From the Desk of AgNo3Solution

Silent Grundner Shutter Mod

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Measuring and sketching out in re-housing the Silent Grundner Shutter.

Since the pneumatic part of the Silent Grundner Shutter were shot or jammed up and stuck (see the previous post here), as expected after 100 years which was made of vulcanised rubber, I had to figure out a way of using it as the bellows were quite fantastic shape and still in good condition.



I had measured and sketch it out as I am quite pleased that it goes well with my Derogy lens.

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All done and good to go

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The rear lens attachment, the internal rim are padded with one sided, 2mm foam tape to grip onto the lens and reduce vibration as well.

The glue joints, which were most likely to be rabbit’s glue, between the bellows and the metal house were sanded and re-glued.

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The bellows were buffed several rounds with Saddler’s leather dressing using cotton tips.

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Highly recommended Leather buffing paste. No petroleum, turpentine, or animal fat which the suppleness of leathers shows and retained after application and buffing.

The bellows did not have any light leak nor loose parts, but the surface did require a bit of leather buffing, which I used ‘Saddler’s Leather Dressing’, which is quite wonderful leather polisher as I use it on most leather materials (books, old dag cases… etc). After few rounds, it came out nice and supple and decreased the chance of the material from cracks and brittle.

Between the bellows and the metal parts, I had used a 3mm foam to dampen the vibration, to reduce any vibration when triggered open, onto the lens and the camera.
I placed a single sided foam tape (2mm) onto the attachment between the SG Shutter and the len’s hood, which does both proper grip when mounted, and also helped to decrease the vibration.

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The external platform with female thread to attach the cable release

The cable release screw (female thread) were taken from an old camera parts, structures were built around the gears and fitted as close to the platform to maximise the push from the metal bit from the cable release.

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Attached cable release.

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A good quality cable release will puch the platform gear down. Cheap stuff… nah.

I had tried using cheap cable release, which does not hold enough strength to push down the platform, which I had then rummage through my store til I found a cable release that is actually gives a solid push when pressed.

I had tried using pneumatic cable release, which was a failure and I was looking forward to use it instead as it had a great length to work with. Unfortunately, it was too weak. I had experimented using large syringe (thanks for the tip Simon), which it did pushed in just a bit, but still not sufficient to open the bellows fully.
Still, all is not lost, as I still have the 40 cm cable release to do the job.

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Mounted and ready

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Tadaa!
 
An angry passport photo selfie it is then…

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My actual first selfie ever… The large black blob on the lower part is my hand releasing (or is the word pressing?) the shutter in front of me with such a bokehness to it.

Improved Ingredient for Developer

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Left: Purified Crystals; Middle: Lea Developer made 9th May 2015; Right: Lea Sugar Developer made 24th May 2015 (Image taken 11th June 2015)

Based on previous incidental finding (refer to this post), I had begun to put in an experiment in finding out the usability of the purified crystals. Using Lea’s Sugar Developer’s formula, it had resulted the same strength and characteristic from the original on both tests.

Though what seemed to be much interest was the appearance of ferric sulphite ‘dust’ within the two developers developed at different time-frame. And the other would be the colour of the purified crystals had yet to change anymore than ‘yellowish’ tinge, even after more than a month, compared to the original use of technical grade (99%) iron (II) suphate heptahydrate, which had turned dark tea, or ‘reddish’.

The new findings were the time frame for filtration differs, which would be advantageous for practitioners to have this mixed a day or two earlier, and would be able to take them for field work without the need for filtration.

I am sure that there’s more factors could be accounted for, or even improved as there’s many variants of formulas to try out and factors to consider such as ambient temperature, exposure to light while contained, etc.

However, new test had been conducted by keeping the developer in a light proof container, which would be one of the factor of reacted in producing ferric sulphite.

I am sharing this findings here, as well as on academia.edu (click here for the
link)

Portable Darkbox

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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.

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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.

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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.

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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.

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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.

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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.

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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)

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Back portion of it with stand

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A flip-lid design

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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!

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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.