Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-18-2015, 11:05 AM - 1 Like   #1
Veteran Member
kindakaa's Avatar

Join Date: Aug 2010
Location: Tatarstan, Russia
Photos: Gallery | Albums
Posts: 307
Pentax 31mm with Sony A7 vs Sony RX1

The weekend tested Sony A7 + Pentax 31mm F1.8 Limited and Sony RX1 (Zeiss 35mm F2.0 lens)
This is not a full test and comparison of lenses, and simply amateur images.
Just did two shots: first RX1, then A7.
At the same ISO and aperture. All shots on ISO=100. Click image to view full size.

Summary:
Pentax is no worse than new Zeiss lens.

f=13


f=13


f=11


f=5.6


f=2.8


f=5.6


f=5.6


f=4


f=4


f=11


f=2


f=5.6


f=11


f=8


f=8


f=2.8


f=11


f=2.8


f=11


f=2


f=5.6


f=8


05-18-2015, 11:21 AM   #2
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 37,882
Interesting... thanks for posting. That would be an amazing PowWow grounds.
05-18-2015, 03:26 PM   #3
Pentaxian
Driline's Avatar

Join Date: Dec 2012
Location: IOWA Where the Tall Corn Grows
Photos: Gallery
Posts: 3,086
Did you make your daughter climb all those stairs? LOL

I like the A7 and FA 31 shots better. More contrasty and the highlights don't seem to be as blown out as the RX.
05-18-2015, 03:37 PM   #4
Site Supporter
Site Supporter
RobA_Oz's Avatar

Join Date: Nov 2008
Location: Tasmania, Australia
Photos: Gallery
Posts: 6,942
Very interesting, thanks. You'd be tempted to say that the FA31 has better micro-contrast, by looking at the clouds, but I'd be cautious about making a definite judgment about that, unless the same body was used for both. I'm assuming the two sensors in the A7 and RX1 were similar, if not identical, and the in-camera processing would be similar, but there's bound to be small differences there.

Thanks for taking the trouble to compare and post these.

05-18-2015, 05:53 PM   #5
Veteran Member




Join Date: Dec 2013
Location: New Jersey
Posts: 930
Thanks for this post. It seems that at F2 FA 31 is sharper and more contrasting a little bit..

Last edited by starjedi; 05-18-2015 at 07:51 PM.
05-18-2015, 10:42 PM   #6
Veteran Member
kindakaa's Avatar

Join Date: Aug 2010
Location: Tatarstan, Russia
Photos: Gallery | Albums
Posts: 307
Original Poster
QuoteOriginally posted by Driline Quote
Did you make your daughter climb all those stairs?
Certenly. She went very quickly. But I had to rest 10 times before you reach the end of the stairs :-)

Before compare, I thought that the results of the Sony RX1 with a new lens will much better than 31 lim. But in the end I was very surprised that the old lens has given very good results.
I think for future FF Pentax camera 31 lim would be an excellent choice.
05-19-2015, 12:37 AM   #7
Pentaxian




Join Date: Oct 2013
Posts: 1,199
QuoteOriginally posted by kindakaa Quote
The weekend tested Sony A7 + Pentax 31mm F1.8 Limited and Sony RX1 (Zeiss 35mm F2.0 lens)
This is not a full test and comparison of lenses, and simply amateur images.
Just did two shots: first RX1, then A7.
At the same ISO and aperture. All shots on ISO=100. Click image to view full size.

Summary:
Pentax is no worse than new Zeiss lens.

f=13


f=13


f=11


f=5.6


f=2.8


f=5.6


f=5.6


f=4


f=4


f=11


f=2


f=5.6


f=11


f=8


f=8


f=2.8


f=11


f=2.8


f=11


f=2


f=5.6


f=8
Thanks for the post. Very interesting real life comparison. It seems to be a dead even match. To my eyes, the 31 has more contrast. The other obvious difference is the warmer colors of the 31. The greens have a more yellowish tint to them.

This comparison reminds me of a wedding I shot back in 2000. Those were the last of my film days. I shot with Nikons and my friend who was the second camera shot with Canons. When I got the proofs back, I noticed the same color difference in the the two systems. Nikon had the warmer colors and the Canon had the cooler colors. I never thought about color difference upto that point. With Photoshop and RAW processing, it is easier to match color theses days but with film it was a lot harder.

