Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Feb 21, 2009, 5:37 PM   #1
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

I checked the focus accuracy, was front focusing heavily. Did focus adjustment on K20D of -10 (max). Was pretty good but would need to go to -12 to be perfect.

Did test at 500mm, 500mm w/1.5X TC, 500mm w/1.7X TC. Both TC's auto focused with the Sigma. Used Tripod, 2 sec timer, F8(AP Priority), ISO200. Will show full frame and 100% Crop. jpegs straight out of K20D.

Ed

500mm Full Frame
Attached Images
 
snooked is offline   Reply With Quote
Sponsored Links
Old Feb 21, 2009, 5:38 PM   #2
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

500mm 100% Crop
Attached Images
 
snooked is offline   Reply With Quote
Old Feb 21, 2009, 5:39 PM   #3
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

500mm 1.5TC Full Frame
Attached Images
 
snooked is offline   Reply With Quote
Old Feb 21, 2009, 5:40 PM   #4
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

500mm 1.5TC 100% Crop
Attached Images
 
snooked is offline   Reply With Quote
Old Feb 21, 2009, 5:41 PM   #5
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

500mm 1.7X TC Full Frame
Attached Images
 
snooked is offline   Reply With Quote
Old Feb 21, 2009, 5:42 PM   #6
Senior Member
 
snooked's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 1,411
Default

500mm 1.7X TC 100% Crop

I will let you draw your own conclusions.

Ed
Attached Images
 
snooked is offline   Reply With Quote
Old Feb 21, 2009, 9:42 PM   #7
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,056
Default

Don't think I'd use it with the 1.7TC - significant drop in quality. Other two look very good!
mtngal is offline   Reply With Quote
Old Feb 21, 2009, 11:51 PM   #8
Member
 
Fl_Gulfer's Avatar
 
Join Date: Apr 2007
Posts: 57
Default

I use the Tamron 1.4 auto TC with mine, seems to work just fine.


Fl_Gulfer is offline   Reply With Quote
Old Feb 22, 2009, 8:01 AM   #9
Senior Member
 
kazuya's Avatar
 
Join Date: Sep 2008
Posts: 1,007
Default

i think id be reluctant to useany TC the crop with no TC is just so sharp, id want mine like that all the time
kazuya is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 1:45 AM.