[Ali]

I’d like to understand flash photography… it sort of baffles me a bit (a lot!) and I wondered if the good people of Pixalo could help. Being the helpful bunch you are I thought it’d be a fairly safe bet

I have Canon 20D and 430EX which I have used together on Auto (*washing mouth out now*) and pictures turn out OK’ish. But…when I try to use in any other mode (Av Tv M etc) it all goes downhill.

I know this has come up before and the consensus seemed to be “Read The Manual”. Well I have and the manual really doesn’t help all that much! It’s probably because I don’t understand the principles so I don’t understanding the content. The manual doesn’t seem to explain the features or how to use it very well. It explains how to press the buttons and change settings but that is about it, no good to me unless I understand what the settings mean.

So here follows perhaps a really stupid example (but because I don’t understand I am probably totally missing the point and am likely to look very dim but if I don’t ask I’ll never learn will I?) I also need to try it again this evening to make sure I have got my example right!

In a totally basic state used indoors:
- Camera to Auto, pop up flash – takes OK’ish picture.

- Camera to Auto, 430ex flash attached and switched on (no buttons pressed on flash other than ‘on’). Take picture – seems OK, much better than the pop-up.

- Camera to Av (setting aperture to the same as the camera picked for Auto). 430ex flash attached and switched on (on (no buttons pressed on flash other than ‘on’). Take picture – pants, flash fires but shutter speed dead slow, picture blurry.

I’m sure I am supposed to press buttons on the flash… or something!

Any advice, help, pointer in the right direction, links to tutorials, anything would be most welcome. I have tried to read about flash but some of the articles I have read leave me feeling more confused than ever.

[stepheno]

I only know how to use a flash - I don't know ho to tell someone else how to use one. I agree with you - flash manuals are a foreign language. All I can suggest is take loads of shots with loads of settings and have a notepad and pencil at your side or look at the exif for each image.

A guru will be along soon and tell you how

[stepheno]

PS - I found this article very helpful but you need to read it, not just skim through.

[JMitchell]

Are you sure it's not accidentally set to rear sync or something like that? Check the flash mode ON THE CAMERA and make sure it's not set to anything other than the standard mode, as this will affect the flashgun.


If it's not that then I'm not sure what it could be, because your camera should default to the flash sync shutter speed if you're in A (Av) mode. If the flash is on eTTL, then I can't really offer any other suggestions....

[sgotwr]

Hi,
when you set you camera to Av mode, it will set the aperture and shutter speed to suite the ambient light, and using the flash as a fill in, that is probably why you are getting blurred images, ( to slow shutter speed and not enough flash).
I have found with a 40d and 580 ex, in Av mode,if I set the exposure compensation to -2 stops, and choose the lowest aperture of the lens, I get good results.(Heres one I took yesterday evening for a local paper, background may be underexposed to much for some)


If I am taking plain run of the mill photos, I leave the camera on P and let it work things out for itself, giving good results most of the time.

For action shots I set the camera to Tv mode, set 250 sec, then let the flash give as much light as it needs, again giving good results.

I am not that experienced with flash myself, but these are what I have found over the last few months.

Alwyn

[brian wright22]

Ok Ali. I have experienced the same problem with my 350D and 430ex flash.
Reasonably ok with the internal pop up flash but does get a bit short of distance and power when selecting a small aperture.

Now I had the same problem as you.I got nowhere by reading the manuals, so I emailed Canon.

For flash pictures using the 430ex flash gun try this .

The best method I have now found is to set the camera to Manual mode. With the 430ex switched on I set the aperture to suit the depth of field required.This does depend on the maximum aperture of lens your using. If the maximum aperture of the lens is f4.0 for a given focal length I use about f 8. Set the flash to Ettl.
Looking through the viewfinder your will see the f8 and the corresponding Shutter speed when you part press down the shutter release button.

This meters the camera to the background of the scene you are pointing at. Now when you press the shutter release to take the picture the 430ex flash will give the correct amount of flash to correctly expose the foreground subject of the scene.

In every mode the Canon Ettl flash system always sets the flash power to suit the foreground element of the scene and the shutter speed is set to correctly expose the background. In no mode does the Flash get altered to affect the background exposure. This is assuming there is some ambient light. If it is pitch black it will expose the nearest part of the scene.

One thing to watch out for is when the camera is set to any mode other than Manual I have noticed that the lens is nearly always set to its maximum aperture, which is not the best arrangement for the sharpest results.
Regards Brian

[stupot]

I recent bought this Ali and although i'm still reading it, its definately so far so good
Amazon.co.uk: Canon Speedlite System Digital Field Guide: J. Dennis Thomas: Books

[stepheno]

Brian has said, very eloquently , what I would have garbled.

[Ali]

Brilliant!

Thank you all for the advise, I will check settings and try out the suggestions this evening/tomorrow. I'll let you know what happens.

I just want to check though - am I right to expect the external flash to work in a similar way the pop up? Or have I really missed the point and should put the flash away?!
eg. if in Av mode aperture set to f5.6, pop up flash pops up and get a shutter speed of say 1/200th - I should get the same (similar) results with external flash?

[JMitchell]

Yes but the main idea of the external flashgun is not (IMO) that you use it as a pop up flash with extra power. Photojournalists do this, but as you can often see their snapshots in the paper often look harshly lit because they just needed to get the picture.
The main idea is creativity, so using bounce flash for completely soft lighting, and off camera flash for interesting effects.
If you had just wanted a more powerful popup, perhaps it would have been better to get something like the Sigma flash that's being sold on here ATM for £90.

Not criticising, just hoping to answer your question, which I might not have done.

[Ali]

Thanks Jack.
No I'm not after extra power - I do want to use it 'properly'. I just trying to work out whether I am right or wrong in my expectations of how it should work. In order to try to explain myself here the pop up is the only comparison I have

[JMitchell]

Then you're right, it should give similar but slightly better results if you use it in an identical fashion to the pop up. Good luck with it, and hope to see some shots soon eh?

J