Light tight Hallway

[bob carnie]

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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)

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http://www.sebastiandarkroomprod.com/design-considerations.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]

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Any thoughts??

Why does Brad Pitt keep appearing in your pix? :confused:

[bob carnie]

He is a good friend trying to give me some help with his likeness

but what about the question??you usually have good ideas



Why does Brad Pitt keep appearing in your pix? :confused:

[Daniel Stone]

<snip>
However you decide to build it, I recommend a painted white stripe along the wall to serve as a guide for those walking through so they can see where the corners are. It need only be 3-4 inches wide.

Painting a white dot IN the corner could work too, or a square. Less reflections too(even if it's just a 3-4" wide stripe, it's still enough surface area)..

just a thought, paint the corner itself, easy to identify/spot( pun intended :p)

[Tin Can]

My 15 years ago college darkroom had this maze setup and it was very good, very dark. I am a nut about total darkness. I have a storefront loft and I blacked out the whole thing. Now I have no windows. A side benefit is very good sound proofing. Chicago outside doesn't exist, until I open my door.

The maze works and some white dots will show the way. Easy to carry anything in and out, I used my elbows as bumpers.


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)

118948

http://www.sebastiandarkroomprod.com/design-considerations.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.

[ROL]

but what about the question??you usually have good ideas

:confused:. Sorry to disappoint Bob, but I've always thought of the maze entry as some kind of black magic – I've seen it work, I guess it works (having used one), but I don't actually believe it works. For me, it is some sort of fiction, requiring more room to employ than other simpler constructions, used in labs with high traffic (which, admittedly, is probably your facility). In any case, you still need real dark to load and develop film or print color (:eek:), unless that is planned for a different area, or is of no concern as a print only space. If those are also concerns, it would appear that pocket doors in the maze have some value, at least in terms of a multi-use space.

[Graham Patterson]

The basic 'U" ought to work. You will have to address the wall, floor, and ceiling surfaces to absorb reflections, including avoiding light reflecting into the maze. The center wall has to be at least twice the width of the passage. Three times would be better. If you actually draw this out and put in the reflection paths you will see that a longer center wall ensures at least two surfaces are involved in reflection. You might also want to put the end wall at a slight angle to encourage reflections back to the light side. The only one I have used was: enter, turn 90 degrees right, move to end, turn 180 degrees left, move forward, and turn 90 degrees right to enter the dark.

[cowanw]

I am afraid you need three reflecting surfaces as per Peter's diagram. Black paint reflects about 2.5% of light. Your question is a good one because the angle of reflectance does influence amount reflected. If you turn your halls on their sides you can get 4 turns in the same space.

[cowanw]

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Like this

[cowanw]

The Maze must be constructed and finished exactly as specified below in order to keep white-light from entering the Darkroom. The dimensions shown in Figure 4 must be followed very carefully. The Maze is considered a room; therefore, space for a 60-inch diameter wheelchair Wheelchair turning circle is required.
http://www.sebastiandarkroomprod.com/darkroom_design.php

I just read this. Do you think this applies in T.O.

[Tin Can]

I just remembered, my college darkroom maze was for the printing and sink area. All film was loaded in a very tight closet. The color room, I never used, was very tight also.

[Dan Dozer]

Bob - I'm a little confused here. I don't know your "dark needs" for your processor, but for Pt/Pd, it doesn't have to be light proof, only void of UV light. Also, you are coating Pt/Pd paper in one room and carrying it to another room for exposure/processing? Sounds a little strange doing it in two different rooms. I'm doing that exact thing as we speak, but that's because the humidity in my darkroom out in the Garage is much to dry and I can humidify a bathroom inside my house to do the coating. However, I haven't really heard of coating and exposing/processing Pt/Pd paper in separate rooms before for any other reason.

[bob carnie]

The coating and film stripping room is separated from the sink and plate burner, as we usually are working with larger projects where more than one sheet gets coated at once.

the room needs to be light tight to load RA 4 processor.... We multi task up here in Canada, moving fast keeps us warm


Bob - I'm a little confused here. I don't know your "dark needs" for your processor, but for Pt/Pd, it doesn't have to be light proof, only void of UV light. Also, you are coating Pt/Pd paper in one room and carrying it to another room for exposure/processing? Sounds a little strange doing it in two different rooms. I'm doing that exact thing as we speak, but that's because the humidity in my darkroom out in the Garage is much to dry and I can humidify a bathroom inside my house to do the coating. However, I haven't really heard of coating and exposing/processing Pt/Pd paper in separate rooms before for any other reason.