Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-06-2013, 08:46 AM   #1
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
K-5 lowest metering limit?

is spec'd as LV0 (LV zero)

K-5 (original) meter specs from page 358 of the manual:


However I recently just got a brand new K-5 (manufacture date 7/23/2012) and shooting at my regular dark jazz club (please see: Kx in Use and now - K-5 in Use)
I found my new K-5 with latest firmware (1.13.23.25) does not seem to be able to meter to as low as my old K-x.

To determine the lowest metering limit - I metered with the lens cap on (and the viewfinder eye-piece covered)
setting ISO5000 (with no exp compensation) P mode, with the 18-55mm kit zoom on 18mm widest,
I managed only 1/8 sec @ f/3.5 -
whereas my K-x managed 1/4 sec same settings.

1/8 sec, f/3.5, ISO5000 is about LV1 - this is one stop short of the lowest spec'd metering limit of the K-5 = LV0
- kind of like buying ISO1600 film and finding out it is only ISO800.

There is also now a very significant input from Ex Finn (posts #6 & #12 linked, in K-5 in Use), as he managed to get 1/4 sec f/3.5 ISO5000 (with 18-55 kit zoom lens, covered/cap on) same firmware (1.13.23.25)

I am trying to determine if there is some settings I am not aware of, since the K-5 is brand new (to me) - so that I can reach the same in spec lowest metering limit that Ex Finn managed to reach.

Any other K-5 owners care to please just meter with the lens cap on, with the 18-55 kit zoom set at 18mm widest setting - @ ISO5000 (no exp compensation), please let us know? - only takes seconds

Thanks for any suggestions and help.

01-06-2013, 09:42 AM   #2
Forum Member




Join Date: Apr 2012
Posts: 78
I am not sure how much this test really gives you usable information. It might also depend on the currently used program line.

Anyways, I did the metering. P (normal), SMC 18-55mm WR, 18mm, ISO fixed at 5000. Resulting exposure is 1/4s, f3.5.
01-06-2013, 09:52 AM   #3
Veteran Member




Join Date: Jan 2007
Location: Northern California
Posts: 475
QuoteOriginally posted by UnknownVT Quote
is spec'd as LV0 (LV zero)

K-5 (original) meter specs from page 358 of the manual:


However I recently just got a brand new K-5 (manufacture date 7/23/2012) and shooting at my regular dark jazz club (please see: Kx in Use and now - K-5 in Use)
I found my new K-5 with latest firmware (1.13.23.25) does not seem to be able to meter to as low as my old K-x.

To determine the lowest metering limit - I metered with the lens cap on (and the viewfinder eye-piece covered)
setting ISO5000 (with no exp compensation) P mode, with the 18-55mm kit zoom on 18mm widest,
I managed only 1/8 sec @ f/3.5 -
whereas my K-x managed 1/4 sec same settings.

1/8 sec, f/3.5, ISO5000 is about LV1 - this is one stop short of the lowest spec'd metering limit of the K-5 = LV0
- kind of like buying ISO1600 film and finding out it is only ISO800.

There is also now a very significant input from Ex Finn (posts #6 & #12 linked, in K-5 in Use), as he managed to get 1/4 sec f/3.5 ISO5000 (with 18-55 kit zoom lens, covered/cap on) same firmware (1.13.23.25)

I am trying to determine if there is some settings I am not aware of, since the K-5 is brand new (to me) - so that I can reach the same in spec lowest metering limit that Ex Finn managed to reach.

Any other K-5 owners care to please just meter with the lens cap on, with the 18-55 kit zoom set at 18mm widest setting - @ ISO5000 (no exp compensation), please let us know? - only takes seconds

Thanks for any suggestions and help.
Sorry, I gave away my kit lenses and do not have a lens slower than f4, but I did perform the following tests:

Sigma 17-50 f2.8 @17mm
P mode, no comp, cap on, ISO5000, eyepiece covered.
.3s @ f2.8 -.9LV

Pentax 16-45 f4.0 @16mm
All other settings as above.
1/8s @f4.0 1.4LV

Pentax FA 50 f1.4
All other settings as above.
1/6s @ f1.4 -2.1LV

The settings the camera chooses seems to be dependent upon the lens attached, which makes sense due to the differing amount of light each lens lets into the system based upon the maximum aperture reported to the camera. The camera also knows some other things about the lens from the chip contained in the lens.

BTW, this test does not test the metering limits as the camera settings are blinking during these tests, indicating that it is under the limit, but there is no way to know how much under with this test. You are only testing what the program line in the camera does when it is in P mode and hits the metering limits with a given lens attached.

You would need to carefully lower the light level and meter a target to see where the metering fails (blinks) with a given lens to see if it reaches the specified lower limit of EV0. It is interesting that the AF system specifications call out the FA 50 f1.4 but the metering system specification does not call out what lens is used to set the specification.

