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Old Aug 14, 2003, 11:08 AM   #1
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Default TTL question

I'm very inexperienced with any flash system, but especially TTL flash.

I was thinking about buying a flash for outdoor fill flash when doing nature photography. I'm going on vacation, and I'd probably use it there.

This may sound very basic, but how hard are modern flashes to use? (I'm talking the Canon 420EX, 550EX or Metz ??-52 class flashes... i.e. high end, powerful.) Would I have to learn and understand so much that taking in on a vacation (a week away) wouldn't be worth it because I wouldn't get good results at my level of experience?

I would use it for things like this. I saw a woodpecker eating a healthy lunch of ants on the side of a tree. He was about 8-10 feet away or so. There was some backlighting, but he was fairly visible. I took several pictures, one I even really liked. But it would have benefited from fill flash. Ignoring the fact that I was shooting through branches (which could reflect and confuse the metering system) is that type of situation easy to use a flash in? Could I just set the flash (say drop its power a stop or two) and take the picture, or do I need to worry about the distance and adjust settings on both the camera and flash?

I find a heron about 15 feet away. I've used the built in flash with ok results. But the flash sync limit starts to effect me. 1/200th is hard at 400mm (x1.6!) In this case there is nothing to interfere, the setting is simple (object in dark'ish environment.) Can I treat the flash as "point and shoot"?

I have a Canon 10D, which fully supports E-TTL, TTL and other letters I don't understand.

Any ideas/help would be great.

Eric
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Old Aug 14, 2003, 2:19 PM   #2
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Eric

You know the flash is not really set up for use on a 400mm... (You can use a more powerful unit or add a tele-adapter though)

On the 10D there's a flash exposure lock mode, very much like the AE lock, in fact it use the same button; However I can see how it would scare your bird away with the pre-flash (most digital camera will need to use the pre-flash to do TTL, since the CCD/CMOS sensor/processor is too busy capturing the real image to evaluate and control the flash the 2nd time around).

The 10D only uses the E-TTL mode which is the latest, the other modes are for older camera. It has the E-TTL wireless mode as well and I guess you can put the flash closer to your subject, but I wonder how this would work during daytime, since this is done by an infrared beam and the range is not that great! I'm guessing here on the Canon, but on the Minolta it's both IR or through the actual flash pulse (since the Canon requires the ST-E2 controller, but the Minolta works with or without the controller through the built-in flash!)

http://www.photozone.de/3Technology/flashtec6.htm
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Old Aug 14, 2003, 4:51 PM   #3
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Default Re: TTL question

Quote:
Originally Posted by eric s
I would use it for things like this. I saw a woodpecker eating a healthy lunch of ants on the side of a tree. He was about 8-10 feet away or so. There was some backlighting, but he was fairly visible. I took several pictures, one I even really liked. But it would have benefited from fill flash. Ignoring the fact that I was shooting through branches (which could reflect and confuse the metering system) is that type of situation easy to use a flash in? Could I just set the flash (say drop its power a stop or two) and take the picture, or do I need to worry about the distance and adjust settings on both the camera and flash?
You need a flash extender to throw the flash light farther way. Check Kirk's web site @ http://www.kirkphoto.com/brackets.html
move to near the bottom for Flash X-Extender, and order the one that fits your flash. Yes, you still can use TTL or E-TTL on your Canon body.

CK
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Old Aug 14, 2003, 5:15 PM   #4
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The one I know about is the better beamer. My point was not to ask about using a flash extender for a subject 50-100 feet away. I expect I'll get one at some point, but not yet.

I was using the 400mm on a bird about 15 feet. I was at 225mm on the 100-400. I know the 550ex will throw a flash 15 feet (heck, the built in flash on the 10D goes about that far.) But I know nothing about TTL or E-TTL. How well it would work in that theoretical situation, how automatic its become....

Has this gotten automatic enough that I don't have to have indepth flash knowledge and experience (guide numbers, distance estimates and stuff), or can I trust E-TTL to generally do the right thing?

