Dead/hot pixel: How much should I expected? (E-PL5)

John_of_LA · Dec 19, 2013

Hi,

Long time no post. I finally got back to photography and upgraded my E-PL1 to E-PL5. I'd like to know how much should I expect the new sensor regarding hot/dead pixel? I did some lens cap test and I got these. The test is done in cold start. Camera has been off for days before the test.

1. ISO200, 1s, 80 hot pixel (luminance > 60)

2. ISO1600, 1s, 3734 hot pixel (luminance > 60)

3. ISO1600, 1/10, 92 hot pixel (luminance > 60)

4. ISO1600, 1/400, 11 hot pixel (luminance > 60)

Says, should I expect clean image @ ISO200, 1s exposure? How about 1s ISO1600? I got quite a bit hot/dead pixel there. I try "pixel mapping" utility, the result is the same. It's like that camera won't register hot pixel for automatic removal.

Did I see it in my picture? Of course, the ISO1600 1/400, saw same location of hot pixel (bright red, bright blue). Only way to remove it is to force run long exposure noise reduction (in-camera dark frame subtraction). To me, it doesn't make sense to run this every time.

Am I expect too much? Or should I rush to service center?

Thanks for sharing your experience,

John

JeanPierre Martel · Dec 19, 2013

John_of_LA said:
Hi,

Long time no post. I finally got back to photography and upgraded my E-PL1 to E-PL5. I'd like to know how much should I expect the new sensor regarding hot/dead pixel? I did some lens cap test and I got these. The test is done in cold start. Camera has been off for days before the test.

I'm not sure that this will work, but before sending the camera for repair, I would try the suggestions in the following article:

http://www.olympusamerica.com/crm/oneoffpages/ask_oly/crm_e_ask_oly_03_09.asp

One stuck pixel (pure white) bugged me since last October on my OM-D e-m5. I've tried "Pixel Mapping" a few days ago and that problem is now completely gone.

So their suggestions for dead pixels might also work for you. Give a try.

John_of_LA · Dec 19, 2013

Thanks for your suggestion but I've already tried the pixel mapping utility. It didn't remove those hot pixels. I'd just like to know how it is compared to other units. May day time pictures look fine but when take slightly longer exposure, it shows up pretty quickly.

IMHO, at base ISO should be good for few secs. Olympus NR will kick in at 4 or more sec, so I guess I should have relatively noise free at 1 sec.

I'm not sure that either I hope too much, or my sensor is going bad, or my camera has issue that won't register hot pixel with pixel mapping....

baxters · Dec 19, 2013

Hmm. I've never been concerned about hot pixels, but I tried your 1/400 at ISO 1600 exposure (M mode and MF) with the lens covered. Sure enough, I see two hot pixels on MY EPL5. Might have been more, but I only looked on the LCD and these appeared with the first press of the magnify button in review. They were red dots.

Pixel mapping got rid of them for me. I doubt that I would see them on most of my EPL5 pix.

So I suppose the odds are you will see a couple if you look for them.

John_of_LA · Dec 19, 2013

Here's a crop of my image that shows the problem. The camera was purchased last month and has less than 1000 shots. Do you think it's normal??

ISO200, 2s, f2, Natural mode. Look at the grey dots on the bottom half. Pixel mapping was just done.

Art_P · Dec 19, 2013

It's there to find check for long exposure hot pixels, which are a different matter than dead pixels- dead pixels will always be dead, and mapping will take care of them, but hot pixels are more dynamic, and are dealt w by capturing a frame w the shutter closed and subtracting those hot pixels from the previous image.

If you have noise reduction set to OFF, you WILL get hot pixels on longer exposures.

An alternative would be to rig some kind of cryogenic cooling system, but besides voiding the warranty and screwing w IBIS, it would probably cause frost on the sensor!

