A digital instrument to test shutter speeds

[paul_poropat]

<p>Hello Everybody. I have spent the greater part of this year designing and testing a camera shutter speed tester. There are some truly unique features of my tester, and I am quite proud of having developed it. The problem seems to be its price. This is no cheap Chinese copy of older technology. I have chosen to use top quality components, and it costs me a good deal in materials and time (direct labor). Is the posted price of $299 just way beyond what film photographers are willing to spend on something that is not a camera? I found references to some of the previously available instruments, but not in regards to selling prices. Just what kind of cost would some of you who rebuild your own cameras find acceptable? Please learn more at my website www.papcoinstruments.com I look forward to your comments.</p>

[conrad_hoffman]

<p>I know what it takes to get something designed, built and on the market. Not easy and frankly difficult to do cost effectively in this country. You get ten points for that right off. Unfortunately I don't think the function is worth near that much to the remaining hobbyists fooling with film these days. Any remaining camera repair shop probably has one of several similar devices produced over the years. The web site doesn't really describe anything interesting that the unit will do beyond what any other shutter tester of the past did. Though the web site looks very nice (I like the circuit background), it isn't very informative and maybe that's part of the problem. You know the old saying, "you have to sell the sizzle to sell the steak." Did you do any market research before designing this? Personally, I want to see rise and fall, so I just use a cheap scope, photo detector and light source. I realize that's beyond most people but a simple meter just doesn't cut it for me. There was a mechanical tester described on the Grimes site that was used to adjust focal plane shutters and showed the full travel performance, though it looked like a PITA to build. </p>

[vinny_walsh]

<p>I recently bought one for $30. It plugs into your computer's mic port and in conjunction with Audacity, records shutter speeds for just about any shutter. There's a guy that sells them on ebay. I personally wouldn't spend $299 on a tester when just the program audacity alone and a computer's built in mic does a pretty good job of recording shutter speeds, at least for me.</p>

[janne_moren]

I do much like Vinny, Audacity and all, except I found plans on the net and built my own - it's simple enough that I've so far just wired it up on one of those white springy prototype boards (don't know what they're called in English) each time I've needed it. I mean, it's basically a photodiode with a bit of signal massaging to avoid frying your computer.

 

I would not spend even $50 no matter how good the meter was and what it did beyond measuring the shutter speed. Frankly, if you can't do it for oh, $20-$30 or so then it's simply not a feasible product.

[mike51664877339]

<p>Try asking this guy to link to your site:<br>

http://cameratester.homestead.com/index.html</p>

<p>I bet a lot of old-camera enthusiasts are tinkerers. As we read above (and below, at APUG) , the sound-card method works for many.<br>

http://www.apug.org/forums/forum147/38369-shutter-tester.html</p>

<p>If you have a serious bench tool, your market might be limited to repair shops. And, as Conrad pointed out, your gizmo has to be pretty special for them to consider it.</p>

<p> </p>

[paul_poropat]

<p>Thanks for your comments. Conrad; My marketing research was purely informal. A lot of fellas on various forums remarked that this sort of tester would be a welcomed tool for those that service mechanical cameras. The design criteria I set for myself were that the instrument be portable (battery operated and no external light source, take it with you to the camera show), it had to be accurate (30 parts per million, that is less than .01 %, yes, I know that is not really necessary, but it shows the design quality), it has to be easy to use (put the retro-reflector at the film plane, aim the laser, trip the shutter, read the display), measure any shutter and any format (I have used it on my Leica IIIf and Zeiss Cocarette). Vinny and Janne; I am familiar with the scope method and sound card method, I didn't consider these to be portable or accurate, (accurate enough for cameras I suppose, portable? not really). Michael; thanks for the info. I guess it only comes down to pricing, because my device will beat any other in terms of performance. Presently I offer the tester as a complete kit, with a nice case, swivel bases, batteries, retro-reflector, and conversion worksheet. I see that it may be necessary to offer just the instrument with no accessories at a lower price, but even that price will be around $200. still a far cry from a few phototransistors. Well...we shall see. Thanks for your responses.</p>

[Gus Lazzari]

<p>Hey Paul, I always mention to the folks on this site to get their camera's curtain travel times (<strong>CTT</strong>) checked & adjusted. (Very important)</p>

<p>Does your unit provide the ability (in milliseconds) to see what each travel time is ?</p>

[paul_poropat]

<p>Hi Gus, My tester measures the open time of the shutter at any portion of the film plane. I use a laser as the light source (a very small point), that bounces off of a retro-reflector (supplied) so the light beam returns to the internal sensor along the same path. This can measure leaf shutters at different positions from the center to the edges, this may help detect a dragging leaf shutter. I cannot measure the effect of the separate curtain speeds, only the exposure at any selected point. I did see a picture of a spinning drum that Leitz used. The construction is pretty simple, but the test involves exposing and processing a roll of film then examining the film and interpreting the resulting light pattern. I thought of building one of these testers but I have only one Leica (a IIIf rd) so not very helpful to me.</p>

[conrad_hoffman]

<p>I'm a test equipment junkie and always want more precision and more digits! In this case, however, the DUT is a mechanical shutter, typically exposing film. Precision just isn't that important here, but getting all the information about what the shutter is doing, is. I use Audacity for sound work, and can see that it would be just super for shutter testing. Portability is of no consequence as I'd never be testing a shutter in the field. I *would* be testing one on my test bench, which is where the computer is. IMO, if you have another shot at this, a similar system that shows a full graph on the computer screen, with cursors for rise/fall and transit time, would be the modern solution. It could be done for less than $250, though I think the market window for a product at that price was over many years ago.</p>