Negative Carrier and Glass Plate

[jaydebruyne]

Hey APUG'ers,

So I've been using my carrier with 2 black 35mm inserts. However, when I bought my enlarger, among other inserts, it did come with a piece of glass which I can use to cover the top of the negative.

What's better to use? Plastic glass less inserts or plastic bottom/glass top? And what are the benefits, if any?

Cheers in advance
Jay

 

[chip j]

A glass top will keep the neg from popping & keep it flat. The only issues are dust on the glass & Newton's Ring. You can solve the latter by using a hair dryer 1 foot from the base side of the neg (for about 10 sec}.

 

[jaydebruyne]

A glass top will keep the neg from popping & keep it flat. The only issues are dust on the glass & Newton's Ring. You can solve the latter by using a hair dryer 1 foot from the base side of the neg (for about 10 sec}.

Aha! Think I'll stick with the plastic inserts then

Cheers!

 

[Adrian Twiss]

Plastic inserts work fine with 35mm film but I find that for medium format (in my case 6x6 and some 6x9) a glass negative carrier is almost essential to keep the negative flat. For me its also an absolute "must" for 5x4 negatives.

 

[miha]

Hey APUG'ers,


What's better to use? Plastic glass less inserts or plastic bottom/glass top? And what are the benefits, if any?

Cheers in advance
Jay

I usually use glass on top. See if your glass looks slightly frostet.

 

[jaydebruyne]

I usually use glass on top. See if your glass looks slightly frostet.

What does it mean if it's frosted?

 

[miha]

What does it mean if it's frosted?

It means it prevents the formation of Newton's rings; It's a good thing.

 

[jaydebruyne]

It means it prevents the formation of Newton's rings; It's a good thing.

Ah ok, I will have a look. Cheers for the info.

 

[MartinP]

I'm curious what enlarger you are using where the neg-carrier is plastic?!

The neg usually curves slightly in a plain carrier, so that the middle of the negative is higher than the edges (which are held in the carrier). The top glass should be able to stop the bulge and keep the negative flat, though a double-glass carrier is better still for flatness and becomes significantly more important with larger formats. When the neg is not flat you will have some difficulty focussing both the middle and the corners at the same time plus the amount of curve of the negative may even change during the exposure -- definitely not helpful.

One occasionally seen problem is the appearance of Newtons Rings between the negative and the glass surface. These can be eliminated by one surface having a very, very, very slightly rough surface -- hence "anti Newton-ring" (ANR) glass in negative carriers. It appears to be slightly grey looking but this does not affect the image, as the glass is above the film. If you use a lower glass too, as in a double-glass carrier, the tiny roughness of the emulsion is usually enough to prevent the ring effect.

If you can get to Photofusion hire-darkroom and training centre, in Brixton, they will be able to show you the differences in the various neg-carrier designs as well as giving all sorts of other advice to "hit the ground running" with your printing. Have fun!

 

[jaydebruyne]

I'm curious what enlarger you are using where the neg-carrier is plastic?!

The neg usually curves slightly in a plain carrier, so that the middle of the negative is higher than the edges (which are held in the carrier). The top glass should be able to stop the bulge and keep the negative flat, though a double-glass carrier is better still for flatness and becomes significantly more important with larger formats. When the neg is not flat you will have some difficulty focussing both the middle and the corners at the same time plus the amount of curve of the negative may even change during the exposure -- definitely not helpful.

One occasionally seen problem is the appearance of Newtons Rings between the negative and the glass surface. These can be eliminated by one surface having a very, very, very slightly rough surface -- hence "anti Newton-ring" (ANR) glass in negative carriers. It appears to be slightly grey looking but this does not affect the image, as the glass is above the film. If you use a lower glass too, as in a double-glass carrier, the tiny roughness of the emulsion is usually enough to prevent the ring effect.

If you can get to Photofusion hire-darkroom and training centre, in Brixton, they will be able to show you the differences in the various neg-carrier designs as well as giving all sorts of other advice to "hit the ground running" with your printing. Have fun!

My carrier is metal, the inserts are plastic. I use a Kaiser VCP6001.

Thanks for the info will have a look at the glass and try it out next time I print!

Regarding training, it's a luxury I can't afford right now, maybe in the future though, but thanks for the info of the centre.

 

[MartinP]

Ahhh, that makes more sense. Kaiser do make decent kit and are still in business if you need any spares of course.

 

[jaydebruyne]

thankfully! And I met a guy in a shop called MR Cad in Victoria, Alex (store owner) who is an avid Kaiser user. Apparently he is the guy who creates all of the inserts for Kaiser. So if I need any spares or repairs I have somewhere to go!

So my glass looks pretty clear to me. At least I can't see any visible sign of frosting. I take it it's not ANG?

 

[jerrybro]

Clear or uncoated is not ANG. I'm a non ANG user and have never encountered the rings on any format.

 

[jaydebruyne]

Clear or uncoated is not ANG. I'm a non ANG user and have never encountered the rings on any format.

Is it worth using the glass on 35mm?

 

[Huub]

It would depend on how the enlarger is built and how warm the negative gets, how snugg the negative seats in it holder and how critical you are. Testing the difference is easy enough.

 

[cliveh]

I would advocate glassless.

 

[jerrybro]

If you are not experiencing negative popping and your current carrier can hold the neg flat enough, then no glass is ok. If you do have a hot lamp, long exposures and the negative is moving during the exposure then you need glass or another way to keep the neg from moving.

 

[DREW WILEY]

Plastic scratches easily and can bow due to differential heat or humidity changes. Not a good idea. Use high quality glass on both sides. You
can get something like this the appropriate size, either plain or antinewton, from Focal Point. It is very difficult to keep a neg flat without glass,
so you might encounter a loss of critical sharpness or even some incidence of double-imaging. Some people get away with the glassless method,
by either short printing times or a cool light source. I always use glass.

 

[DREW WILEY]

Oh.... and Antinewton is not a frosting, but a totally clear pattern. Get the real deal if you need it. Here in my foggy coastal climate, I have to use antinewton glass routinely, for all format sizes. On relatively slick film like TMX, Delta, or ACROS, and all color film, I have to use AN on BOTH
sides. If you have the correct type, it won't affect sharpness, even below the neg.

 

[miha]

My carrier is metal, the inserts are plastic. I use a Kaiser VCP6001.

Hi, check you carrier again, I just did and it's made of plastic, a high quality plastic but plastic nevertheless