I guess it is not surprising that different camera bodies might have different program lines, which are likely the result of design decisions we will never know.

Ray
01-06-2013, 11:48 AM   #4
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
Original Poster
QuoteOriginally posted by TrueFocus Quote
I did the metering. P (normal), SMC 18-55mm WR, 18mm, ISO fixed at 5000. Resulting exposure is 1/4s, f3.5.
Thank you so much, this is the same result as Ex Finn -
however I seem to be only getting 1/8sec with the same settings -
so this makes me wonder if I have some setting that I am not aware of, that is causing my K-5 not to reach the spec'd lowest light metering?

QuoteOriginally posted by Ray Pulley Quote
Sigma 17-50 f2.8 @17mm
P mode, no comp, cap on, ISO5000, eyepiece covered.
.3s @ f2.8 -.9LV

Pentax 16-45 f4.0 @16mm
All other settings as above.
1/8s @f4.0 1.4LV

Pentax FA 50 f1.4
All other settings as above.
1/6s @ f1.4 -2.1LV

The settings the camera chooses seems to be dependent upon the lens attached, which makes sense due to the differing amount of light each lens lets into the system based upon the maximum aperture reported to the camera. The camera also knows some other things about the lens from the chip contained in the lens.

BTW, this test does not test the metering limits as the camera settings are blinking during these tests, indicating that it is under the limit, but there is no way to know how much under with this test. You are only testing what the program line in the camera does when it is in P mode and hits the metering limits with a given lens attached.
I guess it is not surprising that different camera bodies might have different program lines, which are likely the result of design decisions we will never know.
Thank you very much for your efforts -
your 16-45 f/4 seems closest - and the result is close possibly 1/3 stop better.

Re: lowest light limit - please see my thoughts when I first tried to determine the lowest metering limits on my K-x - Post #132 (linked in the Kx in Use)

You are absolutely right - the metering is very dependent on the lens and max aperture.

I am not sweating this -
however it is interesting that my K-x an older and much lesser camera can manage 1/4 sec for the same settings -
I was expecting my new K-5 to at least match this, if not better it -
alas this does not seem to be the case.

Now the only thing I'm trying to find out is why two other K-5 owners managed 1/4 sec with the same settings lens cap on and mine only goes to 1/8sec.

Thanks for helping.

01-06-2013, 12:30 PM   #5
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
QuoteOriginally posted by UnknownVT Quote
I am not sweating this -
however it is interesting that my K-x an older and much lesser camera can manage 1/4 sec for the same settings -
I was expecting my new K-5 to at least match this, if not better it -
alas this does not seem to be the case.

Now the only thing I'm trying to find out is why two other K-5 owners managed 1/4 sec with the same settings lens cap on and mine only goes to 1/8sec.
Have you tried all the various modes for the P line setting? There are 6 choices -- I don't know if the K-x has some or any of those. Could that be the "some setting you don't know about"?
01-06-2013, 05:16 PM   #6
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
Original Poster
QuoteOriginally posted by vonBaloney Quote
Have you tried all the various modes for the P line setting? There are 6 choices -- I don't know if the K-x has some or any of those. Could that be the "some setting you don't know about"?
Thanks but it has to be one where the automation sets the shutter speed - so I have tried Av to get the same exposure.

However BOTH the K-5 owners that managed the 1/4 sec - used P mode - as I requested -
so it isn't because of the P mode.

There are probably many settings on the K-5 I may not be aware of - since the K-5 is new to me -
although I do know the K-x pretty well from over 3 years' worth of use.

Thanks
01-06-2013, 05:32 PM   #7
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
QuoteOriginally posted by UnknownVT Quote
However BOTH the K-5 owners that managed the 1/4 sec - used P mode - as I requested -
so it isn't because of the P mode.
There are six P-modes, as it were. They prioritize different things, so just "P mode" isn't enough information. There is Auto, Normal, Hi-Speed, DOF deep, DOF shallow, and MTF.
01-06-2013, 06:35 PM   #8
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,065
QuoteOriginally posted by vonBaloney Quote
There are six P-modes, as it were. They prioritize different things, so just "P mode" isn't enough information. There is Auto, Normal, Hi-Speed, DOF deep, DOF shallow, and MTF.
I just repeated my test in P mode with all the program lines. Made no difference, still got 1/4 second with the specified settings at 0 EV comp.

01-06-2013, 06:47 PM   #9
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
Original Poster
QuoteOriginally posted by vonBaloney Quote
There are six P-modes, as it were. They prioritize different things, so just "P mode" isn't enough information. There is Auto, Normal, Hi-Speed, DOF deep, DOF shallow, and MTF.
Sorry, you're right, I was not aware of this -
my K-5 is at the default P "Normal" -
it seems to behave similarly to the the P modes of my K-x which does not have the priority choices.

