Super Wide Zooms...Anybody got one?

[Phil Magistro]

Biggie,  I don't use Canon so I'm not sure about which settings you have available, but you should be able to focus on a point and recompose while not losing that focus.  On Nikon's there's a selector where you can choose "S" (Single) or "C" (Continuous) where "S" lets you push and hold the shutter half-way and recompose the photograph, then complete pressing the shutter to take the photo.  There's also a buttton that you can press that will hold the focus (Focus Lock) while you recompose and shoot. Finally there's the ability to change the focus point in the viewfinder to one of eleven areas (some cameras have seven or nine).  I also use a cheat sheet of distances, find something that I think is close to the right distance and focus on it either using the focus lock button or by adjusting the focus area in the viewfinder.

Phil

[RainCrow]

Biggee:  

 Can I get focus to infinity on auto mode?

Weasel:  

...the longer the lens, the shallower the depth of field.
 

DOF (Depth of Focus) is mainly a function of the aperture opening, however Weasel is correct, too.  

To answer Biggee:  Probably not.  Auto mode typically settles on a middle shutter speed, and aperture which gives you an "Average" DOF.  Switch to Aperture Priority mode (the camera will set the shutter speed) and set the smallest aperture possible.  

Now, aperture settings are non-intuative, i.e.  5.0 or 22.  Which one is a smaller aperture opening?  22 (of course).  Here's how I remembered:

Shallow(Small) DOF - Large opening,
Wide(Large) DOF - Small opening

Take the aperture number and make it into a fraction by  putting it under 1/x  , i.e. 1/5 or 1/22.  Now compare the numbers.  Which one is smaller?  Right! 1/22, so a setting of 22 for the aperture gives a wider DOF than a setting of 5.0

Terry

[Phil Magistro]

Biggie,  I missed where you mentioned "Auto Mode".  I guess you mean "Program" because, as far as I know, the 10D doesn't have an "Auto" setting.  If you want to get the maximum aperture by using depth of field you have a number of choices.  You can use the "Landscape" exposure mode on your camera and the camera will preselect the smallest aperture (largest depth of field).  Or you can use "Av" exposure mode and close down the lens to f11 or f16 (depending on the available light).  Or you can use the hyperfocal distance at any f-stop.  The hyperfocal distance will vary by the length of the lens and the f-stop selected.  Here is a link to a chart showing hyperfocal distances.

 http://www.dmcphoto.com/Articles/DOF2/index.html

I believe Canon is a 1.6 crop factor.  If so, use the first chart.

Phil

[mattfromuk]

Sigma don't "copy" lenses, they just reverse engineer the base mounts. Canon, for one, will not release tech on their lenses to that degree! I only use sigma on my pro shoots, most of my lenses are also 2nd hand, so less than 1/2 the price of the canon/nikon version, but easily the same quality. All you need is a large memory card and use the raw setting. My only main tip would be to look at Apple comps if you want to take serious photos! I take my 12" with me every where, edit, check, and send for printing whilst having a coffee somewhere! All my software came with my laptop!

Just my 2 cents!  :-)

[Biggie Hoffman]

Thanks guys! Lots to read and experiment with.
It's too hot to go outside and shoot anyway...............