How to measure speed of a shutter?
Jul 4, 2017 10:50:04 #
I have a couple of box cameras that I would like to measure the shutter speed on. It is my understanding that as these cameras age the springs become weaker and the shutter speed slows down. They aren't exactly precision insturments so I would like to get a rough idea as it would help me in knowing what speed film to buy. Changing film speed is about the only contol I have in adjusting exposure. One is about 80 years old and the other about 65 years old so I am sure the springs in the shutter don't have the strength they once had. Any of our engineering types that can give me a hand? I would appreciate it.
Jul 4, 2017 11:13:04 #
dragonfist wrote:
I have a couple of box cameras that I would like t... (show quote)
As a retired engineer and box camera owner, I would venture to say with aging they are shuttering at 1/50 second.Most are fixed at F16
Jul 4, 2017 11:13:07 #
RWR
Loc: La Mesa, CA
dragonfist wrote:
I have a couple of box cameras that I would like t... (show quote)
The shutter speeds were generally about 1/50 - 1/60 seconds. For a sunny day, any ISO 100 negative film should be fine as long as the shutter seems to be working OK.
Jul 4, 2017 13:52:34 #
Thanks to both of you for your replies. I was thinking along those lines. I guess maybe a roll or two in each should confirm whether or not that will work. I do know that film has a lot of latitude but its always nice to come as close as possible to the right exposure. Of course I realize with a camera with minimal controls I am flying by the seat of my pants. That is what makes these ventures fun.
Jul 5, 2017 06:28:26 #
Jul 5, 2017 06:44:32 #
Jul 5, 2017 06:53:38 #
OnDSnap wrote:
Can get your hands on a Spectrometer?...
Thanks for replying but I wouldn't have a clue as to where I could locate one.
Jul 5, 2017 07:01:18 #
cthahn wrote:
Some expensive equipment is necessary and really not worth the effort.
Thanks for your reply and I believe you are correct. I thought there might be a way that it could be done at home but I had my doubts. I figured it wouldn't hurt to try asking thòugh.
Jul 5, 2017 07:23:49 #
dragonfist wrote:
Thanks for replying but I wouldn't have a clue as to where I could locate one.
I hear you...and not cheap...another method you might try is to compare it to a dslr. Set the dslr to what you may think (just a s a starting point) the box camera is shooting at ....take a series of shots with the dslr at different shutter speeds and compare them to an exposure taken with the older camera in Photoshop. Obviously take them both in same light.
Jul 5, 2017 07:36:25 #
I use a pair of sensors and a oscilloscope. There are some inexpensive shutter tester around.
Any of these should work for your purpose.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR5.TRC2.A0.H0.Xshutter+tester.TRS0&_nkw=shutter+tester&_sacat=0
If you have the bucks this is the one camera manufacturers use to test their camera shutter as well as exposure meter.
http://www.ipernity.com/doc/299425/album/423909
Any of these should work for your purpose.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR5.TRC2.A0.H0.Xshutter+tester.TRS0&_nkw=shutter+tester&_sacat=0
If you have the bucks this is the one camera manufacturers use to test their camera shutter as well as exposure meter.
http://www.ipernity.com/doc/299425/album/423909
Jul 5, 2017 09:01:26 #
dragonfist wrote:
Thanks to both of you for your replies. I was thinking along those lines. I guess maybe a roll or two in each should confirm whether or not that will work. I do know that film has a lot of latitude but its always nice to come as close as possible to the right exposure. Of course I realize with a camera with minimal controls I am flying by the seat of my pants. That is what makes these ventures fun.
Take it to a repair shop they have shutter testers. And with the film today, a shutter speed of 1/50 s VS 1/60 s or 1/200 s VS 1/250 s won't matter anyway. If you can find out what speed film it used originally that might help too. Other than for repair reasons, film cameras were not typically "calibrated" by photographers by testing shutters speeds or iris is they seemed to be consistent, you customized your exposure criteria by making exposure tests and finding your ISO (ASA) for you film and camera. Find an old (film) photo instructional book, or an Ansel Adams "Negative" Book. Library book sales are good places to find cheap old film based photography books. You might even find the method online for free.
What size format film does your Box Camera use? Not a lot available today: 135 (35mm), 120, 220, and cut sheet film 4x5", 8x10".
620 has been gone with a secondary "suppliers" modifying it by re-spooling 120 film. 818, 626, and on and on all gone since 1984. Kodak purged their line back then. You might just find some European source from Free Style.
Jul 5, 2017 09:29:07 #
It has been a long time, 40 or 50 years, but I remember a technique where you photograph your TV and knowing the scan rate you could check the shutter speed based on how much of the screen is lit. I don't remember any of the calculations any more and don't have the desire or time to search for them. Maybe a science teacher or engineer might want to research this and come up with a recommendation.
Jul 5, 2017 10:30:53 #
Leitz
Loc: Solms
dragonfist wrote:
I have a couple of box cameras that I would like t... (show quote)
No need to know the exact speed - you can get a pretty idea if the shutter is OK by snapping it while looking through the lens from the back. It should open and close rather smartly. If it obviously drags, I would not use it.
Jul 5, 2017 13:32:05 #
This is kind of far out, but Toby challenged a science teacher to come up with a simple way to checking shutter speeds. If you have a record player, mark the turntable with a piece of tape and photograph the turntable while it's running. Repeat two more times for accuracy. Print the shots and carefully measure the distance the mark traveled in degrees. Use the formula:
RPM x .0167 Min/sec X degrees/360.
For example for a 78 RPM turntable and a 10 degree travel, it comes out .036 seconds, which rounded up is about 4/100 second or 1/25 second.
I recommend using 78 RPM. Obviously this won't work with extreme shutter speeds, but may help dragonfist.
RPM x .0167 Min/sec X degrees/360.
For example for a 78 RPM turntable and a 10 degree travel, it comes out .036 seconds, which rounded up is about 4/100 second or 1/25 second.
I recommend using 78 RPM. Obviously this won't work with extreme shutter speeds, but may help dragonfist.
Jul 5, 2017 14:32:08 #
Leitz
Loc: Solms
carlberg wrote:
This is kind of far out, but Toby challenged a sci... (show quote)
My thought is that dragonfist would like to know if the shutters are accurate enough to try before wasting a roll of film.
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