Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-10-2013, 12:28 PM   #1
Veteran Member




Join Date: Jan 2010
Location: Durham, nc
Photos: Albums
Posts: 887
Consistent over-exposure with Pentax cameras

Both my kx and my k30 tend to over expose shots in bright sunlight. I often get blown highlights and have to dial in exposure compensation, no matter what mode I'm in. Is there a way to set an exposure mode so that highlights will never be blown? Or is that only a canonikon feature?

Charles.

11-10-2013, 12:33 PM   #2
Pentaxian
LFLee's Avatar

Join Date: Aug 2009
Location: Western MA
Photos: Gallery | Albums
Posts: 2,249
This is pretty strange, as PENTAX is usually known for underexposure (for preserving highlight). Did you check ISO settings? did you use spot metering?
If still fail, do a reset on settings should do the trick.
11-10-2013, 12:36 PM   #3
Site Supporter
gbeaton's Avatar

Join Date: Apr 2012
Location: Montreal
Photos: Gallery
Posts: 326
If you set your metering to use the full frame, it should limit highlight overexposure considerably. But remember, the exposure is determined based on the average exposure of the metered area - spot, centre-weighted or full-frame. I haven't seen a mode that will never blow the highlights - at least not on my cameras.
11-10-2013, 04:17 PM   #4
Veteran Member




Join Date: Jan 2010
Location: Durham, nc
Photos: Albums
Posts: 887
Original Poster
Was using matrix metering, av or tv, and lots of midday bright sun. But it doesn't really matter, highlights are often blown regardless of lighting conditions or attached lens.

Charles.

11-10-2013, 04:38 PM   #5
Pentaxian
maxfield_photo's Avatar

Join Date: Mar 2011
Location: Cincinnati, OH
Posts: 1,216
You could always spot meter on the brightest part of your scene and dial in +2~+3 EVs. Spot metering will render the highlight as middle gray, and the EV compensation will ensure that it doesn't exceed your camera's DR. Now what that may do to your shadows is another matter. Also, if you're shooting JPEGs, set your color space to AdobeRGB, it may prevent highlight clipping on a per channel basis.
11-12-2013, 07:04 AM   #6
Veteran Member




Join Date: Jan 2010
Location: Durham, nc
Photos: Albums
Posts: 887
Original Poster
Here's what I'm talking about. This isn't a particularly hard shot, I don't think. But the highlights are completely blown out. Resized, but exif intact.

Short and sweet:
K-30 with 55-300mm lens.
1/320
f4
ISO200
0.00 exposure compensation
Tv mode


Charles.
Attached Images
View Picture EXIF
PENTAX K-30  Photo 
11-12-2013, 07:52 AM   #7
Site Supporter




Join Date: Sep 2012
Photos: Gallery | Albums
Posts: 1,728
QuoteOriginally posted by ChopperCharles Quote
Here's what I'm talking about. This isn't a particularly hard shot, I don't think. But the highlights are completely blown out. Resized, but exif intact.

Short and sweet:
K-30 with 55-300mm lens.
1/320
f4
ISO200
0.00 exposure compensation
Tv mode


Charles.
You have extreme differences between dark and light in that scene. It probably makes sense to dial in some negative exposure compensation because you're more concerned with protecting the bright areas than the dark.
11-12-2013, 07:53 AM   #8
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 23,769
QuoteQuote:
Or is that only a canonikon feature?
There is a setting in the K-3 menus that gives you the option of not blowing your highlights… I've seen it in the menus but haven't checked it out to see how it might work.

But just in case you're looking for a bit of advice on how to shoot this…

FIrst, you're shooting in direct sun. There isn't a camera or film that's ever been made that can capture the whole dynamic range of this image without filters.. From the highlights to the shadows the ratio from light to dark is probably 20,000/1. So that's your first problem.

Spot metering on the birds head would help some, but you shot this at 0 exposure compensation. What you need to be doing is checking your histogram after taking the image, pushing the EV button on the top of your camera and rolling your EV down, on this shot to minus 2 probably, maybe more, because you have shadow behind the bird is pulling down your metered exposure value, even though it isn't really an important part of your picture.

The camera has to make a decision based on what you tell it when it looks at a scene like this. But you have to tell it. But the image is pretty much ruined by the high contrast caused by direct sun. You're simply asking too much of your sensor. Your assertion that a Canon would do better, i.e. lowering the exposure, keeping the white feathers from being blasted and totally blacking out the area around the eye and beak is not very informed. You wouldn't get a better image doing that. Once you lose details in those areas of the image, they just look like black holes. Given the lighting conditions, your camera made some pretty good decisions.

In fact, any K-series camera K-5 and beyond (K-5, K30, K500, K-01, K-5II, K-5 IIs) is going to give you superior dynamic range, compared to even the most expensive Canons, giving you a bit more latitude to work with in images like this.

I'd be interested to hear what guys who use neutral density filters would say about this. Could this image have been rescued with the use of filters?


Last edited by normhead; 11-12-2013 at 08:13 AM.
11-12-2013, 08:15 AM   #9
Veteran Member




Join Date: Jan 2010
Location: Durham, nc
Photos: Albums
Posts: 887
Original Poster
Well, in subsequent photos I did dial down exposure compensation. What I'm getting at though is there are situations when I never (read: pretty much all the time), and there is no way to keep the auto exposure from doing that :/

Charles.
11-12-2013, 08:22 AM   #10
Site Supporter




Join Date: Jan 2010
Location: Michigan
Photos: Gallery
Posts: 2,073
I reckon center weighted metering etc is quite OK for film which has inherent ability to cope with bright areas by its gamma.

