Using flash effectively - distance

Derben

Derben

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Hi,

I recently purchased a Sigma flashgun for my 400D in the hope of improving lighting for my indoor pictures. It appears I'm doing something very wrong as the pictures look worse.

I'm using auto and I can hear the flash moving in sync with the lens - but the photos are bright at the top and darker at the bottom.

I thought a flash gun would diffuse the light equally - but doesn't seem the case with me. I think the equipment is okay - it's just me doing something wrong. I've tried bouncing the light with bettter affect - anything else I can try. This is mainly for portrates.
 
which lens? Sounds like it's blocking the flash output.
 
Fair point Dave :)
 
I'm :thinking::thinking::thinking: if by 'dark' Derben means 'black or almost' it's more likely a flash sync speed problem

Pop-up flashes reset the camera's shutter speed to the appropriate sync, all others (non-dedicated ones anyway) need you to do it. If the shutter speed is so fast it's not fully open when the flash goes off this creates dark to black banding

:shrug::shrug::shrug:

Awaits example image

DD
 
Sounds like too fast a shutter speed for flash sync?
 
CT said:
Sounds like too fast a shutter speed for flash sync?
Click to expand...

Betty had the flash synch speed problem on her 400D. The shading was down the rhs of the image. Here was me thinking the shutter was moving right to left, hence the initial thoughts about lens shading.

However, checking the thread I realise the camera was in portrait orientation, it's the bottom of the frame which is dark. I'm a doofus :nuts:

for reference :)
 
Show me the guy who says you're a doofus Doddy - I'll have him! :D

I'm not too sure where we are now with this though. Shutters in modern cameras travel vertically (when the camers is held in landscape format) so if the camera was rotated to portrait orientation, then the shutter blinds would be moving left to right or right to left, depending which way the user rotates the camera. :woot:
 
Derben said:
Hi,

I'm using auto and I can hear the flash moving in sync with the lens - but the photos are bright at the top and darker at the bottom.
Click to expand...

There are any number of reasons this could happen. Suffice to say that a flash gun is no panacea. Suffice to further say that if you want to use it 'properly' get it off the hotshoe.

Derben said:
I thought a flash gun would diffuse the light equally
Click to expand...

It won't, not without modifiers (diffuser, reflector, brolly, ....)

Lots more highly relevant info at www.strobist.com

If you want a diagnosis of your particular problem you'd need to show the results you're getting and the setup you're using (location, not gear).
 
Could be you've still got the lens hood on?
 
I'll try and recreate the problem, (shouldn't be difficult), and post some pics with lens info. I think I may be getting too close to my subject to use a direct flash.

What is the best lens to use for portraits with a hotshoe flash gun.
 
I have the Sigma flashgun on my 350D, and I'll wager it's a flash sync problem. Set it in manual at 1/100 and see what happens

Steve
 
Derben said:
I'll try and recreate the problem, (shouldn't be difficult), and post some pics with lens info. I think I may be getting too close to my subject to use a direct flash.

What is the best lens to use for portraits with a hotshoe flash gun.
Click to expand...


Full length portrait or head & shoulders only? Then it depends on what you're trying to achieve too

In my wee studio I shoot mine with an 18-70mm, and will use it right throughout the whole range

However, if you're just after a 'nice' looking perspective in the old-school, a 50-100mm will do fine

DD
 
Derben said:
What is the best lens to use for portraits with a hotshoe flash gun.
Click to expand...

The one you've got. But if you're buying one a Zeiss or Nikkor 85/1.4 is hard to beat.

I don't understand the 'hotshoe flash gun' part, a lens is a lens, a flash is a flash.
 
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