I've been pondering the oft-discussed issue of continuous versus flash light for macro photography. It occurs to me that the best of all worlds might be continuous light with a shutter in the light path, to be triggered after the camera's shutter vibration has subsided--but locked open for initial light setup. This idea seems obvious, but I can't find anything published on it.
I see that some fiber-optic illuminators have an accessory shutter, but have found almost no information on those shutters. Can anyone with experience with these shutters tell me if they have the characteristics necessary to control exposure? Can these shutters be addressed electonically by an automated stacking setup? I'm thinking the best approach might be to build my own, using a view camera shutter between the light and the optical fiber, with a solenoid or other actuator triggering the light shutter.
Canon shooters, of course, have another workable approach with live view. No interest in starting a brand skirmish: Canon junk and Nikon junk are both good. But for some of us, adding a Canon body would entail a substantial expense and hassle (buying another right-angle viewfinder, AC power supply, and remote cord, dealing with a non-Nikon software workflow, and learning the nuances of Canon jpegs and raw files, which differ from Nikon file nuances). And some of us don't want to use live view (I want to keep my sensor as cool as possible).
Any thoughts? Cheers,
--Chris
Shutter for continuous light
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Shutter for continuous light
Last edited by Chris S. on Tue Aug 31, 2010 12:45 am, edited 1 time in total.
How can you have continous light and have the camera shutter open at the same time?
Surplus Shed usually has shutter mechanisms available that are easy to trigger. I missed out on one that was several inches in diameter. Somebody bought them all and tried to resell them on ebay at 10 times the price of Surplus Shed
Surplus Shed usually has shutter mechanisms available that are easy to trigger. I missed out on one that was several inches in diameter. Somebody bought them all and tried to resell them on ebay at 10 times the price of Surplus Shed
Re: Shutter for continuous light
Thoughts, virtual hardware, etc. Too many ....Chris S. wrote:I've been pondering the oft-discussed issue of continuous versus flash light for macro photography. It occurs to me that the best of all worlds might be continuous light with a shutter in the light path, to be triggered after the camera's shutter vibration has subsided--but locked open for initial light setup. This idea seems obvious, but I can't find anything published on it.
I see that some fiber-optic illuminators have an accessory shutter, but have found almost no information on those shutters. Can anyone with experience with these shutters tell me if they have the characteristics necessary to control exposure? Can these shutters be addressed electonically by an automated stacking setup? I'm thinking the best approach might be to build my own, using a view camera shutter between the light and the optical fiber, with a solenoid or other actuator triggering the light shutter.
Canon shooters, of course, have another workable approach with live view. No interest in starting a brand skirmish: Canon junk and Nikon junk are both good. But for some of us, adding a Canon body would entail a subsantial expense and hassle (buying another right-angle viewfinder, AC power supply, and remote cord, dealing with a non-Nikon software workflow, and learning the nuances of Canon jpegs and raw files, which differ from Nikon file nuances). And some of us don't want to use live view (I want to keep my sensor as cool as possible).
Any thoughts? Cheers,
--Chris
Seriously though, this is why I keep playing with LED illumination - you run at low power (probably low current and PWM) for continuous then switch to a high current pulse for flash. I've got a bench setup now where I can run a Cree at 1A + PWM then go to 4A pulses.
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
Re: Shutter for continuous light
Andrew, are you getting a full spectrum with that Cree--no drop in the greens, for example? I know that getting a full spectrum has been hard in the LED world.AndrewC wrote: Seriously though, this is why I keep playing with LED illumination - you run at low power (probably low current and PWM) for continuous then switch to a high current pulse for flash. I've got a bench setup now where I can run a Cree at 1A + PWM then go to 4A pulses.
Cheers, Chris
Re: Shutter for continuous light
Spectra are in this datasheet http://www.cree.com/products/pdf/XLampXP-E.pdf I think it is OK, but then I'm "colour challenged"Chris S. wrote:Andrew, are you getting a full spectrum with that Cree--no drop in the greens, for example? I know that getting a full spectrum has been hard in the LED world.AndrewC wrote: Seriously though, this is why I keep playing with LED illumination - you run at low power (probably low current and PWM) for continuous then switch to a high current pulse for flash. I've got a bench setup now where I can run a Cree at 1A + PWM then go to 4A pulses.
Cheers, Chris
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
Chris,
Novoflex makes a device that allow continuos light and flash trough the same fiber optic guides, unfortulately out of my budget
http://www.novoflex.com/en/products/mac ... ht-source/
I never tested it, but it seems the perfect solution
Novoflex makes a device that allow continuos light and flash trough the same fiber optic guides, unfortulately out of my budget
http://www.novoflex.com/en/products/mac ... ht-source/
I never tested it, but it seems the perfect solution
Pau
Chris there is a shutter for FOSTEC fiber optic light guides that is intended for machine vision and to do pretty much exactly what you want to do.
They are now Schott/Fostec.
It is a substitute front piece on the lamp drawer pull out. It has a shutter built in.
http://spectraservices.com/Merchant2/pd ... Module.pdf
They are now Schott/Fostec.