I noted what Ex Finn just said as well - he still manages to to get the same 1/4 sec under all the P priority settings
whereas under P "Normal" I can only reach 1/8 sec with my K-5

Thanks for pointing me in the right direction.

QuoteOriginally posted by Ex Finn. Quote
I just repeated my test in P mode with all the program lines. Made no difference, still got 1/4 second with the specified settings at 0 EV comp.
Thanks again for checking for me.

Thank you.
01-06-2013, 07:18 PM   #10
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,065
QuoteOriginally posted by UnknownVT Quote
Sorry, you're right, I was not aware of this -
my K-5 is at the default P "Normal" -
it seems to behave similarly to the the P modes of my K-x which does not have the priority choices.

I noted what Ex Finn just said as well - he still manages to to get the same 1/4 sec under all the P priority settings
whereas under P "Normal" I can only reach 1/8 sec with my K-5

Thanks for pointing me in the right direction.



Thanks again for checking for me.

Thank you.
No problem, could you try a different lens just to eliminate it possibly being at fault?
01-06-2013, 11:01 PM   #11
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
Original Poster
QuoteOriginally posted by Ex Finn. Quote
No problem, could you try a different lens just to eliminate it possibly being at fault?
Sure thing -
I have another 18-55 Mk II kit zoom
that I had also already checked and it also gave 1/8 sec with the settings.

The 50-200 kit zoom f/4 (max) same settings gave 1/15 sec
which is only a fraction different from it on the K-x of 1/13sec.

Thanks
01-07-2013, 04:13 AM   #12
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,065
QuoteOriginally posted by UnknownVT Quote
I have another 18-55 Mk II kit zoom
that I had also already checked and it also gave 1/8 sec with the settings
That eliminated that possibility.
01-07-2013, 09:08 AM   #13
Veteran Member




Join Date: Sep 2007
Location: USA
Posts: 1,812
Original Poster
QuoteOriginally posted by Ex Finn. Quote
That eliminated that possibility.
yep, that's about the size of it.

unless I can find whatever it is I have set or not set -
I guess I'll have to accept my copy of the K-5 is sub-par on its lowest metering limit by 1 to 1.3 stops.

Although it is very important to me since I do a lot of low light work that actually is at or below the metering limit -
it is not a deal-breaker - as I have found an easy work around -
when I know I am shooting at the very low light conditions
(big hint I can't see that well, and difficulties with AF - either hunting if AF assist light off - or the AF light comes on )
and I see either 1/13 (@ -0.3 comp) or 1/15 (@ -0.7 comp) my two usual settings at the dark jazz venue -
I know to set exposure compensation to +1 stop (or +0.7), which then will give me 1/4 sec (or 1/5sec) without changes in anything else.

The reason why I prefer to do it this way is because I already use exp comp frequently to adjust to the scenes -
and to use +1 (or maybe +0.7) for dark scenes would seem more "natural" for me.

Thank you very much for the information and continuing to help
01-07-2013, 10:36 AM   #14
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
I still don't understand what you are measuring, but here's something. I don't have the kit lens, but with the 18-250 set on 18mm which gives an aperture of 3.5, if I set to ISO 5000 (I had to get my "EV steps" and "Sensitivity Steps" settings right just to make 5000 available as choice) with caps on, I get 1/10s at 3.5. BUT, if I then switch from matrix metering to center or spot, it goes to 1/4s.
01-07-2013, 11:03 AM   #15
Forum Member




Join Date: Apr 2012
Posts: 78
QuoteOriginally posted by vonBaloney Quote
BUT, if I then switch from matrix metering to center or spot, it goes to 1/4s.
That is the solution! I just re-metered, also covered the eyepiece. Matrix metering: 1/8s. Center Weighted: 1/4s. Spot Metering: 0.3s.
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!
18mm, camera, dslr, f/3.5, k-5, k-5 ii, k-5 iis, k5, kit, lens, meter, pentax k-5, sec
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-5 Odd Metering Flub sadatoni Pentax K-5 8 01-01-2013 08:29 AM
Lowest price EVER on a K-30 BerndM Pentax K-30 & K-50 14 11-22-2012 08:27 AM
missing lowest ISO setting on K-5 / K-7 penties rider Pentax K-5 7 05-08-2011 08:03 AM
Pentax K-5 - buffer limit problem !!! gubak Pentax K-5 19 11-22-2010 09:19 PM
K-5 / K-7 : eight raw buffer limit exists gubak Pentax K-5 54 10-19-2010 10:52 AM



All times are GMT -7. The time now is 12:17 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