Flash for long-range?

After last night, I have really found an appreciation for external flashes. I'm in college and last night our main street (Franklin Street) was crowded with something like 15-20,000+ people. Lightly put, it was crowded

Anyway, I started off the evening taking pictures with the onboard flash of my 20D and sometimes bumping up the ISO and not using a flash. A friend of mine has an old Rebel that he has that has an external Vivitar flash that he got for like $20. I stuck it on my 20D and used it a bit, and saw a world of difference in the quality of my pictures up close with it (much more light, of course). However further back in the crowds (maybe 25+ feet away), it was somewhat darker.

I'm wondering, is there a flash that'd allow me to get more range with my light? I'm seriously wanting to get a flash now (maybe the 550 or 580?) and want something with good range.

Thanks!

It's all about Guide Number, F stop and ISO. See this thread:
https://photography-on-the.net/forum/showthre​ad.php?t=46302
Scott

The Canon 550EX and 580EX Speedlites (and 420EX also, for that matter) have guide numbers of 55, 58 (and 42), expressed in meters @ISO 100.

Be very careful if you apply some unknown Vivitar flash to your camera unless you know the trigger voltage on the flash to be safe. You might have already done major damage to the camera.

---Bob Gross---

Thanks, I'll check that out

How could it damage the camer? I guess I could potentially see it messing up the flash... but either way, when my friend bought the flash it said it was compatible with Canon Rebels, I would assume it should be fine on my 20D. Plus it had a manual and automatic setting, and I left it on automatic... so I guess that would stop it from firing with an incorrect voltage?
I havent noticed any sort of damage to my camera, how would I tell if it's damaged?

Do you mean in the same picture? You really can't properly expose people both close and far with a single flash mounted on the camera. You're battling with the inverse square law. (There are some exceptions - like if you have ceiling to bounce off you could make the length of the path more similar.)

That vivitar probably could have handled 25 feet easily but it would have cut the light output if it saw anything/anyone closer. You could use manual to override that, with the understanding that whatever was in the foreground would end up pure white.

That has nothing to do with it. This is the voltage that the flash applies across the sync line. But if it claims to be safe then hopefully it is. You can put a voltmeter across the flash terminals if you want to test it. My 1970s Vivitar has a HUGE voltage across there but it didn't bother the all metal /all manual cameras that were common at the time.

Exactly. I have an old Vivitar with 170 volts DC on it, so I don't let it get anywhere near my DSLR.

---Bob Gross---

When the camera suddenly fails to function.

Then you know for sure when the Canon Repair Shop gives you the bill for $300 or more.

---Bob Gross---

Yes, in the same picture... my primary concern was "is there a way to extend the range of the flash so things/people further away can be exposed properly?"... I do understand that things up close would definitely get washed out in that aspect, especially assuming the flash flashes directly at them. In some shots I was taking, I noticed some interesting looking costumes off in the distance and zoomed in to get a shot but the flash didn't seem to reach as far as I'd have liked- I guess I should get a good flash and learn how to use its settings for distance and all.

I don't have a voltmeter, but I would assume I could try a flash that's definitely known to work well with the 20D on there and if it works then it should be fine. I'm fairly confident nothing has been damaged because like I said, it said to be compatible with the Rebel, and even his 35-800mm lens for it worked amazingly well on my 20D.


Thanks for all the input everyone, so which would you suggest would be my best option for a flash? Keeping price in mind is definitely a factor, as I want something that'll get the job done and be easy on the wallet. I'm not distinguished enough with external flashes to know all the bells and whistles they have to offer and a lot of that would most likely be wasted on me for the time being.

I've used it quite a bit since using that external flash, both with the onboard flash and without, and haven't seen any signs at all of it beginning to fail.

haha, yeah I'd definitely know for sure at that point

Thanks for the info on that, though, I'll definitely be careful about what I hook up to my camera.

This is an area where an ETTL flash will be better since it reads through the lens instead of its own sensor. At least with ETTL the flash can only be fooled by things that are really in the foreground of your shot whereas a flash with it's own sensor is usually always looking at a fairly wide area.

Which model Vivitar is it? AND how old is it? I'm guessing it's a Vivitar 283?
These have been around a LONG time, and when they first came out, most shutters on cameras were mechanical, so the trigger voltage of these flashes was not as critical, and some of them can run voltage well in excess of the 6 volts or less that is max for EOS DSLR's.
The newer cameras have electronic shutters, as well as low voltage circuit boards in them that can be burned out by the excess voltage that some of the older flashes produce through their shoe.
You need to check the actual voltage with a meter to be sure.
One other option would be to use a safe sync.
-Bruce

First off on the trigger voltage, be careful as Bob stated. Less of an issue on the 20D then the DRebel since the 20D can handle 250v compared to 6v on the rebel.

On the flash, take a look at the Sigma 500 Super DG. It is significantly less then the Canon flashes with much of the same features.

Ovi

I wasn't sure off the top of my head, but after doing a couple Google searches, it looks to be the Vivitar 2000.

Thanks OviV, I'll look into that as an option