Glassless negative carrier?

[jsimoespedro]

Hi all,

My negative carrier has two glass pieces - one is unpolished, acting as a diffuser and the second is clear.

Recently I found some negative carriers without the clear glass. What are the pros and cons?

Pros: No/less dust?
Cons: The negative will sag?

Thanks.

[Neal]

Dear jsimoespedro,

The "unpolished" glass is there so that you don't see Newton's rings caused by putting the smooth side of the film against smooth glass. Obviously there is no issue with the emulsion side against smooth glass.

Glassless negative carriers are much more common and you will see lots of arguments about the merits of both if you search the archives. I made a small and quite unscientific test for myself once and found that the glassless carrier (4x5 negative) made no improvement that I could find. By the same token, a better printer with a better eye might find glass carriers a necessity for producing their best work.

Neal Wydra

[tkamiya]

My understanding is that glass type will ensure the film is flat, thus improving sharpness across the print. However, I also heard it won't make much practical difference unless you are printing very large using high magnifications, such as doing 16x20 or larger from 35mm negatives. I use glassless kind for 35mm all the way up to 6x8, and print up to 16x20. I haven't seen any issues.

[desertratt]

I spent decades in film darkrooms and always thought of negatives carriers with glass to be a pain in the glass. They need to be kept clean, which can be a bear to do. If you have a negative that is badly curled or otherwise out of shape you might want to r esort to a carrier with glass. Otherwise, I think you're better off without the glass.

[Dali]

I also used a glassless carrier for 25 years for both 35mm and 120 negatives and I don't plan to change soon. With glass, the negative might be flatter but I will have for sure to fight against dust. Without glass, I only have to clean both sides of the negative. With glass, I would have to clean 6 surfaces (2 from negative + 4 from carrier)...

[Michael R 1974]

Glass all the way. Blow the dust off right before sandwiching. Done. Then you have the same number of exposed surfaces (2). And if dust settles on the glass it may be out of focus, which can help.

Note the type of enlarger makes a difference. Depending on the type of system, a significant amount of heat can build up at the negative stage - particularly if you're doing a lot of burning and dodging. The heat will tend to warp the negative in an upward direction. So with smaller negatives like 35mm you're more likely to get upward deformation rather than sagging. This is why particularly with smaller negatives flatness in the carrier can be substantially improved by just using glass on top of the negative. For those worried about dust that means less surfaces to clean. I would recommend this regardless of magnification. Flatness is critical.

[mr rusty]

Note the type of enlarger makes a difference

Is this not the real answer? enlargers that transfer heat use glass carriers because distortion caused by heat is a potential issue. Enlargers with little heat transmission can use glassless?

I use a Vivitar V1. The unique "light pipe" means no heat transfer at all from light source to neg. The neg carriers are glassless - why introduce more surfaces if they are unnecessary?

[Michael R 1974]

Well, heat is not the only consideration. There is no guarantee the negative will lie perfectly flat. It depends on the type of film, size of the negative, carrier, clamping force, ambient temp/humidity. The point is there isn't much depth of focus at the negative stage. I'd rather use glass and not deal with any of these potential problems.

[DREW WILEY]

Glassless won't assure you clean negatives! Dust can still blow around and land on your negative;
and I'd rather have the glass in between to keep minor dust out of focus at least. But from a quality
standpoint, glass is a necessity if you want precise results. If you don't ... that's another story.

[PDH]

I use glassless in my D 3 for 35mm to 6X9 and glass for 4X5, I have seen some warping with 4X5. I just took down my Durst 601 which had a glass type carrier and did not have issues other than cleaning and dusting more surfaces, when you live the Desert can be a real pain.