 Charley Andrisano |
Wide-Angle Lens Vs. Built-In Flash I recently took a dozen or more flash pictures (with the built-in flash) indoors at an awards dinner - with my Canon-20-D and a Sigma 10-20MM digital f.4-5.6 lens. Just about every one came out dark. I set my camera's exposure to P, in full auto mode. There was pronounced distortion when I grouped 6 or 7 people in the shot. First, should I be using a mounted flash system to get more area, and distance, and is the Sigma lens a good choice for this project? Or should I be using a different lens? Your reply is much appreciated.
|
|
|
|
||
|
Michael H. Cothran |
Charley, First, and in my opinion, an extreme wide-angle lens such as this is not a good choice for people, unless you are in really, really tight quarters, or you purposely want to distort them. Instead, use a longer focal length lens, and back up a little. Flashwise, every flash has a certain angle of coverage. Built-in flashes will normally cover the angle of view of a 28mm lens at best. If you're using a 10-20mm zoom lens, your built-in flash simply cannot cover this much territory, especially at the wider end. You will need something stronger, and you may have to opt for multiple flash units in order to cover that much ground.
|
|
|
|
||
|
Jon Close |
Ditto the above, except that the built-in flash of the 20D will cover the angle of view of lenses as short as 17mm (28mm is the limit for the built-ins of most 35mm film SLRs). Still, it is not enough coverage for use with the Sigma 10-20 zoom. The 10-20 zoom is also physically large enough to block some of the light from the built-in flash, causing a shadow in the lower part of the photo.
|
|
|
|
||
|
Edward A. Tepper |
The reason you got pronounced distortion was a function of the focal length of the lens, especially at 10mm and not the fact that it's a Sigma. You would have had the same effect with the Canon EF-s 10-22. You might be able to fix that in Photoshop: filters, lens distortion (I'm not sure if that is available in PSE). Next time use a 50-100mm lens. The Canon EF 50 1.8 has a street price of about only US $80 and has excellent optics. It will also allow you to us a fast f-stop and shoot in lower light situations without a flash. The darkness might be due to the fact that the on camera flashes are weak. A separate flash system would help. In P mode the 20D assumes that the foreground will be lit solely by the flash. That could leave the background very dark. With a separate flash unit you could increase the flash power and use a bounce flash technique or a diffuser to get a better result. Even the 580EX will cover only up to 16mm but only if the built in diffuser is used.
|
|
|
|
||
|
Jon Close |
>> "Even the 580EX will cover only up to 16mm but only if the built in diffuser is used." << A slight correction, the 430EX and 580EX will cover lenses as wide as 14mm on a 35mm film and the full-frame 1Ds and 5D models. Used on the smaller sensor'd 10D/20D/30D and Digital Rebels, it is good with focal lengths as short as 9mm (104° horizontal angle of view in both cases).
|
|
|
|
||
|
This old forum is now archived. Use improved Forum here
Report this Thread |
||