Parfocal, EOS40D and Lenses at DVinfo.net

Go Back   DV Info Net > And Now, For Something Completely Different... > Still Crazy

Still Crazy
You say you want resolution? The whole world is watching these digicams.


Reply
 
Thread Tools Search this Thread
Old August 20th, 2008, 09:50 AM   #1
Major Player
 
Join Date: Aug 2003
Location: Los Angeles, CA
Posts: 254
Parfocal, EOS40D and Lenses

Hey guys,

I'm back again with some questions. I've come across some more issues at work with our Canon 40D camera . OUr lens, Ultrasonic 28-135mm has a VERY soft focus to it. We're shooting at full wide and the edges of certain portions of the products come out blurred.

Also, the fact that this lens is not parfocal makes it difficult to focus the larger items.

My questions is, is it normal for this lens to have a soft focus to it? Or am I going to need to send it in to Canon for repair?

We're also looking into buying a better lens for the camera and parfocal feature is a definite must. Which is a good lens that takes very sharp images? I can probably deal with it if it's not parfocal, I would just really perfer it. I noticed Tamron lenses are really good. We used a fellow co-workers tamron film lens with the 40D amd took superior photos.

I tried attaching a full res. image but the resolution is way too big. 3888 x 2592

Any thoughts or ideas?
__________________
-Roger Rosales
www.rogerrosales.com
Roger Rosales is offline   Reply With Quote
Old August 20th, 2008, 02:52 PM   #2
Major Player
 
Join Date: Jan 2007
Location: Portland, OR
Posts: 949
Quote:
Originally Posted by Roger Rosales View Post
We're shooting at full wide and the edges of certain portions of the products come out blurred.
Are you sure that the edges are within the depth of field?

Quote:
Originally Posted by Roger Rosales View Post
My questions is, is it normal for this lens to have a soft focus to it?
It depends on your standards. Look at this 28mm f/4 comparison with the much more expensive EF 24-105 f/4 L (mouse over to compare).


Quote:
Originally Posted by Roger Rosales View Post
Which is a good lens that takes very sharp images?
Canon EF-S 17-55 f/2.8 IS. The cheaper Tamron 17-50 f/2.8 and Sigma 18-50 f/2.8 also have excellent resolution (MTF).
Daniel Browning is offline   Reply With Quote
Old August 21st, 2008, 09:14 AM   #3
Major Player
 
Join Date: Jan 2008
Location: Utrecht, NL | Europe 3rd Rock from the Sun
Posts: 612
If you're using autofocus you could also be experiencing a problem with backfocus. Esp. when you're using longer focal lengths. Try if you can focus better manually.

The D300 lets me input offsets for backfocus adjustments for lenses, but I don't think the D40 can accommodate those.

George/
George Kroonder is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > And Now, For Something Completely Different... > Still Crazy

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 03:56 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network