From the Desk of AgNo3Solution

Portable Darkbox

Overall view of the portable darkbox

It was built fairly quickly. Maybe not… well, it took 2 weeks on and off as I do have a day job at this moment.

The box were gathered literally at a worthless price as one could find something like this scattered on the street. It was taken in, sanded and coated with wood dye. The internal part of the box were coated with Bonda Seal, just to add bit more protection as I know there will be some sort of silver nitrate spill that will eat away the surface (probably right through it at some point).

The overall of the surface area within the darkox were covered with anti-slip mat, which lowers the chance of any glasswares, plate holders & whatnot, from going everywhere in the dark.

The original box had a high density foam on its lid, which was quite interesting as I could cut away with surgeon’s knife to slot in various contraptions.

With bits and pieces, and ample of reference around the net of various designs. I knew what should be in it on a basic level, and listed of what will be my own miniaturised darkroom on the field, of what I need and want as well. This needs to emulate familiar environment, at least the expected tools that I usually use at my own darkroom-ex-bathroom.

The handle was taken off from an old torn bag, the arms to hold the dark cloth was simply done with a couple of hacked broom sticks. Perfectly angled 45 degrees as expected from standard road sweepers.

Images below and its caption will describe better of what was installed in it.


Pneumatic gas strut (80N) is sufficient to hold the box’s lid cover properly, which weight less than 5kg. The developer tray (fits well for 8×10) will do well for plates up to 5×7). It works beautifully opening up slowly and held the lid in place.


A couple of small shelves were installed and drilled into (made of bamboo ply). The hand-held suction cup is placed underneath one of the shelf.


The silver bath box, and its holder. A regular digital countdown timer placed near it for quick tap on operation soon after the plate dunked into the silver bath.


Two small bits of neodymium magnets glued onto the foam, and as well as on the plate holder (not shown). This will secure the plate holder away from the surface and from falling off the shelf. A small digital thermometer and hygrometer rests next to it (which has its own sensor and probe). This is helpful for me to be aware if the overall tempreature of the darkbox is too humid/hot and whether if I need to cool off my developer.


My most favourite tool in the darkroom, the metronome.

The metronome is particularly helpful for me as I do find it difficult to concentrate to count up the required 15 seconds. My mind usually wander off and sometime I engrossed on visual inspection of the developing plate, which I tend to lost count. The setting of it is clocked at 60 beat per minute (the tempo is at Larghetto setting), and its quite loud as well. I might invest in a digital metronome as few time on the field, if the darkbox isn’t properly leveled, the pendulum doesn’t swing in its proper motion to give exact timing.


If I do not use the large 5×7 silver bath, I usually carry a ‘mini’ silver bath tank, which does quarter plate (around 230mL usage)

Back portion of it with stand

A flip-lid design


An elastic band of the dark cloth, which wraps securely around my body when entering the darkbox. It was really a hassle to fit this one in at this size manually!


The final look of it. Not so pretty, now that I am looking at it, it does look like a devil’s head somewhat. Quite eerie contraption!

This is barely half of what was brought into the field; the camera, tripod,  canisters of water, containers for plate and its holders, various small tools etc. Though the entire box is being wrapped with this dark cloth, a kind of a gunny sack. Which comes as an issue as I need to air-out my box and the darkcloth after each session, as it does accumulates the ether & alcohol fumes.

Well, its nothing new but just another list of inventory for me to clean up, just like most of other tools after and before use. I do spend half of the time cleaning up as much as I prepare the chemistries to do work.