Re: [Cameramakers] Bellows and movements

[Daniel Rhoades]

I'll let you know what worked for me but I would suggest getting Jon Grepstad's book on camera building(http://home.online.no/~gjon/).  Great referance even if you decide not to build his exact design and the book is not expensive or hard to find, just place your order.   >How long should the bellows be? I am assuming that the longer is for closeup and the shorter is for infinty and wide angle. I made mine 17".  I found this to be the optimum length for the focal length I was using that still allowed for good bellows compression.  I used a straight bellows with my 4X5 due to the ease of design and construction.  Using this design didn't add much (a couple of ounces) to the weigh of the camera and ensures that I'll have enough room for more lenses in the future no matter how large (ie, I build a back frame for a 8X10 I can use the same front frame).  You can make your bellows as long or as short as is needed for the tasks you want to accomplish.  Oh, and by the way, making a bag bellows is easier than making the pleated bellows.   >How much movement is necessary? I assume at some point it is no longer useful. I assume each of these movements has a name. Tilt, swing, rise, fall and shift.  The amount of movement you will have is a function of the image circle of your lens and the design of the camera.  Each has a different function and I would suggest getting a book on LF camera use as this would also give you pictoral examples of what each movement can do.   >Should both the back and the lens have movements, or just the lens? That is completely up to you and what you plan on shooting.  I have this one caveat though.  If you build your own camera why not give yourself all of them to their greatest extent?   >Anyone have any ideas on back rotation? Spring back construction? I saw graflock backs on two different cameras, but in absence of one of these mechanical marvels, how would you manage the spring part of this back, I was considering breaking a couple mouse or even rat traps to make center mounted spring arms. I am sure someone has already come up with a better way. Again, I suggest Jon's book on LF construction.  His rotating back is quite elegant and functional.  It uses a spring back contruction.  Believe it or not the spring tension required to hold the back on is not much.  I went to the local car shop and bought a pair of replacement wiper blades ($2.99), removed the rubber and I had aluminum leaf springs that worked like a champ!  Easy and cheap. >I also say a fresnel on one of the viewing scrren, this may sound naieve but it looked exactly like those full page magnifiers that you use on a small print book. Would one of these work or is ther some special quality that they need to possess? >While I am on this, how big is an actual ground glass for a 4x5? What is the purpose of the lines. Some had a grid, some had little corner hash marks some didn'thave any lines at all. If I make my own glass, could I just pencil these on? What is the normal thickness of a ground glass, looked like 1/8" or so, guess I could steal one out of one of those dimestore picture frames and frost it somehow. Is it only frosted on one side? Could I just get that etching cream or do I have to take ti to a sand blaster? I've noticed that just about anything will work as long as you like the results.  I used 500 grit Aluminum Oxide powder on double thick glass and made two nice bright focusing screens.  A fresnel is not nessesary but if you want it, try out your suggestion. DO NOT USE ETCHING CREAM.  I tryed that several times and could never get as even and bright a screen as with Aluminum Oxide powder.  The glass is only ground on one side, use double thick glass so you don't have as worry about breakage in the field.  The size is 4X5 with the corners cut off (your choice of how much).  This allows the air to escape when you collapse your bellows.  I don't use a grid on mine, they aren't really nesessary, but they aren't hard to put on, again, how and what kind is up to you.  The lines are to help you align the picture on the screen.   >Lenses seemed to all be on something like a 4"x4" (or possibly 10x10cm?) lens boards is this a standard size? If it is, what are the exact dimensions of these lens boards, how thick are they? Make your own lens board.  They aren't hard to make and then you don't have to worry about standard dimensions.  Also, the thickness is up to you and the type of lens you have.  If it uses a flange then you can make it is thick as you want.  If it uses a retaining ring then you'll have to figure out how much room you have.  If you use want to use brass or aluminum I would suggest getting a door kickplate from Home Depot (or like place) and cutting it out of that.  Thin enough but sturdy enough to do the job.   Hope this helps.   Dan Rhoades www.rhoadescameras.bizland.com             Get your FREE download of MSN Explorer at http://explorer.msn.com