Poptart
Screw Loose & Fancy-Free
So I'm finally making one, because I've never liked even the 4-bladed easel's curly paper edges. I'm using a blower from a dirt devil electric broom (which I never used anyway) so it'll be battery-powered & rechargable. The easel will be 10X15 if I can flatten out the thick sheet of aluminum I have. I figure I'll drill lots of tiny holes in it and seal the hoses and base with silicone. The vacuum fan is going to be fitted into a hardwood box to control the noise. Any advice frm someone who's done this type of project would be great.
jano
Evil Bokeh
What's a vacuum easel for? I did a search on google and found a few do-it-yourself hints and tips, but nothing really mentioned the use.
oftheherd
Veteran
jano said:
To hold the paper flat(er). For the fanatic dark room worker.
djon
Well-known
If you're REALLY a fanatic for sharpness, get an electric train transformer (12V DC output) and a socket adapter that will allow you to put a 12V automotive dome lamp (or perhaps tail lamp) in your enlarger...over condensers, of course. I think I got my adapter from Omega or Durst. You control light output with the electric train transformer.
Then plan on getting the ABSOLUTE best possible sharpness from your enlarging lens...and get that sharpness at full aperture (because diaphragm blades hurt resolution when the light's genuinely directional). Focus becomes very critical...you'll need a focus aid.
Then plan on getting the ABSOLUTE best possible sharpness from your enlarging lens...and get that sharpness at full aperture (because diaphragm blades hurt resolution when the light's genuinely directional). Focus becomes very critical...you'll need a focus aid.
djon
Well-known
...I've seen vacuum easels made with pegboard fyi...I think the plenum (space) under
the pegboard might have been 2" and I think a shop vac was used...must have been noisy...and what about dust? Sadly, enlargers don't have Digital Ice.
the pegboard might have been 2" and I think a shop vac was used...must have been noisy...and what about dust? Sadly, enlargers don't have Digital Ice.
Poptart
Screw Loose & Fancy-Free
Dust won't be an issue: the unit is sealed. I have read a few guides on the internets that say to use an old refrigerator compressor but you need to find a particular type. I also have a compressed air compressor but I can't figure out how to make the piston-style compressor into a vacuum pump--can't locate an air intake. It's quieter than the dirt devil fan.
Poptart
Screw Loose & Fancy-Free
djon said:
That's an approximation of a point light source. My earlier project wasa fiber optic head for cold printing with extreme sharpness . . . mine's one-of-a-kind (with triple condensors!) and works great But the problem of non-flat paper still defeats edge sharpness with an ordinary easel because of paper curl--especially fiber-based. Hence the vacuum frame. You can align your enlarger till doomsday and still have an unsharp plane of focus otherwise.
Wayne R. Scott
Half fast Leica User
I built my vacuum easel from pegboard, 1x4 clear finished pine lumber and 1/8" hard board.
The directions are in Petersen's Guide to Photo Equipment You can Make. Maybe you can find a copy at your library.
I use a small hand held vacuum or a shop vac.
Wayne
The directions are in Petersen's Guide to Photo Equipment You can Make. Maybe you can find a copy at your library.
I use a small hand held vacuum or a shop vac.
Wayne
Poptart
Screw Loose & Fancy-Free
What amount of pressure can you maintain with pegboard? It seems to me that the holes would be too big . . .do you mask the unused part of the easel?
V
varjag
Guest
Point light source actually helps greatly with edge sharpness: many would argue that the sharpness fall-off is an inherent shortcoming of condensor enlargers.
Point light was very much in favor among dedicated amateurs on this side of Iron Curtain. Typical way was installing a microsope lamp (they are small and without swivels in glass) with its spiral in vertical orientation.
Point light was very much in favor among dedicated amateurs on this side of Iron Curtain. Typical way was installing a microsope lamp (they are small and without swivels in glass) with its spiral in vertical orientation.
Wayne R. Scott
Half fast Leica User
Poptart said:
Yes, I mask off unused portion when I do 11x14's. I built it for 16x20 which requires no masking.
Holes too big? I haven't had any paper fall through them yet.
Wayne
djon
Well-known
"That's an approximation of a point light source.... You can align your enlarger till doomsday and still have an unsharp plane of focus otherwise."
No, it's literally a definitive point source.
My solution uses exactly the same lamp as Durst/Omega/Beseler (they literally specify an automotive dome lamp). I used a Durst 609, which has better condensers than other enlargers (rectangular, optically coated etc). In other words, I used the "definitive" point source, not an approximation.
My particular Durst, and point source heads in other enlargers, enjoys a mechanism allowing the lamp itself to be focused (and moved laterally for who-knows-what purpose).
