Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-06-2009, 10:44 PM   #1
Veteran Member
res3567's Avatar

Join Date: Sep 2008
Location: Houston Tx.
Photos: Gallery
Posts: 1,876
Green Button

My green button seems to overexpose images when use manual focus lenses with no AE contacts. It is especially bad on bright sunny days. Since the exposure compensation does not work in this capacity I have to do it manually. Any one else have this problem?

04-06-2009, 10:53 PM   #2
Damn Brit
Guest




Use a smaller aperture, or lower ISO, or faster shutter.
You just have to get used to the camera and reading the conditions (maybe read up on exposure as well)
Once you've got the hang of it, it'll be second nature.
04-06-2009, 10:56 PM   #3
Veteran Member
res3567's Avatar

Join Date: Sep 2008
Location: Houston Tx.
Photos: Gallery
Posts: 1,876
Original Poster
QuoteOriginally posted by Damn Brit Quote
Use a smaller aperture, or lower ISO, or faster shutter.
You just have to get used to the camera and reading the conditions (maybe read up on exposure as well)
Once you've got the hang of it, it'll be second nature.
Thanks Man! I will give it a try!
04-06-2009, 11:50 PM   #4
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,198
QuoteOriginally posted by res3567 Quote
My green button seems to overexpose images when use manual focus lenses with no AE contacts. It is especially bad on bright sunny days. Since the exposure compensation does not work in this capacity I have to do it manually. Any one else have this problem?
I assume that yours is a K10D or a K20D. This is a known issue. IME, the exposure is generally correct at large apertures (say, faster than f/2.8). The smaller the aperture, the more pronounced the overexposure.

So you need to know the character of each manual lens and adjust exposure accordingly. Until then, meter at max aperture of the lens, then keep doubling the shutter speed and halving the aperture until the desired settings.

A more permanent fix is to replace the current focusing screen with an LL-60 or LI-60 focusing screen (designed for the *ist series). Unfortunately, they are becoming rare these days.

I have 2 K10D bodies; one has the LL-60 screen.

04-06-2009, 11:58 PM   #5
Veteran Member
res3567's Avatar

Join Date: Sep 2008
Location: Houston Tx.
Photos: Gallery
Posts: 1,876
Original Poster
QuoteOriginally posted by SOldBear Quote
I assume that yours is a K10D or a K20D. This is a known issue. IME, the exposure is generally correct at large apertures (say, faster than f/2.8). The smaller the aperture, the more pronounced the overexposure.

So you need to know the character of each manual lens and adjust exposure accordingly. Until then, meter at max aperture of the lens, then keep doubling the shutter speed and halving the aperture until the desired settings.

A more permanent fix is to replace the current focusing screen with an LL-60 or LI-60 focusing screen (designed for the *ist series). Unfortunately, they are becoming rare these days.

I have 2 K10D bodies; one has the LL-60 screen.
Thank You! Goodness! I got two swift reponses! That is why I love this forum. Yes, mine is a K10D.
04-07-2009, 12:34 AM   #6
Damn Brit
Guest




You are using spot metering aren't you? If you meter on a dark area, the camera will overexpose, on a bright area it will under expose. Try and meter on something that is somewhere between the two, AE lock and then recompose. If you get it right and the camera still over exposes at least you have a starting point from which to change the settings.
04-07-2009, 12:41 AM   #7
Veteran Member
xjjohnno's Avatar

Join Date: Jan 2009
Location: Melbourne Australia
Photos: Gallery
Posts: 2,115
I've found that more of an issue with some lenses and not others. Some meter fine while others over expose so I won't go blaming the exposure metering so much as how it works with some lenses. And it's consistent with those lenses.
04-07-2009, 12:43 AM   #8
Damn Brit
Guest




QuoteOriginally posted by xjjohnno Quote
I've found that more of an issue with some lenses and not others. Some meter fine while others over expose so I won't go blaming the exposure metering so much as how it works with some lenses. And it's consistent with those lenses.
You still have to meter though regardless of the lens you use so it's a case of knowing your equipment.

04-07-2009, 03:16 AM   #9
Site Supporter




Join Date: Sep 2006
Location: WV
Posts: 1,495
Insofar as your problem is especially bad on bright sunny days, I have two suggestions.

1. Buy Brian Peterson's Understanding Exposure. Read the entire book cover to cover (won't take too long). Then re-read the chapters titled "The Sky Brothers" and "Mr. Green Jeans".

2. Apply the "Sunny 16" rule.

3. Bonus suggestion: Go to this website: Ultimate Exposure Computer

After you've done all this, you'll still need to know your equipment, as Gary said.

