Brilliant !!Originally Posted by Ron Lee
I have a Sinar with a Sinar Shutter, and but tops out at 1/60. I've often wanted to take photos outdoors at higher speeds.
Could the same shutter be adapted to fit on a variety of lenses ?
over 1 million
under 1 million
Brilliant !!
I have a Sinar with a Sinar Shutter, and but tops out at 1/60. I've often wanted to take photos outdoors at higher speeds.
Could the same shutter be adapted to fit on a variety of lenses ?
It sure can. Lets say your largest lens glass size was 3" and your smallest lens glass size was 1.5", then I would cut the envelope to slightly over the glass size and then build the sleeve to your barrel size, say 3.25". then using a firm foam rubber cut to fit your smaller barrel size. Because the shutter is so light a moderate foam rubber will support the weight. I am in the process of building a lens shade to snap on the shutter, a filter holder that can be adjusted for the proper filter and larger ones. Also a flash sync is in the process, it is a relatively simple fix. Be patient and we will have a very productive shutter very soon. Ken, I would like to send you one to test if you would post your findings on this forum and return it later to me. Let me know your lens size and your barrel size and I will put one together for you.
In photography, when you use exposure speeds of 1/1000 s you are splitting hairs, and very much so. By saying it's not so you just add to your technical ignorance expressions.
Let's not avoid the main issue here - Ron is selling a product about which he boasts that it is "more accurate than any shutter made". Nobody with common sense can deny that this statement is fraudulent. What we have here is more than an amateur with his technical ignorance.
I hope that somebody on Ebay will give him a lesson that a product for 150 $ needs to deliver what is boasted about it. That is obviously not the case here.
In the country I'm for the moment being, to send a parcel, even a small one, to the US would cost several tens of dollars. Your "few pennies of shipping cost" is therefore nonsense. Damn yourself... And again, try to see the people, who will pay 150 $ for this shutter, tooted as more accurate than any shutter, just to discover the truth behind this 150 $ "accurate shutter"...
It really doesn't matter? If you need to measure precisely the amount of tilt on your front standard, then to calculate the effective change of the exposure, then to make exposure corrections and all this with a shutter sensitive even to the wind direction and its strength - it doesn't really matter? Good for you...
You know, I'm sure everything you're saying or ever said is right. But man, what is your problem? Seriously.It really doesn't matter? If you need to measure precisely the amount of tilt on your front standard, then to calculate the effective change of the exposure, then to make exposure corrections and all this with a shutter sensitive even to the wind direction and its strength - it doesn't really matter? Good for you...
GPS; there you go again making false and misleading statements saying that we make the most accurate shutter made; this is what is stated in the description of which you refer; "We want to produce a product that will outlast all others and be more accurate than any shutter made. Weighs only 4.5 oz.", you are misleading readers and stand to be corrected in almost everything you state. I personally would bar you from this forum and any others that I had control of if it were me. There is another thread related to bashing, try it.
Ron, the product you want to make - a shutter "more accurate than any shutter made" - is the shutter you sell on Ebay?
When it comes to misleading statements, why do you mislead people with your technically false statement (in the Ebay title!) that your shutter is a "focal plane shutter"? Let alone your other misleading statements in your Ebay listing in the description of your shutter...
Just so that people could see what is the technical description of the shutter on Ebay:
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"Up for sale is a focal plane shutter, newly built of the finest most durable materials available. These shutters are hand crafted with attention to the smallest details. It takes several hours to assemble, calibrate and test each one of these units. We want to produce a product that will outlast all others and be more accurate than any shutter made. Weighs only 4.5 oz.
This shutter is a gravity powered shutter not needing any springs or other devices that weaken or fail over time. This shutter is non-invasive to your camera. It is designed to slip onto your lens and can be adjusted with foam to fit any lens barrel from 3” down to 1.5” lens. If you have a lens in a shutter that is not accurate, then set it to “T” and slip on this shutter for one that is as accurate as Newtons law of gravity.
This shutter is calibrated at speeds from 1/15th of a second to 1/1000th of a second. This shutter can be tilted forward or to the side for added speeds under 1/15th of a second. It comes with complete instructions from the designer and architect. Some of those that have bought this shutter, who knows the crew, have nicknamed the shutter the “Gatts Guillotine” because it slices off a piece of light, they say.
We offer these units at a 'Buy it Now' introductory price of $150.00 . These units are limited to production because we can only build and test a few each week. I am linking you to a page with photos of the unit on camera and photos taken with the shutter. I am sure that you will be more than delighted to shoot with this unit. http://picasaweb.google.com/Kymtman/...Oim-srI1r_IQA#
The cable release is for reference only. It is not included.
We have been designing and testing these units for the past six months, and now they are ready for your camera. Shipping USPS $5.95 Not ready to ship overseas. US and canada only.
If you have questions please don't hesitate to email me. I'll do my best to give you a truthful answer as possible. I have several lenses in Ilex shutters etc., but I find myself using my own built shutter for the simple reason that I can trust the results.
The cable release is for reference only. It is not included.
We have been designing and testing these units for the past six months, and now they are ready for your camera. Shipping USPS $5.95 Not ready to ship overseas. US and canada only.
If you have questions please don't hesitate to email me. I'll do my best to give you a truthful answer as possible. I have several lenses in Ilex shutters etc., but I find myself using my own built shutter for the simple reason that I can trust the results."
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The shutter is still listed as a "focal plane shutter" even if it is not in any case such a shutter...
I've seen only two types of shutters, the focal plane and the leaf, this isn't for sure a leaf shutter is it. Now what is misleading about " We want". Now prove to me it isn't more accurate over time than any spring powered shutter. Gee when are you going to let up. It seems that I can't rectify the title description or at least at this time in the listing. I will list the next one without the word "focal plane" if that suites you. Now on to newer and better things. Lets discuss how to calculate the speeds between the lens and focal plane of the film. I spent a few minutes this morning to answer some ones question about how the speed changes when a shutter is placed between the lens and film.
Shutter speeds:
Someone wanted to know how to calculate the shutter speed of a shutter placed behind the lens. Let us look at the conical projection behind the lens and move the shutter to different places along the center line and calculate the image circle at each place. Now let us use some hypothetical values in the equation . Rear diameter of lens =40mm , focal length =250mm, Image circle =215mm ( just enough to cover a 5x7) well almost. Now lets place the shutter at the very back of the lens with a 1mm slit and say the shutter is moving across the projected image at 10mm per second (quite slow wouldn’t you say). At that position it would take 4 seconds to move across the lens and exposing the film. Now move the shutter to a new location say 25mm along the center line. Calculate the IC (image circle) at that point. We find if we divide the projected image circle at the film plane (215) by 2 and subtract one half of the diameter of the lens we have 87.53mm, now divide this by the focal length (250) we get 0.35012, the tangent of the angle of projection above the straight line of the lens. Using 20mm (1/2 of the lens diameter) into account we can figure the foci of the lens. I’ll not get into that. Now multiply 25mm by 0.34012 we get approximately 8.75mm, now double this and add the 40mm for the lens and you get a total of 57.5mm IC diameter, taking the shutter 5.75 seconds to cross at the rate given. Using same formula of simple trig we get @50mm IC=75.01(7.5 sec.), @125mm IC=127.53 (12.75 sec. ) and @ 250mm (at the film) IC=215.06 taking 21.5 seconds to cross the film plane. You can think of this as a cone of ice cream being sliced at these points. Definitely the closer to the film plane the longer it takes thereby giving a slower exposure speed. These are my calculations and one mode of thinking to solve the speed problem. I will state that I stand to be corrected.
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