K20 screen preview problem?

pentaxmz · 12-16-2008, 06:58 PM

Hello folks,

Has anyone noticed this issue. I am fairly new to the K20D but this can't be normal.

When I preview photos, on the K20D LCD screen, any bright white regions flash rapidly as per the example I uploaded.

Hopefully an animated gif (nope-it converts it to jpg) displays in this forum. Okay, I uploaded a wmv, in order to approximate the effect I see on my screen, play this wmv in a video viewer with continuous looping.

What is going on? This is terribly annoying.

Your comments are appreciated.

Attached Files

flashing bright spots.wmv (66.4 KB, 196 views)

nixcamic · 12-16-2008, 07:48 PM

This is flashing to show over/under exposure, I personally like it, but if it bothers you, it can be disabled in the menus, I'm not sure exactly how on the k20d, but it is possible.

pentaxmz · 12-16-2008, 07:53 PM

Originally posted by nixcamic

This is flashing to show over/under exposure, I personally like it, but if it bothers you, it can be disabled in the menus, I'm not sure exactly how on the k20d, but it is possible.

If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area. The example wasn't a good one because its a terrible photo.

Anyhow, it good to know its by design and I can turn it off.

farfisa · 12-16-2008, 07:56 PM

It's a feature

Go into Menu > Playback > Playback display
Hit right on the 4-way selector, then make sure Bright/Dark area is unchecked.
Do the same for Instant Review and Digital Preview.
Then enjoy your K20!

(I turned it off too)

Last edited by farfisa; 12-16-2008 at 08:06 PM.

pop4 · 12-17-2008, 06:13 AM

Originally posted by pentaxmz

If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area. The example wasn't a good one because its a terrible photo.

I didn't look at the video example, but flashing occurring on any bright-white spot or area means that it's working: the area that's flashing is overexposed.

Marc Sabatella · 12-17-2008, 09:42 AM

Originally posted by pentaxmz

If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area.

Right - any bright-white area is probably overexposed in at least one of the three color channels. I don't use this feature either, but make no mistake - it is *working* correctly.

pentaxmz · 12-17-2008, 09:52 AM

Originally posted by pop4

I didn't look at the video example, but flashing occurring on any bright-white spot or area means that it's working: the area that's flashing is overexposed.

I am not sure how useful that feature is. It seems like the flashing also occurs on properly exposed photos where there are bright highlights. Annoying really but I am happy I can turn it off. I do wish the Pentax engineers would have directed their efforts toward the unfinished live preview instead.

Thanks to everyone for their help.

rfortson · 12-17-2008, 11:12 AM

It's annoying, but then blown highlights are annoying. I think the "blinkies" (as I call them) along with the histogram give you a couple of very good tools to make sure you get the best exposure you can with your shots.

BTW, you'll also get a flashing yellow light in areas of the shot where it is underexposed to the point of no detail.

Marc Sabatella · 12-17-2008, 12:55 PM

Originally posted by pentaxmz

I am not sure how useful that feature is. It seems like the flashing also occurs on properly exposed photos where there are bright highlights.

Only if those highlights are in fact overexposed - meaning they've exceeded the bounds of what the camera can capture. If this happens in all three color channels - R, G, and B - then the result will be a pure white highlight with all detail lost. If it happens in just one or two channels, the color will just be off, but it could be off by quite a lot, and detail will be lost in that case too.

So the warning isn't trying to tell you the picture is overexposed as a whole - it might indeed overall be right where you want it. but it is very definitely telling you that particular *areas* of the picture are overexposed. the idea is that this way you can judge for yourself if those areas areas you care about or not. So for example, if you take a picture of a person standing next to a lamp, you *expect* to see the bulb itself overexposed if the person is to be anything other than a silhouette, and you wouldn't worry about losing detail in the light bulb. But it would be useful to know if you've accidentally blown out any highlights in the skin tone as well, because you don't want to find later you've lost the detail in some areas of the skin. And make no mistake, this is not some rare corner I'm talking about - this sort of thing can happen quite often, and it isn't always obvious just from looking at the picture on the LCD.

Still, I prefer the LCD to just show me the picture, so I have the blinkies turned off too. But I also check the histogram whenever i take a shot that looks like it might have issues with blown highlights. That won't tell me *where* the blown highlights are (so I can't distinguish between blown highlights in a lamp versus in the skin tones), but it's better than nothing. I also shoot RAW which allows me to recover a fair amount of blown highlights in PP.

Anyhow, people who take this seriously really rely on the the blinkies to tell them where any blown highlights might be. In a "professional" camera like the K20D is trying to be, that's definitely going to be more valuable than live view, but that's also kind of beside the point, because "blinkies" cost almost nothing to implement, whereas liveview in a DSLR is a very complex feature that necessarily involves some major design issues and compromises. It's not like saving the few minutes it took to implement "blinkies" would have made much difference the months of engineering effort needed to get liveview working. Plus, the "blinkies" were already implemented in previous models - they really came for free.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
kx vs k20 focus screen brightness	kelvybear	Pentax DSLR Discussion	0	02-14-2010 10:06 PM
DOF preview problem	Pusiek	Pentax DSLR Discussion	4	09-04-2008 02:05 PM
Using old screen in K20	gamgee	Pentax DSLR Discussion	13	07-11-2008 11:33 AM
k20 dof preview	bimjo	Pentax DSLR Discussion	3	03-14-2008 05:03 PM
Regarding K20/200D screen	lol101	Pentax News and Rumors	3	01-24-2008 04:36 PM

12-16-2008, 07:48 PM	#2
nixcamic Veteran Member Join Date: Jun 2008 Location: Guatemala Posts: 354	This is flashing to show over/under exposure, I personally like it, but if it bothers you, it can be disabled in the menus, I'm not sure exactly how on the k20d, but it is possible.

