Light tight Hallway

[bob carnie]

Its been awhile since I made one of these, see attached images and plan done by three year old.


How much distance should I have Ie overlap to create a light tight walkin entrance.. My new location just needs to have two walls to create the overlap and an opening cut out.

Where you see the doorway now a colour processor is going to jut out. Any thoughts??

thanks

Bob

[Peter Mounier]

Since light doesn't bend, all you should need is for the walls to overlap just a little bit, provided the entrance is painted black to eliminate reflections.
Here is a floor plan I found that illustrates that ...
(attached screen grab of the pertinent page)



http://www.sebastiandarkroomprod.com...iderations.pdf
This plan presumes the door is in a public place with dimensions to make it ada (americans with disability act) compliant, but a smaller scale should work as well.

[bob carnie]

Judging by what I posted as a diagram it is less turns so I am more concerned about the overlap distance, I will paint black,,, but your diagram is not what I envision for this space and it does have one more turn in its configuration.

[Fred L]

last newspaper darkroom I worked in had maybe 2 or 3 feet ? They also had pocket doors for the Versamat which saved a lot of space as well.

[Daniel Stone]

Bob,

Are you open to installing blackout curtains in each of the straight sections of the hallway? Not hard to wave away when walking through them, but will certainly keep stray light from bouncing off of the black paint(if you can see it, it isn't black enough !)

-Dan

[bob carnie]

I am trying to make it a open hall as the room will be a coating room for pt pd as well as a loading room for RA4 processor so people will be walking through with material in their hands.

Bob,

Are you open to installing blackout curtains in each of the straight sections of the hallway? Not hard to wave away when walking through them, but will certainly keep stray light from bouncing off of the black paint(if you can see it, it isn't black enough !)

-Dan

[Jerry Bodine]

Bob, many years ago I attended a workshop that had a group darkroom. The walk-in entrance was created by hanging two very black heavy curtains from rods on the ceiling that allowed the overlap to be varied as needed. Just a thought.

[Daniel Stone]

Another thought:
Instead of just painting the hallway's walls black, could/would you be open to installing black velvet top to bottom?
A friend of mine was gifted a couple of rolls of the black "cinefoil"(set name, it's ultra heavy duty aluminum foil, painted flat black on both sides, and comes in 12",24" and 48" rolls). Anyhow, he got 2-3 of the 48" rolls. He is a nut about having ABSOLUTE BLACK in the darkroom. Only light where he wants it. So, he devised a system that works EXTREMELY well. Here's his procedure:

1. Painted walls of the D/R around enlarger, his film-loading room and print processing area normally, with traditional house paint. He used a flat, medium-grey paint for this. Nothing too special.
2. He then 'crinkled' the cinefoil so it created a dimpled/highly irregular pattern. Different depths of crinkles, etc. He would cut 4x4' sections of cinefoil, then gently crinkle it up into a ball, taking care to not tear it in the process. Once crinkled into a ball, he'd then stretch it back out to a sheet(with crinkles, it would shrink to ~30"x30" or so(approx loss of 18" on each dimension after crinkling).
3. He then took 3/4" length drywall screws and black plastic nylon washers and covered the desired areas of wall section desired with this material/technique.
Result: Even with his 10x10 CLS head on full-blast, and some small bits of light peeking out from the enlarger head(only due to extra venting needed for a 2000 watts of light, so he left those "holes" there), there is practically ZERO light reflections from the walls, or areas covered by this method.

He only resorted to this rather "extreme" method because of his prior career involvement with stealth aircraft design and radar testing procedures and knowledge that strategically designed, yet somewhat "random" angles can deflect light/sound/etc very effectively. He also noticed that there was less echo effect in the darkroom with noise from his speaker system(he listens to music while printing). It looks kinda funny when the lights are on, but it's what counts when the lights are off that really matters

[bob carnie]

I think black paint will do , I used this system first year college I just not sure how much overlap to do .. I will be getting the construction dude to make the two walls and cutting out the existing wall for passage.

[ROL]

Any thoughts??

Why does Brad Pitt keep appearing in your pix?