Differences in brightness between consecutive shots in manual mode (K-5)

vonBaloney · 10-29-2012, 02:12 PM

Originally posted by vzbx

Yes... and no I think. Maybe someone with a better knowledge of how WB works can correct me if I'm wrong, but AWB still allows you to see the colors changing, it's just that the camera proprely balances them so that you picture doesn't appear yellowish, or blueish etc.

Well, the WB setting is a single parameter, it doesn't treat different parts of the image independently. Auto white balance just sets that number for you. With a time lapse that included a sunrise or sunset, I'd *want* that blue or orange cast over those parts of the resulting video as contrast to the "neutral" daytime stuff, whereas with a single image maybe I would and maybe I wouldn't depending on what effect I was trying to achieve.

Quote:

I think in this case what happened is that with little ambient light, such as in the pictures above, the camera had trouble finding the right WB and was applying a different one with almost every shot. Sunlight reflection on the clouds could also have played a part as someone mentioned before. So far that's the only logical explanation that I can come up with.

Yes, that's right -- if you check the WB parameter on those shots, you'll find they are all different, which doesn't work when you put the images together in a video. It is fixable if you shoot RAW -- you can set them all to the same thing later. But best just to put it on a neutral daytime setting that you expect will be right for most of the video and then let the sunrise and setset go ahead and have a cast which will look fine in a time-lapse -- it actually looks weird without it.

**JimJohnson** · 10-29-2012, 06:22 PM

Originally posted by vzbx

Hello everyone,

I was wondering if anyone could provide an explanation as to why I get such big differences in luminosity
- Jpeg, 2M,

My 2¢ worth.... I have been less than thrilled with the inconsistency in Pentax's in-camera jpeg rendering with my K-r. Unless I really really want/need those functions that are only available when I shoot only jpeg, I shoot RAW+ (stores both RAW and jpeg). I use the jpegs for quick sorts or shots where the outcome isn't fussy. Everything else is built from RAW.

vonBaloney · 10-29-2012, 06:47 PM

Originally posted by JimJohnson

My 2¢ worth.... I have been less than thrilled with the inconsistency in Pentax's in-camera jpeg rendering with my K-r. Unless I really really want/need those functions that are only available when I shoot only jpeg, I shoot RAW+ (stores both RAW and jpeg). I use the jpegs for quick sorts or shots where the outcome isn't fussy. Everything else is built from RAW.

Huh. I only shoot RAW so if there is any weirdness with that (different rendering from shot to shot) using jpg that could also be a possible explanation. But AWB should be off for a time-lapse in any case as that will definitely create inconsistencies...

vzbx · 10-30-2012, 01:38 AM

I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources

lister6520 · 10-31-2012, 11:55 AM

Originally posted by vzbx

I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources

I would try a few shots in raw anyway top see if the inconsistency shows up there as well. My guess is that there could be some looseness in the aperture mechanism, either on the lens or the camera. However tat wouldn't explain why it happens only in low light.

Try shooting at full open aperture and confirm visually that the aperture blades are indeed fully open - they could be sticking a bit and not opening all the way - I've had that happen on some old manual lenses.

vzbx · 11-05-2012, 07:59 AM - **2 Likes**

I asked Pentax if they could tell the color temperature applied on jpeg images and they just confirmed to me that it's impossible. Their suggestion was the same as the one given by vonBaloney: choose a fixed setting for the white balance. Wise suggestion.

I've managed to put together a fairly decent time-lapse video with some of the images taken that day. The result is on YouTube. Don't forget to choose HD quality, or else it's blurry (the video is in 1080x720):

You Tube

Thanks again for your help and suggestions

cyclone3d · 11-05-2012, 01:22 PM

Originally posted by vzbx

I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources

What are your computer specs?

What version of the Pentax utility are you running?

vzbx · 11-05-2012, 01:55 PM

Originally posted by cyclone3d

What are your computer specs?

Windows Vista Family Premium - Intel Core 2 CPU 6600@2.40 GHz - RAM 2 Gb - NVIDIA GeForce 8500 GT

Originally posted by cyclone3d

What version of the Pentax utility are you running?

The latest I think (v4.35). I know this is not the place to complain, but it's the worst piece of software on my computer. It's slow and not really user friendly. Pentax really need to work on that imho. I tried Photoshop Camera Raw but I couldn't get the same colors as with Pentax Digital Camera Utility.

