High noise IR

[lurker]

IR sifus, can tell me why my shots in ISO 100-400 have so much noise in it?

exif
exposure 1 sec, f11, 50mm ISO 100

[eawtan]

Originally Posted by lurker IR sifus, can tell me why my shots in ISO 100-400 have so much noise in it? exif exposure 1 sec, f11, 50mm ISO 100

How did u arrive at the "correct exposure" ?
From my experience, when shooting with the camera meter, lots of stray light enters from your viewfinder causing the exposure to be "off" by 2-3 stops.

Try:
- covering the viewfinder.
- bracket (+1 to +5 in 1 stop steps).

I typically bracket +-1 stop from my "correct" exposure... sometimes the over or under shot is better!

[Pablo]

Hi lurker,

1sec at f11 and only 100ISO is pushing it a bit I think.

What camera are you using ?

With a Canon 20D you would probably needing around 3sec at 400ISO for f11.

I cant say for the Nikon D70 but would be lower than 3sec at f11 400ISO I think

[tomcat]

What camera and IR filters did you used for this shot ? Noise usually occur as a result of excessive post-processing. Could it be that the original image was extremely under-exposed (as could be expected from the very small aperture used) and you had to carry out extensive post-processing to correct the exposure. Another observation is that there are a lot of green colour in the shot. In normal IR images, there are usually little if any green.

[lurker]

i am using a 300D with hoya R72 filter.

i use AF with the filter on

[teerex]

Originally Posted by lurker i am using a 300D with hoya R72 filter. i use AF with the filter on

Can you post your unprocessed out of camera pic and the EXIF? Would like to have a look.

[lurker]

Originally Posted by teerex Can you post your unprocessed out of camera pic and the EXIF? Would like to have a look.

that is a 100% crop pic after auto levels in PS. No other PP done

[Adiemus]

my... that's really noisy.

[lurker]

okie, my original out of cam pic should be underexposed coz most of the time there is not much of anything in it. Black frame with some shade of dark red.

How is a proper out of cam IR pic should look like?

[Pablo]

Originally Posted by lurker i am using a 300D with hoya R72 filter. i use AF with the filter on

Hi lurker,

I am guessing that exposure time etc would be similar to the 20D (guess).

If so, depending on the lens used, I would expect anywhere from 3 to 15sec time required for f11.

With my 50mm f1.8 mkII I set around 2 to 4sec, my 28-135mm 3.5-6 at least double that time.

Also, I trun off the auto focus once I have put the IR filter on (this stops the camera trying to re-focus).

Cheers.

[lurker]

shutter 1/4
aperture 2.8
iso 400
50mm

lens used 50mm 1.8
only resized

so do i get a sharper pic if i AF 1st without the filter, then put on the filter and switch to MF?

[PandaOng]

Originally Posted by lurker okie, my original out of cam pic should be underexposed coz most of the time there is not much of anything in it. Black frame with some shade of dark red. How is a proper out of cam IR pic should look like?

Check out this thread by Max2.8. It should give you a good start for IR-photography. "IR Tutorial". From you pix, when you saw the reddish tone. it could be you have not set the white balance. Read point No.3 & 4.

[lurker]

Originally Posted by PandaOng Check out this thread by Max2.8. It should give you a good start for IR-photography. "IR Tutorial". From you pix, when you saw the reddish tone. it could be you have not set the white balance. Read point No.3 & 4.

tq for the link

[Pablo]

Originally Posted by lurker shutter 1/4 aperture 2.8 iso 400 50mm lens used 50mm 1.8 only resized so do i get a sharper pic if i AF 1st without the filter, then put on the filter and switch to MF?

Yep, it works for me. I leave Auto focus on untill I have screwed the IR filter on fully.
This way it seems to hold the focus still. If you switch to manual before putting filter on, you tend to move the focus.

As Panda Ong mentioned, it seems that you need to do a white balance as per IR-Tutorial.

Cheers

[lurker]

here are two latest test pics... still having some problem getting sharp pic.

[jbma]

I too seems to have a problem with noise. Is it due to not enough sunlight. I shot mine at f8 with 4-6 secs shutter speed. Can anyone advise. Thanks.

[lurker]

well a 10 image pano of KL


4 image vertical pano

[PandaOng]

Wow cool....not only have you got the IR-effects....but also tried something that is different. great Job

The building on the right have been clipped off.

[loupgarou]

noise issue is due to improper exposure, you need to have the bell type exposure, otherwise shadow noise will kill you.

[lurker]

Originally Posted by loupgarou noise issue is due to improper exposure, you need to have the bell type exposure, otherwise shadow noise will kill you.

im am getting the hang of it now been using 4sec exposure at f11 ISO 400.

But still dunno how to make the sky in the image to show up blue and tree snow white. I have done a custom WB using IR image of leaves only.