It is a substitute front piece on the lamp drawer pull out. It has a shutter built in.
http://spectraservices.com/Merchant2/pd ... Module.pdf
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Charles Krebs
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- Joined: Tue Aug 01, 2006 8:02 pm
- Location: Issaquah, WA USA
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I know it may sound archaic and not too exciting, but a mechanical double cable release can be readily used for such an arrangement. One part can be set up to trip a switch to open the camera shutter, and then the second to release a mechanical shutter on the light. A "press" type shutter could be used on the light (no manual re-cocking needed). Old Polaroid MP3 and MP4 shutters are this type and can often be picked up very reasonably.
At the very least, it wouldn't be hard to set it up for little expense to see if it is, indeed, a technique that "works" for you. Then, if it is, you could get more sophisticated and track down an electronically controlled shutter and make the whole thing a little "fancier" with electronic controls.
You would need to work in "subdued" room light but I don't think that should present much of a problem.
At the very least, it wouldn't be hard to set it up for little expense to see if it is, indeed, a technique that "works" for you. Then, if it is, you could get more sophisticated and track down an electronically controlled shutter and make the whole thing a little "fancier" with electronic controls.
You would need to work in "subdued" room light but I don't think that should present much of a problem.
I kind of got the impression that Chris wanted to have a single light source that would a) give constant "low" illumination or b) give a strobe length (<1/1000") flash.
The "price on application" Novoflex does that. Home brew versions involve stripping the innards out of a flash gun and lining up a high power led behind the tube with both feeding into a fibre optic bundle, or going for a very high power led.
The "price on application" Novoflex does that. Home brew versions involve stripping the innards out of a flash gun and lining up a high power led behind the tube with both feeding into a fibre optic bundle, or going for a very high power led.
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
Andrew, got to say that the spectral characteristics in that data sheet scare me a bit. Looks like a big dip just below green, among other things. But if your experience leads you to think it's OK, that says a lot--hard to argue with results, and you're picky.
Pau, I've repeatedly considered the Novoflex Macrolight Plus that you point out. But in addition to the high cost, I get an impression that it might not be a robust solution. For example, I don't see any indication that the light guides can be swapped out for others--it would be better if it could accept standard light guides from Fostec or another big player. Maybe it does, but I don't see anything about that in the specs. And there is no iris, which I sense would be pretty important to controlling the continuous light without altering color. And the provision for a speedlight type flash seems limiting--I'm already wanting to move away from my battery-powered speedlights into something that operates on mains power. I could well be wrong in this impression--but I haven't been able to find much in the way of reviews by actual photographers.
G4lab, I've seen that shutter at the Schott Fostec site, but can find no specs on it. I'd like to know that range of shutter speeds it allows, and how it is actuated. Do you by chance know?
Charles, thanks for the suggestion to try a press shutter, and if it works, to consider an electronic shutter. I knew that self-cocking shutters existed, but had no idea what they were called--what a difference it makes to know a search term. May well go that route. I also appreciate the confirmation that the idea of shuttering a continuous light source isn't ridiculous. Seemed logical enough to me, but since it also seems an obvious idea and I don't see anyone doing it, I wondered.
What I see shaping up in my head is building something of my own. Ideally, it would have both a continuous light source and a mains-powered flash. It would have a shutter and an iris. It would have a nosepiece (right word?) sized to accept standard light guides. Put a couple of computer fans in it to keep everything cool. Doesn't sound like rocket science--but I might well be missing something. I have an old f/.75 lens (if memory serves) with a huge front element and a small rear one, that I believe came off of some device that monitored a CRT screen way back when. Am thinking this might be just the thing for concentrating the light from something like an Alien Bees flash and sending it down a light guide. Time to experiment.
Thanks all, very very much.
Cheers,
--Chris
Pau, I've repeatedly considered the Novoflex Macrolight Plus that you point out. But in addition to the high cost, I get an impression that it might not be a robust solution. For example, I don't see any indication that the light guides can be swapped out for others--it would be better if it could accept standard light guides from Fostec or another big player. Maybe it does, but I don't see anything about that in the specs. And there is no iris, which I sense would be pretty important to controlling the continuous light without altering color. And the provision for a speedlight type flash seems limiting--I'm already wanting to move away from my battery-powered speedlights into something that operates on mains power. I could well be wrong in this impression--but I haven't been able to find much in the way of reviews by actual photographers.
G4lab, I've seen that shutter at the Schott Fostec site, but can find no specs on it. I'd like to know that range of shutter speeds it allows, and how it is actuated. Do you by chance know?
Charles, thanks for the suggestion to try a press shutter, and if it works, to consider an electronic shutter. I knew that self-cocking shutters existed, but had no idea what they were called--what a difference it makes to know a search term. May well go that route. I also appreciate the confirmation that the idea of shuttering a continuous light source isn't ridiculous. Seemed logical enough to me, but since it also seems an obvious idea and I don't see anyone doing it, I wondered.
What I see shaping up in my head is building something of my own. Ideally, it would have both a continuous light source and a mains-powered flash. It would have a shutter and an iris. It would have a nosepiece (right word?) sized to accept standard light guides. Put a couple of computer fans in it to keep everything cool. Doesn't sound like rocket science--but I might well be missing something. I have an old f/.75 lens (if memory serves) with a huge front element and a small rear one, that I believe came off of some device that monitored a CRT screen way back when. Am thinking this might be just the thing for concentrating the light from something like an Alien Bees flash and sending it down a light guide. Time to experiment.
Thanks all, very very much.
Cheers,
--Chris