Any reason not to leave flash on HSS all the time?

Using a 600EX on 5D3. Any reason not to just leave it on HSS all the time?

Yes..... Battery life!
Your Flash will always emit a Pre-Flash signal in HSS Mode, just in case if there are other flashes in the area to read it, therefore, those Pre-Flases can prematurely and will significantly run down your battery life.....

The Loft Studios wrote in post #15284783
Yes..... Battery life!
Your Flash will always emit a Pre-Flash signal in HSS Mode, just in case if there are other flashes in the area to read it, therefore, those Pre-Flases can prematurely and will significantly run down your battery life.....

The flash emits a pre-flash anytime it's in ETTL mode.

There are plenty of people who keep HSS on, so the flash automatically adjusts (using HSS) if the shutter speed goes beyond the sync-speed.

You know what... I read that question from the OP ALL WRONG!!! LOL
I was thinking Master/Slave Mode..... Ignore the answer I provided - *BRAIN FART*

I have noticed one thing about HSS I hadn't expected on my 5D with a max sync speed of 1/200. Even though I'd expect a single flash pop at 1/200, seeing as it can sync at that speed without HSS, if HSS is enabled I still lose close to 2 stops of flash power at that shutter speed. I'd gotten in the habit of using 1/160' when shooting with the flash so even if I leave HSS on, I'll still get the flash power I expect.

noob question
HSS = ?

XKxRome0ox wrote in post #15285067
noob question
HSS = ?

High Speed Sync. Its the ability of a flash to strobe very quickly which lets you shoot with a higher shutter speed than your camera's max sync speed. Without HSS, you'd either get the shutter speed forced down to sync speed or have the flash only lighting part of the frame, depending on how you're set up.

No reason not to leave it in HSS.

Technically there really isn't a reason to not simply leave HSS enabled. But from the standpoint of having max control over your process and equipment, leaving HSS off until needed means that you do not inadverantly end up at a shutter speed faster than X-sync but do so only with deliberation and knowledge.

I know that in the heat of battle I have discovered (unpleasantly) that the Av shutter speed is a very long one, ruining my ability to shoot off multiple exposures in rapid succession. Conversely, since HSS loses flash range and power, I would not want the flash to simply shift into HSS and lose range without me being fully aware!

Thanks for the input everyone... I shoot Av a lot with available light and want to start using fill flash more. Not having to worry about overshooting the sync speed would be one less thing to worry about.

mike_d wrote in post #15285100
High Speed Sync. Its the ability of a flash to strobe very quickly which lets you shoot with a higher shutter speed than your camera's max sync speed. Without HSS, you'd either get the shutter speed forced down to sync speed or have the flash only lighting part of the frame, depending on how you're set up.

Not sure if you are at not familiar with the abbreviation HSS or High Speed Sync in general. If you want to know more about it here is a pretty good video. It is a Pocket Wizard (PW) ad but has some of the best animations I have seen. It helped me understand it better.

Note: You don't need PW to make it work if the flash is on camera. It is for off camera flash applications.

http://www.pocketwizar​d.com …wizard_controlt​l_optimiz/

mike_d wrote in post #15284877
I have noticed one thing about HSS I hadn't expected on my 5D with a max sync speed of 1/200. Even though I'd expect a single flash pop at 1/200, seeing as it can sync at that speed without HSS, if HSS is enabled I still lose close to 2 stops of flash power at that shutter speed. I'd gotten in the habit of using 1/160' when shooting with the flash so even if I leave HSS on, I'll still get the flash power I expect.

Yep. On a 5D Classic it's better to switch it off.
http://neilvn.com …-even-when-not-neededs/p1
http://neilvn.com …02/high-speed-flash-sync/

convergent wrote in post #15286171
Thanks for the input everyone... I shoot Av a lot with available light and want to start using fill flash more. Not having to worry about overshooting the sync speed would be one less thing to worry about.

Practice using Tv and M for outdoor fill. Tv with shutter speed at X-sync will maximize your flash range, battery life and recycle time. You'll still need take a deliberate approach and use an ISO that gets your aperture in the range you want.

Then try M. There aren't many situations where the light is too variable to make Manual mode a viable option.

digital paradise wrote in post #15286222
Not sure if you are at not familiar with the abbreviation HSS or High Speed Sync in general. If you want to know more about it here is a pretty good video. It is a Pocket Wizard (PW) ad but has some of the best animations I have seen. It helped me understand it better.

Note: You don't need PW to make it work if the flash is on camera. It is for off camera flash applications.

http://www.pocketwizar​d.com …wizard_controlt​l_optimiz/

Thanks for the video... I had forgotten the details of what HSS was doing, so this was a good refresh. In my case, I'm using 600EX-RTs so I can do what they are describing off camera without the PWs.

Curtis, considering the above, help me out here, please.
I was out and about shooting a small town near my home, nice, interesting old buildings, and a great sky. So I wanted to keep the sky detail. I dialed in whatever exposure kept the sky and obviously the building went dark, even though I was using my 600 ex on camera. I figured I was too far away. This is shot with the 24-70 II. But, from what I believe was about the same distance, I upped the ISO from 400 to 1000. Better exposure, I think, but how come it didn't also blow out the sky?