Vacuum easels...recommended?

[bob carnie]

I completely agree. I like vacuum easels for contact work but have found for murals there is no issue if every thing is leveled.

I don't believe vac easels are necessary for prints larger than 20X24. Nice, but not essential. If you are able to level your film stage, lens, and printing platforms (as with the use of a laser alignment tool), depth of focus with this degree of enlargement should allow for some amount of imperfectly flat roll papers.

[Jim Jones]

Thanks Jim!

I appreciate your reply. That value should be the same for any size board if the holes are the same size. So what are the size of the holes and the spacing?

Asher

The little 11x14 vacuum easel I made had 624 small holes on a 1/2 inch grid. I don't remember the hole size; probably less than 1/32 inch. The size isn't critical as the volume of air moving through them is low. Large holes and high vacuum could cause dimpling of thin paper. The vacuum cleaner I used could pull only a few lbs of vacuum.

The 32x40 inch vacuum tables used at work years ago had a heavy glass top that hinged up for access and sealed against the table frame in use. They drew the vacuum through canvas, so the hole size and pattern wasn't visible. I believe the hose to the vacuum pump was well under an inch inside diameter.

[Herb Cunningham]

I use a Nuarc with their pump, works like a champ for contact printing for large negatives, especially large digital negatives.

You should try local photo shops. They quite often have them sitting around in the back, be glad to get them out of the house.

[Drew Wiley]

I would never, ever print even a 20x24 Cibachrome without vacuum. For one thing, its
a very dark heat-absorbing paper which often requires long printing times and will buckle; for another thing, it retains a degree of much greater degree of image detail
than paper media, so warrants nitpicky technique. By comparison, I notice that the
latest generation of Crystal Archive RA4 paper lies remarkably flat, even better than
the previous Super C, and of course the printing time for C papers in general is quite
fast. I haven't done anything on the new paper bigger than 20x24 yet, but basically
figured out I didn't need vacuum in this size. With the polyester-base rolls (Fuji CA
Supergloss), I'm sure I'll revert to vac regardless. The friend on mine who did the most
commercial mural work back in lab days simply tacked the paper coming off the vertical roll with two very long magnetic bars, top and bottom. But another friend
who specialized in high-end Ciba always always used vac for the big 60" Ciba rolls.
I figure my own work had to significantly exceed commercial lab quality; so vac
was a must with polyester-based stock, and still is with certain curl-prone black
and white papers (seems to be the papers I've had around just a little too long which
give me the most problems). So no right or wrong per se here, just intelligent options.

[Asher Kelman]

I use a Nuarc with their pump, works like a champ for contact printing for large negatives, especially large digital negatives.

I'll see if I can find one to look at. I want something v. large. 52"x76" or more for 50" Cibachrome paper and also for much smaller contact prints

You should try local photo shops. They quite often have them sitting around in the back, be glad to get them out of the house.

Yes, I should do that before spending any money on building one! Now often these are vertical. Is there any problem doing contact printing with the easel vertical?

Asher

[Asher Kelman]

But another friend
who specialized in high-end Ciba always always used vac for the big 60" Ciba rolls.

Is that 50" or do they also make 60"? I looked and B&H has 50" but not 60" rolls.

Asher

[Drew Wiley]

B&H is not an industrial distibutor. Big labs typcially bought from various manufacturers
like Ciba-Giegy, Fuji, Kodak, and even Forte directly. The products selection was way
bigger than what you'd find at any retailer, though these might have had on hand the
full price list for the sake of special orders. Now B&H, Freestyle, etc stock only min
amts of Ciba if any at all, and have an arrangement to have it shipped directly from
the importer. The overall selection of color materials has of course significantly diminished in recent years. An annoyance to me is that Crystal Archive is no longer
available in 30x40 sheets, and not even in 30-inch wide rolls. You have to buy it in
32" wide rolls, so that to fit my particular drum, I have to cut it twice, once for length,
and next two inches off width. I have the ability to do that, but it's a nuisance. Ilfochrome is still packaged in 30X40 sheets but has become quite expensive, mostly
due to the predictable raw materials and shipping inflation which has affected quite
a range of products nowadays. Anyway, I think Ciba was once available up to 6 ft
wide. Most seriously equipped big labs had XY cutters which could turn a roll into
any smaller size they wished. These cutters are still valued in for wide-format laser
printing, so are rarely a bargain even used. And they take up a lot of space.

[Drew Wiley]

Asher, another point - big Ciba prints require tremendous light output, esp given the
fact that to obtain good tonality it needs to be heavily silver masked, that is, unless
you known some pretty sophisticated tricks. So we're talking about true industrial scale colorheads and processing and all the nasty permits and health issues that come with that. If you really want to get into that, I know someone who has all the gear
for sale, but he won't offer it on the open mkt. But just to set this stuff up requires a
very serious investment. The more modern option, Fuji Supergloss, is unfortunately only
available in 32-inch rolls and not cut sizes at all. You can find other sizes for sale,
but they're all older material, not the current Type II. Maybe we can talk about this
more in person later in the month.

[Asher Kelman]

Asher, another point - big Ciba prints require tremendous light output, esp given the
fact that to obtain good tonality it needs to be heavily silver masked, that is, unless
you known some pretty sophisticated tricks.

Drew,

I'm planning to use 30,000 Watt.seconds for the flash.

At f22 I should be O.K. assuming an ISO of 3. Does that cover the "Silver Masked" comment or not?

Asher

[Drew Wiley]

Not even close, Asher. For Ciba you'll need a max aperture of the enlarging lens around f/8 or even less or you'll run into hopeless reciprocity issues on a big print. Masks typically need to be around .60 density for most LF transparencies, or even as high as .90 - that's two or three stops added to what is already a very slow paper.
Now if you're experimenting with in-camera Ciba, that's another story. But I'm a bit
confused by you referring to both large print sizes and flash exposure within the
same context.