Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-10-2012, 01:20 AM   #1
Veteran Member
FruitLooPs's Avatar

Join Date: Dec 2007
Location: New Zealand
Photos: Gallery | Albums
Posts: 434
K-30 Tungsten vs CFL Test

I see people are asking about this, or at least Tungsten light tests.

I hope someone with a faster accurate lens can try out some more tests, mine is only with the 18-55mm @ 5.6 and 55mm AWB & JPG. My 17-50 F2.8 is far too out of whack to be used for such a test haha.







I don't know anything about the K-5 issues, or how serious they were etc. I leave these results entirely up to your interpretation It's dark out so no natural light comparison.

The focus chart is a pretty flimsy bit of printer paper, so some user error could have occured YMMV sue me etc

07-10-2012, 01:44 AM   #2
Veteran Member




Join Date: Nov 2006
Location: Brighton, United Kingdom
Photos: Gallery
Posts: 311
If you ping me the sheet I can try to test it under these lighting conditions as well. But with the Tamron and the 18-135mm lenses.

I take it we are looking for a focus "miss" on the latter shot?
07-10-2012, 02:14 AM   #3
Pentaxian
Raffwal's Avatar

Join Date: Oct 2010
Location: 6457' North
Posts: 806
The focusing chart in question is probably by Yvon Bourque:

PENTAX DSLRs: Front or Back Focusing Problems? Free test (Lens Alignment) charts for Pentax, Nikon, Canon, Sony, Olympus.
07-10-2012, 02:25 AM   #4
Veteran Member
FruitLooPs's Avatar

Join Date: Dec 2007
Location: New Zealand
Photos: Gallery | Albums
Posts: 434
Original Poster
Yes those charts, direct link for them is here: http://www.k10dbook.com/newchart.pdf

If you have a more sturdy paper it would be a help. I've only had the K20D prior to this, but I hear lots of chatter about the K5/Kx front focusing in tungsten lighting that was making people wild - just how much i'm not sure.

I only have one true tungsten light left (my porch, hence the brick pattern background for tungsten lol) and its literally freezing out so no more testing from me tonight! All my others are energysavers.

I must say though, I would be surprised if this glitch still occurred after the re-working of AF detect in the camera.


Last edited by FruitLooPs; 07-10-2012 at 02:33 AM.
07-10-2012, 04:41 AM   #5
Veteran Member




Join Date: Nov 2006
Location: Brighton, United Kingdom
Photos: Gallery
Posts: 311
I'm going to have to find a tungsten bulb. Could be challenging, they're stopping producing them in the EU!

I suppose that is one way of solving the tungsten issue!
07-10-2012, 04:45 AM   #6
Veteran Member




Join Date: Jun 2009
Location: Chicago Suburbs.
Photos: Gallery
Posts: 450
thanks for the link

Nice chart to test with, thanks.
07-10-2012, 05:33 AM   #7
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Thanks to each of you guys!
07-10-2012, 11:28 AM   #8
Veteran Member




Join Date: Mar 2007
Location: U.K.
Posts: 685
Was this done using a tripod or something solid as a camera base? With hand-held it's so easy to move a bit after getting a focus lock. They look quite close to dead right viewed full size.

07-10-2012, 11:54 AM - 1 Like   #9
Senior Member




Join Date: Feb 2011
Location: Chicago, IL
Photos: Gallery
Posts: 168
Can someone summarize what the results are? Every time I look at people shooting charts and brick walls, my eyes cross and my brain shuts off.
07-10-2012, 12:44 PM   #10
Site Supporter
Deimos's Avatar

Join Date: Oct 2010
Location: Kingdom of Wonder
Posts: 1,707
QuoteOriginally posted by chiane Quote
Can someone summarize what the results are? Every time I look at people shooting charts and brick walls, my eyes cross and my brain shuts off.
looks like there is still some front focusing, but not to the point where you would likely miss focus (with that lens), need to see it with a f1.4-2.0 really as thats where you are going to have issues but nice test
07-10-2012, 01:48 PM   #11
Veteran Member
FruitLooPs's Avatar

Join Date: Dec 2007
Location: New Zealand
Photos: Gallery | Albums
Posts: 434
Original Poster
QuoteOriginally posted by SteveB Quote
Was this done using a tripod or something solid as a camera base? With hand-held it's so easy to move a bit after getting a focus lock. They look quite close to dead right viewed full size.
1st is tripod indoors, second on a stack of books. Shouldn't be any movement.

This lens also has quite a bit of correction adjustment applied to it (-7) so I too would like to see another lens tested like F2.8 The chart is flimsy though, so if the front section is bowed slightly outward in one and inward in the other that could influence results etc. Not ideal, but better than nothing - like I said i'm not sure if the K5 was out by like 20cm in low tungsten light or not, if it is then you can probably safely say this isn't an issue.
07-10-2012, 03:21 PM   #12
Veteran Member




Join Date: Nov 2006
Location: Brighton, United Kingdom
Photos: Gallery
Posts: 311
Hi Guys,

Sorry this is on my todo list but had to work late. Will try to get to it tomorrow.
07-10-2012, 04:20 PM   #13
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by Pheo Quote
Hi Guys,

Sorry this is on my todo list but had to work late. Will try to get to it tomorrow.
What!? Work before doing our bidding! What is this world coming to!>!
07-10-2012, 11:15 PM   #14
Pentaxian




Join Date: Sep 2007
Location: Boston, MA
Posts: 7,411
Hey guys.

I've only had a K-30 in my possession for a few hours now, but I've taken a few BS SOOC JPEG shots in very dim light here in my office area this evening. The room is currently lit by 2 CFL bulbs under shades (don't actually have any tungsten in my house). Both with the FA 43 Limited wide open (f/1.9):


ISO 3200, 1/20sec (click for full size)


ISO 3200, 1/50sec (click for full size)

Less useful than a focusing chart, but the accuracy looks superb to my eye. Very pleased over here. Didn't take long to focus, either.
07-10-2012, 11:17 PM   #15
Pentaxian




Join Date: Sep 2007
Location: Boston, MA
Posts: 7,411
And just for kicks, here's one in natural light earlier today:


f/2.2, ISO 100, 1/2000sec
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!
cfl, flickr, k-30, k-50, light, pentax k30, pentax k50, test, tests, tungsten
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Which Daylight CFL bulbs? stainsor Troubleshooting and Beginner Help 6 06-18-2012 08:06 PM
CFL Color Temperature for Photography UnknownVT Flashes, Lighting, and Studio 2 06-11-2012 08:39 AM
Sports CFL - The non game - 11 shots daacon Post Your Photos! 13 09-15-2011 11:20 AM
Sports CFL Eskimos vs Stamps daacon Post Your Photos! 2 09-12-2011 05:18 AM
Hello from CFL Jason 407 Welcomes and Introductions 3 07-27-2011 06:08 PM



All times are GMT -7. The time now is 06:30 PM. | 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