Can I trun on the safelight when I developing 4X5 in tray ?

[andrew_hoi]

Hi,

I would like to develop 4X5 in tray...

However, I don't know can I trun on the safelight or not ?

Can I do it while in developing ....

[bob_sunley]

Only if you want black film :( . Actually, it all depends on what kind of film and what safelight you have.

[rjjackson]

normal black and white film is sensitive to almost all visible light. if you're using green or blue sensitive film (such as x-ray film) yes, you can. otherwise, no.

[brucecahn]

Color requires darkness. With B&W you may use a darkgreen safelight. Kodak makes or made one that is safe. It should be dim and not at all close. I do not use it. I have fogged film holding it up for inspection with a dark green light, but if you keep it away from the light and don't hold it up it is OK.

[rjjackson]

bruce, i've fogged film with the green safelight too. to make it dim enough to not fog i found it useless for determining development. were you able to make it useful? from my experience orthochromatic films are best for visual development. i use this method reliably for my pinhole images since i rarely know the real speed of the x-ray films (experimenting with many brands and expired sheets) and usually pull the development to tame contrast. i haven't tried to load any in a 4x5 holder but they might be a bit too thick. anyway, huge grain, so i wouldn't suggest x-ray film anyway except for the sake of trying it out.

[mike_earussi1]

The safe answer is no unless the film is orthochromatic.

[andrew_hoi]

So, can anyone tell me which safelight good for TMAX400 ....

[alexander_ghaffari]

I think that all of the safelights for panchromatic film are so dim that they are useless. I think Kodak says that you can use a certain green safelight with most panchromatic films. If you really want to see what you are doing, perhaps infrared goggles and the IR light source emitted by that would be helpful to you, albeit expensive.

 

I have always developed in total darkness (handy for messing around with IR film as goggles are harmful to them), so perhaps someone can tell us how useful the green safelight is for checking development of the film. I imagine that to see shadow detail and whatnot that the light would not be bright enough for that.

[leicaglow]

Yup, only if it's ortho, or if you've got a minute or two in Fixer. No safelight will work for TMAX. Maybe nightvision goggles?<g>

[johnmarkpainter]

I know that W. Eugene Smith developed 35mm Film by inspection with a Green Safelight.

As far as I know, he only ever used Tri-X.

 

He was also insane and made great prints from Negatives that other people would have thrown away so I wouldn't assume

to be able to do everything the way he did.

 

jmp

[ronald_moravec1]

No light is safe to pancromatic films like T-max.

 

Use an audable timer.

 

Cover the tray with something dark between agitations like the backing cardboard that comes with 8x10 paper.

 

My timer sits on a shelf and and the red light is turned down. Then I used a fogged piece of film over the light to make it almost invisable. It is also baffled so no light can get from the timer to the film in a direct path.

 

Green light inspection can only be used when the film is almost finished on then only for a few sec. The newer technology is infrared goggles. The film is not sensitive to IR light at any time.

 

Gra_Lab timers have an audable feature that makes a sound every 30 sec. Have a flap over the light baffled as I described above that you can flip up if you lose track of the time.

 

Any light you can see will fog the film.

[paul_miller10]

Back in the 70s I worked for an aerial photography company and I developed thousands of feet of 9 1/2 inch B&W aerial film by inspection using a green safelight. We had to develop by inspection because we were processing in large tanks with these huge stainless steel rewinders. The developing time would vary by how long the film was--a short roll would develop faster than a long roll because of the rewinding back and forth varied the agitation and replenishment of the developer on the film surface.

The way development by inspection works is that you guesstimate from experience how long the development should take. development is done in total darkess. When you think you are close to the proper density, you briefly turn on the safelight to check the density and then turn it off. Since the emulsion appears white and the developed parts are grey and black, it's like looking at a reverse print. When you think you have the proper density you stop and then fix.

Development by inspection is a craft learned through experience.

[nickc1]

Even with ortho film you need to be careful - orange/brown safe lights which are OK for paper are not safe with ortho film in my experience - only red ones.

[profhlynnjones]

Scientifically yes, practically no with pan film. The light levels are so low that the eyes must be fully accomodated by either total darkness or red Xray goggles for 45 minutes to 1 hours.

 

It is a lot easier with with ortho but if you get heavy handed you will fog the film.

 

Besides, it really takes many hours of practice and much wasted film to judge development "by inspection". When it looks good by safelight, it is hopelessly too thin!

 

Lynn

[laurentvuillard]

No No No and besides : What is the point? For BW there is some tolerance in processing and it is easy to keep developper dilution and temperature constant. Agitation may vary slightly and affect slightly density but you run far less risks than trying to guess density on unfixed film with a serious risk of fogging on the top!