[Supernaut]

Is the cheaper 720nm filters from China at ebay any good? The filters from well known brands tend to cost more than I can justify.

[vk4akp]

Hi guys, thanks for all the good info and links to articles.

I'm new (read very green) to IR photography and photography in general but I am interested in having a go at taking some IR shots.

I have a Pentax K200D and I don't wish to modify it (remove the internal CCD filter).

I have seen on Ebay some ROCOLAX 52mm IR filters in the 720, 760, 850, & 950 ranges. Aprox AU$21 each delivered.

Has anyone any experience with this brand vs quality and results etc? I do realise that a Hoya R72 is the filter of choice.

I was going to start out with just a 720 but I am happy to buy at least two different value IR filters up front and maybe more later if there is much advantage in having a few different ranges? So perhaps someone could expand on the benefits of this a little for me please? And operational differences?

A quick settings list for my camera would be helpful also if possible and suggestions on post processing software (Preferably PD).

Thanks. ~Ken~
.-.-.

[creampuff]

One can use just about any IR filter you can get your hand on. The most common just happens to be the Hoya R72. Whether you use a generic made in China, brandless or a branded one like Cokin, Tiffen, B+W or Heliopan, they will all vary a little in terms of spectral response (i.e. you get different colours).

If one selects an IR filter with a progressively higher cutoff wavelength (nm), it will produce images with less colour information, so you will get almost black or white images. Not only that, to get a decent exposure, the camera's exposure will have to be increased for much longer the stronger the IR filter used.

Shooting IR with a normal unmodified DSLR is a 2 step process:

A) Capturing the image
1) With the IR filter over the lens, set the camera's custom manual white balance. To do this go to the Fn menu and navigate to the WB settng.

2) Aim the camera at a patch or green grass or foliage in bright sunlight and ensure that it fills the viewfinder and there is sufficient exposure to get a reading.
Why green leaves or grass? Because leaves reflect a lot of IR light, that's why they appear lighter.
How bright is bright? If you are using a 720nm filter or weaker, you can just make out the scene in the viewfinder if there is bright sunlight lighting the scene.

Using Manual mode is the best mode as one would have to dial in more exposure compensation if using any of the Auto modes. Use the camera's histogram to assess if you have a decent exposure. At this stage, whether the images are blurry or not is immaterial as you want to lock in a usable WB reading. If you get a NG, repeat until the camera can set the custom WB. A good exposure should give a sepia like image, not red.

3) Once you have the WB set, you can proceed to shoot. Remove the IR filter in front of the lens, compose the scene in the viewfinder, put on the filter and shoot. Experiment with exposure settings (ISO, shutter speed and aperture) until you get a decent exposure. Use that histogram!

A few pointers to note:
Focus shift
If you use the viewfinder to focus or rely on the camera's AF to lock focus, your images may not appear pin sharp. This is because you're relying on the visible spectrum to set focus whereas the optimum point of focus for the IR wavelength is different. This problem is more pronounced if a stronger IR filter is used. Solution is to stop down to a smaller aperture and let DOF handle the slight focus shift.

Long exposure times
The IR filter will reduce light transmission to the camera's sensor. Exposure times will most often fall within the handshake threshold (1/20 sec to a few seconds) so use a tripod or prop the camera to something secure to get sharp pictures.

Noisy images
There is a temptation to up the camera's ISO to shoot with higher shutter speeds. Don't do it. The camera's sensor is recording with mostly the red channel and less with the blue and green. So increasing the ISO will exercebate camera noise and is difficult to correct later.

Lens use
I found it much quicker to use an AF lens. Using old manual lenses are too fiddly, especially where focusing is concerned. But whether a manual or AF is used, be aware that some lenses are prone to hot spotting (a noticeably brighter overall spot in the middle of the image). Stopping down will show up the hot spotting even more. Solution is to test and use a lens that doesn't exhibit hot spots (eg. DA 18-55mm, DA 14mm). Since IR landscapes are pretty common, based on actual testing the DA 12-24mm, DA 16-45mm and Sigma 10-20mm all show varying degree of hot spots.

B) Post Processing
1) Open the image in Photoshop or a program the can do a channel swop.
2 Open Levels or Curves and either use the Auto Levels button to stretch the histogram or set the white point at the brightest part of the image.
3) Under Channel Mixer, adjust the Red output channel, move sliders to 0%, blue to 100%; adjust the Blue output channel to 0%, red to 100%; go to the Green output channel and adjust red to 50% and blue to 50%.
This can be made into an action to save time.
4) You already have your basic IR image. Any tints can be tweaked in Hue/Saturation. You can further manipulate the image further.

