Quick Infrared filter strength question

bernard0368

Longshanks, The image that you are using for the custom w/b is wrong.

Focus on the grass better if you have a tripod. Set the exposure manually with the filter fitted. The settings will be very close to the same as if the filter was not fitted. 10sec is too long. The image will appear black though. (basically as if you are taking a normal photograph) Set this as custom w/b, now make sure that you change the white balance on the camera to custom. Compose the image with the filter off, put the filter back on. Using the M setting set the shutter speed to bulb the f-stop at 5.6. Using a remote take the snap leave it going for 2mins next one at 3min and final one at 4min. Then see which works best. on the playback these images will have a reddish tint.

.Longshanks.

bernard0368 wrote: »

Longshanks, The image that you are using for the custom w/b is wrong.

Focus on the grass better if you have a tripod. Set the exposure manually with the filter fitted. The settings will be very close to the same as if the filter was not fitted. 10sec is too long. The image will appear black though. (basically as if you are taking a normal photograph) Set this as custom w/b, now make sure that you change the white balance on the camera to custom. Compose the image with the filter off, put the filter back on. Using the M setting set the shutter speed to bulb the f-stop at 5.6. Using a remote take the snap leave it going for 2mins next one at 3min and final one at 4min. Then see which works best. on the playback these images will have a reddish tint.

Thanks for the above.....now i need to apologise in advance as i must be getting annoying now..... but i'm still having trouble. I set the WB exactly as above and got the black image i needed.

The used this custom WB, framed the shot, reattached filter. The first pic below was for 4 minutes, but they all came out a green colour.

NB it was bright but overcast when i took these (i don't have patient to wait for the next sunny day with nice clouds )

All pics at f5.6 and ISO 100

Original after 4 min exposure


Auto levels and auto contrast


Revered reds and blues


Any suggestions?


Thanks,
Kevin

melekalikimaka

set the wb after you take the shot???

.Longshanks.

Yep - set up the custom WB as described above. Then turn it on and took 4 min exposure that turned out green....?

bernard0368

You are on the right track here. Sun Is important in taking Infared. I found with the 40d I was getting a green image as well. When I Used auto w/b on the image in raw processing it would give the red I was used to before. I had a qiuck look at the image you took.

.Longshanks.

Good to know im moving in the right direction! I'll have another go at this next week when get back from a trip that cameras aint allowed (a stag do ). Maybe i should be shooting raw?

melekalikimaka

yes in raw, wb correction is impossible without raw

CabanSail

+1 for RAW.

I was wondering why there was all this carry on about WB when if you shoot RAW then you just select the WB you want in PP

.Longshanks.

The penny dropped when bernard0368 & melekalikimaka mentioned raw. Changing the custom WB again in the raw converter gave the pink/red look i need before going anything else in PS. Before this i though setting the custom WB on the camera was enough but this made all images initially come out green

Anyways, finally some success. Need better subject but at least now i know what to start doing before trecking off the local lake or hillside

Cheers again guys for all your help.

Now to figure out how to get more colour into the final pic...!

Click for larger version on flickr

TheNorthBank

Longshanks100 wrote: »

The penny dropped when bernard0368 & melekalikimaka mentioned raw. Changing the custom WB again in the raw converter gave the pink/red look i need before going anything else in PS. Before this i though setting the custom WB on the camera was enough but this made all images initially come out green

Anyways, finally some success. Need better subject but at least now i know what to start doing before trecking off the local lake or hillside

Cheers again guys for all your help.

Now to figure out how to get more colour into the final pic...!

Click for larger version on flickr

Excellent stuff. Looking forward to seeing some more of your IR stuff now!