Post 20. Making the front bellows

   After looking at a lot of posts, tutorials and videos about making bellows, and making the set of straight bellows by myself, I feel I understand the principles well enough now to make them my own way. The best tutorial I found is here, and I will more or less follow it:

https://www.picto.info/RS_texts/bellows_RS.pdf

  I went ahead and ordered 3 yards of a blackout liner fabric for curtains that is fairly heavy, black on one side and light silver grey on the other, and 56" wide. I will make the front bellows the traditional way in  three layers with cardstock stiffeners sandwiched between the curtain liner and a black coton fabric I already have. The front bellows is tapered from 22"to 9", and must extend about 24". So the ribs have to be unequal in width to produce that 13" taper. In order to calculate the dimensions precisely, I will use millimeters instead of inches, and make a bellows that tapers from 550 mm to 200mm, with a total extension of about 750mm. The fabric panel for each side of the bellows need to be somewhere around 750 x 1.7 = 1275mm. The ribs on the straight bellow I mad were 1", so we want our ribs to be on average around 25mm, except that we need unequal ribs. So we will need around 50 fold for 25 ribs. Each side panel must taper a total of 175mm over 25 ribs, so the difference between the wider and the narrower fold needs to be 175/25 = 7mm, making the narrower one 25mm -3.5mm = 21.5mm and the wider one 25mm + 3.3mm = 28.5mm. Since there needs to be a space between the cardstock stiffeners so the bellows can fold , we could cut those stiffener ribs 21mm and 28 mm, leaving exactly 1mm of space between them for the folds. The total length will be 50mm x 25 = 1250mm. The entire set of top, sides and 1/2 bottoms will be drawn right on the grey side of the black out fabric stretched flat on a board(disregard the dimension on the sketch bellow):

  Here is a preliminary scale layout of one panel in inches:

 

    Actually, there are two ways to go: 

        1. Make all the ribs pointed following the zigzag folding pattern and glue them all. In that case, the two bottom halves need to be glue together overlapping about an inch, making a cone shaped unit that will need to be carefully folded making the bellows. Either the ribs will be made of two halves side by side(weak point), or overlapped (then there is a double thickness in the middle of the bottom).

        2. Cut the ribs for the side panels without the points, which allows using a plywood shape to glue the fabric panels together before gluing the ribs, and making a square tube instead of a round conical unit, which will have a stronger bottom panel and will be easier to fold, but will possibly have weaker soft corners, since the ribs on the sides don't have points.

    Different makers have used different glues: brushed on contact cement, acrylic, 3M Spray adhesive, etc... I would rather stay away from spray adhesive as my experience has been that the stuff will come loose 5-10 years down the road. I don't want to use contact cement either, as it will in places bleed through the fabric and make a mess. And then it may eventually come loose. Plus the ribs have to be spaced perfectly lined up with the drawing 1mm apart, and repositioning is not possible with it. My choice would be Yes paste, but it remains water soluble. There are several fabric glues on the market that I will try, as well as tacky glue, Modge Podge, Acrylic Gel Medium, and my old acid free PVA bookbinding glue. I will just have to do test patches with a few ribs.

 

Post 19. Update

     Well, I keep roaming the internet for information and ran across a wonderful web site created by a guy from Slovenia who has built a business pouring and selling his own home made silver gelatin "Zebra" dry plates. He is very thorough in his explanations and in his videos and blogs. He pours his plates using a syringe, which seems a lot easier than the traditional method.  He also has developed a way to produce better and lighter Tintypes and Ambrotypes on black glass by adding Potassium Thiocyanate to the developer. I definitely want to try that. 

https://zebradryplates.com/

   Randy came by for a while this afternoon and I updated him on what I had learned about silver nitrate bath maintenance, pouring plates, etc... We checked the density, and it was way  off the 1.07 mark, all the way in the 1.4's. The pH was also way off at 5.5, which could explain the fogging. We also noticed a deposit at the bottom of the jar that looked like silver precipitate, same stuff that I found at the bottom of the failed sensitizing tank.  Randy practiced pouring some plates with a syringe and a mixture of water, gelatin and watercolorI concocted to practice with without wasting expensive and smelly collodion. He found it easier, if still tricky. My thumb is in such bad shape right now that I cannot do much.

Post 18. Planning the next test session

    Google says a liter of 9% silver nitrate bath can sensitize over two hundred 5x7 plates. And it can be sunned or boiled to remove contaminants,  replenished with silver nitrate crystals, and the pH adjusted with nitric acid.

  Unfortunately, I lost half of the silver nitrate since Sunday. There was a leak in the tank, and the silver nitrate seems to have oozed out first, eaten up the silicone aquarium glue and even seem to have warped the plexiglas... I understand now why the few tanks offered for sale are expensive and built literally "like a tank"!

   I will dismantle it, reassemble it with an acrylic, cyanocrilate or epoxy glue, and encase it in a tight wooden box with a fitted lid and latches as the one above. In the meantime, we will just have to sensitize the next plates in a tray using the half liter I have left. 

   I asked Google some silver nitrate bath questions, and got answers, and follow up questions answers. The jest of it is that to get consistant results, the silver nitrate bath needs to be often checked and maintained so the density for a 9% solution is 1.07 and the pH remains acidic at 4 for ambrotypes, keeping the temperature between 65 and 72. The plates will sensitize faster if the temperature is higher, with a base time around 3 minutes. Over sensitizing can cause fogging, as can a pH above 5. However, lower pH's decrease sensitivity. The level of iodides is also critical to sensitivity, and should remain near saturation level for optimal sensitivity. Higher levels increase grain size. Iodide is primarily sensitive to blue and UV. Adding bromide in  40/60 ratio extends sensitivity into the green range, which is better for portraiture, but with lower speed. Workflow has to get faster as temperatures rise.

   I ordered both vinyl and nitrile black gloves, some 5x7  replacement glass for picture frames, a lab hydrometer kit to test the density of the silver nitrate bath, and three 500ml amber bottles. I already have a thermometer.

  Now, the problem with the lack of contrast. Well, the wet collodion Ambrotype process is inherently low contrast on purpose, the plates are underexposed and underdeveloped so a weak negative can appear like a positive when placed in front of a black background. We will have to find the right combination of exposure and development time, and that is a bit of an art more than a precise thing. According to some "experts", development time should be cut to 15 or 10 seconds if the image is overexposed and appears too fast, and extended up to 20 seconds or so if the image is slow appearing.

   I am concerned my model set up in the dining room may let in too much outside light and might be fogging the plates a little, so I moved everything upstairs to a dark attic room. 

   Another possible source of fogging actually may simply be the safelight. I have used it for years processing black and white paper, but who knows. So we will have to do a fogging test. 

   The more pictures I look at and collect from Pinterest though, the more I am leaning towards rough altered images, double exposures, with blurred areas, hand writing, scribbles scratches and blemishes, even painting on them, adding color, gold or silver leaf, collaged paper. In other words a very long way from picture perfect Hollywood portraits... 

I like these very  much:

     I also have always had a fondness for vintage mugshots:

   But then that is what I personally like. Once the camera is built and set up, my partner in crime Randy and I can both do our own thing with it, and hopefully get to play and shoot the same models in very different ways, with totally different results. There are after all also plenty of options besides the wet collodion thing we are starting with: dry collodion, liquid silver gelatin emulsion, Ilford reversal paper, X-RAY sheet film , rephotographed photo paper negatives, etc...

   We really need to practice pouring, a lot. So I mixed a liter or so of a slightly viscous golden colored gelatin solution to practice blanks with without wasting the collodion. 

Post 17. Testing the test kit

     Well, so far not so good.  First we tried using a light meter set at 0.5 ASA and doing exposure stripes of just a black, a grey and a white cards with 1, 2, 4, etc... flashes. The resulting very weak and low contrast plate vaguely showed the three cards, but strangely no exposure increment stripes... I can't fathom why.

    Having just barely finished my silver nitrate tank and plate holder for this first test, I didn't have a holder to dip the plate and take it out of the tank, so I grabbed a thin brass rod and bent it to make a makeshift holder. That was a double mistake. The acrylic plate floated up, we had to somehow fish it out, and the brass reacted with the silver nitrate...  

   So I bought some 1/4"x1/4" and 1/8"x1/8"square and 1/4"x1/8"rectangular plastic rods at the model store and made a plate dipper with grooves that would prevent the 5x7 acrylic plate from floating away.

  Last Sunday, I decided to set up a test stage using an anatomical model with fair skin and glass eyes in front of a black paper background, and a grey scale:

  For the first test, I made a mess trying to pour collodion on the plate directly from one of the Erlenmeyer Flask that came with the kit , but still went ahead and dipped it in the silver nitrate tank, making another mess because the tank was vey full and it made the solution spill over, wasting some. I left it anyway in the silver nitrate bath for 3 minutes or so (it is not supposed to be really critical) while I mopped up the spill. That plate dipper drags out too much solution too, so I will have to make a slighter one with 1/8"x1/8" rods instead of 1/4" rods.

   I used one full power flash of my strobe placed 3 feet from the subject with the lens wide open. I developed it under a red safe light until the negative image came up, washed it to stop the development, turned the lights on, bleached it in the fixer, dried it, and sprayed a coat of black lacquer on top.

  I should explain that rather than putting the plates in front of a dark paper or cloth, I found I got deeper blacks and better contrast by simply spraying a coat of black lacquer over the dry collodion emulsion. That may not be archival, but will work fine for initial tests. 

  The plate is on the dark side, the grey scale is blurred and there are irregular lighter swirls caused by the bad collodion pour, but at least I HAD AN IMAGE!