Give it a try...

[res3567]

I used my K100D for IR photography a couple of years ago and had pretty good results. I wrote up a description of my post processing technique so I wouldn't forget what i did. If interested, take a look at Frank's Intro to Digital Infrared Photography to see what i did.

Here's an example of what i was able to achieve using the K100D + DA 18-55mm + R72 filter + Photoshop CS2



Frank

Wow! That is so coool and that i the effect I desire most from IR Photography; that ghostly white foilage, and erie dremlike effect!

[xs400]

Frank,
Can you submit your article to the forum for "Pentax Photography Articles"? I think your article is a great explanation with wonderful illustrations regarding the how to's of IR photography.
I've done IR before, in the film / my own darkroom days. I can see myself wanting to do IR with my K10D, but I don't have the time to do it now. I'll be wanting to reread your article in the future. I'm sure many others on this list will find your article instructive as I did. This is a perfect topic for the Article subsection which would probably be the first place many of us would look for info.
(just my opinion and suggestion)
Brian

Thanks for the suggestion. I will update the write up and do just that.

[vk4akp]

I've read a few links now on this and some don't mention setting the white balance against a bright IR source.

How important is this? Or is it just a different method of doing things? or is it for creating different results?

Also what public domain software could you recommend for doing the post processing?

.-.-.

[vk4akp]

OK, I got a filter from Ebay.

It has a manufacturing flaw in it though. A small pin head mark in the glass about one 3rd distance from the center and also a slight run off line from the mark also.

I have also found it's impossible to keep clean. I have tried every thing I can think of.

I don't know how critical this is? But I haven't noticed anything in the pictures yet.

Here are a couple of quick images I tried. I don't have a tripod yet so I just sat the camera on a bucket and used the IR remote so as not to bump it.





The RAW images can be downloaded from the index directory by right clicking and saving the links.

http://shazam.zapto.org/igal/pentax-k200d-ir/index.html

I didn't try setting the white balance etc against the grass or anything yet. These were just taken by setting the exposure to the last two longest values available in the camera.

Id' be interested to see what could be made with them if anyone feels like having a quick play and then re-posting the results.

.-.-.

[creampuff]

As mentioned earlier, you need to set your custom White Balance... shooting normally through an IR filter (as your red tinted images show) won't produce the IR effect.

[vk4akp]

OK. Sorry, I'll do a couple more again tomorrow.

I didn't set the white balance as I was concerned about setting it back again correctly.

But I'll give it a go.

.-.-.

[kent]

Hi there. Sorry for bringing old thread to first page. Few days ago I bought the popular r72 and started to play with it. However all I can get is harsh red images. It is ok for BW images when converted but I want some great looking pics like white grass and tress and colorful sky. WB setting doesn't help and setting channel mixer red section slider to 0% makes picture just black. I am posting few samples,without any corrections. Ussualy pics are more red but today I managed to get them with more orange tint.

[vk4akp]

Hi Kent!

Well I'm glad you did bring this thread up again.

I've been wanting to have another go at this for some time now myself but other commitments have slowed down my photography activities lately.

I never did have any luck getting it all to work with the IR filter either.

I had one go at pointing the camera at the grass with the filter on and setting the white balance but it didn't seem to change much.

Perhaps one of the IR guru's here could help out with a more detailed description of what to do on the K200D menu's?

Myself, I only bought one of the cheap Chinese IR filters.

I did notice a couple of manufacturing marks on the glass. Also when I cleaned it the writing on the side of the metal housing just wiped straight off!

However for $20 delivered I guess it's still worth the money to try the idea out and I can always invest in a better one once I start seeing results.

Anyhow, I look forward to reading more in this thread on how to get it all happening.

.-.-.

[vk4akp]

Actually, it's been a while and I just scrolled up the page.

Everything we need to know is set out step by step in an earlier msg above by CreamPuff! (TNX!)

I will print it out and have another go and let you know how I go this time.

.-.-.

[SF1]

Hi,

Really enjoying my IF modded *ist DL2. Generally using it with the 10-17 fish-eye zoom, also nice results with the kit lenses. Have attached a .pdf "how to" to supplement other instructions that are already available online.

Cheers!

[kent]

Just simply incredible! I want to look my pictures like yours,only without modding Ok ,at least to have such a white grass and blue sky

[calicojack]

Really nice job. They look just like good Infared Film shots. I especially love the first one. An ideal location for this effect!