--
Art P
"I am a creature of contrast,
of light and shadow.
I live where the two play together,
I thrive on the conflict"

baxters · Dec 19, 2013

Art_P said:
If you have noise reduction set to OFF, you WILL get hot pixels on longer exposures."

What's the difference between setting it to ON and AUTO? Does it force the second exposure fro subtraction in ON mode?

Yes, I think the OP has hot pixels arising from the sesnor heating up. Thises cannot be mapped.

By the way, my two red pixels turned out to be one single pixel that was white when magnified and viewed on my PC monitor. I saw double when looking up close at the camera screen, but these old eyes of mine have seen Mickey Mantle and President Eisenhower in person. Knowing where it was, I found it again in a few earlier EPL5 shots where the same area was dark. Glad it's mapped out.

John_of_LA · Dec 19, 2013

baxters said:
Art_P said:

If you have noise reduction set to OFF, you WILL get hot pixels on longer exposures."

Click to expand...

What's the difference between setting it to ON and AUTO? Does it force the second exposure fro subtraction in ON mode?

ON is always on. AUTO, the NR will kick in for exposure longer than 4 secs regardless of ISO.

I have it set to AUTO, so it won't apply to my image. When I set it to ON, it does double exposure and those dots are gone.

baxters said:
Yes, I think the OP has hot pixels arising from the sesnor heating up. Thises cannot be mapped.

By the way, my two red pixels turned out to be one single pixel that was white when magnified and viewed on my PC monitor. I saw double when looking up close at the camera screen, but these old eyes of mine have seen Mickey Mantle and President Eisenhower in person. Knowing where it was, I found it again in a few earlier EPL5 shots where the same area was dark. Glad it's mapped out.

So, I guess, it is what it is?? I tested this from cold start and camera has been off for days. To be frankly, I expect it to perform better... or at least be able to map out. It doesn't make sense that I have to turn on long exposure noise reduction for a 1/400 shots.

joeletx · Dec 19, 2013

The Exif shows the exposure time is 2 seconds; it is definitely pixel noise due to long exposure and shooting lens cap. Even my E-5 got pixel noise from shooting the moon at ISO-200 until I turned on noise reduction. My new E-M1 is set to Automatic by default and I think the new Pen's do have the Auto setting as well. The manual basically said the camera Auto setting turns on noise reduction when shooting overly dark subject with long exposure time. I am not sure what determines long or dark.

baxters · Dec 19, 2013

John_of_LA said:
So, I guess, it is what it is?? I tested this from cold start and camera has been off for days. To be frankly, I expect it to perform better... or at least be able to map out. It doesn't make sense that I have to turn on long exposure noise reduction for a 1/400 shots.

No, you paid for a camera where you can shoot at 1/400 and the defects map out. Like mine. So if it's under warranty, consider getting a replacement.

John_of_LA · Dec 19, 2013

joeletx said:
The Exif shows the exposure time is 2 seconds; it is definitely pixel noise due to long exposure and shooting lens cap. Even my E-5 got pixel noise from shooting the moon at ISO-200 until I turned on noise reduction. My new E-M1 is set to Automatic by default and I think the new Pen's do have the Auto setting as well. The manual basically said the camera Auto setting turns on noise reduction when shooting overly dark subject with long exposure time. I am not sure what determines long or dark.

Well, yes, I expect some as well.

But my question is 100+ hot pixel (luminance 60+) @ 2s, base ISO is normal or not? What about your camera? I've just wanna know that should I bother sending it in or not. I'd really like to use my new camera during holidays.

Search

Dead/hot pixel: How much should I expected? (E-PL5)

John_of_LA

Senior Member

JeanPierre Martel

Senior Member

John_of_LA

Senior Member

baxters

Veteran Member

John_of_LA

Senior Member

Attachments

Art_P

Forum Pro

baxters

Veteran Member

John_of_LA

Senior Member

joeletx

Senior Member

baxters

Veteran Member

John_of_LA

Senior Member

Similar threads

Keyboard shortcuts