05-19-2015, 02:00 AM   #8
Veteran Member
redcat's Avatar

Join Date: Jul 2014
Location: Paris
Photos: Gallery
Posts: 1,931
thanks for sharing, the difference is minor and on a Pentax, the FA31 is unbeatable
05-19-2015, 03:42 AM   #9
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 9,866
I see no reason to regret my choices.
05-19-2015, 03:43 PM   #10
Pentaxian




Join Date: Oct 2009
Location: North
Photos: Gallery
Posts: 4,481
Interesting and thanks to the shootout.

I read a long discussion on FM forums where it came down to FA31ltd being one of the better choices as a 35mm replacement to the RX1 (on A7).
It was more focused on the technical aspects of the likely 35mm lenses though.

What you have done here is certainly interesting.
In real World use and pictures, the 31ltd seems better for those shallower DOF shots to me. (despite all that discussion on technical qualities)
But thats what Pentax said when they designed the Limiteds as well. (that they slightly disregard numerical values for a more 'descriptive' rendition of real world objects)
05-19-2015, 04:55 PM   #11
Site Supporter
Site Supporter
RobA_Oz's Avatar

Join Date: Nov 2008
Location: Tasmania, Australia
Photos: Gallery
Posts: 6,942
QuoteOriginally posted by Sandy Hancock Quote
I see no reason to regret my choices.
"Je ne regrette rien" perhaps?

Neither do I, and what this comparison does show is that a 14 year-old Pentax interchangeable-mount film-era lens design can perfectly well hold its own against a modern fixed-mount digital Zeiss lens design.
05-21-2015, 10:48 AM   #12
Veteran Member




Join Date: Dec 2010
Location: SoCal
Photos: Gallery | Albums
Posts: 518
The boken on the Zeiss at F2 looked a little more pleasing than the 31mm.
Other than that..
08-07-2015, 08:33 AM   #13
Senior Member
richmondthefish's Avatar

Join Date: Jul 2013
Posts: 218
Cool comparison. I'll have to revisit these images on my retina iMac at home but on this HP display at work I'm generally liking the output of the FA31 a little more but they are close. FA31 seems a little cleaner though not sure if I would actually favor that look on all the photos. I'd say the portrait might favor the RX1 but that also has a tiny bit advantage in focal length.

Sony A7 bodies are cheap now so maybe a consideration for me to find a full frame use for my FA77
08-07-2015, 11:01 AM   #14
Loyal Site Supporter
Loyal Site Supporter




Join Date: Mar 2015
Photos: Gallery | Albums
Posts: 6,378
Nice shots. The FA 31 is definitely in my future.

How do the Sony body and the Pentax lens interface? I assume, given the mirrorless nature, that some sort of glassless adapter could be used, but what about stop-down and data contacts? Or are we in the same sort of situation as with Takumars on Pentax DSLRs, with the lens being manually stopped down and metering in aperture priority mode?
08-07-2015, 11:14 AM   #15
Loyal Site Supporter
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 15,023
QuoteOriginally posted by pathdoc Quote
Or are we in the same sort of situation as with Takumars on Pentax DSLRs, with the lens being manually stopped down and metering in aperture priority mode?
Correct.
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!
31mm with sony, 35mm, a7, a7 vs sony, ff, focus, k-mount, lens, pentax, pentax lens, rx1, shots, slr lens, sony, zeiss
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sony A7 with Pentax Lenses: A Review Adam Non-Pentax Cameras: Canon, Nikon, etc. 35 10-14-2016 05:35 PM
Sony a7 vs current Pentax APS-C cameras stillshot2 Non-Pentax Cameras: Canon, Nikon, etc. 35 07-28-2015 11:44 AM
Pentax FA 31mm limited on Sony A7 Eisenheim Non-Pentax Cameras: Canon, Nikon, etc. 7 12-11-2014 08:57 PM
DSLRmagazine: Sony A7r vs Nikon D800 and A7 vs Leica M test. Sony is the best! Clavius Non-Pentax Cameras: Canon, Nikon, etc. 3 01-14-2014 10:25 AM
Pentax K-3 vs Sony A7 in one picture Uluru Photographic Industry and Professionals 10 10-17-2013 09:52 PM



All times are GMT -7. The time now is 08:52 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