Olympus UK E-System User Group
Olympus UK E-System User Group

Join our unique resource for Olympus Four Thirds E-System DSLR and Pen and OM-D Micro Four Thirds photographers. Show your images via our free e-group photo gallery. Please read the e-group.uk.net forum terms and conditions before posting for the first time. Above all, welcome!


Go Back   Olympus UK E-System User Group > Cameras, lenses and system accessories > Camera conference

Camera conference General and model-specific E-System camera chat.

Reply
 
Thread Tools Display Modes
  #1  
Old 7th March 2008
emirpprime
Guest
 
Posts: n/a
E-420 Contrast AF on older lenses works... + 25mm full res shots

To quote another forum

"For those of you that don't read Spanish:

In the press release Olympus states that only Zuiko 14-42 mm f3.5-5.6, 40-150 mm f4-5.6 and the new 25 mm f2.8 can make use of the new contrast autofocus. Quesabesde made a test with the older 14-42 lens and the 14-54 lens. The contrast autofocus did work also with those lenses, although it is only possible to use three focus points and Facial Detection does not work. But focussing is performed correctly, without mirror slapping back and forth."

This is in reference to this link. It also includes what seem to be full res jpegs taken with the 25mm f2.8 (very impressive looking btw)


So this brings me to my question. Does anyone know a technical reason why contrast detect AF shouldn't work with any lens? Is it simply a case that the camera relies on a 'contrast profile' for each lens to fully function? I could imagine that they use this to make it faster, and with other lenses it is slower so they don't want to officially support for fear of disappointing. This perhaps makes it likely that Firmware updates to lenses will add these profiles and so expand the use. Or am I way off base? Any ideas?

All the best,
Phil


ps - have a look at the 25mm samples. It looks like CA is VERY well controlled. I don't own any of the kit lenses (except the 14-54) but this looks a cut above. Perhaps Tatsuno does have some meaning...
Reply With Quote
  #2  
Old 7th March 2008
ianc ianc is offline
Full member
 
Join Date: Nov 2007
Location: West Kilbride, Ayrshire
Posts: 241
Thanks: 0
Thanked 0 Times in 0 Posts
Likes: 0
Liked 0 Times in 0 Posts
Re: E-420 Contrast AF on older lenses works... + 25mm full res shots

The samples are impressive. It looks like this lens could be a goody especially with the smaller 400 series bodies.

Ian C.
Reply With Quote
  #3  
Old 7th March 2008
Ian's Avatar
Ian Ian is offline
Administrator
 
Join Date: Jul 2007
Location: Hemel Hempstead, Hertfordshire, UK
Posts: 11,411
Thanks: 415
Thanked 2,443 Times in 1,232 Posts
Likes: 829
Liked 1,652 Times in 739 Posts
Re: E-420 Contrast AF on older lenses works... + 25mm full res shots

I'm just finishing off a technical article for Four Thirds User on this subject.

The 25mm, 14-42 and the 40-150 f/4-5.6 are all contrast AF mode compatible but the latter two already out in the wild require a firmware update.

The interesting news is that Olympus Japan confirmed to me that the contrast detect AF system should be compatible with Panasonic's system as demonstrated in the DMC-L10 DSLR. So contrast AF in live view should be possible with the Leica 14-50 f/3.5-5.6 and the 14-150.

Ian
__________________
Founder and editor of:
Olympus UK E-System User Group (http://e-group.uk.net)
Four Thirds User (http://fourthirds-user.com)
Digital Photography Now (http://dpnow.com)
Olympus camera, lens, and accessory hire (http://e-group.uk.net/hire)

Twitter: www.twitter.com/ian_burley
Flickr: www.flickr.com/photos/dpnow/
Pinterest: www.pinterest.com/ianburley/
NEW: My personal BLOG ianburley.com
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Any experience of OM lenses on DSLRs? Sam M Lens focus 27 16th July 2008 08:37 PM
Deciding 'When' and 'How' to go part-time / full-time theMusicMan The lounge 6 9th April 2008 08:40 PM
New Oly 25mm Pancake 'Standard' ndl0071 Standard zoom and mid range 8 7th March 2008 08:40 PM
New E-420 DSLR and 'pancake' 25mm f/2.8 Digital Zuiko announced Ian Announcements 28 5th March 2008 06:56 PM
Editorial on the new E-420 and 25mm pancake lens Ian Announcements 0 5th March 2008 07:36 AM


All times are GMT. The time now is 03:22 PM.


The Write Technology Ltd, 2007-2019, All rights reservedAd Management plugin by RedTyger