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12-30-2015, 04:21 AM   #1
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Dark RAW images from K50

Hi all,

I received my K50 today with the DAL 18-55mm and DAL 55-200mm today. This is my very first DLSR and I am just starting off. I noticed that there was a grainy appearance in the VF with both kit lens and even without any lens on. A quick read through some of the threads in this forum helped me understand that it is normal for this camera to have such graininess as it helps perceive DOF better (? that is what I got from reading the other threads ?). Tried my hand a while longer and I kind of get how that graininess actually helps understand which parts are in focus and which are not. I had previously purchased a D3300 with the same kind of lenses and it had a relatively clearer VF, but what seemed to be in focus through the VF when viewed on my Mac,was usually a bit off focus. I returned the D3300 and finally got the K50. ( Loving it so far)

The main reason for creating this thread is that I want to shoot all images in RAW and later fine tune them in Picasa and iPhoto ( still learning the basics of Lightroom and its plethora of features ). However when I took a few shots with adequate lighting, they all came out pretty dark. Is it normal for the K50 to do this? Viewing those pictures in iPhoto showed them to be dark ( like the camera LCD ) but Picasa for some reason was auto correcting and showing me a much closer to the original setup shot.

Need advice on what to do!

Thank you!

12-30-2015, 06:01 AM   #2
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What mode were you shooting in? Manual or letting the camera do its thing? What metering were you using, spot, average etc. Where were you taking the pics? Low light indoors etc. It's an awesome camera, maybe have a play and see if you can get the exposure right.
Sorry for so many questions, it will help determine whasts happening
12-30-2015, 06:26 AM   #3
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My understanding is that Pentax cameras are designed to underexpose slightly as 'normal', simply because you can recover detail in underexposed shots, but not from overexposed ones.
12-30-2015, 07:03 AM   #4
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Please post a couple of examples with the EXIF attached so we can get an idea of the settings you are using. I'm curious also about the grainy appearance in the viewfinder, that certainly does not sound normal.

12-30-2015, 07:44 AM   #5
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That's weird. Unless some settings have been changed, it was a returned camera, or something is wrong with the aperture motor, it shouldn't do that. Try doing a factory reset & get the latest firmware.
12-30-2015, 08:20 AM   #6
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QuoteOriginally posted by shanx Quote
I noticed that there was a grainy appearance in the VF with both kit lens and even without any lens on. A quick read through some of the threads in this forum helped me understand that it is normal for this camera to have such graininess as it helps perceive DOF better
It's not grainy at all on my K-50. It's very lightly "UV Filtered", like if you had "light" sunglasses on, but that is all.

QuoteOriginally posted by shanx Quote
However when I took a few shots with adequate lighting, they all came out pretty dark.
What do you call "adequate"? Because in my experience with the K-50, when shooting in RAW in somewhat low light (which is interior during the day, for example), you have to expose +0.15 at least to come closer to what your eye see, but that is pretty much it, 0.15 is not nothing, but it's not very dark either. So yeah, I'd say the K-50 slightly underexposes (which is normal I think, as RAW has tons of information in "dark" that you can use easely in post-prod, but when something is too light, you're f***ed: burned is burned.)

For me to help, please post a picture taken in interiors (your living room for example) during the day, and maybe also a picture of outside (the street) during the day, with EXIF (metadata of the image) or your setup (example: ISO100, F/4.0, 1/80'', 28mm)
12-30-2015, 10:37 AM   #7
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QuoteOriginally posted by Grippy Quote
What mode were you shooting in? Manual or letting the camera do its thing? What metering were you using, spot, average etc. Where were you taking the pics? Low light indoors etc. It's an awesome camera, maybe have a play and see if you can get the exposure right.
Sorry for so many questions, it will help determine whasts happening
metering mode will have a huge effect on how the camera reacts to a scene. as will the actual subject. a white cat in "adequate" light in spot metering will result in a very dark image. a black cat in the same light with same metering may have blown highlights everywhere. and "adequate" light is rather ambiguous to begin with. see the "sunny 16 rule". indoors, you may very well be in f4 1/25th of a second territory for a neutral gray subject.