**mattt** · 11-05-2012, 06:20 PM

I found great performance increase going to Win7. An increase in Ram to 8 gb would help for sure. I don't do any thing so large as this, but adding RAM and updating O/S made vast improvement in my 6 year old PC.

vzbx · 11-06-2012, 02:07 AM

Getting more RAM would certainly improve performances, no doubt about that. But that won't hide the fact that Digital Camera Utility is a clumsy piece of software. Correcting chromatic aberrations is a nightmare for example. With my current computer configuration I have no problem working with Photohop, Camera Raw, or editing music with Soundforge, or editing a 5Gb video (the sunrise time-lapse I did). Why can't Pentax DCU deal with 50 RAW images without using all the computer's ressources? Beats me.

cyclone3d · 11-07-2012, 10:20 AM

Originally posted by vzbx

Windows Vista Family Premium - Intel Core 2 CPU 6600@2.40 GHz - RAM 2 Gb - NVIDIA GeForce 8500 GT

The latest I think (v4.35). I know this is not the place to complain, but it's the worst piece of software on my computer. It's slow and not really user friendly. Pentax really need to work on that imho. I tried Photoshop Camera Raw but I couldn't get the same colors as with Pentax Digital Camera Utility.

2GB RAM with Vista is just asking for trouble. The CPU should be fine for the Pentax DCU.

I would upgrade to at least 4GB of RAM.

Racer X 69 · 11-13-2012, 03:52 PM

Originally posted by vzbx

I took 2300 photos on that morning, . . . . . .

2300 shots in one morning!?!?!

Holy cow! And I thought I took lots of pictures.

In 1986 I burned through 28 36 exposure rolls of Kodachrome 64 at the Champ Car/Trans Am race weekend in Portland, Oregon. It cost a small fortune for processing, but I wound up with lots of great images.

11-13-2012, 03:52 PM	#27
Racer X 69 Moderator Man With A Camera Join Date: Jun 2010 Location: The Great Pacific Northwet, in the Land Between Canada and Mexico Photos: Gallery \| Albums Posts: 28,078	Originally posted by vzbx I took 2300 photos on that morning, . . . . . . 2300 shots in one morning!?!?! Holy cow! And I thought I took lots of pictures. In 1986 I burned through 28 36 exposure rolls of Kodachrome 64 at the Champ Car/Trans Am race weekend in Portland, Oregon. It cost a small fortune for processing, but I wound up with lots of great images. Last edited by Racer X 69; 11-13-2012 at 05:10 PM. Reason: What?

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10-29-2012, 02:12 PM	#16
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by vzbx Yes... and no I think. Maybe someone with a better knowledge of how WB works can correct me if I'm wrong, but AWB still allows you to see the colors changing, it's just that the camera proprely balances them so that you picture doesn't appear yellowish, or blueish etc. Well, the WB setting is a single parameter, it doesn't treat different parts of the image independently. Auto white balance just sets that number for you. With a time lapse that included a sunrise or sunset, I'd want that blue or orange cast over those parts of the resulting video as contrast to the "neutral" daytime stuff, whereas with a single image maybe I would and maybe I wouldn't depending on what effect I was trying to achieve. Quote: I think in this case what happened is that with little ambient light, such as in the pictures above, the camera had trouble finding the right WB and was applying a different one with almost every shot. Sunlight reflection on the clouds could also have played a part as someone mentioned before. So far that's the only logical explanation that I can come up with. Yes, that's right -- if you check the WB parameter on those shots, you'll find they are all different, which doesn't work when you put the images together in a video. It is fixable if you shoot RAW -- you can set them all to the same thing later. But best just to put it on a neutral daytime setting that you expect will be right for most of the video and then let the sunrise and setset go ahead and have a cast which will look fine in a time-lapse -- it actually looks weird without it.

10-29-2012, 06:22 PM	#17
JimJohnson Loyal Site Supporter Join Date: Jan 2012 Location: Summer:Lake Superior - Michigan Winter:Texas Hill Country Photos: Gallery Posts: 2,774	Originally posted by vzbx Hello everyone, I was wondering if anyone could provide an explanation as to why I get such big differences in luminosity - Jpeg, 2M, My 2¢ worth.... I have been less than thrilled with the inconsistency in Pentax's in-camera jpeg rendering with my K-r. Unless I really really want/need those functions that are only available when I shoot only jpeg, I shoot RAW+ (stores both RAW and jpeg). I use the jpegs for quick sorts or shots where the outcome isn't fussy. Everything else is built from RAW.