Alignment ISN'T a problem with a well designed enlarger that uses well-designed carriers (that tends to point to very old Dursts such as my 1960s vintage item, or Durst Labadors...the monsters with the chrome tubular columns... though I've seen exceptional scientific work done even with Omegas and Beselers, not famous for alignment).
A vacuum board isn't necessary in practice for extreme flatness unless one is using paper with problems: Speed Easels hold paper very flat if they're properly maintained.
No, it's literally a definitive point source.
My solution uses exactly the same lamp as Durst/Omega/Beseler (they literally specify an automotive dome lamp). I used a Durst 609, which has better condensers than other enlargers (rectangular, optically coated etc). In other words, I used the "definitive" point source, not an approximation.
My particular Durst, and point source heads in other enlargers, enjoys a mechanism allowing the lamp itself to be focused (and moved laterally for who-knows-what purpose).
Alignment ISN'T a problem with a well designed enlarger that uses well-designed carriers (that tends to point to very old Dursts such as my 1960s vintage item, or Durst Labadors...the monsters with the chrome tubular columns... though I've seen exceptional scientific work done even with Omegas and Beselers, not famous for alignment).
A vacuum board isn't necessary in practice for extreme flatness unless one is using paper with problems: Speed Easels hold paper very flat if they're properly maintained.
jbtran
Member
Just a quick suggestion if it gets too noisy for you: Line the inside of the box with open-cell foam (1/2 inch minimum) to reduce noise level.
titrisol
Bottom Feeder
Yes, plastic sheets work great for masks.
If you use metal stell would be better than AL since you can use magnetic sheets that will not fall.
Also steel is easier to paint than aluminimum
If you use metal stell would be better than AL since you can use magnetic sheets that will not fall.
Also steel is easier to paint than aluminimum
Poptart said:
djon
Well-known
Magnetic strips are great, especially if you're printing horizontally (which is another common application for vacuum easels).
Poptart
Screw Loose & Fancy-Free
I was simply referring to the clear-bulb-only approach; I though it unlikely that your system employed a calibrated rheostat for controlling current to the bulb.djon said:
My alignment statement, in context, referred to the futility of having a well-aligned enlarger focused on a curly piece of printing paper--which is all commercial printing paper--not the problem of aligning a particular enlarger.
djon
Well-known
"point light source"as provided by Durst/Omega/Beseler uses small, clear 12 V DC bulbs (literally common automotive dome lamps). A large directional source is by definition not a point light source, especially if it's diffused.
Calibration is only calibration. My shoes are calibrated (size 11, US). We can calibrate just anything, but it's not necessarily part of the process. My shoe calibration may be helpful when I'm shopping for shoes, but it's only a fascinating topic for conversation otherwise. I can't tell you how many buxom young blondes I've picked up with scintillating shoe-size conversation.
My electric train transformer put out 12V, precisely. The rheostat allowed zero to 12. There are little marks that serve to calibrate, to the extent that's helpful. This calibration is simply an alternative control for exposure (like f-stops) if one decides to standardize on the same exposure time (eg 20 sec). Color temp does vary with voltage, that might have an influence on variable contrast paper, but this isn't a significant issue using graded paper.
And, in any case, the rheostat control makes a toy train transformer into a better tool than the fixed voltage that's traditionally used in point light source.
Calibration is only calibration. My shoes are calibrated (size 11, US). We can calibrate just anything, but it's not necessarily part of the process. My shoe calibration may be helpful when I'm shopping for shoes, but it's only a fascinating topic for conversation otherwise. I can't tell you how many buxom young blondes I've picked up with scintillating shoe-size conversation.
My electric train transformer put out 12V, precisely. The rheostat allowed zero to 12. There are little marks that serve to calibrate, to the extent that's helpful. This calibration is simply an alternative control for exposure (like f-stops) if one decides to standardize on the same exposure time (eg 20 sec). Color temp does vary with voltage, that might have an influence on variable contrast paper, but this isn't a significant issue using graded paper.
And, in any case, the rheostat control makes a toy train transformer into a better tool than the fixed voltage that's traditionally used in point light source.
Poptart
Screw Loose & Fancy-Free
Okay, I've got the blower fitted to the box and the fan-to-box & hose-to-framebox linkage (lengths of alum tube) and now I just need to make the frame. I've settled on maple cab facing for heft with baltic birch ply bottom and I'm considering making it big enough to accept uncut 16 X 20. The platform with airholes, I've found, can be bought pre-drilled at Ace hardware--in bright aluminum sheet. Nice and flat. Then flexi hose, silicone sealant and luck are all I'll need.
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djon
Well-known
This is fun. I'm eager to hear a comparison between vacuum and non-vacuum...needn't waste a huge paper on that, you could use small bits in corners...
Poptart
Screw Loose & Fancy-Free
djon said:
I bought a variable 0-15V transformer today in anticipation of trying this . . . can you post a link to the directions for the bulb?