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Old Aug 29, 2013, 9:34 PM   #1
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Default High speed sync flash

I'm new to using flash for shots but I was trying to take high speed shots and use my flash but was limited to 1/250 when I popped up my onboard flash on my Canon 60d. I did some research and found out that I need an outboard flash for the hot shoe that can high speed sync because I want to take some indoor shots at 1/2000 or faster. I read but I'm unsure what kind of flash unit I need that will speed sync with my Canon. I have been looking at the Sunpak PF30X/DigiFlash 2800 E-TTL, but their description doesn't say whether it has high speed sync feature. If a flash unit says it's E-TTL capable does that mean that it can high speed sync? Does the Sunpak PF30X/DigiFlash 2800 E-TTL have high speed sync and if not can anyone give me a list of flash units that have HSS capability that will work with my Canon 60d? Thanks for any help.

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Old Aug 30, 2013, 8:21 AM   #2
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If you want to freeze motion, High Speed Sync won't necessarily do it for you.

The reason for the limit of 1/250 second for flash is to leave the sensor exposed so the flash can illuminate the scene for the duration of the flash. DSLRs use focal plane shutters that act independently to uncover, and then cover the sensor. The fastest flash sync speed of 1/250 is to ensure that the entire image sensor will be exposed when the flash goes off.



The duration of the flash might be 1/320 second (if the flash isn't very powerfuland/or the scene is very dark) or it can be as fast as 1/80,000 (if the flash is very powerful.)

High-Speed Sync is used for faster shutter speeds because of the likelihood that the duration of the flash will be longer than the time between when the bottom curtain has fully uncovered the sensor and the top curtain has started covering it. The way it works is that, instead of using one powerful flash to illuminate the entire frame, it uses five much less powerful flashes to illuminate those portions of the frame that happen to be exposed at the time.

So if you're trying to freeze action, High-Speed Sync may not be what you want. You'd probably be better off getting a very powerful flash to get a very short duration flash, and leave the shutter speed at the flash sync speed.

After all, it's the duration of the flash that freezes the motion, not the shutter speed.
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Old Aug 30, 2013, 9:53 PM   #3
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Quote:
Originally Posted by TCav View Post
If you want to freeze motion, High Speed Sync won't necessarily do it for you.

The reason for the limit of 1/250 second for flash is to leave the sensor exposed so the flash can illuminate the scene for the duration of the flash. DSLRs use focal plane shutters that act independently to uncover, and then cover the sensor. The fastest flash sync speed of 1/250 is to ensure that the entire image sensor will be exposed when the flash goes off.



The duration of the flash might be 1/320 second (if the flash isn't very powerfuland/or the scene is very dark) or it can be as fast as 1/80,000 (if the flash is very powerful.)

High-Speed Sync is used for faster shutter speeds because of the likelihood that the duration of the flash will be longer than the time between when the bottom curtain has fully uncovered the sensor and the top curtain has started covering it. The way it works is that, instead of using one powerful flash to illuminate the entire frame, it uses five much less powerful flashes to illuminate those portions of the frame that happen to be exposed at the time.

So if you're trying to freeze action, High-Speed Sync may not be what you want. You'd probably be better off getting a very powerful flash to get a very short duration flash, and leave the shutter speed at the flash sync speed.

After all, it's the duration of the flash that freezes the motion, not the shutter speed.
Thanks for the info. I'll try it with my onboard flash but I ordered a Newer TT560 which has different power settings. I hope that works as well.
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Old Aug 31, 2013, 9:22 AM   #4
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what are you trying to capture using 1/2000 shutter speed?
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Old Aug 31, 2013, 1:52 PM   #5
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what are you trying to capture using 1/2000 shutter speed?
As I said I'm new to high speed flash photography and have been learning how to take high speed shots recently without using high speed shutter. I've been wanting to take shots of water splashing and so forth and have learned that it's possible to do it with a flash instead of high speed shutter.
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Old Aug 31, 2013, 4:12 PM   #6
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The more powerful the flash, the shorter the duration of the flash, and the faster the motion you can freeze. And you can slow it down (make it last longer, getting more motion blur) buy reducing the power.
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Old Aug 31, 2013, 4:18 PM   #7
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Just one little oops in your excellent explanation, TCav.
"High-Speed Sync is used for faster shutter speeds because of the likelihood that the duration of the flash will be longer than the time between when the bottom curtain has fully uncovered the sensor and the top curtain has started covering it."
I believe you meant 'shorter' rather than 'longer'.

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Old Sep 1, 2013, 1:04 PM   #8
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Default New shots

I recently took some photos of water drops without having to use a high speed shutter and just using my onboard flash. I had the shutter at the maximum allowed which is 1/250, but from what I am learning, I could use a lower speed shutter and still get the same results. Any helpful critique would be welcome.
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Old Sep 1, 2013, 4:42 PM   #9
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Great start!
Since there doesn't appear to be any Exif info with your photos, I will have to guess that you are using your lens' widest aperture, which works well for emphasizing a part of the frame. If you want to have more of the picture in focus, and reduce some of the blurred highlights, try closing the aperture down somewhat, to f/8 or f/11 and compare.
The pop up flash on the camera is giving you a lot of reflections directly back into your lens. You can reduce these by using either a diffuser on the onboard flash, a hotshoe flash with bounce and/or diffuser, or off-camera flash.
Interesting, and nice shots. I'm not trying to be critical, just suggesting things to try you may not have thought of.

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Old Sep 1, 2013, 5:06 PM   #10
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Great start!
Since there doesn't appear to be any Exif info with your photos, I will have to guess that you are using your lens' widest aperture, which works well for emphasizing a part of the frame. If you want to have more of the picture in focus, and reduce some of the blurred highlights, try closing the aperture down somewhat, to f/8 or f/11 and compare.
The pop up flash on the camera is giving you a lot of reflections directly back into your lens. You can reduce these by using either a diffuser on the onboard flash, a hotshoe flash with bounce and/or diffuser, or off-camera flash.
Interesting, and nice shots. I'm not trying to be critical, just suggesting things to try you may not have thought of.

brian
Thanks for the tips. I've also ordered a sync cord so that I can place my flash in different positions. Anxious to see what new results I can get.
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