Pix of your home-built cams here please

[Dan Fromm]

Thanks, Barry. I downloaded pinholedesigner a while ago, wanted to know what Chris had done.

[narsuitus]

.0073 times the square root of the focal length

Just for clarification, this formula for calculating the optimum pinhole size measures the focal length in inches not millimeters.

[Steve Smith]

Just for clarification, this formula for calculating the optimum pinhole size measures the focal length in inches not millimeters.

It shouldn't make any difference. Measure the focal length in inches, the hole size will be in inches. Measure it in millimetres, the hole size will be in millimetres.

Steve.

[Christopher Colley]

seeing as I have no easy way of cutting or measuring a hole so small I enjoy simple guesswork!

yay pinholes

[semeuse]

Haven't built a whole camera (yet) but I've built a couple of lenses for my 8x10 field camera.
picture of 400mm lens with f16 stop installed: link
picture taken with same: link

[barryjyoung]

seeing as I have no easy way of cutting or measuring a hole so small I enjoy simple guesswork!

yay pinholes

Oh yes, we do indeed have a way of both cutting and measuring pinholes.

1. Get the book by Jim Shull entitled "The Hole Thing". What a great book! Your library can inerlibrary loan a copy for you if they don't have it. I sometimes see them on bookfinder.com and on ebay.com.

2. If you cannot get the book because like me you are too tired cold or scared to do so, then get ye to the nearest fabric store and buy an assortment of hand sewing needles. Measure the needle with a micrometer or go to any machine shop where they will happily measure the needles for you and write the diameter on the handy masking tape tabs you have already attached to the needles so they don't have to.

3. Push the desired needle eye first into a pencil eraser which is still attached to the pencil. It makes them muche easier to handle that way. Try to make it coaxial with the pencil which is now the handle for the needle.

4. Put a piece of aluminum foil onto a piece of cardstock (Cap'n Crunch boxes are made from the industries finest card stock). Press the neddle into the foil while spinning the handle (pencil). This will make a very nice and perfectly round hole of the diameter you desire. If you believe this statement skip step 5 and imediately begin making breathtaking opinhole images.

5. Oh ye of little faith. If you just HAVE to measure the pinhole, it can be done using a microscope. Focus the microscope on your calibrated needle. Tape a piece of velum (special drawing paper made from sheep intestines or something) over the eyepiece of a standard light microscope. mark the shadow cast on the velum by the needle. replace the needle with the pinhole and voila! you can compare the diameter of the calibrated needle to the diameter of the pinhole. Clever huh?

Good luck.

[Harrigan]

Barry you just killed pinholes for me. God why do you people have to be so damn technical about everything? To me the beauty of a pinhole is in the soft image not another technical excersice is getting the perfect super sharp image creating pinhole. I use a regular lens for that.

I just use a PIN and put a HOLE in some metal and put that on a box or a tube and have fun. Getting out the microscope to measure the hole just takes all the fun out of it for me.

[barryjyoung]

Barry you just killed pinholes for me. God why do you people have to be so damn technical about everything? To me the beauty of a pinhole is in the soft image not another technical excersice is getting the perfect super sharp image creating pinhole. I use a regular lens for that.

I just use a PIN and put a HOLE in some metal and put that on a box or a tube and have fun. Getting out the microscope to measure the hole just takes all the fun out of it for me.

I didn't say you had to. So poke holes in foil with a pin and have fun.

[robopro]

OR, if you want a 'perfect' hole -- and it just HAS to be, for example, .432 mm in diameter, just have it laser drilled in a piece of .001 brass shim stock.

[argus]

Let's stop talking pinholes over here and have a look at a camera with a real lens...

I promised not to build another camera after the summer of 2006 untill 1st january 2007... but I did
I only did the finishing touch last week. I was inspired to build it after I acquired a brand new Cambo 8x10 bellows for very little money... the rest just came by itself!
Total weight is about 6 kilograms.

So here it is, the Cambara 810.

Here shown with a classic heavyweight Schneider-Kreuznach Symmar 360/620mm f5.6 lens, fitted on a 6x6" (15,2x15,2cm for us decimal-guys) square lensboard.
(I also have the 300mm and 240mm variants, but this little baby is more impressive)




We'll have a look at how much the camera wil groan at full extension with this 1820 gr. front weigth added.
Full extension at 770mm and it does not move a hair, partly thanks to the Wolf tripod and lightweight Gitzo nr. 4 head:




Focussing is done by 2 systems:
- the front rails are slotted and have a tension lock;
- the rear reals have a delrin rack&pinion gear. I had some doubts about the robustness of the delrin gear, but 3 months of testing and adjusting took away all doubts.
I'm not a big fan of front movements, except for rise&fall, so I did not incorporate the others...




I am in favour of rear movements, what is proven in the next few pictures:
- tilt, only limited by the bellows;
- 12 degrees of uncentered, individual left and right swing;
- 7,8cm shift in both directions, that means 13,6cm of travel along the horizontal axis.