Fill flash vs. flash as main light: please explain (1 Viewer)

Hi, I posted a thread a few days ago asking for tips for my new flash unit but unfortunately received no answers. I hope that if I post a more general thread instead of the one I wrote for a specific flash unit I'll get more people involved.
What I'd really like to know is what settings are you people using in these two situations:
1)Flash used as fill (for instance to properly expose a backlit subject or help eliminate shadows on the bird)
2)Flash used as main light. In my case for photography in very dark conditions under forest canopy (rainforest or cloud forest).
The last one seems to be the main problem so far, results are poor and seem very artificial (birds get that horrible "white-eye" reflection effect) even with the flash set at -3 EC.
I tried both using a better beamer and without it, but my subjects have been quite close so far.
What are your settings? Please share.

I thought about sharing the settings I've been using so far (just three days for now).
Equipment: Canon 30D and 400mm f5.6 with 580EX II and BB. Flash zoom is set to 50mm when the better beamer is attached.
Flash unit is set to E-TTL. The camera is set always to Av mode with E-TTL II set to evaluative.
Now, when there is good light and I am using the flash as fill, I select the C.Fn-03 (flash sync speed in Av mode) to "auto", then I turn on the "high-speed sync" on the flash so I can shoot at any speed and hope this way I have a better chance to stop movement than I would have with 1/250 fixed speed. Then I try to properly set the EC and the FEC, usually the last one will be a negative value, like -1 1/3 or -2, so the flash light won't be so harsh.
This hasn't been so difficult so far, just need some more practice!
When I really get confused is when the speed drops below 1/250. Then I turn off the high-speed sync and I've tried various settings but with terrible results. With very low speeds such as 1/60 or less, The birds gets scared by the strong preflash and start moving even before the photo has been taken, results are usually blurry images.
Then I thought to switch C.Fn-03 to "fixed (1/250sec.) flash sync speed" as I thought that this would improve my chances to freeze motion a little bit. I think (but I am probably wrong) that with this setting I am switching to using flash as main light, but I can't seem to get a decent photo. I feel quite lost here...I really need to learn how to use the flash in low light situations as that's where I will be using it most of the time, but I'd like to obtain more or less naturally looking images..is that impossible or I just need to find my way around?

When you want to use the flash for fill, you should use the Av mode as you are doing. However, I don't see why you need to turn-off high-speed (FP) mode when you end up with a shutter speed slower than 1/250. If you set the sync speed to 1/250 and then turn on high-speed sync mode, it should automatically turn off for shutter speeds of 1/250 or slower (and the camera should show this).

If you want to use the flash as the main light source, you should set the exposure to manual mode. Then you can experiment with various shutter/aperture combinations to see what works better for you.

Unless you are using second-curtain sync, you (or the birds) should not be able to notice the difference between the pre-flash and the actual flash.

Here is the best resource on the web about how the EOS flash system works and how to use it:

http://photonotes.org/articles/eos-flash/

Another Good Resource

Arthur Morris's writings, "Advanced Bird Photography II" in particular, speak very directly and clearly to the situations you describe.

Check his site for ordering information:

www.birdsasart.com

Best of luck. I'm sure you'll find an answer to your problem.

Steve in Houston

macshark said:

When you want to use the flash for fill, you should use the Av mode as you are doing. However, I don't see why you need to turn-off high-speed (FP) mode when you end up with a shutter speed slower than 1/250. If you set the sync speed to 1/250 and then turn on high-speed sync mode, it should automatically turn off for shutter speeds of 1/250 or slower (and the camera should show this).

Click to expand...

Thanks for your answer! You are right about that, I can leave on the high-speed sync all time, if speed drops the camera will realize that and act consecuently.

If you want to use the flash as the main light source, you should set the exposure to manual mode. Then you can experiment with various shutter/aperture combinations to see what works better for you.

Click to expand...

To be totally honest, manual mode sounds really scary to me, probably is just too difficult for my poor brain to understand how to use it beeing just a beginner. I've read about it in the link you mentioned (the Canon EOS flash bible), but I thought it sounded way too complicated to use for me. :-C That's why I was trying to stick to Av mode.

