What are these RED dots in sky ????

[Raj]

Hi.

Just wondering, when I take night shots, the portion which should appear perfactly black (like sky in night) has red dots in it. This becomes more evident when I zoom in
Check this (original size so you can zoom in)

http://www14.plala.or.jp/rajkaori/IMG_0540.JPG

Images looks OK at my monitor settings but if I zoom in I can see red dots (noise ??)
What is this ? This image is from my 20D with parameter 1.

Any help is appriciated. I hope I explained this correctly (if not its because of three glasses of chardonny :-( I had)

Thanks as usual for your help & sorry for posting so many kanashi stuff :-(

[Liang]

That is noise. Try use the Noise Removal software (like NoiseWare) to remove it.

[wtfmate]

They are called Hot pixels. Ocassionally they'll pop up when shooting with a long exposure

[michael.luczkow]

hey raj, i see some light noise, but i don't see any hot pixels. where put a circle around what you are talking about. that picture looks pretty clean to me.

[michael.luczkow]

and where in japan are you? I'm down here in Oki :-)

[Raj]

Micheal I am in Tokyo.

These red dots are spread out throughout the black portion, i.e in sky.
I shot this pic at iso 100
Am I supposed to get noise at ISO 100 with a camera of 20D' callibre ?
Is this normal ?

[michael.luczkow]

i just don't see any red dots man. do you have an LCD for your computer? maybe you've got a few dead pixels on your monitor :-) seriously though, I just don't see what you're talking about.

[pcasciola]

I don't see it either. I even took your photo into Photoshop and sampled the corners of the images, and the red, green and blue levels are almost identical. Not sure if it will help, but Parameter 2 is slightly less noisy than Parameter 1. It will require a little more post processing for sharpness and contrast adjustments, but you will get less noise in general, especially at higher ISOs.

I did a hot pixel/noise test a while back with my 20D, and I really didn't see much except in the corners, until I did a 5 minute ISO 1600 expsoure, when I did start to see the red you are talking about in a 100% crop:

http://photography-on-the.net/forum/showthread.php?t=46024

[ssim]

I did the same as Phil. At a 300% magnification of the image I couldn't find any evidence of the red dots. Red dots are typical of hot pixels and will normally only show up on very long exposures.

[pierrot]

I can't see any red dot (apart from the red air-traffic beacon on the right top corner of the insurance building :D )

[HKFEVER]

Please circle the red dots and re-post it on the forum again.

[Persian-Rice]

I only saw one on the right side..........but if you are seeing red, green, blue, yellow or purple dots, you have a case of the "hot pixel". They are totally random and show up on long exposures. Nothing you can do but clone them out later.

Almost all cameras get these.

[tim]

i just don't see any red dots man. do you have an LCD for your computer? maybe you've got a few dead pixels on your monitor :-) seriously though, I just don't see what you're talking about.

I 2nd this - are you using an LCD with your PC?

[FlyingPete]

I 2nd this - are you using an LCD with your PC?

I 'Third' this, I have loaded the image into Photoshop, and blown it out with levels, there are not hot or stuck pixels visable anywhere in the sky. In fact the detail of the trees above the stairs was quite clear, I was suprised how much dynamic range there actually was!

Looks like you have a good camera then!

[rosie777]

After careful consideration, I 've concluded it could be the serious yet relatively unknown condition called "The Chardonnay Effect"?
;)
Rosie

[Raj]

Rosie, I have to admit that must be the case :( :(

Guys I sincerely apologize to you. I think I was confused & irrational yesterday.

OK to begin with, I shot pics in RAW + JPG & hence was working in PS on both of them (& had a bottle of chardonny at my side :(). I realized this morning that I was seeing RED stuff evident on the RAW images not JPG's. Also my discription was incorrect - red dots implied red "dots", however what I see is not dots referring to hot pixels but looks like uniformly distributed noise patterns. I have uploaded two such RAW & JPEG's sets at:

www14.plala.or.jp/rajkaori

To add more to it - Yes I was viewing pics yesterday on my laptop's LCD. I wanted to do some PS'shppoing on one of the RAW image at work today & then upload it for you guys to view BUT at my work PC (LCD dual monitor) I dont seem to have enough resolution :( black sky is "jet black" here for same image.

So I guess I messed up royally & posted a wrong issue & created pain for all of you unless you find something on the pics I posted just now & if this is the case then I sincerely apologize to all of you & will ask CDS to remove this post so that it does not confuses other viewers.

:cry: :cry: :cry: :cry: :cry: :cry: :cry:

[michael.luczkow]

again man, those pics look clean. stop whining and shoot! :-) :-)

[Raj]

Yep !
I will PM moderators to delete this post.

Cheers

[tim]

No need to apologise or have the thread deleted Raj, everyone makes mistakes, and this was a pretty minor one. So long as you learned something it was worthwhile :)

[pcasciola]

Yeah, Raj, no problem at all. Look at all the time we've wasted talking about the proper terminology for crop factor. At least in this case we were all looking at a picture instead of arguing semantics while our cameras sat idly in our camera bags. ;)

[Persian-Rice]

You learned one thing, dont use LCD for image editing, My goodness do I find it a pain to do any colour "fixing" on an LCD. I do it , then load it on a CRT and it looks like crap.

[Raj]

You learned one thing, dont use LCD for image editing, My goodness do I find it a pain to do any colour "fixing" on an LCD. I do it , then load it on a CRT and it looks like crap.

Any particular reason for this ? These days I would assume more & more people to be using LCD monitors rather than CRT's . Appriciate if anyone can enlighten me on this..

BTW as I mentioned earlier pics look so different on the my personal laptop & work monitor which is also LCD ...

[michael.luczkow]

an LCD can not produce very many colors