Digital IR help needed!

[aim54x]

As I have been posting IR images from my D80IR it is no secret that I have been experimenting with this medium. However, this is pretty much the only forum that I frequent and I only know of a few other members that work with IR so I am hoping that you will come out of the woodwork and help me along this learning experience by sharing what you have encountered and any tips you have.

Currently I have questions about:
-focus, my D80IR has been adjusted for focus, but I still find that infinite focus rarely locks (even in MF I dont get the confirmation dot)
-lenses (Rooz Im looking at you!) do you find any lenses perform better than others in the IR spectrum? I have done a bit of reading in regards to lenses and found that not everything that is said about lenses is correct (ie 50mm f/1.8 is recommended but mine hotspots!)
-CWB, what have you used to set CWB? do you reset CWB? Is there a Kelvin setting that I can use/adjust instead?
-postprocessing - do you find that you have to adjust contrast a lot? what do you do in post?

[chrisk]

Focus: have not had an issue with the d60's whopping amount of af points. lol

Lens: bjorn has excellent ratings for lens' specifically for IR on his site. I use the kit lens mainlly for this cos its small, is flexible in range and cos im shooting at f8 i find it perfectly fine in sharpness. have found the 16-35 acceptable in most cases, mudh better than the 14-24 when i had it. My primes are essentially useless. The 50 and 35 produce severe hotspots. Havent tried the 60 or 105.

Cwb: i set it every time i go out. All i do is point it at a particularly green patch of grass. Sometimes i might have to take a few readings depending on the day and the grass but have to make sure its only green in that vf. Any largish patches of brown screws you over. I also do it in the sun, not in the shade. I have tried doing this on a bush or green foliage but found the results to be unacceptable probably cos there is just too much interference with shadows and shades.

Pp: i just follow the tutorial that i found on lifepixel. I created a photoshop macro for this a while ago to get the channel switching going and then finetune contrast and colour depth from there. A typical s curve is what i find works, albeit much much steeper than what i would use for regular shooting. Im sure there are better ways but i found this to be the simplest and the results are great.

Hope this helps cam.

[aim54x]

Chris, thank you for taking time to reply.

I think I will have to start a list of lenses I have found useful for IR (starting with my own collection). But it good to hear that I am not the only one that has had trouble with the 35mm 1.8 DX and 50mm 1.8D. I am intrigued by your finding that the zoom lenses seem to suit the camera better, but I did find the 18-55mm DX to work very nicely, although my Tamron 17-50 does seem to block out a lot of IR light.....

As for CWB. I set it once, a while ago and have been using the same one since (set as per your description actually) but I think I will try resetting it again next time I am out and about with the D80IR.

[aim54x]

My findings so far in terms of lenses and suitability (i will update this as I use more of my lenses for IR):

Primes
-Voigtlander Color Skopar 20mm f/3.5 SL II - no hot spots but will flare
-Nikkor AF-S DX 35mm f/1.8 - will hot spot at times
-Nikkor AF 50mm f/1.8D - will hot spot as you close down
-Voigtlander Nokton 58mm f/1.4 SL II - From f/2.5 onwards will hot spot dramatically
-Nikon AI 135mm f/2.8 - no hot spots or flare, but have only used lightly so further testing needed

Zooms
-Tokina AT-X DX 10-17mm f/3.5-4.5 Fisheye - no hot spots or flare
-Zoom Nikkor AF-S DX 16-85mm f/3.5-5.6 VR - no hot spots or flare
-Tamron SP AF 17-50mm f/2.8 Di II - no hot spots or flare BUT seems to transmit a lot less IR light

[glamy]

Hi Cameron,
I used to carry a green bag from Woolworth in my boot to set the WB, too hard to find grass at times... Have not done much IR lately (past few years...), still thinking of converting my D70.

[chrisk]

Hi Cameron,
I used to carry a green bag from Woolworth in my boot to set the WB, too hard to find grass at times... Have not done much IR lately (past few years...), still thinking of converting my D70.

goddamit what a freakin great idea !

