My K5 has problem or....really a big bug!

Marco_Pochi · 10-25-2010, 11:15 AM

Once I try to shoot some high iso photo (iso 12800, 25600 or 51200), I find that when I set the NR other than AUTO mode. The photo comes out with strange color...... This happens frequently for ISO 51200......

Any one have the same problem???

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Noidea · 10-25-2010, 11:20 AM

It looks like you have cross-processing turned on

Marco_Pochi · 10-25-2010, 11:25 AM

I have turned it off.

When I got a problem photo, I changed iso to 800 and shoot again, the photo was normal....

Once I change it back to 51200......It happened again......

JohnBee · 10-25-2010, 11:28 AM

I'd try resetting everything, removing battery etc. it before calling it.
If it does it after that... I think it's quite clear what needs to be done.

Cannikin · 10-25-2010, 11:42 AM

It's pretty hard to tell what color the picture really looks like at 51200 on my K-5 because of all the noise, but I didn't notice anything particularly off at 12800 or 25600, Auto NR Off, JPEG or RAW. The chroma noise at 51200 can make the color look somewhat off, but overall the color looks roughly correct on my camera.

You're going to have to post larger pictures from both low and high ISO for us to be able to see what's going on. We can't tell anything from that small photo, because we don't know what that scene looks like at low ISO.

EDIT: Unless you're talking about the yellow band in the middle of that picture. Is it supposed to be more or less white across the whole thing? If so, then no, my camera doesn't do that.

Not that I personally would ever really use 51200, or 25600 for that matter anyway. There's a reason they're "expanded" ISO, and not selectable by default. Unless you have crazy NR skills like JohnBee, they're not really usable.

Wheatfield · 10-25-2010, 11:59 AM

I don't suppose that picture is illuminated by florescent light is it?

telfish · 10-25-2010, 12:07 PM

What sort of lighting? I got something similar at a Hockey game once under some sort of Sodium lighting. It gave a strobe effect and a strange color tone.

imtheguy · 10-25-2010, 12:08 PM

Originally posted by Wheatfield

I don't suppose that picture is illuminated by florescent light is it?

Thats the right question to start. I use 5000K compact flourescent lamps to examine prints at night. I get some shots looking exactly like the OPs sample when I use the lamps to light a focus chart.

deadwolfbones · 10-25-2010, 12:56 PM

Yeah, fluorescents will cause weird color banding.

Clicker · 10-25-2010, 01:17 PM

Looks like a flouresent tube reflection ... indoors i always manually set my WB.

telfish · 10-25-2010, 01:30 PM

The reason that you are getting banding at some ISO's and not others if you are shooting under florescent or other light with a definite flicker is that the shutter speed will vary with the ISO and the flicker will produce these off color banding effects that will coincide with those shutter speeds. Try the camera outdoors in daylight at the higher ISO's and I believe these issues will be absent.

inferno10 · 10-25-2010, 01:52 PM - **1 Like**

Definitely appears to be fluorescent lighting. Based on the EXIF, you were shooting at 1/1250s. Fluroescent lighting usually flickers on and off at twice the frequency of your current (usually either 1/120s or 1/100s, depending where you live). Because your shutter speed was faster than the cycle time for the light, your camera captured the time between an on and off phase. If you sync up your shutter speed to 1/60s or 1/50s (again depending on your mains frequency), you shouldn't see that band appear anymore, as the fluorescent light will have fully cycled on/off, thus evenly filling the scene with light.

The other issue w/ fluorescent lighting is that the spectrum of light isn't nearly as wide as other light, so you'll still need to fix the white balance with the image.

In short, this is not a problem with your K-5; any camera can experience this issue, as it's mainly due to shutter-speed .

- Jason

kittykat46 · 10-25-2010, 07:24 PM

I don't think I've ever been in a bright enough place under artificial lighting to use 1/1250 sec shutter speed.
I guess this is unchartered territory, made possible by the K-5's unbelievable ISO range.
If you can't replicate the problem under normal sunlight, then that's the likely explanation, and the solution is to avoid such a high shutter speed indoors.

twitch · 10-25-2010, 07:35 PM

I've heard of this problem with floruesent lights and high shutter speeds. Short answer is there is nothing wrong with the camera, it's simply a "feature" of that type of lighting that isn't visible to the naked eye, but is only seen when captured on a camera at a fast enough shutter speed.

kittykat46 · 10-25-2010, 07:51 PM

Another "effect" you may see under fluorescent lights, especially the long-tube types, if your shutter speed is fast enough - you may see different parts of the room unevenly lit.

The human eye doesn't react fast enough to "see" this...

