Slip on focal plane shutter

[GPS]

A new slip on focal plane gravity fed shutter is now ready for anyone who may be interested in one. Photos of the shutter and photos taken with the shutter on a LF camera can be seen at this link;

http://picasaweb.google.com/Kymtman/...Oim-srI1r_IQA#

If you are interested contact me at rtincher@prtcnet.org or rtincher@hotmail.com
These shutters really work from speeds 1/1000 down to 1/8. I have been using a couple of them for the last six months.
Let me know what you may think about this lightweight (4.4oz) unit.
Thanks in advance:

Ron,
unless you have moderator's permission, business self promoting threads are not allowed on this forum.

The Thorton-Pickard that is for sale now is much more expensive and looks to out weight the Gatts/Tincher shutter many time over. I don't have to defend the Gatts/Tincher shutter, it has proven itself time and time again! Reich, do you mean the actual travel speed of the shutter? It falls at 32 feet per second, according to Newton.

As already mentioned, your shutter is not a focal plane shutter. The fact that you sell them as such on Ebay violate also the Ebay policy. You're misleading people with that description.
Also, Newton speaks about free fall. Your shutter is not falling with free fall. If you measured its speed electronically you would find out that you cannot guarantee its precise speed - it has none.

[Ron Lee]

Yes, it works up to and slightly beyond a 45 degree tilt.
No, it isn't too expensive. Consider the cost of having a lens set in a shutter and the cost of that shutter and furthermore how long will it stay accurate and in my opinion this one is a bargain knowing that you can use it on a variety of lenses. In the photos that you looked at the lens was a 12" Kodak commercial Ektar in a Ilex #4 shutter.

[Ron Lee]

The replies to my original announcement of the shutter led into debates about the shutter. I was led to believe that a new product that was beneficial to the members of this forum could be announced. If not here then where? All references to my email were intended for more information about the item. I will gladly bow out if I have crossed any guidelines. Please accept my apologies.

[Kirk Gittings]

R0n, this bengs in New Products and requires moderator approval first. Srry, My keybard is missing a few letters this morning.
New Products:A forum for announcements of a commercial nature related to large format photography. Moderator approval is required before posting promotional items.
I wi mve it.

[benrains]

Looks like a nice product to me. Some people are maybe being a little over enthusiastic about their nit-picking (i.e. it's not a focal plane shutter). Focal plane shutters are located at the back of the camera where it'd be immediately in front of the focal plane--hence "focal plane shutter". What you've created is a variant of what I've heard referred to as a "drop shutter". I think they used to be fairly common on cameras made back in the late 1800s.

The nit-pick I would add is that you said the travel speed is 32 ft/s taken from Newton's gravity calculations. Which isn't true! 32 ft/s is a velocity, whereas gravity accelerates, and Newton's gravitational value is 32 ft/s^2 (32 ft per second per second.) The only time at which an object in free fall in earth's gravity is traveling at 32 ft/s is 1 sec into the fall. You can still do the shutter speed calculations based on that acceleration, it's just a little more work... or a maybe a lot more work if you try to take friction into account (probably you can ignore the friction unless the lens is tilted forward or backward.)

Still, as long as the calculations are sorted out properly, it would be a very useful device for timing those exposures that are less than 1 second long. I'm not sure what the limit would be, but I'd guess that times at least as fast as 1/30th or 1/60th of sec would be possible.

[Ron Lee]

It really doesn't make that much difference about how fast it drops as long as it is repetitively constant each time, in which it is. The materials chosen work together with almost no resistance. The unit has been calibrated with a shutter tester to speeds from 1/1000 to 1/15th and are always there. I found that you can tilt the shutter forward or to the side to slightly slow the travel enough for about 2/3 stop. The photo of the house in the link was shot early morning and the neg is perfect if there is such a thing.

[Ken Lee]

Genius !!

Since some barrel lenses can get rather large, how wide can it accommodate ?

Too bad this posting was sent as a poll. I normally ignore them, as I presume do others.

You might get more interest if you post as a regular message.

[GPS]

It really doesn't make that much difference about how fast it drops as long as it is repetitively constant each time, in which it is. The materials chosen work together with almost no resistance. The unit has been calibrated with a shutter tester to speeds from 1/1000 to 1/15th and are always there. I found that you can tilt the shutter forward or to the side to slightly slow the travel enough for about 2/3 stop. The photo of the house in the link was shot early morning and the neg is perfect if there is such a thing.

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From Ebay description - "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 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."
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Ron, apart from the fact that you don't get the Newton law (I didn't want to go deeper into it), you mislead yourself and others with your technical ignorance. Stating that this shutter is "repetitively constant each time", that it "will be more accurate than any shutter made" is the uttermost technical nonsense. As is your statement of "almost no resistance"...etc.
You yourself realize that a mere inclination of the shutter changes already the shutter times... That is the case for all of its time settings, of course. Now, the shutter is not only sensitive to this mechanical inclination but also to the wind blowing around the camera (against it especially) as that changes the slide's resistance against the fall also, etc. Even if you had ball bearings there to limit the friction to repeatable values, even then the precision wouldn't be there.
You'd be much better off if you deleted the technical nonsense from the description and presented it as what it is - a crude timing device that in some circumstances can do... I wouldn't be surprise if somebody who takes your claims as true were very angry when discovering the reality - after all, if the reality cannot stand behind your claims you prepare yourself some surprise for a device of 150 $ tooted this way. And very justly so...

[Ron Lee]

I realize that everyone can't be pleased all the time especially if they have been rode hard and put up wet and been left with a raw disposition. Those I ignore, the ones who knows all about everything. You'll find one in every crowd. In my 68 years in life I have run into many of those types. Its better to ignore and prove them wrong with their own theory. With over 500+ shots with the shutter and an accurate Luna Pro, not one shot was incorrect. The proof is in the pudding, and it taste so good. The Newton law I understand but how many of the general public understands. When in Rome speak Italian!

[Ron Lee]

Ken Lee
The larger the lens the larger the shutter. I have a shutter on an Industar 37 300mm with a barrel size of 3.5". The shutter measures 5x12.5" The shutter in the photos measures 4x10.5". A fellow is having one built that has a lens that measures barrel size of 4.25". I suppose one could be made to fit almost any lens.