[aim54x]

Hi Cameron,
I used to carry a green bag from Woolworth in my boot to set the WB, too hard to find grass at times... Have not done much IR lately (past few years...), still thinking of converting my D70.

Good tip!

[Murray Foote]

Hi Cameron

Your ultimate source of information is possibly herebut it will cost you about $28 for a year's subscription.

[aim54x]

Hi Cameron

Your ultimate source of information is possibly herebut it will cost you about $28 for a year's subscription.

Thank you for the link. I will consider taking out a subscription but at the moment I do have to watch where I am putting my pennies as I am currently between jobs and only holding onto one day a week in a casual role

[Murray Foote]

Lloyd Chambers has lots of info on what lenses are good but I think the real crunch is in how you post-process. Never having read his offerings, I don't know how good he is on that.

I went to an IR presentation a while ago and got a handout that included various links. I didn't transfer them to my browser and was about to say I'll let you know when and if I find them when I remembered - they're on the CPS web site.

[aim54x]

Lloyd Chambers has lots of info on what lenses are good but I think the real crunch is in how you post-process. Never having read his offerings, I don't know how good he is on that.

I went to an IR presentation a while ago and got a handout that included various links. I didn't transfer them to my browser and was about to say I'll let you know when and if I find them when I remembered - they're on the CPS web site.

Thanks for the link...If nothing else it did give me a starting point for a Kelvin WB starting place. I guess I will just have to keep playing until I find something that I am happy with

[robert]

It took me a while to admit it but Digital IR is so much more convenient than film- anyone remember loading and changing Kodak HIE in the dark! I ended up using Ilford SFX for convenience and a slightly dialled down IR look. I'm not sure if i prefer the lack of grain in digital though- although looking at some old darkroom enlargements I cant believe how grainy those things were!!

As far as Custom White Balance- i tend to shoot and use each time i go out as the light will be different- clouds, time of day etc, but this really only aids the preview screen and gives a start place when shooting RAW. i dont think its too critical and looking at your B&W images Cam the WB seems fine.

I'm on an old Canon so cant comment on hotspots and lenses for Nikon, other than to say it is a reality with some lenses. If you see some colour or contrast change in the centre of the image it will be hotspot- though this varies depending on aperture used.

I get focus confirmation on my 300D, though i do still see more images where the focus could be better. Wouldnt mind live view as i find using it on my 5dII for focus really nails focus- even after exhaustive micro adjust for each lens. i gues you get to focus on the exact spot you want rather than the wider selection from a dot in the viewfinder. As far as our cameras without live view i guess its just a matter of shoot and chimp.

Re PP i have now accepted that i dont shoot unless its really bright sunshine, there is just too much selective editing when an area is in sunlight next to a cloud covered area, and the dynamic range of my old camera is not great. i guess it's more of a personal thing and there are plenty of examples of shadow and indoors in the link from Murray F. I still use quite a few layers of specific sections to dial up the contrast- rocks dont need as much as foliage etc. i also tend to set the exposure using the white dropper in levels on the foliage i want to glow, enlarge it a bit and try a few different leaves to see which one doesnt blow out the rest of the image. And yes i do have to bump contrast alot. i think it depends on taste. I tend to set the contrast in RAW for the general impression i want and then select areas using layers to bump local contrast, eg a small gorup of trees or rock face to balance the other face which is in the sun etc.

If you look at the old film IR the contast was often black and white with not too much tonal gradation- though i think it was more often than not too harsh and digital does produce a nicer tonal gradation. Kind of comes down to how 'harsh' or eye popping you want- i guess experimentation and asking the forum on different options/versions might be the way to go.

As far as false colour there are a few tutorials floating around so they would be a good place to start- channel swapping etc, but i tend to do a few versions and end up sticking with the B&W anyway.

Having said all of this I guess its just like conventional photography- take lots of photos and notice what makes one image more pleasing than another.