Unless you are using second-curtain sync, you (or the birds) should not be able to notice the difference between the pre-flash and the actual flash.

Click to expand...

That is true, I can't see any difference between them, but the thing is that when I take a picture at slow speeds and low light conditions I actually can see the burst of light through the viewfinder, isn't that the preflash? I thought it was, as if the shutter was already open, wouldn't be impossible for me to see the flash? (Not at all sure about that, just a question, sorry if it's dumb).

Steve Gross said:

Arthur Morris's writings, "Advanced Bird Photography II" in particular, speak very directly and clearly to the situations you describe.

Click to expand...

Thanks, but I can't find that book in Arthur Morriss's website list, there's only a CD called: "The art of bird photography II". However, it may be a while before I am able to use my credit card again. ||

Sorry, "The Art of Bird Photography II" is the correct title. My mistake.

gatafrancesca said:

To be totally honest, manual mode sounds really scary to me, probably is just too difficult for my poor brain to understand how to use it beeing just a beginner. I've read about it in the link you mentioned (the Canon EOS flash bible), but I thought it sounded way too complicated to use for me. :-C That's why I was trying to stick to Av mode.

Click to expand...

In Av mode, the flash will strictly function as a fill-flash, i.e., the scene will be metered as if the flash is not present, and the flash is simply used fill in the shadows. If you want flash to be your main light source, taking multiple shots at different settings in the M mode appears to be the best approach. Depending on the situation, you either set the shutter speed or the aperture to the value you need, and vary the other until you get "good enough" results with the flash.

Thanks macshark! I guess that someday I will try M flash out and see what happens.
But for now I've been experimenting with Av and fill flash and I think I've succeded in getting some decent results (actually I am pretty satisfied right now). I guess it all depends on practice and finding out the settings that are better for you. I've already taken more than 1000 photos with my new 30D in just four days!

I answered your original thread, and I'm such a nice man that I've copied it here for you (some of the things have come up already):

When using flash for birds, I suggest as a starting point you set your camera to P mode (or M) to expose for the flash as the main light. Av and Tv expose for the ambient light, so you may end up with too-slow shutter speeds in low light conditions. P, Av and Tv modes are all good for fill flash in good light. I turn my flash down a little as when shooting something so small in the frame as a bird, and because Canon gear tends to overdo the flash for my taste.

If you want the view of an expert, you might try Art Morris' PDF book Art of Bird Photography II.

http://photonotes.org/articles/eos-flash/ has lots of useful stuff on it.

To be totally honest, manual mode sounds really scary to me, probably is just too difficult for my poor brain to understand how to use it beeing just a beginner. I've read about it in the link you mentioned (the Canon EOS flash bible), but I thought it sounded way too complicated to use for me. :-C That's why I was trying to stick to Av mode.

Click to expand...

Francesca, 'Manual mode' is probabaly much easier than you think.

Just put the camera in Manual, flash on ETTL and start with the max sync speed of 1/250 and set the aperture to what you want to get the correct depth of field. I also find I need maybe -1/3 to -2/3 flash comp most of the time.

Only downside is the background will be dark because you are exposing for the bird only. Choosing a slower shutter speed will make it brighter as will a bigger aperture.

It is also the only way to completly freeze any movement in a dull or dark situation. You don't even need a tripod doing it this way if you are very close to the subject.

'High Speed Sync' will not freeze anything because the flash duration is the same as the shutter speed.

You can try all this in the house before you go again. :t:

That is true, I can't see any difference between them, but the thing is that when I take a picture at slow speeds and low light conditions I actually can see the burst of light through the viewfinder, isn't that the preflash? I thought it was, as if the shutter was already open, wouldn't be impossible for me to see the flash? (Not at all sure about that, just a question, sorry if it's dumb).

Click to expand...

You're right, the busrt of flash you see in the viewfinder is the preflash as the mirror is up when the main flash goes off so you won't see that.

Thanks jdj and Mick! I guess I will give this M mode a try. It's beeing raining everyday lately and the forest is way too dark to use flash as fill. But I will try it at home first as you said.
Cheers