60 sec exposures, red dots on the pics?

kedo_b

kedo_b

Suspended / Banned
Messages
27
Name
Keith
Edit My Images
Yes
Hi all, following one of those "what tripod should i get?" thread I got a benbo trekker which I have to say I'm very pleased with, today was my first complete day out with it and although a wee bit fidly, the versatility is great :thumbs:

Anyways it was falling dark and I ended up doing some 30 and 60 second exposures, all was good until I was checking the pics on my computer and I found red dots that look like dead pixels in some of the photo's. Anyone know what it is?

Cheers
 
Just digital noise. Quite normal on long exposures. Some cameras have noise reduction settings that will attempt to cancel this out, but I'm not sure about the Olympus? It probably has, but the last Olympus I had was an OM1...

cheers
 
kedo_b said:
Hi all, following one of those "what tripod should i get?" thread I got a benbo trekker which I have to say I'm very pleased with, today was my first complete day out with it and although a wee bit fidly, the versatility is great :thumbs:

Anyways it was falling dark and I ended up doing some 30 and 60 second exposures, all was good until I was checking the pics on my computer and I found red dots that look like dead pixels in some of the photo's. Anyone know what it is?

Cheers
Click to expand...

They're not "dead" pixels, they're "hot" pixels. Perfectly normal to see some of these on long exposures.

Bob
 
cheers for the quick replys!
It's the first time out using the tripod, so also the first time I've been doing long exposures. Was a bit worried there was a underlying problem, but thankfully not.

For some reason I turned off the noise reduction and noise filter off, don't really know why I did that. Think I'll turn them back on.

Thanks again
 
The only problem with in-camera noise reduction is that it takes a 'dark' frame to compare to your picture frame to work out where the noise is. The dark frame will match the settings of your picture frame, so if you have just made a 60 sec exposure, the noise reduction will take a 60 sec dark frame, which can seem like an eternity when you are waiting to take the next shot.
 
You can sort them out pretty easily with the clone or heal tools in editing if you don't have the time for long exposure noise reduction to kick in.
 
Cheers again, yeah having to wait an extra minute sounds a bit bone to me, a minute of cloning in the house is better than a minute spent in the dark outside!

Might head down the park again this afternoon and catch the twilight for some more long exposures, as it dumped a good few inches of water over here.

If I have any sense I might also take a torch with me, walking through the forest in the dark was a bit of an effort
 
Whether it's easier to clone or wait will depend on how long an exposure I think. Did a half hour exposure today and I think it would take me a couple of weeks to clone out all the hot pixels. There are other ways to remove noise, dedicated software etc but I can't tell you much about that
 
Bill Roberts said:
Just digital noise. Quite normal on long exposures. Some cameras have noise reduction settings that will attempt to cancel this out, but I'm not sure about the Olympus? It probably has, but the last Olympus I had was an OM1...

cheers
Click to expand...

my bottom drawer olympus has the noise reduction for long exposures..
 
What camera are you using, Canons updated their firmware for some cameras to reduce this.

Matt
 
You must log in or register to reply here.
Back
Top