Eric
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Old Aug 14, 2003, 5:51 PM   #5
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Quote:
Has this gotten automatic enough that I don't have to have indepth flash knowledge and experience (guide numbers, distance estimates and stuff), or can I trust E-TTL to generally do the right thing?
... You've got it! everything is automatic on the 10D and is E-TTL only: It works with the built-in, the 550/420EX (on or off the camera), even with multiple units within a separate group with different ratio (a better manual is included with the 550EX!).

The other modes are: A-TTL which is older (EZ series), with straight 'TTL' only even older still, and dated back to my antique A1 or F1 Canon's!
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Old Aug 14, 2003, 11:05 PM   #6
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Quote:
Originally Posted by eric s
The one I know about is the better beamer. My point was not to ask about using a flash extender for a subject 50-100 feet away. I expect I'll get one at some point, but not yet.

I was using the 400mm on a bird about 15 feet. I was at 225mm on the 100-400. I know the 550ex will throw a flash 15 feet (heck, the built in flash on the 10D goes about that far.) But I know nothing about TTL or E-TTL. How well it would work in that theoretical situation, how automatic its become....

Has this gotten automatic enough that I don't have to have indepth flash knowledge and experience (guide numbers, distance estimates and stuff), or can I trust E-TTL to generally do the right thing?
The reason I provide the flash extender info is because 15 feet is almost at the fringe of most flash guns. The extnder will concentrate the flash output to a smaller light cone, and provides higher intensity. Because the light still goes out from your flash in E-TTL mode (or whatever TTL mode that is suitable to your camera), the camera can still control the flash. However, flash compensation may be needed in extreme situation.

CK
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Old Aug 15, 2003, 1:57 PM   #7
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The Canon 550EX has a guide number of 180 @ ISO 100.

Assuming this web page is correct:
http://www.shortcourses.com/how/guid...idenumbers.htm

Then with an fstop of 8, that turns into

180= 8 * X

Where X is the effective distance to the subject. X is there 22 feet. For f5.6 it is 32 feet. This is an expensive flash, but still, it seems like it should reach beyond 15 feet without an extender. And if I bumped the ISO, it would reach even futher. How well, I don't know. Gotta read that web page more.

The flash extenders are very cool products, though. I will probably get one if I get a more powerful lens (more than 400mm, or something which takes a TC well.) My fear was that I'd have to play with flash compensation a lot to get anything useful. I'm not at a stage where I'll be able to learn about that in the week I have before my vacation.

Eric
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Old Aug 15, 2003, 2:34 PM   #8
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Eric

Don't forget there's also the FEB mode, ie Flash Exposure Bracketing!

... What I've found with the 550EX Flash Exposure lock is it's spot on everytime, and why should it not not? It measured the flash Through-The-Lens including by the seashore with a CP filter on during fill!
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Old Aug 16, 2003, 3:16 AM   #9
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Eric, just FYI, according to a friend of mine that uses Canon equipment, and owned a Metz 54MZ-3 for his film bodies, his Metz didn't work properly with his D60, and after waiting and waiting for Metz to introduce a module to fix this issue he finally gave up and bought a 550EX. He's much happier now I too had trouble getting the 54MZ-3 to work on my D100, and gave up waiting and bought an SB80-DX. For TTL, I think the camera manufacturer's flash units can't be beat, price/performance wise. The Metz did light up better than the SB80-DX, but at the expense of manually adjusting it everytime. I'm not a Canon guy, but I just wanted to let you know of some issues I've seen with 3rd party flash units.
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Old Aug 16, 2003, 10:59 AM   #10
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marokero

Thanks for the info. I've heard mixed things about that Metz flash myself. It seemed to be split 50/50 between "works great" and "always have to drop the flash by X stops".

Part of my reason for going to the Metz would be that I can use it with multiple brands (free me up to buy what ever brand pocket sized camera I wanted and still use the flash with it.)

I'm leaning against this right now, though.

Eric
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