For a dslr photo of a subject like that bird you could use spot metering on or near to the brightest part and lock the exposure before recomposing.
The ist ds and K-01 here tend to expose a spot metering of gray/whire or skin tone at about 160/255.
(I just tried on our first snow, the K-01 is about 160/255 and the ist ds tends to be a little more under exposed, about 140/255. So there is plenty of overhead on each of those cameras.
The K-01 manual does not say how matrix mode is processed.

With spot metering on the white part of the bird the brightest would be seen as the left most part of the histogram, a test shot might be needed to get it down below 180/255 or so.
11-12-2013, 08:33 AM   #11
Site Supporter
gbeaton's Avatar

Join Date: Apr 2012
Location: Montreal
Photos: Gallery
Posts: 326
Here's a neat trick I use sometimes if I want to set the exposure and keep it. I especially use this with my film camera which only has spot metering. This is good for shots where the lighting doesn't change, like outside on a sunny day or an overcast day or if the shots will be taken in the shade, etc...

The reason why this works is that you are "mimicking" an incident light meter and using its reading to set the exposure which is the best way to achieve proper exposure.

I put the camera in manual and use spot metering.. point it at my palm of my hand - placed in the light - and press the green exposure button. This fixes the manual exposure. I then add 1 EV to the exposure and voila! I have a perfect exposure setting.

The palm of my hand is 1 stop brighter than mid (18%) grey. So the camera's meter will fix the exposure 1 EV below proper exposure. This is why I add 1 EV to compensate.

You can try this with a grey card and you won't have to do any compensation but my hand is always with me and I don't have to carry the grey card around.

Give it a try. You won't have to worry about blown highlights ever again
11-12-2013, 08:39 AM   #12
Site Supporter




Join Date: Jan 2010
Location: Michigan
Photos: Gallery
Posts: 2,073
gbeaton , do you mean add or subtract.
I just tried that and it works well when I stop down by 1 stop eg move from f/11 to f/16.
11-12-2013, 08:44 AM   #13
Pentaxian




Join Date: Sep 2008
Location: Phoenix, AZ
Posts: 1,417
QuoteOriginally posted by normhead Quote
I'd be interested to hear what guys who use neutral density filters would say about this. Could this image have been rescued with the use of filters?
Neutral Density filters won't solve this, because all it will do is force the ISO higher or aperture more open to compensate for less light. When shooting birds or wildlife, neither of those effects are desirable. A standard ND filter affects the whole image so the dynamic range would still be as great, just the lights and darks would be darker to the camera (as if someone turned down the lights)

Norm, you defined the problem perfectly, the highlights on the bird compared to the dark background and several other dark image areas forced the camera to compromise.

This is a no chance in hell of ever getting the exposure right image without photographer knowledge/help.

This is a spot metering on brightest area of subject, +EV comp. The camera is in a lose-lose situation in this image.

Sorry to say, but this image demonstrates "user error" or at least inexperience with compensating for tough lighting conditions.
It's not the camera's fault, it's the photographer's.

BTW, film is even less forgiving, it has far less dynamic range than current DSLR sensors, so film wouldn't solve this problem either
11-12-2013, 08:50 AM   #14
Site Supporter
gbeaton's Avatar

Join Date: Apr 2012
Location: Montreal
Photos: Gallery
Posts: 326
I just tried it again to see make sure I didn't get my math wrong. Yes, I have to compensate by +1 EV. (Actually, I found it was best at +2/3 EV but I didn't want to get into details until now

The +1EV compensation is for a typical caucasian. If you are dark skinned, you may have to compensate in the other direction.. but most people have light coloured palms. So the compensation will be slightly different for each person but it will always be the same. Experiment and you will know where you lie in the Zone system!

@wombat2go - "gbeaton , do you mean add or subtract.
I just tried that and it works well when I stop down by 1 stop eg move from f/11 to f/16."

Last edited by gbeaton; 11-12-2013 at 08:52 AM. Reason: add reference:
11-12-2013, 08:51 AM   #15
Site Supporter
altopiet's Avatar

Join Date: Sep 2010
Location: The Great Karoo, South Africa
Photos: Gallery | Albums
Posts: 1,915
QuoteOriginally posted by nomadkng Quote
Neutral Density filters won't solve this, because all it will do is force the ISO higher or aperture more open to compensate for less light. When shooting birds or wildlife, neither of those effects are desirable. A standard ND filter affects the whole image so the dynamic range would still be as great, just the lights and darks would be darker to the camera (as if someone turned down the lights)

Norm, you defined the problem perfectly, the highlights on the bird compared to the dark background and several other dark image areas forced the camera to compromise.

This is a no chance in hell of ever getting the exposure right image without photographer knowledge/help.

This is a spot metering on brightest area of subject, +EV comp. The camera is in a lose-lose situation in this image.

Sorry to say, but this image demonstrates "user error" or at least inexperience with compensating for tough lighting conditions.
It's not the camera's fault, it's the photographer's.

BTW, film is even less forgiving, it has far less dynamic range than current DSLR sensors, so film wouldn't solve this problem either
I'm sure the not-to-be-mentioned-camera-who-will-make-it's-appearance-this-century will have no problem dealing with this matter...even with imbeciles like me using it...
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!
exposure, k-30, k-50, mode, pentax k30, pentax k50
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax Takes Over Cameras for Ricoh! Driver3 Pentax News and Rumors 58 02-18-2012 02:00 PM
K-5 bounce flash over exposure with response from Metz efkelly Pentax K-5 24 03-15-2011 08:52 PM
Over-exposure with TC stillshunter Pentax SLR Lens Discussion 2 04-03-2010 11:40 AM
Over exposure with K10D istDL-K10D Pentax DSLR Discussion 25 11-01-2008 09:31 AM
Exposure with different cameras. Deni Photographic Technique 17 04-17-2008 12:38 PM



All times are GMT -7. The time now is 03:42 AM. | 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