Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version 2 Likes Search this Thread
10-20-2018, 08:07 PM   #1
Junior Member




Join Date: May 2016
Photos: Gallery
Posts: 29
K-30 underexposed pics - is or me or the camera?

Lately I've been unhappy with a lot of my shots with my K-30 (with Sigma 18-250) - the latest ones seem underexposed and to have a brown cast. I've read another thread where bright sunlight appears to result in underexposed shots, and I've read about the K-30 aperture motor problem, but I'd like some feedback on these please. Apologies for the dirty lens by the way.

The 2nd pic was taken immediately after the 1st - just zoomed in.

The last pic is how I expected the 2nd last one to look like.

Attached Images
View Picture EXIF
PENTAX K-30  Photo 
View Picture EXIF
PENTAX K-30  Photo 
View Picture EXIF
PENTAX K-30  Photo 
View Picture EXIF
PENTAX K-30  Photo 
View Picture EXIF
PENTAX K-30  Photo 
10-20-2018, 08:23 PM   #2
Moderator
Site Supporter
Loyal Site Supporter
MarkJerling's Avatar

Join Date: May 2012
Location: Wairarapa, New Zealand
Photos: Gallery | Albums
Posts: 20,408
Looking at your first image, Exposure 1/250 and Aperture F/5.6 - all good.
Your second image, Exposure Time 1/2000 and Aperture F/5.6 - it's no surprise that this image is darker.

Your fourth and fifth images are interesting, however:
Your fourth image, Exposure Time 1/320 and Aperture F/13.0, appears the same in your fifth image. That sort of behaviour may be the aperture solenoid, but that would not hold true for the difference between the first and second shots.
10-20-2018, 08:36 PM   #3
Junior Member




Join Date: May 2016
Photos: Gallery
Posts: 29
Original Poster
I don't think I changed settings between 1st and 2nd - would have been aperture priority - set on f5.6, auto ISO.
The last pic was PPed from the raw.
10-20-2018, 08:56 PM   #4
Site Supporter
Site Supporter




Join Date: Sep 2010
Location: Blue Hill, Nebraska
Photos: Gallery
Posts: 494
Do you accidentally have your exposure metering set to spot? If so, change it to either center weighted or matrix and I'll bet the problem goes away. Here's a link that may help Camera metering modes explained

10-20-2018, 09:03 PM   #5
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,597
Looks like the problematic ones are both in spot and center-weighted metering. As a go-to, you should be using matrix metering unless the lighting itself is tough.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
10-21-2018, 01:07 AM   #6
Site Supporter
Site Supporter




Join Date: Dec 2016
Location: Southeastern Michigan
Posts: 4,558
Spot metering is ok- only if you know how and when to use it. For most situations, matrix is the way to go.
10-21-2018, 07:21 AM   #7
Veteran Member
CarlJF's Avatar

Join Date: Sep 2014
Location: Quebec City
Posts: 1,185
Yeah, spot metering was selcted. If you only only at the center part of the badly exposed pictures, the center spot is perfectly exposed. In #1, it exposed for the patch of trees in background, on #2 it exposed for the white part in front the building (which end up 18% grey as it should), #3 expowed for the white cloud and so on... So, the camera just have done what you ask it to do: just exposed for a small patch in the center without taking care of the whole picture.

As other said, matrix metering is the way to go unless having a good reason to switch to matrix or spot metering. Spot metering is really tricky to use and should be reserved for very specific sitiuations.

10-21-2018, 02:49 PM   #8
Moderator
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 10,526
EXIF on 4th picture (whale) says centered weighted averaging for meter mode.
10-21-2018, 03:40 PM   #9
Site Supporter
Site Supporter




Join Date: Dec 2016
Location: Southeastern Michigan
Posts: 4,558
Well, the difference between the 1st and 2nd photo is easy to explain. The 1st is shot at f/5.6 and 1/250 sec and the 2nd at f/5.6 and 1/2000 sec, so of course the result with the same lighting conditions will be very different. Spot metering is the likely culprit. Same with photo 3 shot at 1/1600 sec shutter speed. No doubt you believed the meter's indication for exposure, since you were shooting in the manual mode. One reason for shooting in Manual mode is to meter off a chosen section of your scene, then reposition the camera for your shot. Your set exposure will then remain where you put it, even though the meter will now be showing an off-centered over or under exposure. This is also the way spot metering is used. If you do this and just point the camera without consideration of the lighting present, just the way you want to frame your shot, and set exposure by the meter indication, it may not go well.