This is a lot to absorb, but remember, gear won't make you a better photographer, knowledge and experience will.
04-07-2009, 11:32 AM   #10
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
There's several things that could be going on here, most of which have already been touched on, but at least couple that haven't, and they are worth listing explicitly. Here are the ones I haven't seen others mention:

- With manual exposure lenses, multi-segment ("matrix") metering is not available - the camera will switch to center-weighted mode. That will create differences in exposure from what you might be used to, and since center-weighted mode cannot protect highlights like multi-segment can, it often leads to overexposure compared to muliti-segment.

- The lens could be defective - the aperture blades might not be closign quickly enough, causing the aperture to be larger when the pciture is taken than it should be.

Here is my restatement of the possibilities that have already been raised:

- It could be a combination of high ISO and large aperture that is causing the camera to need a faster shutter speed than it can actually. If the camera is reporting 1/4000" shutter speed, chances are good that it wishes it could gone faster. Reducing ISO or stopping down would allow the camera to shoot with.

- The K10D and K20D do have a specific issue related partly/mostly to the focus screen that causes poor exposure with manual exposure lenses, especially when stopped down.
04-07-2009, 02:06 PM   #11
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
follow this link

welcome to the club

check here for the (probable) cause in my opinion

https://www.pentaxforums.com/forums/241716-post69.html
04-07-2009, 03:04 PM   #12
Senior Member




Join Date: Mar 2009
Photos: Albums
Posts: 113
QuoteOriginally posted by MPrince Quote
Insofar as your problem is especially bad on bright sunny days, I have two suggestions.

1. Buy Brian Peterson's Understanding Exposure. Read the entire book cover to cover (won't take too long). Then re-read the chapters titled "The Sky Brothers" and "Mr. Green Jeans".

2. Apply the "Sunny 16" rule.

3. Bonus suggestion: Go to this website: Ultimate Exposure Computer

After you've done all this, you'll still need to know your equipment, as Gary said.

This is a lot to absorb, but remember, gear won't make you a better photographer, knowledge and experience will.
Thanks for the link to Ultimate Exposure Computer. It "brightened" a few underexposed areas in my understanding, when the meter fails.

Steve N
04-07-2009, 08:51 PM   #13
Senior Member




Join Date: Mar 2009
Location: Perth - Australia
Photos: Albums
Posts: 214
Hi Guys

I notice here that you are saying generally the green button over exposes? i have an auto chinon 50mm f1.7 that at large apertures meters fairly well but as the aperture gets smaller and smaller the green button has a tendancy to under expose (pictures darker than i expect)

is this again down to the focus screen issue? is it worth changing it for a split screen? or as suggested trying to get a *ist screen?

Thanks in advance as usual

Steve
04-07-2009, 09:09 PM   #14
Veteran Member
OregonJim's Avatar

Join Date: Mar 2009
Location: Willamette Valley, Oregon
Posts: 1,329
Might I suggest investing in a handheld light meter? You can get older ones for dirt cheap. I carry a Gossen Pilot in my pocket at all times. It's less than 1/2 the size of a pack of cigarettes. I find it much easier to use than the in-camera meter. One advantage is that you can test yourself even if you don't have a camera with you: "Lets see, this looks like about a 125 f/16 day @ ISO 100" - whip out the meter and see how close you are. It's also easier to selectively meter parts of a scene - you don't have a heavy camera pushed against your face that you have to point all over the place. The analog meter also helps some people to "get it" quicker as you can see all shutter speed/aperture combinations at once. And one last advantage is that it frees you from having to remember the quirks of each camera body/lens combination (does this one underexpose by 1/2 stop or overexpose by 2/3 stop?)

Just my 2 cents worth...

Last edited by OregonJim; 04-07-2009 at 09:18 PM.
04-07-2009, 11:32 PM   #15
Veteran Member
res3567's Avatar

Join Date: Sep 2008
Location: Houston Tx.
Photos: Gallery
Posts: 1,876
Original Poster
QuoteOriginally posted by Damn Brit Quote
You are using spot metering aren't you? If you meter on a dark area, the camera will overexpose, on a bright area it will under expose. Try and meter on something that is somewhere between the two, AE lock and then recompose. If you get it right and the camera still over exposes at least you have a starting point from which to change the settings.
No I was not. I was using the multisegment. I will try that to!
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!
button, camera, dslr, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Green button - who really uses it? jpzk Troubleshooting and Beginner Help 45 01-07-2011 01:59 PM
Green button fekish Troubleshooting and Beginner Help 4 10-06-2010 03:33 PM
That Green Button - Useful! photog Pentax DSLR Discussion 0 07-03-2009 02:07 AM
The green button desldan Pentax DSLR Discussion 5 12-23-2008 08:13 PM
green button Fl_Gulfer Pentax DSLR Discussion 38 09-04-2008 10:45 PM



All times are GMT -7. The time now is 08:33 AM. | 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