10-29-2012, 06:47 PM	#18
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by JimJohnson My 2¢ worth.... I have been less than thrilled with the inconsistency in Pentax's in-camera jpeg rendering with my K-r. Unless I really really want/need those functions that are only available when I shoot only jpeg, I shoot RAW+ (stores both RAW and jpeg). I use the jpegs for quick sorts or shots where the outcome isn't fussy. Everything else is built from RAW. Huh. I only shoot RAW so if there is any weirdness with that (different rendering from shot to shot) using jpg that could also be a possible explanation. But AWB should be off for a time-lapse in any case as that will definitely create inconsistencies...

10-30-2012, 01:38 AM	#19
vzbx New Member Join Date: Oct 2012 Location: Liège Posts: 16 Original Poster	I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources

10-31-2012, 11:55 AM	#20
lister6520 Veteran Member Join Date: May 2012 Posts: 733	Originally posted by vzbx I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources I would try a few shots in raw anyway top see if the inconsistency shows up there as well. My guess is that there could be some looseness in the aperture mechanism, either on the lens or the camera. However tat wouldn't explain why it happens only in low light. Try shooting at full open aperture and confirm visually that the aperture blades are indeed fully open - they could be sticking a bit and not opening all the way - I've had that happen on some old manual lenses.

11-05-2012, 01:22 PM	#22
cyclone3d Veteran Member Join Date: Nov 2010 Location: Huntsville, Alabama Posts: 511	Originally posted by vzbx I always shoot in RAW but for a time-lapse that's simply impossible. I took 2300 photos on that morning, in RAW that would be way too heavy for my computer to handle. With 50 photos in RAW, Pentax' Digital Camera Utility software already hogs all my computer ressources What are your computer specs? What version of the Pentax utility are you running?

11-05-2012, 01:55 PM	#23
vzbx New Member Join Date: Oct 2012 Location: Liège Posts: 16 Original Poster	Originally posted by cyclone3d What are your computer specs? Windows Vista Family Premium - Intel Core 2 CPU 6600@2.40 GHz - RAM 2 Gb - NVIDIA GeForce 8500 GT Originally posted by cyclone3d What version of the Pentax utility are you running? The latest I think (v4.35). I know this is not the place to complain, but it's the worst piece of software on my computer. It's slow and not really user friendly. Pentax really need to work on that imho. I tried Photoshop Camera Raw but I couldn't get the same colors as with Pentax Digital Camera Utility.

11-05-2012, 06:20 PM	#24
mattt Site Supporter Join Date: Feb 2011 Location: Niagara Photos: Gallery \| Albums Posts: 3,907	I found great performance increase going to Win7. An increase in Ram to 8 gb would help for sure. I don't do any thing so large as this, but adding RAM and updating O/S made vast improvement in my 6 year old PC.

11-06-2012, 02:07 AM	#25
vzbx New Member Join Date: Oct 2012 Location: Liège Posts: 16 Original Poster	Getting more RAM would certainly improve performances, no doubt about that. But that won't hide the fact that Digital Camera Utility is a clumsy piece of software. Correcting chromatic aberrations is a nightmare for example. With my current computer configuration I have no problem working with Photohop, Camera Raw, or editing music with Soundforge, or editing a 5Gb video (the sunrise time-lapse I did). Why can't Pentax DCU deal with 50 RAW images without using all the computer's ressources? Beats me.

11-07-2012, 10:20 AM	#26
cyclone3d Veteran Member Join Date: Nov 2010 Location: Huntsville, Alabama Posts: 511	Originally posted by vzbx Windows Vista Family Premium - Intel Core 2 CPU 6600@2.40 GHz - RAM 2 Gb - NVIDIA GeForce 8500 GT The latest I think (v4.35). I know this is not the place to complain, but it's the worst piece of software on my computer. It's slow and not really user friendly. Pentax really need to work on that imho. I tried Photoshop Camera Raw but I couldn't get the same colors as with Pentax Digital Camera Utility. 2GB RAM with Vista is just asking for trouble. The CPU should be fine for the Pentax DCU. I would upgrade to at least 4GB of RAM.