10-25-2010, 11:42 AM	#5
Cannikin Veteran Member Join Date: Mar 2010 Location: SW Washington Posts: 833	It's pretty hard to tell what color the picture really looks like at 51200 on my K-5 because of all the noise, but I didn't notice anything particularly off at 12800 or 25600, Auto NR Off, JPEG or RAW. The chroma noise at 51200 can make the color look somewhat off, but overall the color looks roughly correct on my camera. You're going to have to post larger pictures from both low and high ISO for us to be able to see what's going on. We can't tell anything from that small photo, because we don't know what that scene looks like at low ISO. EDIT: Unless you're talking about the yellow band in the middle of that picture. Is it supposed to be more or less white across the whole thing? If so, then no, my camera doesn't do that. Not that I personally would ever really use 51200, or 25600 for that matter anyway. There's a reason they're "expanded" ISO, and not selectable by default. Unless you have crazy NR skills like JohnBee, they're not really usable. Last edited by Cannikin; 10-25-2010 at 11:59 AM.

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10-25-2010, 11:20 AM	#2
Noidea New Member Join Date: Oct 2010 Location: London Posts: 21	It looks like you have cross-processing turned on

10-25-2010, 11:25 AM	#3
Marco_Pochi New Member Join Date: Apr 2010 Posts: 4 Original Poster	I have turned it off. When I got a problem photo, I changed iso to 800 and shoot again, the photo was normal.... Once I change it back to 51200......It happened again......

10-25-2010, 11:28 AM	#4
JohnBee Veteran Member Join Date: Sep 2008 Location: Newrfoundland Photos: Albums Posts: 4,667	I'd try resetting everything, removing battery etc. it before calling it. If it does it after that... I think it's quite clear what needs to be done.

10-25-2010, 11:59 AM	#6
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	I don't suppose that picture is illuminated by florescent light is it?

10-25-2010, 12:07 PM	#7
telfish Veteran Member Join Date: Aug 2009 Location: NY Posts: 407	What sort of lighting? I got something similar at a Hockey game once under some sort of Sodium lighting. It gave a strobe effect and a strange color tone.

10-25-2010, 12:08 PM	#8
imtheguy Site Supporter Join Date: Mar 2009 Location: Virginia Beach Photos: Gallery \| Albums Posts: 2,950	Originally posted by Wheatfield I don't suppose that picture is illuminated by florescent light is it? Thats the right question to start. I use 5000K compact flourescent lamps to examine prints at night. I get some shots looking exactly like the OPs sample when I use the lamps to light a focus chart.

10-25-2010, 12:56 PM	#9
deadwolfbones Veteran Member Join Date: Sep 2007 Location: La Crescenta, CA Posts: 7,450	Yeah, fluorescents will cause weird color banding.

10-25-2010, 01:17 PM	#10
Clicker Veteran Member Join Date: May 2008 Photos: Gallery Posts: 3,241	Looks like a flouresent tube reflection ... indoors i always manually set my WB.

10-25-2010, 01:30 PM	#11
telfish Veteran Member Join Date: Aug 2009 Location: NY Posts: 407	The reason that you are getting banding at some ISO's and not others if you are shooting under florescent or other light with a definite flicker is that the shutter speed will vary with the ISO and the flicker will produce these off color banding effects that will coincide with those shutter speeds. Try the camera outdoors in daylight at the higher ISO's and I believe these issues will be absent.

10-25-2010, 01:52 PM - 1 Like	#12
inferno10 Veteran Member Join Date: Feb 2007 Location: San Francisco, California Posts: 342	Definitely appears to be fluorescent lighting. Based on the EXIF, you were shooting at 1/1250s. Fluroescent lighting usually flickers on and off at twice the frequency of your current (usually either 1/120s or 1/100s, depending where you live). Because your shutter speed was faster than the cycle time for the light, your camera captured the time between an on and off phase. If you sync up your shutter speed to 1/60s or 1/50s (again depending on your mains frequency), you shouldn't see that band appear anymore, as the fluorescent light will have fully cycled on/off, thus evenly filling the scene with light. The other issue w/ fluorescent lighting is that the spectrum of light isn't nearly as wide as other light, so you'll still need to fix the white balance with the image. In short, this is not a problem with your K-5; any camera can experience this issue, as it's mainly due to shutter-speed . - Jason

10-25-2010, 07:24 PM	#13
kittykat46 Veteran Member Join Date: Dec 2007 Posts: 923	I don't think I've ever been in a bright enough place under artificial lighting to use 1/1250 sec shutter speed. I guess this is unchartered territory, made possible by the K-5's unbelievable ISO range. If you can't replicate the problem under normal sunlight, then that's the likely explanation, and the solution is to avoid such a high shutter speed indoors.

10-25-2010, 07:35 PM	#14
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	I've heard of this problem with floruesent lights and high shutter speeds. Short answer is there is nothing wrong with the camera, it's simply a "feature" of that type of lighting that isn't visible to the naked eye, but is only seen when captured on a camera at a fast enough shutter speed.

10-25-2010, 07:51 PM	#15
kittykat46 Veteran Member Join Date: Dec 2007 Posts: 923	Another "effect" you may see under fluorescent lights, especially the long-tube types, if your shutter speed is fast enough - you may see different parts of the room unevenly lit. The human eye doesn't react fast enough to "see" this...