Tension Carrier for 8x10, ye olde glass/non glass questions...

[resurgance]

Hiya,

After shooting mostly MF and 4x5 for a year or two, have come across a Devere 5108 that was kindly yet reluctantly sold to me by a very active film photographer.
That same photog, is extremely handy and had constructed his own 4 corner pin-tension negative carrier for 8x10. Great idea! Am about to start work on my own, different design, but same principle, of attaching corner hole punched negatives to spring loaded pins with some lateral movement - obviously no vertical movement.

Anyhow, am also making an LED head to mimic my sensationally awesome Model 3 LED VC head from modern enlarger lamps, so will have;
- no fan
- no heat
- diffusion source.

I have been using the standard Devere 504 carrier with only bottom glass on my 504 enlarger then taping negs flat with lithographers tape with reasonable success, however with 8x10 think glassless will be the ticket, but FLAT!
I have an environment that is somewhere in the middle of dry and humid. Some probs with static, and some with dust. Actually i find static is a pain, but I know there are certain things I can do, boil the jug, careful clothing choice, etc.

Wondering about your experiences with tensioning negatives - have seen some old threads, as well as extreme points of view. Ive used both glass and glassless up to 4x5 and find dust a pain, but love flat negs and subsequently sharp images. Have also had probs with newtons rings too, and have sometimes swerved them by packing up the edges of the negative before I tape it with paper or similar thin material.

This tension carrier has not been made yet, it is a blank canvas - Will try differing strengths of spring - I have no idea how flat it will get.

In my mind, a piece of horizontal rope will require a parabolic amount of tension to go from nearly flat and level to actually level, but that I guess all depends on weight of said rope. The aforementioned photog who showed me his design really rated the end prints and ease of use.
Am counting on the fact that negs are fairly light, but will be interesting to see how much tension is needed and also will have to find point where it damages neg. holes will be 2.5mm and pins will be 2.5mm machine screws so even pressure on inside diameter of hole.

Any thoughts or experiences on tensioning negs will be appreciated!

[Neal Chaves]

I am very happy with the 8X10 carrier that came with my Beseler 45 VXL 810 enlarger. It grips the negative with smooth clamps only by the two long sides. The idea behind is that after the negative is in place, the carrier will expand slightly in the warmth of the light head. I wish there was a similar one for 4X5, as it is far better than the Beseler Negaflat with its sharp little teeth.

The Beseler 8X10 carrier is probably very difficult to obtain today, but a good machine shop could duplicate it quite easily.

[Tin Can]

I am very happy with the 8X10 carrier that came with my Beseler 45 VXL 810 enlarger. It grips the negative with smooth clamps only by the two long sides. The idea behind is that after the negative is in place, the carrier will expand slightly in the warmth of the light head. I wish there was a similar one for 4X5, as it is far better than the Beseler Negaflat with its sharp little teeth.

The Beseler 8X10 carrier is probably very difficult to obtain today, but a good machine shop could duplicate it quite easily.

I bought Beseler 8x10 glassless holder right here. It is a wonderful and simple device. It's doesn't need heat, my head produces no heat.

Glennview.com makes his own custom one of any size.

[Bob Salomon]

"Ive used both glass and glassless up to 4x5 and find dust a pain"

But then the dust will be on the negative and I would rather clean glass then film.

"Have also had probs with newtons rings too"

You said that you use the bottom glass. That is frequently not anti-Newton glass since Newton rings form when the base side of the film comes in contact with regular glass. Normally the base side is facing the lamp and the emulsion side faces the paper. So are you printing base side down?

Also, even without heat, film curls towards the emulsion side so glass keeps that from happening, a tensioned carrier will not prevent that from happening. You need the film not to move during the exposure to get the optimal quality out of a properly aligned enlarger, quality lens used at optimal aperture and magnification and a high quality piece of film. Going glassless will not meet these criteria.

[ic-racer]

Since your LED head will likely be a diffusion source, I'd not give up on a glass carrier without trying it, assuming you got a glass carrier with the 5108.

One way to determine your springs is to buy a few springs ( http://www.mcmaster.com/#extension-springs/=u4dsdr) and tug on the film with the spring through the hold, until it breaks through, and note the spring length. To get a safety factor of 1/2 the break-through tensoin, plan on making the frame so the spring winds up being 1/2 the 'rip-through' length when all 4 corners of an 8x10 negative are suspended.

[Bob Salomon]

Since your LED head will likely be a diffusion source, I'd not give up on a glass carrier without trying it, assuming you got a glass carrier with the 5108.

One way to determine your springs is to buy a few springs ( http://www.mcmaster.com/#extension-springs/=u4dsdr) and tug on the film with the spring through the hold, until it breaks through, and note the spring length. To get a safety factor of 1/2 the break-through tensoin, plan on making the frame so the spring winds up being 1/2 the 'rip-through' length when all 4 corners of an 8x10 negative are suspended.

Sounds like this will also require an awful lot of film handling to get the film positioned properly in that type of carrier.

[Tin Can]

My 8x10 film is drying very flat, both HP5 and Ektascan. I tray develop single sheets and hang dry from 2 pinpoints and make there sure is no curve in the film between the two pins. I dry it slow at ambient. Drying curved is avoidable. It lays dead flat on my light table and when mounted in the Beseler glassless carrier I sight across it and it is still very flat. It does require careful loading. I blow any dust off the top and bottom. I also do not let my negs lay around very long. Once dry, they go straight into my enlarger and I shut the neg chamber which is nearly lighttight and thus free from air movement and dust. Since my head makes no heat, it needs no ventilation. No fan, no vibration, no dust.

I spent my life making metal flat in large chunks to within 0.001" While my eyes are bad at focus, I can see flat better than most.

I have four 8x10 AN glass carriers, I don't use them now. Saving them just in case I become convinced they are better...

Of course I am new at this but, I can see which way the wind is blowing.

Almost forgot, I can now use my V700 film scanner holders as glassless holders for enlarged contact sheets of smaller formats. The V700 4X5 works best, MF and 35mm roll are all warped.

[Bob Salomon]

".....the neg chamber which is nearly lighttight and thus free from air movement and dust."

That statement is like someone being almost pregnant. Either it is or it isn't. If it is nearly then it isn't immune to air movement. Maybe reduced but not immune.

[Tin Can]

".....the neg chamber which is nearly lighttight and thus free from air movement and dust."

That statement is like someone being almost pregnant. Either it is or it isn't. If it is nearly then it isn't immune to air movement. Maybe reduced but not immune.

Bob, I do my best. It's all I can do. I have clumsy old hands, cleaning and handling glass for every negative is a real PITA.

[Kevin Crisp]

I have the 8X10 Beseler. I hated working with the glassless carrier that is supposed to stretch the film flat. The glass one, with the white plexi or whatever the diffuser is on the top has been great. No Newton's rings, ever, and it has been almost 25 years. Yes, I have to dust the negative and the carrier when I put the negative in, but it isn't like I'm slamming through 8X10 or 4X10 negatives at such a rate that I mind. I'd have to dust the negative anyway. I use the same one for 5X7's too, but with a mask inserted one slot above in the head to keep extra light from around the edges lighting up the darkroom. Maybe I'm just lucky with no rings, but this has been my experience. Something about that diffuser and the base side of the negative just don't cause a problem for me.