15. Building the box

     The final size for the back standard is 23 3/4"H x 22 1/2"W, so the inside of the box needs to be exactly 24"x22 3/4",  and the outside  and the lids will be 25 1/2"x 24 1/4".

     A sheet of oak plywood at Home Depot is almost $100, so as much as I would like to make the whole box look like solid oak, I think I will just use some 21"x25"pieces of birch plywood I already have, and  use  strips of oak to cover the edges of the plywood and extend them to the required 25 1/2", which will also give a better anchor to the screws holding the piano hinges.

    So here is the first lid stained, and the second lid in progress:

     Next step is a couple of coats of wipe on polyurethane.

14. More testing the lens

   I found on Amazon the other day a really good deal of $69 for a Goddox 400 watts strobe.

   I have had a box of photographic darkroom supplies stored in my attic for 30 years, and found in it a box of 8x10 Kodak T-Max100, a full bottle of HC-110 Kodak developer and a bag of fixer. I questioned Google about using such old film and chemical, and the answer was rather encouraging and suggesting to give a couple more stops of exposure.

    So Randy came over to play yesterday afternoon, loaded up a couple of 8x10 holders with that nearly antique film, and shot some portraits of me as a test of that lens I got for our Big Berta. We mixed a quart of developer and fixer, and processed the film in a rolling tank I used 50 years ago to process 8x10 Cibachrome prints. The first sheet came out blank, so he increased the exposure for the next two. This time, even though it looked blank again on first look, there was a faint image visible over a white background. I processed the last sheet this morning using about 3 times more HC-110 concentrate to mix the developer, and got a still very weak but stronger image:

   I scanned it and processed it in Photoshop. The result surprised me as, disregarding the dust sots due to my dropping the negative on the floor, the tonal range is pretty good for such a grossly underexposed negative

and the image is pretty sharp:

    We will figure out exposure issues at a later date, as the purpose of the test was to see how sharp the lens is, and that is quite satisfactory at f9 for our ultimate purpose.

13. Testing the lenses

  I finally got around to mounting that 1940 Bausch and Lomb 6 1/2 x 8 1/2 Tessar on my 8x10 view camera, and even though it is called a 6 1/2 x 8 1/2, it seems to cover the whole 8x10 frame at 8 ft from the subject. There is no focal length indicated on these lenses, and Google gives it between 180mm and 210mm. The maximum aperture on the ring is 4.6, and the glass diameter is 53mm, so that would calculate to roughly 53 mm x 4.6 = 243mm. In any case, it is on the short side for an 8x10 as a portrait lens. But then again, I tend to like shorter lenses.

  While I was at it, I made a wooden mounting plate and tested the big 60cm f9 Apo Tessar. With my maximum bellows extension of 25", I can focus on the rainbow neon about 12 ft away. As big as that front lens is though, it is still rather dim... And we won't know until the 16x20 camera is finished whether it covers that format satisfactorily.

12. Making the bellows

      The very thin vinyl I used to make the bellows for the 8x10 I built 40 years ago was very thin, yet  held up very well, so I looked for some more of the same both at MASCO and Bonds Brothers.  Unfortunately, they didn't have it. I considered ordering on Amazon the cheap Chinese stuff they sell for boats upholstery and that people complain about being too thin, but it comes folded in a bag and full of creases.  I ended up buying the thinest material they had at Bonds Brothers,  which is like a heavy 60" wide re-enforced waterproof tent fabric. It is black on both sides. But it turned out very heavy compared to the original, and I wish I had not bought it. 

     It is too thick to do a traditional bellows construction with ribs between two layers of fabric, so I will try to just fold it as is. I did a test cutting a 15" strip from the roll of vinyl, and it worked, sort of. I first drew all the lines and folds with a white grease pencil, and just  started folding. I used a steel roller to press the creases and clips to hold the folds in place while doing the corners. I used two pieces of wood and two vise clamps to press the folds really hard. It could work, but will be difficult for the full x4 bigger bellows.

      Well, I got the vinyl, so why not give it a go! I rolled it out on the dining table and laid out every fold with a china grease pencil. I can clean the lies later with naphta. The folds will be 1 3/16', and so is the overlap for the corners. The sides will be 22".

    

     started folding and pressing the creases with my steel roller, but then it would be hard to do every fold that way, so I started just folding by hand and creasing with my fingernails.  I use large steel office clips to hold the folds together and to press the corners. I will need more of those, so I ordered some even larger ones.  It is getting kinda messy... Hope a dozen will do...

11. The front standard is now complete:

   The bracket is made just like the one holding up the rear standard, out of 1/4" aluminum.

10. Designing and making the front standard

     I was originally going to keep things very simple, as we really won't need raises, tilts and swings much to shoot our collodion glass plate portraits. But then why not build a fully functional view camera. I have after all all the time in the world in my hands.

    I started toying with two possible design:

but finally settled on the same as for the back standard, except without the rack and pinions:

   Obviously, that decision means I will have to make a set of bellows for the front too.

   I used the remaining oak plank to make a 9"x9" frame to which the 5.5"x5.5" lens board will be attached:

9. Making the frames for the back standard

   I had some oak pieces, and so did  my friend Randy, so we had enough between the two of us to make the front and the back standards. It was actually harder to make the back because it has two fitted units, as we want to be able to shoot both vertical and horizontal 16x20's plates. Both pieces have to be perfectly square so the back frame can be rotated 90 degrees and go back in its slot. Plus oak is a hard hardwood. Anyhow, I managed to get it done, not perfect, but good looking enough now that it is stained a red oak color:

 

    I will let the stain dry overnight, and coat it with a satin finish wipe on polyurethane

    I have not decided whether to make the U shaped bracket that will hold the back and allow tilts and swings out of a single piece of 1"x1/8" steel, or use the 1/4" aluminum pieces and 1/8" angle I already have. If I want a true early 19th century look,  aluminum would be a tad anachronistic as it wasn't extracted from bauxite until the 1890's... Steel would take a little less space, but aluminum would look better, and I am already using it for the plate holder and the ground glass holder anyway. So aluminum it is:

    I made brass brackets to support the rear frame and brass springs at the top to hold it tight.  The side aluminum brackets are slitted to raise the back and the whole thing part can swing.