     For the second test, I cut a 5x7 piece of aluminum flashing and painted it black with lacquer. So this is technically a tintype instead of an ambrotype. I moved the camera and the strobe a little close at 2.5 feet and did one full power flash wide open. I switched hand, but the pour of collodion was still messy and wasteful. I developed about 15 to 20 seconds and ran water over it. I could not see any image, but after the fixer bath, I did get one, rather dark: 

   For test #3, I used a plexiglas plate. I moved the flash back to about 4 ft to try to give less exposure and slightly more time in the developer. And it did come out the best so far, lighter and with more contrast, except that the plate got badly scratched when I pulled it out of the silver nitrate tank, and my pour is still creating messy swirls(I will claim that clumsiness is because of my shriveled up left hand and a bad cut from a table saw on the thumb of the right hand) :

  Since a little less exposure yielded better results, I tried the fourth test with the lens stopped down to f8, and the resulting plate ended up with almost no image. 

  For the fourth test, the exposure was the same as #3, but I extended the develpment time to roughly 30 seconds, and ended up with a very dark image:

     

   Finally, I did my last plexiglas plate with the same exposure, but with a short development time, and it turned out better than the last one, but also too dark:

   So plate #3 was apparently the sweet spot in terms of both exposure and development, and we will have to try and define the best development time better next time.

   The plexiglas plates having been easy to use and having worked well, I ordered more to continue testing.

   

16. The rack and pinion focusing system, the silver nitrate tank

    On the Big Berta front, I have moved along albeit slowly building the beast, but made some progress. The wood panels require sanding, staining, and multiple coats of wipe on varnish, and have to dry overnight after each coat, so it is slow going.

   Both lids are now finished with several coats of wipe on varnish, and I have started working on the focusing mechanism. I have two 20" racks and two 0.5 MOD pinions to match.  My plan was to use an 8-32 threaded rod as the shaft because it fits the brass knurled knobs I bought, but I just realized it wasn't stiff enough across the 24" of the lid, so I will use a 1/4" steel rod instead, and use the other two brass knobs I have that can accept a larger hole. I ordered two new pinions with a 6mm bore to fit. The threaded rod will be covered with brass tubing. The brass knobs will be drilled and tapped 1/4-24 to fit the threaded rod.

    The shaft will go through a brass tube that will be attached to a caddy sliding between two guides. The caddy is a 7 1/2" x7 1/2" x 3/4" piece of birch plywood with a slot in which the brass tube will be glued in position. To facilitate the sliding, a 7 1/2" x 8" x1/8" piece of teflon is attached to the bottom side by a dozen recessed flat head screws. It will be guided by two 3/4" x 1/8" strips of wood and held down by two 1"x 1/8" aluminum flat bars.

 

    I did more research on the ambrotype chemicals and kits, and ended up ordering from another supplier. Basically, the only expensive chemical in the kits is the silver nitrate. One liter of 10% bath is $458 at Bostick and Sullivan, but only $238 at UV Photographics, 

   So I ordered the larger 8x10 kit from them for $370, plus an extra different developer to test.

   I then considered making the silver nitrate tank to sensitize our 4x5, 5x7 and 8x10 test plates in the first stage of our project. The one liter of solution we get with the kit is actually barely enough to fill a very thin 8 1/4" x 11" x 11/16" tank(inside dimensions). So I ordered a 12"x 36" sheet of 1/4" thick black plexiglas, cut the panels and am now ready to assemble the tank as soon as I get the special aquarium silicone glue. When we get to the 16x20 plates, we will have to sensitize them in a rocking tray in the darkroom, because a proper tank would just require way too much silver nitrate solution(around 4 to 5 liters, costing over a $1000). 

 

   Next I need to make the plate holders, and I am still hesitating between two different designs, and whether to make it a spring back or not. We will need both an 8x10 holder (with 4x5 and 5x7 inserts), and a 16x20 plate holder with set of inserts so we can shoot 4x5 or 5x7 test plates before we splurge with a 16x20( which takes 16 times more silver nitrate than a 4x5...).

   Every time I get into a new project, painting, sculpture, projections, whatever, I spend a good deal of time researching what has already been done, and that helps me figure out what it is I really like and what turns me on. That initial inspiration always ends up brewing, simmering, and after some brainstorming and experimenting leading to something that is personal, and hopefully has not been done before.

   So I have been surfing Pinterest looking at and collecting all kinds of black and white portraits, new and old. There is so much material out there I just keep scrolling pretty fast until something catches my eye, for whatever reasons. There are a lot of good portraits of famous people by famous photographers, lots of perfectly lighted flawless images, but I don't really pay attention to the names, as there is a world of difference between a good portrait and a work of art. I cannot define exactly what is that special quality that transcend a mere photograph, I just know it when I see it, and there are ultimately very few that pass that test. 

    I also have been rummaging through 30 years worth of digital files and selecting in a special folder the portraits I shot on occasion over the last 50 years. I still like very much the wacky series of nudes I shot of three models I hired once for two hours or so. The shots were planned ahead and the props at the ready, so we got a lot done in a couple hours. And the young hairless model was so humorous, creative and expressive that we got along and played very well together, coming up with a number of unplanned shot.