85mm - 200mm for portraits?

[Kylersk]

I was reading Canons tips area on their HSOforum and noticed it said to use an 85mm-200mm lense for portraits. So, I tried it. Wow! I was really impressed. Yesterday, I tried to take a chrismas photo of my family. I wish I knew to try the Telephoto (75-300) lense instead of the 18-55mm lense.

Being the photo newbie that I am, I thought the Telephoto was used to reach out and grab far away shots, while the 18-55 was for closer shots. Guess I was wrong?

Now, my question is, what's the main advantage of the 18-55mm lense? Both are the Canon cheaper lenses.

[Steve Foss]

A wide angle lens is best when you NEED a wide angle, when you're in cramped quarters and have to get in a wide sweep of items, or if in a landscape shot you want the same thing from farther back.

The telephoto makes such a great portrait lens because its depth of focus is so much shallower than a wide angle lens. This renders the background blurry, focusing attention on the subject. When I'm on a wedding or informal portrait shoot, I almost always stand off and use the 100-400L IS for nice tight portraits. Lets you stay out of people's way, and it blurs that background nicely.

As an example, look at my avatar. That was shot by a client using a Canon 500mm f4L from 100 yards away. Notice the foreground, which is just a few feet in front of me, and the background are completely blurred, which puts the emphasis on the subject. If my client had shot that from up close with a wide-angle lens, all the vegetation around me would have been in focus and very distracting for a portrait.

So, the key is that wide-angle and telephoto lenses have inherently different depths of focus. If your 18-55 is at 18mm and f5.6, the depth of what's in focus can be measured in a few feet. The 500mm at f5.6 would have a depth of focus measured in bare inches.

The tradeoff here is that shooting portraits with a telephoto is great for single subjects or couples who are on the same focus plane, but if you're shooting a handful of people, some standing in front of or behind each other, it's hard to get everyone in focus with a powerful telephoto because of that shallow depth of focus.

Here are a couple examples from an imformal portrait shoot I did yesterday on Lake Vermilion. The first image was shot with the 17-40L at about 20mm and about f7.1. Notice all the elements surrounding the family that are in focus. But I needed the wide angle because there wasn't room to back up far enough for a telephoto and still get the image. Note for nitpickers : Glints in the glasses will be removed in photoshop after prints are ordered.

This one was shot with the 100-400L IS at 400mm and f7.1. Background is quite blurry, emphasizing the mom and daughter, and by making sure the background was a couple hundred yards away it made for a greater amount of blurring.

[Kylersk]

Thanks for the reply!

This photo may not be the greatest technically wise,... But I really like it.

This camera (Canon Digital XT) has sooo many features, I dont know If I'll ever get them figured out. =) For now, i'm mainly just trying the different auto modes it has.

[Steve Foss]

Looks nice to me. Very sweet catchlight in the girl's eyes, too. Any way you can knock it down to about 600 or 700 pixels across and re-post it? It's about twice as wide as my browser window, which makes me scroll back and forth and I can't see the whole image at once because it's so big.

Good work, though.

[Kylersk]

Thanks, I resized it..

[Steve Foss]

Thanks for the resize!

Have fun learning the ins and outs of the XT. Lots to learn there, and no doubt you've already found out how good a friend the owner's manual can be. I still only know about half to 2/3 of what my 20D can do, and most of the time I've got to consult the manual on how to do some things even after I remember the camera's capable of doing them.

[sparkyaber]

Steve, thanks for your above post explaining the lenses. That was very informative.