12-16-2008, 07:53 PM	#3
pentaxmz Veteran Member Join Date: Dec 2008 Location: Seattle Posts: 659 Original Poster	Originally posted by nixcamic This is flashing to show over/under exposure, I personally like it, but if it bothers you, it can be disabled in the menus, I'm not sure exactly how on the k20d, but it is possible. If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area. The example wasn't a good one because its a terrible photo. Anyhow, it good to know its by design and I can turn it off.

12-16-2008, 07:56 PM	#4
farfisa Veteran Member Join Date: Nov 2008 Location: Toronto, Canada Photos: Gallery Posts: 1,274	It's a feature Go into Menu > Playback > Playback display Hit right on the 4-way selector, then make sure Bright/Dark area is unchecked. Do the same for Instant Review and Digital Preview. Then enjoy your K20! (I turned it off too) Last edited by farfisa; 12-16-2008 at 08:06 PM.

12-17-2008, 06:13 AM	#5
pop4 Veteran Member Join Date: Aug 2007 Location: YMML Photos: Gallery Posts: 1,879	Originally posted by pentaxmz If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area. The example wasn't a good one because its a terrible photo. I didn't look at the video example, but flashing occurring on any bright-white spot or area means that it's working: the area that's flashing is overexposed.

12-17-2008, 09:42 AM	#6
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by pentaxmz If that its purpose, it certainly doesn't work because the flashing occurs on any bright-white spot or area. Right - any bright-white area is probably overexposed in at least one of the three color channels. I don't use this feature either, but make no mistake - it is working correctly.

12-17-2008, 09:52 AM	#7
pentaxmz Veteran Member Join Date: Dec 2008 Location: Seattle Posts: 659 Original Poster	Originally posted by pop4 I didn't look at the video example, but flashing occurring on any bright-white spot or area means that it's working: the area that's flashing is overexposed. I am not sure how useful that feature is. It seems like the flashing also occurs on properly exposed photos where there are bright highlights. Annoying really but I am happy I can turn it off. I do wish the Pentax engineers would have directed their efforts toward the unfinished live preview instead. Thanks to everyone for their help.

12-17-2008, 11:12 AM	#8
rfortson Veteran Member Join Date: Sep 2006 Location: Houston TX Photos: Gallery Posts: 2,129	It's annoying, but then blown highlights are annoying. I think the "blinkies" (as I call them) along with the histogram give you a couple of very good tools to make sure you get the best exposure you can with your shots. BTW, you'll also get a flashing yellow light in areas of the shot where it is underexposed to the point of no detail.

12-17-2008, 12:55 PM	#9
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by pentaxmz I am not sure how useful that feature is. It seems like the flashing also occurs on properly exposed photos where there are bright highlights. Only if those highlights are in fact overexposed - meaning they've exceeded the bounds of what the camera can capture. If this happens in all three color channels - R, G, and B - then the result will be a pure white highlight with all detail lost. If it happens in just one or two channels, the color will just be off, but it could be off by quite a lot, and detail will be lost in that case too. So the warning isn't trying to tell you the picture is overexposed as a whole - it might indeed overall be right where you want it. but it is very definitely telling you that particular areas of the picture are overexposed. the idea is that this way you can judge for yourself if those areas areas you care about or not. So for example, if you take a picture of a person standing next to a lamp, you expect to see the bulb itself overexposed if the person is to be anything other than a silhouette, and you wouldn't worry about losing detail in the light bulb. But it would be useful to know if you've accidentally blown out any highlights in the skin tone as well, because you don't want to find later you've lost the detail in some areas of the skin. And make no mistake, this is not some rare corner I'm talking about - this sort of thing can happen quite often, and it isn't always obvious just from looking at the picture on the LCD. Still, I prefer the LCD to just show me the picture, so I have the blinkies turned off too. But I also check the histogram whenever i take a shot that looks like it might have issues with blown highlights. That won't tell me where the blown highlights are (so I can't distinguish between blown highlights in a lamp versus in the skin tones), but it's better than nothing. I also shoot RAW which allows me to recover a fair amount of blown highlights in PP. Anyhow, people who take this seriously really rely on the the blinkies to tell them where any blown highlights might be. In a "professional" camera like the K20D is trying to be, that's definitely going to be more valuable than live view, but that's also kind of beside the point, because "blinkies" cost almost nothing to implement, whereas liveview in a DSLR is a very complex feature that necessarily involves some major design issues and compromises. It's not like saving the few minutes it took to implement "blinkies" would have made much difference the months of engineering effort needed to get liveview working. Plus, the "blinkies" were already implemented in previous models - they really came for free.