Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-13-2007, 09:49 PM   #1
Veteran Member
Hannican's Avatar

Join Date: Oct 2007
Location: Irvine, CA
Photos: Gallery
Posts: 476
Are all DA lenses built for small sensor?

In otherwords...

If we all buy DA lenses, and Pentax puts out a full-frame camera, will we all need to buy the NEW full-frame DA (whatever they'll be called) lenses, or be SOL?

Just wondering...

-Tim

12-13-2007, 11:39 PM   #2
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 9,144
QuoteOriginally posted by Hannican Quote
In otherwords...

If we all buy DA lenses, and Pentax puts out a full-frame camera, will we all need to buy the NEW full-frame DA (whatever they'll be called) lenses, or be SOL?

Just wondering...

-Tim
Actually, Pentax built the full frame lenses first. They are called FA or D-FA lenses.
12-14-2007, 12:13 AM   #3
Veteran Member
Hannican's Avatar

Join Date: Oct 2007
Location: Irvine, CA
Photos: Gallery
Posts: 476
Original Poster
DFA I was wondering if those were full frame supportive...

But still, if we buy DAs and then want to move to full frame... will DAs work?

-Tim
12-14-2007, 12:17 AM   #4
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 9,144
QuoteOriginally posted by Hannican Quote
DFA I was wondering if those were full frame supportive...

But still, if we buy DAs and then want to move to full frame... will DAs work?

-Tim
The lenses will work, but they will not cover the full frame. They will vignette. Some don't vignette at the longest focal lengths, but all will vignette at the wider focal lengths (zooms). I suspect that the primes will all vignette. The circle produced behind the lens is not large enough to cover the 24x36 mm frame. It is designed to cover the roughly 12x13 frame of the sensor. This allows the lens to be quite a bit lighter than the full frame lens of the same focal length and speed.

Edit: Oops, that sensor size is obviously incorrect - try "about 16 X 24"


Last edited by Canada_Rockies; 12-14-2007 at 12:22 AM. Reason: Dumb sensor size
12-14-2007, 12:18 AM   #5
Veteran Member
Hannican's Avatar

Join Date: Oct 2007
Location: Irvine, CA
Photos: Gallery
Posts: 476
Original Poster
I see...

Thank you for the information!

I'm not sure how it will affect my purchasing decisions, if at all, but I feel better knowing this.

Thanks again Albert

-Tim
12-14-2007, 05:30 AM   #6
Veteran Member
Finn's Avatar

Join Date: Feb 2007
Location: Phoenix
Photos: Gallery
Posts: 1,056
Actually, the DA40 WILL work with a 35mm-sized sensor because it is the same design as the old M 40mm.
12-14-2007, 05:51 AM   #7
Forum Member




Join Date: Nov 2007
Location: Denbigh, Wales
Posts: 63
The one obvious difference between D-FA and DA is that the D-FA has an aperture ring...
12-14-2007, 06:01 AM   #8
Site Supporter




Join Date: Nov 2006
Posts: 187
Perhaps when Pentax releases a FF camera a APS-C mode will be provided as an option to allow use of the DA lenses without vignetting.

12-14-2007, 07:29 AM   #9
Veteran Member
kb244's Avatar

Join Date: Dec 2007
Posts: 318
QuoteOriginally posted by Finn Quote
Actually, the DA40 WILL work with a 35mm-sized sensor because it is the same design as the old M 40mm.
I wondered about that, its probably the same optical construction in terms of what glass goes where. But clearly the DA40 is worlds sharper than the old M40. But I can confirm that the DA40 works on a film body. However it needs to be a film body that has electronic contacts (Kaf) and the camera must be able to allow you to manually input an aperture from the camera itself, as you don't have an aperture ring. It seems plenty of the electronic film cameras cut cost on the body by pretty much assuming it would be redundant to offer any other means to control a lens aside from the aperture ring. As such it seems the PZ series and newer (the SF-1 wouldn't work and some others I tried) will work with the DA40 without worry that it'll always stop down to f/22 whenever you fire a shot.

The other lens definitely will vignette, tried a 16-45, you could clearly see the fall off at 16 to 20, though not as noticeable in the viewfinder at around 21-22. It is at least however a softer falloff than say other brands of lens designed for digital, such as the Tamron Di-II, or the Canon EF-s which will have a much sharper circle outline at any focal length, since the back element is cut to size as well. Being designed for digital also means that even if you start reducing the vignetting, the edge sharpness and quality might suffer greatly as they had no reason to design it for crisp edge to edge on the whole surface of the glass.

But looking at the lens line up, I can't imagine a full frame variation is in the market any time soon for pentax, but for the film lovers theres always the FA and older mounts, at least they're the only company that makes DSLR with the best backward compatibility across all of its models. Myself if I got another DA lens it would be strictly for the digital, otherwise I'll concentrate on FA lens as I do plan on getting a better film body.
12-14-2007, 07:32 AM   #10
Veteran Member
kb244's Avatar

Join Date: Dec 2007
Posts: 318
QuoteOriginally posted by baldeagle21b Quote
Perhaps when Pentax releases a FF camera a APS-C mode will be provided as an option to allow use of the DA lenses without vignetting.
Very doubtful, even if they did release a full frame camera, the DA lens problem is a physical limitation as it was only designed to cover the APS area. IF pentax releases a full frame camera, they'll probably do so in the same manner that Nikon did releasing new lens designations (kinda like FA, but maybe call it FA2 or FX who knows) for both format.

But least with the Nikon full frame camera, it'll auto-crop the sensor (lower megapixels obviously) for the DX lens coverage, which not even the Canon full frame bodies do (course most of their EF-s lens also protrude back into the camera body making it difficult to make it fit into a full frame body). Perhaps pentax might follow the same route, and you would just have to use a full frame lens to utilize all the pixels on the camera sensor.
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!
buy, da, da lenses, full-frame, k-mount, lenses, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
small cameras, big lenses gazonk Pentax News and Rumors 62 08-24-2010 01:08 PM
Best way to carry multiple small lenses for quick reach. pcarfan Pentax Camera and Field Accessories 44 07-18-2010 04:13 AM
DA* lenses are they built to last ? ABCWinter Pentax SLR Lens Discussion 45 05-12-2009 02:06 AM
macro shooting with small focal length lenses pete_pf Pentax SLR Lens Discussion 16 11-04-2008 04:35 AM
Built-In Flash + Old Lenses k100d Pentax DSLR Discussion 18 04-06-2008 04:39 PM



All times are GMT -7. The time now is 01:59 AM. | See also: NikonForums.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