warm tone fiber flat on the easel.
any ideas?
using a saunders 4 blade easel and a lpl 4550 enlarger
thanks!

Maris Rusis
10-Nov-2017, 16:46
Paper flatness is not at all critical for most enlarging ratios. The image depth of field at the easel level is several millimetres and a good 4 blade easel will hold paper much flatter than is actually needed. On the other hand depth of focus at the negative level is very small and a tiny change of focus makes a big difference in the sharpness of the projected image.

dave4242
10-Nov-2017, 16:51
@maris,
ok so i am getting sections of the print that are out of focus while most of it is in focus.
the negative is sharp and is not the problem
any recommendations?

xkaes
10-Nov-2017, 17:04
We need more details. Is the paper held down on the edges, or not? If it is, does it pop up in the middle?

Have you aligned the enlarger with the baseboard? You can do this by taking a scrap negative, cutting an "X" in the emulsion from corner to corner with a needle, etc., putting it in the enlarger and focusing one of the corners. You can usually do this "by eye". If all the corners are not sharp, you need to align the enlarger and the baseboard. Check you owner's manual.

dave4242
10-Nov-2017, 17:27
hi
using a saunders 4 blade easel and a lpl 4550 enlarger
the enlarger is a one post and head enlarger on a baseboard so theres no alignment option
the easel is holding down the paper but i am getting areas of out of focus while the negative is tack sharp
using Ilford warmtone fiber 11x14 paper

Jac@stafford.net
10-Nov-2017, 17:37
hi
using a saunders 4 blade easel and a lpl 4550 enlarger
the enlarger is a one post and head enlarger on a baseboard so theres no alignment option
the easel is holding down the paper but i am getting areas of out of focus while the negative is tack sharp
using Ilford warmtone fiber 11x14 paper

I built a platform on top of the base board to support a Saunders 16x10 easel. It has three level screws to bring it to absolute alignment. I'm sure several of us can elaborate if necessary.
.

dave4242
10-Nov-2017, 17:43
@jac
ok thanks appreciate the insight

xkaes
10-Nov-2017, 17:48
There may not be an option to adjust it, but a scratched negative is still a good test -- unless you have a focusing aid that you can use in each corner. If nothing else, open up the lens all the way and tell us if the image on the easel appears focused in ALL corners -- WITHOUT the paper.

dasBlute
10-Nov-2017, 18:15
I keep small flat magnets on each blade, but I'd check the alignment as well...

Jac@stafford.net
10-Nov-2017, 19:39
@jac
ok thanks appreciate the insight

Stay tuned. I will be situated to inform in detail in a week or so.
.

dave4242
10-Nov-2017, 21:17
@tim
Thanks!

Merg Ross
10-Nov-2017, 22:14
My guess is an alignment issue, as suggested by xkaes in post #8. Also, are you using a glass negative carrier? This is an interesting post, there will soon be an answer!

dave4242
10-Nov-2017, 22:20
no glass carrier just the standard one thanks!

Merg Ross
10-Nov-2017, 22:43
The negative is perhaps not flat at the carrier stage. That may be the problem. It is less likely to be at the easel; see post #2 by Maris.

David Karp
10-Nov-2017, 23:21
These enlargers can be aligned, but it can be difficult. I learned a tip from John Sexton. Loosen the fasteners on the column and slide shims made from pieces of 120 film. You can also use aluminium foil for small adjustments.

Willie
11-Nov-2017, 06:38
Might try using a large piece of glass over the paper for a print and see if that stops the out of focus areas. If so, it is the paper waviness making it out of focus. You aren't going to print through glass every time, just for a test to hold the paper flat. If that solves the problem a vacuum easel may solve your problem. Or try some light adhesive on the easel to hold the paper flat.

If the glass does not solve the problem it is the negative. A glass carrier will solve problems with a negative that is not flat.

dave4242
11-Nov-2017, 08:01
Thanks everyone really appreciate the help!

JMO
11-Nov-2017, 09:33
So far I am finding this thread interesting and helpful! I have an LPL 4550 enlarger and use a Saunders "V-Trac" VT1400 easel, both of which were acquired from another LF user earlier this year and moved into my darkroom. I had to do some shimming to get my negative carrier, the baseboard and the easel all level at the same time (while the enlarger column also appears straight and true). With that, I haven't noticed such focus/sharpness issues using 11x14in Ilford WT or Classic FB papers, but the practical diagnosis and remedy tips being offered to the OP here are helpful. It's good to hear that the precise flatness at the easel level is less critical, so I'll keep an especially sharp eye on the negative carrier. Thank you all...

xkaes
11-Nov-2017, 11:06
It's good to hear that the DOF at the easel level is less critical, so I'll keep an especially sharp eye on the negative carrier. Thank you all...

"Less critical" doesn't mean unimportant, of course. Most darkroom users, especially when buying a used enlarger, don't even consider aligning the negative carrier and the baseboard.

And, as usual, unfortunately, some people lose a lot of sleep and buy expensive tools to solve/resolve it. It's easy to test for, and most of the time, easy to fix.

Ulophot
11-Nov-2017, 16:26
I join the others waiting to see the outcome. Alignment is frequently an issue. However, I use a paper safe and had a problem with Warmtone curling (edges up on the emulsion side) some years ago. It was a humidity issue; the darkroom, with no running water, was really dry in the winter. Once the humidity returned to normal levels, the paper relaxed and lay fairly flat.

ic-racer
11-Nov-2017, 21:04
Reads as if you are not letting the negative heat up enough. Keep warming it until the focus is stable, then cap the lens with the light still heating the negative (or swing the red filter in place), place the paper and set the timer. Uncap the lens (or swing the red filter out) and start the timer.

Maris Rusis
12-Nov-2017, 16:56
Paper flatness is remarkably irrelevant in making typical enlargements. For example paper can be as much as an inch (!) out of flat when enlarging 35mm to 16x20 and it makes no difference to sharpness. Negative flatness is, on the other hand, super-critical and ic-racer is probably on the money about the negative "popping" in reaction to heat from the enlarger.

jose angel
13-Nov-2017, 00:36
any ideas?

(Not a fix but a different approach).
>The silly paper thickness. Change your paper source. Other manufacturers made papers that simply remain flatter.
>Use your paper. Looks like some papers get worst along the time, so don`t let it grow inside the box (humidity?). Buy smaller batches, better envelops instead of boxes. Keep them flattened under weight.

Pere Casals
13-Nov-2017, 03:41
hey all,
i seem to be having an issue with keeping my ilford warm tone fiber flat on the easel.
any ideas?
using a saunders 4 blade easel and a lpl 4550 enlarger
thanks!

To have paper perfectly flat, I place a 10mm thick glass on the bed, I spray on it some 3M Re Mount glue. IMHO I gets as flat as if it was in a vacuum table. I used that to test enlarger alignment...