In the case of the whale's tail, center-weighted metering was selected (why?). Within the central portion of the frame there's snowy mountains and bright sky included, which can cause the meter to indicate less exposure. Center-weighted can be misleading also, depending on what is within the frame. For this type of shot, matrix would be the best type of metering. If wanting to use the spot meter, you'd need to train the camera on a mid-tone area of the scene for your meter reading, then reposition the camera for the shot. With the Pentax Hyper Manual feature, you can quickly do this by using the green button to take the reading and set the exposure.
10-21-2018, 04:05 PM   #10
Veteran Member




Join Date: Apr 2017
Photos: Albums
Posts: 327
One thing to consider is the manual white balance of the first two photos because they were taken simultaneously unlike the other photos of different time and dates.
When you fully pressed the shutter button and displayed on Lcd the captured image, did you press any arrow on the controller to specify the light measuring area? or press the green button to select the center as your choice. If you did not specify the measuring area, the resulting photo takes the kelvin temperature settings.
10-21-2018, 04:24 PM   #11
Site Supporter
Site Supporter




Join Date: Dec 2016
Location: Southeastern Michigan
Posts: 4,558
QuoteOriginally posted by Penview52 Quote
One thing to consider is the manual white balance of the first two photos because they were taken simultaneously unlike the other photos of different time and dates.
When you fully pressed the shutter button and displayed on Lcd the captured image, did you press any arrow on the controller to specify the light measuring area? or press the green button to select the center as your choice. If you did not specify the measuring area, the resulting photo takes the kelvin temperature settings.
I just noticed that manual white balance was used instead of auto white balance. Usually with Pentax DSLR cameras of recent years, the auto white balance turns out quite well. The exception might be some artificial lighting situations. But I still think the improper use of metering was the main problem with exposure in these examples.

The matrix metering takes all sections of the frame into evaluation. But even it can be fooled by extreme lighting situations, hence the reason for having the SCENE modes on amateur-oriented camera models. Pentax offers more advanced features and build quality on such cameras than other brands do, so even advanced photographers purchase them, sometimes as secondary models to their main camera. I own the K-S2 as my smallest, lightest model, and enjoy the fact that it also has a very good complement of advanced amenities. I have never used any of the SCENE modes, but they are a good convenience for others who might use the camera, and also a selling point. There are SCENE settings for numerous situations, like snow scenes, for example. With a lot of bright snow, the camera's meter, even matrix, will sense "too much bright white" and will back down exposure, resulting in gray snow and dark people. When you know what to expect, you don't need the SCENE mode to compensate. If you want to continue using any of the auto-exposure modes- "P", Av, Tv, etc. you simply use the exposure comp button to increase exposure by around 1-1/2 stop or so and keep shooting. If using Manual mode, and spot meter, you choose a mid-tone area to set your exposure and go from there.

Last edited by mikesbike; 10-21-2018 at 04:45 PM.
10-22-2018, 01:36 AM   #12
Junior Member




Join Date: May 2016
Photos: Gallery
Posts: 29
Original Poster
OK, it looks like it's me. The underexposed shots were probably from using not the best metering, and other things were maybe getting adjustments wrong under pressure in bright light. I've no idea how 'manual white balance' could have got set, as I don't touch that knowingly.

I was hoping you'd say the camera, because I want an excuse to get a KP, or at least a K-70. ... and maybe a DA 18-135mm F3.5-5.6 ED AL [IF] DC WR.
10-22-2018, 04:43 AM   #13
Moderator
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 10,526
Center weighted metering was used in SLRs until matrix metering became available in the 80s. Pentax DSLRs default from matrix to center weighted meter with lenses that do not have "A" contacts, e.g. K, M, M42, T-mount and many 3rd party lenses.

I recall there being an article in Popular/Modern Photography on Minolta's center weighted metering pattern in the X series was designed to de-emphasize the upper portion of the landscape frame to account for the majority of pictures (from Minolta's analysis) have bright sky. A pattern that the other manufacturers soon copied.

Nikon soon pioneered the matrix metering system and still excel in that area.
10-22-2018, 06:21 AM   #14
Veteran Member




Join Date: Apr 2017
Photos: Albums
Posts: 327
Jim - just little understanding about manual white balance is needed, as you said....." I've no idea how 'manual white balance' could have got set, as I don't touch that knowingly".

After taking a shot the image is seen on lcd and press green button to select the center image as measurement of light to take the whole image similar to the center, but do not press the shutter again because it will not process the correct color temperature of that next photo shoot., ( maybe it resulted as dark photo as i do not know the effect of it ) until camera is ready for the next shot.

Just take the auto white balance ( AWB ) and camera will select the best for you.
I believed that either you set as spot or center weighted is acceptable by practice and you will see the difference.

Other point to consider is clean your lens because this affect the auto focusing function of the camera.
10-22-2018, 07:28 AM   #15
Site Supporter
Site Supporter
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 17,891
one other thing to consider in the first and second shots. the sun is behind the photographer is there an issue with light entering the viewfinder?
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!
camera, k-30, k-30 underexposed pics, k-70, kp, pentax help, photography, pic, post, shots, troubleshooting, viewfinder

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bright sun, underexposed pics. Where did I get the settings wrong? lushdimple11 Troubleshooting and Beginner Help 43 11-03-2018 11:15 PM
underexposed pics with Sears MC 50mm 1.7 amyf Troubleshooting and Beginner Help 6 10-31-2012 06:49 AM
Underexposed pics with new Sigma EF 530 DG Super Flash. What I'm I doing wrong? ismaelg Flashes, Lighting, and Studio 8 02-09-2011 01:46 PM
People Ways to fix severly underexposed pics?? outsider Photo Critique 11 02-06-2011 09:32 PM
Underexposed pics k10d jjfdvm72 Pentax DSLR Discussion 85 02-26-2008 05:57 PM



All times are GMT -7. The time now is 07:34 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