Hi,

Been reading up on using the pop-up flash on my Elan 7E for slight fill-in's when required. Being a fairly recent entrant to the art of photography, I'm one of those people for whom the Elan II flash FAQ was designed. But even after reading the FAQ, I have the following question left unanswered:

Does the handholding-rule-of-thumb (you can handhold a lense at shutter speeds of bigger than 1/focal length) hold for flash photography? More specifically, if my pop-up flash synch's up to 125ms, I am shooting a macro photo at 300mm and I want to use the pop-up flash to eliminate some nasty shadows (yes I know it is better to use a dedicated off-the-camera-flashgun, but bear with me), will I need to put the camera on a tripod at this focal length, or can I shoot out of the hand?

Thanks Jaco

-- Jaco van Tonder (longbow@mweb.co.za), December 11, 2001

Answers

Jaco, a few comments. First the flash duration is very short, typical 1/1000-th of a second or less. If you use the flash as a main source of light the flash will freeze the motion of the subject. You may dial in a longer exposure time to use the natural light for the background. Some unsharpness caused by camera shake may be acceptable, the background may be unsharp already if it is out of focus.

When you use fill-in flash the rule of thumb still applies. If you choose a longer exposure time your main object will be blurred by camera shake whereas the shadows will be sharp because here the short flash duration applies.

Please keep in mind that longer lenses will block part of the light from the pop-up flash, if not all. Perhaps it is easier to use some sort of reflector to fill in the shadows, but in that case you need a tripod anyway because you can't handle the camera and the reflector at the same time.

Just my thoughts on the subject,

-- Jos van Eekelen (jos@compuserve.com), December 11, 2001.

Thanks Jos

Any tips on when I should start getting worried about the lense blocking out the pop-up flash? Obviously it will be worse the closer the subject is to the lense. I have two zooms atm: The canon 28-105mm and the Canon 100-300mm. Can anybody give me a pointer as the focal length and subject distance combinations that would cause me trouble?

Thanks Jaco

-- Jaco van Tonder (longbow@mweb.co.za), December 11, 2001.

I have seen the 28-135 IS lens block the light of the pop-up flash a couple of times, but I can't remember the exact settings. It probably occurred at or near the 135 mm setting, at close distance. There was a thread on this matter on one of the internet forums some time ago, I don't remember the details but it all came down to mounting the camera on a tripod and drawing an imaginary line between the lower side of the flash, over the top of the lens to the floor and then looking through the viewfinder at which setting of the lens the place on the floor becomes visible. Assuming that the length of the lens doesn't change. This may take some experimenting and I don't know where and how the aperture setting of the lens fits into this equation. The above should at least get you started. Perhaps other forum members have additional advise about this.

-- Jos van Eekelen (jos@compuserve.com), December 11, 2001.