That's funny. I'm not too proud to give you a :) for that.
...Mike
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DAMMMN! Thats GENIUS!
It's just a square aluminum plate, a spacer, and another plate the size of the lens board. Machined here on the Bridgeport. I've used this several times with good results, no vignetting, and I mount a shade and/or filters on another SG standard on the track, too.
The shutter kick isn't bad at all, the real limitation being the wobbly Saltzman design.
http://new55project.blogspot.com
Yep, I just read Bill Kumpf's post,& was goin' to ask a question,but,as it's most informative & easy to u/stand,+ one would hope any LF Photog' would have enough little grey cells to make one,but ?.
The thought that the shutter blade accelerates while dropping,with subsequent uneven exposure,suddenly became self explanatory.
As our Image is upside down, then the ground area would get marginally more exosure than the sky,which would be great for Landscapes---or am I wrong ?.
I'm studying this because I've acquired (yep a bit stupid I know-but could not resist it ) a great big Kodak Ektar,& I have to make a shutter about 6" square so,
any quick sensible thoughts appreciated, Kind R'grds to one & all.
Rubber bands were mentioned along with the problem that they dry out.
I make my own "rubber bands" out of sections of inner tubes. I get blown out inner tubes from bicycle repair shops for free. I suppose other sizes can be found for other tires such as wheel barrows to automobiles to trucks.
It seems the idea of a simple shutter got lost along the way, though I did appreciate the ingenuity.
As for the matter of being committed to horizontal exposures as mentioned on page 1, simply calibrate for a vertical exposure, and when you rotate the back subtract 1/4 for a 4:5 proportion, or 1/3 for a 2:3. If you have to rotate the camera, same calculations, just mount the shutter to allow rotating it 90 degrees.
I really should have taken the time to compliment Bill Kumpf on the article. I use my oscilloscope to calibrate as well. The entire article was thorough and very professional. I hope to post soon on a simple rotating shutter design.
If you believe you can you do it, you can!
The Guillotine shutter is simple, fairly compact, and reliable when properly constructed. A simple rotary shutter may be bulky and more prone to vibration, but can be extremely consistent and accurate. A good example is the 35mm Mercury and Mercury II cameras made between the late 1930s and about 1950. Seventy-five years ago Harvard University tested several shutters for use in a solar coronagraph. The Mercury shutter was chosen for its accuracy and reliability over Leica, Contax, and Argus. The Mercury had an error of 5% at 1/1000 second. The others gave exhibited errors of about 50% at their top speeds. The Mercury shutter was still performing accurately after 112,000 cycles in intense heat and sub-zero temperatures.
in need a very sinple design that operates with just a push, can be spring loaded but i need a shutter that opens and closes quickly (or a design so I can make it myself). The iris shutter on a camera is too complicated for my project but it would be ideal if i could get a simpler version. I just want to know some resources/suppliers names or alternative ideas to the camera shutter. Thanks for any help.
http://www.earlyphotography.co.uk/site/shuttern.html
Hope that is not too complicated.
nice work .... could you do the calculation if we consider a SLOT , with variable width, somehow like the focal shutter found in SLR ... ??
Thanks !!!
thanks .... very instructive ..................
Here we go again
Could somebody please help me with the math? I have some parts in the post were the numbers just don't add up. Could somebody tell me what is the 'Tt' here: "The trailing edge drop distance, Dt =((g* Tt^2 ) / 2) Dt =3.5245" as I cannot find it in the article.
Thanks so much
It looks as though the line immediately before that...
Tl= 0.1018 + 0.0333 = 0.1351 second
...has a typo at the start and should really be...
Tt= 0.1018 + 0.0333 = 0.1351 second
...as it is intended to represent the trailing-edge time, not the leading-edge time.
Thank you very much for your help. Now I got everything in place. Also I got tricked by the Imperial system in use :)
sliding lackier!!!
Some of our members use a beyond simple drop plate shutter of various designs
no hole
then hole
then no hole
Gravity works
I use Packards and their prices are dropping