Hot pixels on new *ist DL.

[vulcan]

I just received my Pentax *ist DL the other night and have been playing with it all day. I'm very pleased with it, minus one very anoying problem.

I've discovered that it has a very strong tendancy to produce hot pixels. At first I thought it only occured at iso 3200 on longer exposures, but I discovered tonight that with noise reduction disabled even at ISO 200 it will produce hot pixels in the same locations starting on exposures longer than 1/8 s. Albeit, they are much much less noticeable at iso 200 than at iso 3200.

Now, I've talked to two of my friends who are profesional photographers and they both said that this shouldn't happen and that they have never seen it happen with their cameras. On the other hand I've been told by others that it is totaly normal and that I should be happy thats all I have. In my own experience I have never had this problem occur to this degree with any digital camera I have ever used. I wouldn't be terribly concerned about it, but these problems were noticeable in the first pics I took with the camera.

Can anyone else with the DL (actualy, anyone with any dSLR) do me a favor and try to same type of shots I did with my camera and post them? Firstly, disable noise reduction in the custom settings, set to ISO 200, then switch over to manual mode set the exposure time to 1s (makes the hot pixels easy to find if they are there), and take a shot with the lens cap on. Basicly, I want to find out if this is the norm for camera, or if I just get a cam with a really flaky ccd.

Heres some samples...

http://www.vulc4n.com/images/test2.jpg

http://www.vulc4n.com/images/test3.jpg
http://www.vulc4n.com/images/hicont.jpg

both of the above were taken at iso 3200 to really bring out the hot pixels that are produced. I These still occur at the lower iso leves, but they are nto nearly as prevalent. The contrast of the second shot was increased, and as you can see the hot pixels are in the exact same places as in test3. If this is the norm I guess I will just have to live with always using noise reduction mode (which still doesn't get rid of the hot pixels consistently) and eiditing the rest on my computer.

Thanks for taking the time to read this, and I appriceate your responses.

[jeisner]

This is normal if you are going to shoot at higher ISOs with long exposures you will get hot pixels, especially when you turn the noise reduction off...

The noise reduction isn't actually noise reduction like noise ninja has, all it does is a thing called dark frame subtraction... It basically takes another shot with the shutter closed to determine where the hot pixels are and it 'subracts' those pixels from the other 6 million pixels...

Your 'professional' friends have never seen it as they have never turned it off and maybe don't even understand what it is about...

All cameras have these kind of pixels, it is just the camera, if you don't disable the feature (not all allow you too though) will remove them without you every knowing...

Now if this is happening at lower ISOs and higher framerates where noise reduction is not active, then you have a problem (I have seen this in ALL brands BTW) and if it is under warranty you take it back and they will remap the sensor for you...

[vulcan]

This is normal if you are going to shoot at higher ISOs with long exposures you will get hot pixels, especially when you turn the noise reduction off...

I actualy discovered the 'problem' with noise reduction on, I turned it off to see determine wahat else was going on. I'll post an example of what I'm seeing in real world shots with noise reduction on if I can get something.



Now if this is happening at lower ISOs and higher framerates where noise reduction is not active, then you have a problem (I have seen this in ALL brands BTW) and if it is under warranty you take it back and they will remap the sensor for you...
Out of curiosity, where does the noise reduction mode kick in at on the *ist DL?

I was in contact with Pentax earlier today to ask them about remaping the ccd. I was hoping it had a remaping mode like some olympus and KM cameras do. The rep I talked to said that it can only be remaped by sending it back. In my opinion they should provide the end user a method to remap the sensor on their own, wether it is within the camera itself or it uses an image downloaded to the computer and special software to determine the correct mapping which is then sent to the cameras EPROM.

EDIT: Could you reccomend some certain settings to use that woudl be consistent with "lower ISOs" and "higher framerates".

[jeisner]

In my opinion they should provide the end user a method to remap the sensor on their own,

I agree.. Only Oly and KM have done that though...


Could you reccomend some certain settings to use that woudl be consistent with "lower ISOs" and "higher framerates".

My last two cameras were alright, but my DS when I first got it had this problem.. They actually replaced the whole CCD with a new one, which is up to 9,000 shots now and still no problems...

My DS sensor got replaced as I could take shots at ISO 200 and 1/125 and still clearly see half a dozen hot/stuck pixels..

The Pentax service here in Australia is really good I dropped the camera off and they fixed and shipped back to me within the same week (dropped off Monday got back on the Friday).. My friend sent back his Canon 20d and they took around 3.5 weeks for a remapping and they wanted to charge him for it.. It depends on your local service reps though...

P.S. If you shoot RAW and use something like Adobe or Rawshooter they will automatically remove the hot pixels without you ever knowing they were there..