8. Designing a rack and pinion focusing mechanism

   This is a really big back to move, and it will require  two coupled rack and pinions to keep the moving plate from binding.  The back lid of the box  is going to be about 24". I would prefer a brass rack and pinion, but I could find only one on ebay in a 500mm size length.  Those sold by Edmunds are too expensive, so I settled for two 0.5 Mod  8mm x 8mm x 500mm steel racks 

with matching .5Mod 16 teeth pinions with a 3mm hole.

         I sketched the setup roughly in my notebook. The racks will be attached to the lid /base, and the shaft and pinions to a guided sliding cart to which the back of the camera will be attached.

    We will need two substantial brass knurled focusing knobs to turn the two pinions mounted on the same shaft.  We will also need similar smaller brass knobs to attach the front board and the back so we get tilts,  and two larger ones for swings.  Specialized Knobs are very hard to find is expensive, but I found a cheap alternative in drawer knobs on Amazon.  I got a pair of 28mm brass knobs for a mere $8. The mounting screws are 4mm, so I will have to modify the pinions to accept a 4mm shaft.

a pair of T knobs to lock the front and back swings for $10:

and a 6 pack of 26mm brass knobs for $8 to lock the tilts:

     I also ordered some real wide knobs from eBay for $15:

   

    Here is the basic layout of the box:

     Here is the layout of the focusing rack and pinions mechanism:

and a detail view:

7. DESIGNING THE PLATE HOLDER

    Before I design the back itself, I have to start with the plate holder. I spent some time sketching idea in my notebook,  which will be refined and drawn on scale once I decide which among many designs I like best. I am striving to keep the camera as small and light as possible, and am trying to fit it all in a 24"24" x8" box.

    I always try to use materials I have around the studio rather than going to the store and spending money. I happen to have bunch of left over 3/4" x 12"x 1/16" U shaped aluminum channel, and a bunch of 1/2"x3/4" mahogany sticks from Guatemala that fit perfectly inside, so I designed a holder that would use them. All I will need is a piece of thin steel or aluminum for the slide and a plywood hinged door. To make sure that it will be stiff and solid enough, I glued a test corner with cyanocrylate (crazy) glue, and was amazed how strong it was. I cant break it  apart. It is not as attractive as a solid wood plate holder, but collodion is messy, and aluminum is easier to clean.

   This is the basic idea, and the ground glass holder can be made exactly the same way except for the back door:

     Here is a more refined drawing:

6.Why Big Berta?

    Some of you might wonder why I am calling this camera and this entire project Big Berta,  Old Baby Boomers might know, but I would venture that most younger people have no idea. You see, my grandfather fought in WW1, and I often heard him talk about "La Grosse Bertha". It was a huge canon  that the German army used to shell Paris from 100km away, which was unheard of at the time. Made by Krupp, it was named after his daughter Bertha...

   It shot huge 42mm shells:

 

      Cameras are used to shoot too.  The name just came to mind when I decided to build that big gun to shoot huge 16x20 images. 

5. FINAL DESIGN

      I spent some time today finishing the basic design for the camera. It is a very large field camera design, with the closed camera being a 24"x24"x8"box. I will stain the wood and use brass braces to make it look like a 19th century contraption.

  I will try to keep the weight down with cutouts where is will not affect the rigidity of the open structure.

  All the dimensions are not quite set, as I need to first design and build the plate holder and the back frame on which it will fit. I actually want the back to be able to accept also 11x14, 8x10 and 5x7 plate holders, so we do not have to do exposure and development tests on large 16x20 glass plates.

  I have a bunch of black tight weave polished chintz fabric that I believe will work fine for the front extension, and possibly also for the bellows if I glue two layers together with sandwiched card stock forms for each pleat. 

4. DESIGNING BIG BERTA

       In a first stage, I want to build a basic 16x20 camera to shoot portraits with the 600mm lens we now have. We do not need any camera movements except focusing, but it has to extend to at least 1200mm, which is just under 48".  I would like it to fold in a box for transport and be as light as possible, but it has to bear the weight of that 2.5 pounds lens up front.

      I started with the idea of a big box similar to my 5x7 design with a bellows up front:

               

    Then I thought of a way to make the box much lighter and foldable by using black fabric:

    The entire apparatus would then fold into a relatively small box about 24"x24"x 6" thick. The open 24" lid length added to the 6" thickness of the box would provide 30" of extension, and the bellows could easily extend another 18", which would give us 48" total. The 2.5lbs lens would need solid support, and that could be provided by a double sliding track attached to the lid like most field cameras.

    The problem is that it would be very hard to reach the focusing knobs.

    We need the bellows and focusing knobs in the back. Why not open the box on both sides, which would give us a 54" base, and allow very close head shots:

    Now I think I am getting somewhere. The bellows would just be a larger version of those I made years ago for the 8x10, and would only need about 30" total extension. They will be a little heavy, but the track just underneath will support them and prevent sagging. 

    Time to draw a 1/2 scale blueprint. 

    This is how far I got today: