Remote flash using Canon Rebel 6i and old strobes
Jan 24, 2017 13:15:15 #
I recently purchased a Canon EOS Rebel 6i and I'm trying to see if I can use some inexpensive studio strobes I purchased many years ago (Medal Light PG3000C). I already know that they are not compatible with the Rebel 6i directly, but I was trying to see if I could use the slave function on the strobes triggered by the built-in flash on the Rebel 6i. The odd thing is that the strobes fire when I press the shutter half-way but before the shutter releases. I thought the strobes were activated only when they sensed the light from the main flash. I'm not sure if the strobes are just completely incompatible with the Rebel 6i or if I have a wrong camera setting. Any insight from the forum would be appreciated. I'm new to the forum and this is my first post. Thanks in advance for any help!
Jan 24, 2017 14:27:39 #
Pat, welcome to the Hog!
I'm not familiar with your camera, but I'll assume the strobes can be fired using infrared and when your shutter is pressed half way it sends out an infrared focus assist beam that triggers the lights.
In the camera menu, turn of the focus assist and see if that helps.
But it's possible that the strobes are not triggered by light but only infrared.
But give it a shot. All of my strobes are triggered by light.
Good luck and again, welcome!
SS
I'm not familiar with your camera, but I'll assume the strobes can be fired using infrared and when your shutter is pressed half way it sends out an infrared focus assist beam that triggers the lights.
In the camera menu, turn of the focus assist and see if that helps.
But it's possible that the strobes are not triggered by light but only infrared.
But give it a shot. All of my strobes are triggered by light.
Good luck and again, welcome!
SS
Jan 24, 2017 15:21:59 #
As Sharpshooter said, it may be your focus assist. They may also fire pre-maturely if they have only a simple slave function, and you are using TTL with the on-camera flash. If I want to trigger my studio strobes via the optical slave function I use manual (at lowest setting) on-camera. Otherwise, the TTL pre-flash will interfere.
Jan 25, 2017 14:35:35 #
This you will use a lot, I use it on my Canon rebel.
http://www.ebay.com/itm/CamFi-CF101-Wireless-Remote-Camera-Controller-Capture-Transmit-For-Canon-Nikon/252574969398?_trksid=p2047675.c100012.m1985&_trkparms=aid%3D777003%26algo%3DDISCL.MBE%26ao%3D1%26asc%3D38530%26meid%3D54690f70bf994848adb137d51d70c9ee%26pid%3D100012%26rk%3D5%26rkt%3D12%26sd%3D262720753948
I don't like strobes I use Continuous Lighting it better I see what I get before I shot.
http://www.ebay.com/itm/CamFi-CF101-Wireless-Remote-Camera-Controller-Capture-Transmit-For-Canon-Nikon/252574969398?_trksid=p2047675.c100012.m1985&_trkparms=aid%3D777003%26algo%3DDISCL.MBE%26ao%3D1%26asc%3D38530%26meid%3D54690f70bf994848adb137d51d70c9ee%26pid%3D100012%26rk%3D5%26rkt%3D12%26sd%3D262720753948
I don't like strobes I use Continuous Lighting it better I see what I get before I shot.
Jan 25, 2017 23:40:08 #
amfoto1
Loc: San Jose, Calif. USA
Welcome!
You probably bought an EOS Rebel T6i. (There's no such thing as a "6i"... but there are T6i, T6s, T6, 6D and 60D. All of them will be similar to below, except the full frame 6D doesn't have a built-in flash and would only do some of the things described with an accessory flash unit fitted to the hot shoe.)
Canon cameras "communicate" with off-camera flash by strobing the on-camera flash, which old-style optically trigger flashes might "see" and interpret as a flash going off and fire themselves too early. That might be what's happening. Make sure your built-in flash is not set to "Master" and trying to control other flashes off-camera. If you were instead using an accessory flash rather than the built-in pop-up, those use different types of communication... near-IR in some cases, or radio waves in the "R-series" flashes. IR or radio might not trigger the studio strobes, but you aren't out of the woods yet...
Another possibility, whenever the on-camera flash is set to ETTL mode, it will fire twice for each exposure. Before the shutter opens, it emits a low-power (1/64) flash that it uses to illuminate your subject and measure how much light will be needed for the "real" exposure, which comes a fraction of a second later and is synced with the opening of the shutter. Often that low-power initial flash will set off optically triggered, off-camera flashes, too early to sync up with the shutter opening. To prevent this, set the on-camera flash (either type: the pop-up built-in or an accessory flash fitted to the hot shoe) to Manual, rather than ETTL.
The most certain and safe way you could use those older flashes or strobes would be to get a set of radio transmitter and triggers. The transmitter fits into the hot shoe of your camera. Then you need a trigger at each of the off-camera strobes and will need to set their output manually.
Radio triggers will give really good range (probably more than you need, possibly up to 100 feet or more). They also don't require line-of-sight, the way optical triggering does.
Using radio triggers also nicely isolates your camera from possibly too-high trigger voltages of some older flashes and strobes. It was more of a problem with older Canon from the late 1990s and early 2000s, some of which were only able to handle 6 or 12 volts. Some of the 1970s and 1980s flashes triggered as high as 300 or 400 volts and could damage those cameras! More modern DSLRs are built to handle up to triggering at up to 250 volts, so are safe with all but the highest trigger voltage old flashes and strobes.
Actually T6i don't have a universal PC sync cord socket, such as is provided in many cameras for wired triggering of many studio strobes (usually plugged into a mini-RCA socket on the rear of the strobe). There are adapters that can be fitted to the hot shoe to provide a standard PC sync socket (the radio transmitter mentioned above may have one, too)... These may or may not isolate the camera from any excessive triggering voltage. I'd be cautious about using any of these. But there used to be a device called a Wein SafeSync that protected the camera from excessive voltage, while providing a PC sync socket via the hot shoe. I don't know if those are still being offered. (Note: "PC" in this case stands for "Prontor-Compur", two of the major shutter manufacturers of the past, who standardized this type of socket across most cameras, replacing several other earlier designs).
There will be no worries about frying your camera with excessive trigger voltage, if you use some sort of radio system. Those come in all sorts of prices. (Sorry, but the CamFi unit linked above is not what you need... That's a remote camera controller, so that you can operate the camera wirelessly from a tablet or laptop... possibly even a smart phone.)
In fact, for simple studio strobe triggering, probably all you need are very basic radio units such as these:
http://www.ebay.com/itm/16CH-Wireless-Remote-FM-Radio-Flash-Speedlite-Trigger-w-2-5mm-4-Receivers-/311544737650?hash=item4889836f72:g:sj4AAOSwx-9Wuotg
Or these:
https://www.amazon.com/Godox-Channels-RT-16-Transmitter-Kit/dp/B015CGESYK/ref=sr_1_3?s=electronics&ie=UTF8&qid=1485405992&sr=1-3&keywords=radio+trigger
I haven't used either of those particular systems (and there are many different ones), so really can't say how well they are made or work. This is just for reference as to the type of radio transmitter and receiver you most likely need. All these do is fire the strobe. They don't have any means of other control such as adjusting the output remotely. In other words, they have no "ETTL" functionality (which might be wanted if using modern flash ETTL capable off-camera). But this should be okay since those strobe units are probably not ETTL or any other type of remote control, either. Most studio strobes have an optical trigger, as yours appear to... but those will be fired by anything resembling a flash going off, as described above. They also are a royal pain if anyone else is shooting nearby with flash!
Radio triggers are the solution. Both the above examples are 16-channel, too.... so can be set to a different frequency than other radio triggers being used nearby, if that ever occurs.
One last thing... Many studio strobes do not reach peak output as fast as portable flash. So very likely you'll need to use slightly slower than the standard flash sync speed of the camera (1/200). Experiment with 1/160 and 1/125. (Obviously, you also won't be able to High Speed Sync or Rear Curtain Sync with studio strobes. Those are only available with dedicated portable flash and a few of the most advanced modern strobes.)
You probably bought an EOS Rebel T6i. (There's no such thing as a "6i"... but there are T6i, T6s, T6, 6D and 60D. All of them will be similar to below, except the full frame 6D doesn't have a built-in flash and would only do some of the things described with an accessory flash unit fitted to the hot shoe.)
Canon cameras "communicate" with off-camera flash by strobing the on-camera flash, which old-style optically trigger flashes might "see" and interpret as a flash going off and fire themselves too early. That might be what's happening. Make sure your built-in flash is not set to "Master" and trying to control other flashes off-camera. If you were instead using an accessory flash rather than the built-in pop-up, those use different types of communication... near-IR in some cases, or radio waves in the "R-series" flashes. IR or radio might not trigger the studio strobes, but you aren't out of the woods yet...
Another possibility, whenever the on-camera flash is set to ETTL mode, it will fire twice for each exposure. Before the shutter opens, it emits a low-power (1/64) flash that it uses to illuminate your subject and measure how much light will be needed for the "real" exposure, which comes a fraction of a second later and is synced with the opening of the shutter. Often that low-power initial flash will set off optically triggered, off-camera flashes, too early to sync up with the shutter opening. To prevent this, set the on-camera flash (either type: the pop-up built-in or an accessory flash fitted to the hot shoe) to Manual, rather than ETTL.
The most certain and safe way you could use those older flashes or strobes would be to get a set of radio transmitter and triggers. The transmitter fits into the hot shoe of your camera. Then you need a trigger at each of the off-camera strobes and will need to set their output manually.
Radio triggers will give really good range (probably more than you need, possibly up to 100 feet or more). They also don't require line-of-sight, the way optical triggering does.
Using radio triggers also nicely isolates your camera from possibly too-high trigger voltages of some older flashes and strobes. It was more of a problem with older Canon from the late 1990s and early 2000s, some of which were only able to handle 6 or 12 volts. Some of the 1970s and 1980s flashes triggered as high as 300 or 400 volts and could damage those cameras! More modern DSLRs are built to handle up to triggering at up to 250 volts, so are safe with all but the highest trigger voltage old flashes and strobes.
Actually T6i don't have a universal PC sync cord socket, such as is provided in many cameras for wired triggering of many studio strobes (usually plugged into a mini-RCA socket on the rear of the strobe). There are adapters that can be fitted to the hot shoe to provide a standard PC sync socket (the radio transmitter mentioned above may have one, too)... These may or may not isolate the camera from any excessive triggering voltage. I'd be cautious about using any of these. But there used to be a device called a Wein SafeSync that protected the camera from excessive voltage, while providing a PC sync socket via the hot shoe. I don't know if those are still being offered. (Note: "PC" in this case stands for "Prontor-Compur", two of the major shutter manufacturers of the past, who standardized this type of socket across most cameras, replacing several other earlier designs).
There will be no worries about frying your camera with excessive trigger voltage, if you use some sort of radio system. Those come in all sorts of prices. (Sorry, but the CamFi unit linked above is not what you need... That's a remote camera controller, so that you can operate the camera wirelessly from a tablet or laptop... possibly even a smart phone.)
In fact, for simple studio strobe triggering, probably all you need are very basic radio units such as these:
http://www.ebay.com/itm/16CH-Wireless-Remote-FM-Radio-Flash-Speedlite-Trigger-w-2-5mm-4-Receivers-/311544737650?hash=item4889836f72:g:sj4AAOSwx-9Wuotg
Or these:
https://www.amazon.com/Godox-Channels-RT-16-Transmitter-Kit/dp/B015CGESYK/ref=sr_1_3?s=electronics&ie=UTF8&qid=1485405992&sr=1-3&keywords=radio+trigger
I haven't used either of those particular systems (and there are many different ones), so really can't say how well they are made or work. This is just for reference as to the type of radio transmitter and receiver you most likely need. All these do is fire the strobe. They don't have any means of other control such as adjusting the output remotely. In other words, they have no "ETTL" functionality (which might be wanted if using modern flash ETTL capable off-camera). But this should be okay since those strobe units are probably not ETTL or any other type of remote control, either. Most studio strobes have an optical trigger, as yours appear to... but those will be fired by anything resembling a flash going off, as described above. They also are a royal pain if anyone else is shooting nearby with flash!
Radio triggers are the solution. Both the above examples are 16-channel, too.... so can be set to a different frequency than other radio triggers being used nearby, if that ever occurs.
One last thing... Many studio strobes do not reach peak output as fast as portable flash. So very likely you'll need to use slightly slower than the standard flash sync speed of the camera (1/200). Experiment with 1/160 and 1/125. (Obviously, you also won't be able to High Speed Sync or Rear Curtain Sync with studio strobes. Those are only available with dedicated portable flash and a few of the most advanced modern strobes.)
Jan 26, 2017 12:42:16 #
Thanks for the thoughtful response! You are correct, my camera is the Canon EOS T6i. I'll look into your suggestions.
Jan 26, 2017 12:46:24 #
Thanks for the response, Sharpshooter! I looked into that, and it turns out that there is a pre-flash that I didn't notice, which is probably causing the premature firing. (Sorry, I should have noticed that.)
I'm very impressed with all the thoughtful (and fast!) responses to my post. I'm glad I found Ugly Hedgehog.
I'm very impressed with all the thoughtful (and fast!) responses to my post. I'm glad I found Ugly Hedgehog.
Jan 26, 2017 12:50:20 #
Pat756 wrote:
Thanks for the thoughtful response! You are correct, my camera is the Canon EOS T6i. I'll look into your suggestions.
Have a look at Yongnuo radio triggers:
Inexpensive, no ETTL capability
http://www.amazon.com/YONGNUO-RF-603C-II-C3-Wireless-Remote-Trigger/dp/B00JVEXRE2/ref=sr_1_2?ie=UTF8&qid=1485452856&sr=8-2&keywords=yongnuo+trigger
More expensive, supports ETTL, for devices with that capability
http://www.amazon.com/YONGNUO-YN622C-KIT-including-Controller-Transceiver/dp/B00NW3KNZO/ref=sr_1_3?ie=UTF8&qid=1485452856&sr=8-3&keywords=yongnuo+trigger
Good luck
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