that's just an example of why there's no simple answer.

your histogram will give you much more information and is much more reliable as to exposure than your eye or what you see in the viewfinder or on the LCD after the shot. If you truly want to get into how to expose properly for digital, I suggest googling "expose to the right" or "ETTR". learning how to read and "control" your histogram will give you much more consistent results.

however chimping a histogram requires time and patience, which for certain shots (action) you won't have. if that's the case, then we get back to metering mode, subject and exposure compensation controls.
12-30-2015, 03:45 PM   #8
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Try shooting in RAW + JPEG and compare the two?I have a K-30 and sometimes mine are about a stop darker when viewing the RAW file as opposed to the JPEG.Which leads me to ask why that is?Some are identical in the exposure and other times the RAW file appears a stop or so darker than the JPEG,i first thought it was applying my chosen exposure compensation only to the JPEG and not the RAW file but checking the EXIF shows that it happens at times when there is no EV compensation used.

12-30-2015, 05:54 PM   #9
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Never use spot metering unless you really have to and you never really have to.
Check that the EV compensation is on "0".
12-30-2015, 06:05 PM   #10
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QuoteOriginally posted by bschriver11 Quote
Try shooting in RAW + JPEG and compare the two?I have a K-30 and sometimes mine are about a stop darker when viewing the RAW file as opposed to the JPEG.Which leads me to ask why that is?Some are identical in the exposure and other times the RAW file appears a stop or so darker than the JPEG,i first thought it was applying my chosen exposure compensation only to the JPEG and not the RAW file but checking the EXIF shows that it happens at times when there is no EV compensation used.
In-camera jpg settings can lighten the image. Some of the default ones (e.g. Bright) do a little, and the parameters in any of them can be adjusted (e.g to increase/decrease brightness, saturation or contrast). It's possible the brightness parameter has been bumped up on the selected preset.

The other (more likely) explanation is that shadow protection is affecting the exposure levels in the jpgs.
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/265011-highlight-sha...ion-usage.html
https://www.pentaxforums.com/forums/172-pentax-k-3/282312-contrast-highlight-...djustment.html

Highlight protection works on both RAW and jpg images, but shadow protection only works on jpgs.

@shanx, welcome to the forum. You might find the PF recommended settings for the K-50 helpful: https://www.pentaxforums.com/reviews/pentax-k-50-review/recommended-settings.html (The whole of this review pays re-reading.)

---------- Post added 12-31-15 at 12:18 PM ----------

QuoteOriginally posted by SpecialK Quote
Never use spot metering unless you really have to and you never really have to.
I've used it a bit, for example for a bird in shade against a bright sky.

Last edited by Des; 12-30-2015 at 06:16 PM.
12-30-2015, 06:42 PM   #11
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QuoteOriginally posted by Des Quote
I've used it a bit, for example for a bird in shade against a bright sky.
Well, yes, there is that :-) I was on vacation through the Painted Desert environs and I accidentally bumped the meter to spot. Luckily, most things in the desert are medium toned so it did not really matter and I did not notice until I got to a car museum where the black cars/chrome reflections really did a number on the exposure :-)
12-30-2015, 07:34 PM   #12
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First of all, so overwhelmed by the responses received on this forum.

QuoteOriginally posted by Grippy Quote
What mode were you shooting in? Manual or letting the camera do its thing? What metering were you using, spot, average etc. Where were you taking the pics? Low light indoors etc. It's an awesome camera, maybe have a play and see if you can get the exposure right.
Sorry for so many questions, it will help determine whasts happening
Initially tried to let the camera do its thing in auto and switch to Aperture Priority. JPEGs of the same image turned out to be brighter than the RAW images.

QuoteOriginally posted by ramseybuckeye Quote
Please post a couple of examples with the EXIF attached so we can get an idea of the settings you are using. I'm curious also about the grainy appearance in the viewfinder, that certainly does not sound normal.
I will do so.Away from my camera right now. Will do so as soon as I get back.

