Disqus - Latest Comments for Michael Moore

Re: Radio Popper

revjim — Fri, 21 Mar 2008 13:57:03 -0000

Thank you!

The site you referenced, as well as the guide number table on the back
of Sigma EF-500 DG Super helped a lot.

For those that would rather not go find this information, I've tried to
lay it all out here: http://revjim.net/2008/03/21/high-speed-sync-au...

Re: Radio Popper

Michael Moore — Thu, 20 Mar 2008 16:39:04 -0000

Sorry for not being clear. Here's a good article on HSS that explains it better and in much more detail: http://www.rpphoto.com/howto/view.asp?articleID...

Re: Radio Popper

revjim — Thu, 20 Mar 2008 16:31:02 -0000

I guess i'm not fully understanding the aspect where the faster shutter speed leads to reduced flash output. I'll do some reading tonight and maybe I'll understand your point better.

Thank you for the information.

(Sent via Blackberry)

Re: Radio Popper

Michael Moore — Thu, 20 Mar 2008 16:10:08 -0000

That's true, but if you use a faster shutter speed, you'll need to open up the aperture to compensate for the light loss of using the HSS mode which balances everything out. If you keep the aperture stopped down and also increase your shutter speed, the sky will indeed get darker but the flash output will be equally lower since you lose about a stop of flash power for every stop of shutter speed you go beyond the camera's x-sync.

I wish it didn't work this way since I'd love to be able to overpower the sun from a distance with a single speedlight, but the only way to do this is to use more flashes or use a camera with an electronic shutter that's capable of syncing at higher speeds without forcing the flash to go into HSS mode (my Canon G9 point-n-shoot can sync up to about 1/640 or 1/800 when using a radio trigger, although it's not 100% reliable). Of course, you can still overpower the sun if you're lighting a small area from a close distance and zoom the flash head to 105mm (or even use one of those Better Beamer things), but lighting a large group from a distance requires different equipment. Maybe now with the RadioPoppers, it will be possible to use two zoomed HSS flashes to light up a large group with one on either side of the camera. This would be pretty much impossible in bright light with the IR/light pulse slave system.

Re: Radio Popper

revjim — Thu, 20 Mar 2008 15:24:04 -0000

I understand what you're saying. And you're correct, of course. These RPs are not making the flash any more powerful. But, by allowing a faster shutter speed it can help to make the sun less powerful.

(Sent via Blackberry)

Re: Radio Popper

Michael Moore — Thu, 20 Mar 2008 14:57:18 -0000

Sorry, I don't think I was 100% clear. There's no real gain in power when switching to high speed sync. If you're shooting at f/2.8 in the sun, then you'll need to compensate by increasing your shutter speed to about 1/8000 which will cut the power of the flash output by about 5 stops due to the strobe action of HSS mode (and in effect, balances with the much wider aperture). This won't help you overpower the sun, but it does give you many more options in the available apertures you can use.

As for David's photo, the flash is only about 1-2 feet away from the subject and at that distance it's very easy to overpower the sun. Sorry, I hope this doesn't sound argumentative, I just don't want people to get the wrong impression of what is possible with the RPs and be disappointed.

Re: Radio Popper

revjim — Thu, 20 Mar 2008 12:15:03 -0000

That's precisely what I mean. Before now, the only way to overpower
the sun was to shoot at f/16 of f/22 and crank your flash output as
high as it would go. With Radio Poppers a shot in the same ambient
lighting conditions can be made at f/2.8 or f/4 and with a lot loss
power required.

You can look at David Hobby's test photo
(http://www.flickr.com/photos/31454864@N00/23396...) taken in
daylight and from a reasonable distance to see just how far beyond the
sunlight we can get our strobes and from what great distance using
this new product. And, as you indicated, even without the distance
issue, getting and IR based trigger to take in bright sun can be
difficult. This will eliminate much of that issue.

On Thu, Mar 20, 2008 at 7:01 AM, Disqus

Re: Radio Popper

Michael Moore — Thu, 20 Mar 2008 12:00:27 -0000

I don't think the high speed sync option will help to overpower the sun, since most hotshoe flashes that I know of drop drastically in power once you enable HSS (I've found it's about equivalent to one stop loss for every increased stop in shutter speed, so it pretty much balances out when trying to overpower the ambient). One nice thing about it is that we won't have to shoot at f/16 or /f22 with wireless flash in the sun anymore. You could always use two or more flashes with Radio Poppers for more sun-killing power though (and this should be much more feasible with the Radio Poppers since it's tough enough to get just one IR flash to fire in bright sun).