Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-27-2011, 11:55 AM - 1 Like   #1
Loyal Site Supporter
bwDraco's Avatar

Join Date: Jul 2010
Location: New York
Photos: Albums
Posts: 1,015
K-r overall performance with AA battery holder

This thread is related to https://www.pentaxforums.com/forums/pentax-k-r-forum/168045-slower-autofocus-eneloops.html but is a more in-depth performance analysis of the K-r when running on AA batteries. I just got my AA battery holder D-BH109 today, and I started testing it with Duracell alkaline batteries. (Note that I don't have any Ni-MH batteries available to use on this camera, and I don't plan on using my lithium batteries yet.) All of the performance differences noted below are presumably due to the lower operating voltage of four AA batteries: 6 volts versus 7.4 volts with the Li-ion rechargeable battery.

As noted in the above thread, autofocus speed is slower, with the in-body AF motor running at about the speed of the K-x. Average end-to-end autofocus travel time on the DA L 55-300mm lens was 0.82 seconds on AA batteries compared to 0.70 seconds on the Li-ion battery, a 17% difference. Note, though, that while the in-body AF motor is slower, AF performance will still be better than on the K-x since the performance gains with SAFOX IX on the K-r relative to SAFOX VIII on the K-x are not lost. In live view, autofocus performance is slower by an extremely small margin and will not likely be significant for most users.

Continuous shooting speeds suffered similarly as well, dropping to a theoretical maximum* of 4.8 fps, compared to 6.1 fps on the Li-ion battery, a 27% difference. This is similar to the specified speed of 4.7 fps on the K-x. This appears to be due to slower overall mirror/shutter operation: shutter lag and viewfinder blackout time are both marginally increased and shutter recock is noticeably slower.

In both cases, operational speed is reduced to about that of the K-x, which I find interesting and likely to be more than a coincidence. However, action shooting performance will still be higher overall than the K-x because of the aforementioned AF system improvements.

--DragonLord

*The "theoretical maximum" speed is achieved with the camera in manual exposure mode, manual focus, continuous high drive mode, 1/6000s shutter speed, lens wide open, and ISO 200. It is not intended to be a representation of practical speeds, but indicates the absolute highest speed at which the camera can shoot.


Last edited by bwDraco; 12-27-2011 at 03:29 PM.
12-27-2011, 12:52 PM   #2
Veteran Member
kcobain1992's Avatar

Join Date: Dec 2010
Location: Bucharest, Romania
Photos: Gallery
Posts: 1,409
Just out of curiosity, does the camera still front-focus under tungsten light?
12-27-2011, 02:57 PM   #3
Loyal Site Supporter
bwDraco's Avatar

Join Date: Jul 2010
Location: New York
Photos: Albums
Posts: 1,015
Original Poster
QuoteOriginally posted by kcobain1992 Quote
Just out of curiosity, does the camera still front-focus under tungsten light?
The camera does exhibit slight, but tolerable, front focus under all lighting conditions at close focusing distances, but these are the situations you would prefer to use live view instead of the optical viewfinder. I have not tested for focus accuracy with the different battery types. However, as this is dependent on the AF sensor, which is an electronic component, it is unlikely to be affected by the battery type.

I've updated the original post to add more quantitative data.

--DragonLord
01-03-2012, 10:41 PM   #4
Loyal Site Supporter
bwDraco's Avatar

Join Date: Jul 2010
Location: New York
Photos: Albums
Posts: 1,015
Original Poster
I've posted a review of the AA battery holder. See Pentax D-BH109 AA battery holder for K-r reviews - Pentax Camera Accessories: Database and Reviews.

--DragonLord

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!
af, autofocus, batteries, battery, camera, fps, k-r, k-x, kr, li-ion, pentax k-r
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-r Battery Holder BH-109 Available @ Adorama Adam Pentax Price Watch 8 10-30-2012 06:40 AM
Can I store my batteries in the battery holder? LIJ Pentax K-r 5 02-07-2012 12:31 PM
New battery and holder info please robs Pentax K-r 6 06-12-2011 09:01 PM



All times are GMT -7. The time now is 01:39 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