QuoteOriginally posted by The Squirrel Mafia Quote
That's weird. Unless some settings have been changed, it was a returned camera, or something is wrong with the aperture motor, it shouldn't do that. Try doing a factory reset & get the latest firmware.
I dont think it was a returned camera. When I powered it on for the for the first time, it had all the setting at stock. Also I took quite a few images and then checked for the shutter count on this forum. It was around 41 ( more or less the number of shots I took with it).

I haven't tried a firmware update yet, pics definitely retain their detail in post.

QuoteOriginally posted by vankasteelj Quote
It's not grainy at all on my K-50. It's very lightly "UV Filtered", like if you had "light" sunglasses on, but that is all.


What do you call "adequate"? Because in my experience with the K-50, when shooting in RAW in somewhat low light (which is interior during the day, for example), you have to expose +0.15 at least to come closer to what your eye see, but that is pretty much it, 0.15 is not nothing, but it's not very dark either. So yeah, I'd say the K-50 slightly underexposes (which is normal I think, as RAW has tons of information in "dark" that you can use easely in post-prod, but when something is too light, you're f***ed: burned is burned.)

For me to help, please post a picture taken in interiors (your living room for example) during the day, and maybe also a picture of outside (the street) during the day, with EXIF (metadata of the image) or your setup (example: ISO100, F/4.0, 1/80'', 28mm)
The graininess appears only in the viewfinder. I don't know how a UV filter would look. Since the VF appeared grainy, I took the lens off and looked at a lamp using the VF and it seems to have a grainy pattern. I must mention that this does not affect image quality at all. They come out crisp and no signs of graininess.

QuoteOriginally posted by SpecialK Quote
Never use spot metering unless you really have to and you never really have to.
Check that the EV compensation is on "0".
I haven't changed the metering option at all. Its on the default one. Also EV compensation is set to 0.

Still gonna try to play with the settings and take some more pics to see whats up with it.

I have attached an untouched JPG image of a lamp i was trying to shoot. Also i tried to take some pics of the internals and you can make out a grainy appearance on the prism .

Please let me know if its okay for that pattern to be there. It has not affected any of my images.
Attached Images
View Picture EXIF
PENTAX K-50  Photo 
View Picture EXIF
IPhone 6s Plus  Photo 
View Picture EXIF
IPhone 6s Plus  Photo 
12-31-2015, 06:05 AM   #13
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What you are likely seeing is Apple software failing to recognize the highlight correction tag in Pentax DNG files. Technically, when the highlight correction kicks in, the image is actually underexposed by one stop and then the in-camera JPEG engine boosts the output by one stop... except in highlight areas which is how the scheme works. Most software does the same thing. It recognizes the tag to boost the image display by one stop except in highlight areas. For some unknown reason, Apple software doesn't see this tag to make the adjustment to Pentax DNG RAW files and hence you see an underexposed image. Interestingly, Apple software does recognize highlight tags in Pentax PEF RAW files and hence works correctly.

Try switching the RAW image file format from DNG to PEF and see if the problem remains. If it goes away then you'll know for sure the issue resides in your computer and not your camera.
12-31-2015, 08:25 AM   #14
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QuoteOriginally posted by shanx Quote
I dont think it was a returned camera. When I powered it on for the for the first time, it had all the setting at stock. Also I took quite a few images and then checked for the shutter count on this forum. It was around 41 ( more or less the number of shots I took with it).

I haven't tried a firmware update yet, pics definitely retain their detail in post
OK. That is weird then. Here are the links to the US & Japanese sites for the V1.02 firmware.

This is funny, though.

K-50 | Ricoh Imaging
^ The USA site shows no firmware for the K-50 available.

Latest K-50 Firmware Update : Software Downloads | RICOH IMAGING
^ But this is the latest version on the "Japanese" site for the K-50. Go figure.

The folks at Ricoh/Pentax need to get it together.
12-31-2015, 10:37 AM   #15
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The grainy pattern that you are seeing when you look at the mirror through the lens mount is the pattern of the Fresnel of the focusing screen. That might also be what you are seeing though the view finder.
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