Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-22-2009, 05:02 PM   #1
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Sigma 105mm sharpness wide open

at F/2.8



AND A 100% CROP




this is about as informal as it gets..... I was just relaxing in the cool weather of the afternoon with my camera in hand. I thought to myself, "this lens seems ULTRA sharp.... I wonder how it will do wide open" so I tried it. This was just a quicky handheld at F2.8 exposed so the background wouldn't be blown out (thats why its a little dark).

these are straight out of the camera minus resizing. My K200d was used.

(manual focus btw)


Last edited by yeatzee; 07-22-2009 at 05:08 PM.
07-22-2009, 05:21 PM   #2
Veteran Member




Join Date: Apr 2008
Location: Minnesota
Photos: Gallery
Posts: 1,530
I have the non-DG version of this lens and I will concur with your unscientific findings. I love this lens. I had both the 50 and 105 at one point but traded the 50 for a FA50 1.4 and my kit was complete. I spent a good amount of time with this lens mounted on my camera when I was at the zoo a couple days ago.
07-23-2009, 02:47 AM   #3
axl
Veteran Member




Join Date: Mar 2007
Location: Nove Zamky, Slovakia
Photos: Gallery | Albums
Posts: 7,181
I have the DG EX version, and I have to say that your findings are 100% correct. I love the lens straight from 2.8. If only the AF was tad faster and quieter...

BR
07-23-2009, 01:22 PM   #4
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Original Poster
Yeah, though even if it did have a faster AF I would still never use it. Im an all manual kind of guy

07-23-2009, 02:29 PM   #5
Veteran Member




Join Date: Apr 2008
Location: Minnesota
Photos: Gallery
Posts: 1,530
It's a Macro lens... AF isn't supposed to be fast... the focus throw is ginormous!
07-23-2009, 03:10 PM   #6
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Original Poster
Anyone expected lightning AF from a macro lens is seriously ill-informed.
07-23-2009, 04:00 PM   #7
axl
Veteran Member




Join Date: Mar 2007
Location: Nove Zamky, Slovakia
Photos: Gallery | Albums
Posts: 7,181
QuoteOriginally posted by MrApollinax Quote
It's a Macro lens... AF isn't supposed to be fast... the focus throw is ginormous!
QuoteOriginally posted by yeatzee Quote
Anyone expected lightning AF from a macro lens is seriously ill-informed.
I know this all too well, but until recenlty it was my only fast lens after 50....
BR
07-24-2009, 11:33 AM   #8
Veteran Member
Miserere's Avatar

Join Date: Sep 2007
Location: Boston
Photos: Gallery
Posts: 1,994
yeatzee, either the top shot isn't the full frame you photographed, or your second shot isn't a 100% crop. Which is it?

07-24-2009, 11:45 AM   #9
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Original Poster
the top is slightly cropped because of people in the picture....but not by much??
07-24-2009, 01:50 PM   #10
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Original Poster
I dont see how its not a 100% crop though? I zoomed in to 100%/ 1:1 and cropped what filled the picture window. it looks the same as when I zoom in to 1:1/ 100% meaning it should be a 100% crop ???
07-24-2009, 01:54 PM   #11
Veteran Member




Join Date: Apr 2008
Location: Minnesota
Photos: Gallery
Posts: 1,530
The comment was that either the first shot was cropped OR the second one isn't a 100% crop. Since you said the first is true then that is what happened. Likely the comment meant with the first frame being the size it is the 100% crop of that frame would have led to a much larger exploded view of the flowers.
07-24-2009, 02:08 PM   #12
Veteran Member
Miserere's Avatar

Join Date: Sep 2007
Location: Boston
Photos: Gallery
Posts: 1,994
QuoteOriginally posted by MrApollinax Quote
The comment was that either the first shot was cropped OR the second one isn't a 100% crop. Since you said the first is true then that is what happened. Likely the comment meant with the first frame being the size it is the 100% crop of that frame would have led to a much larger exploded view of the flowers.
Yes, exactly.

From the top image, and the 100% crop below, I calculated the size of the top photo to be about 1590 pixels wide. As the size of a K200D file is 3872 x 2592 pixels, then the top photo has been cropped 40%, which is sizeable.

Not a big deal, I was just trying to figure out why the 100% crop FoV was so large.
07-24-2009, 03:48 PM   #13
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Original Poster
ha, alright
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sigma 30mm F1.4 reflections - happen on all F1.4 lenses wide open? Muggins Pentax SLR Lens Discussion 14 11-13-2009 11:43 AM
For Sale - Sold: Sigma AF 28-105mm f/2.8-4 fast wide-angle zoom, ships worldwide! wallyb Sold Items 17 10-22-2009 07:26 PM
77/1.8 wide open... igor Post Your Photos! 14 08-17-2009 05:36 AM
Sigma Zoom Wide Angle-Telephoto 28-105mm f/2.8-4 Aspherical IF Autofocus Lens for Pen jon pafford Pentax SLR Lens Discussion 0 10-12-2008 01:19 PM
Which 50/1.4 is best wide open? Big I Pentax SLR Lens Discussion 5 08-05-2008 09:23 AM



All times are GMT -7. The time now is 03:27 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top