Infra Red Filters

[Throttle]

hi all, i got a cheap ir filter to try out so i thought i would let you know how i got on with it. IR images look unusual as grass and leaves reflect ir light well and end up almost white in shots. The filter i got is a square filter that fits a lee holder and it is black to the eye so no visible light gets through.
I found the filter i got needs an exposure of 30 to 60 seconds in sunlight similar to a big stopper and i used the histogram showing each colour channel to get the best result. The main issue i found was focus as ir light focuses differently to visible light and you cant tell if its focused correctly until after you take the shots.
Here is the result i think i set the focus for this shot at 10 meters

[/url]St Michaels Church Caerhays Cornwall by Robert A Scott, on Flickr[/IMG]

The shots come out of camera with a red cast so post processing is a matter of adjusting the colour channels to suit and you can got some interesting effects it found increasing the green and reducing blue channel worked well. Personally i prefered the mono look.

let me know what you think and if anyone else has any ir shots please add them them

 

[D.P.]

Did you remove the IR filter from your sensor?
If you really get in to IR photography it is worth getting an older DSLR and sending it off to get the IR filter removed.

Sensors are naturally very sensitive to IR wavelengths so a filter is in place to block IR light. The IR filter you put in front of the lens is actually a visible light filter and only permits IR light, so obvious with the sensor block IR light and the lens filter blocking visible you don't get much light through. If you mod the camera then you get exposure times close to normal.

Also if you are a Nikon shooter Bjorn Rorslet has useful reviews of lenses indicating IR performance. Some lenses do much better than others and it has little to do with the visible light image quality.
http://www.naturfotograf.com/index2.html


I have always wanted an IR set up but after using a friend Hoya IR filter I realized I need to buy a modified camera. These can be quite cheap because you can get away with a much older camera with older sensor. You can remve the AA filter at the same time to improve sharpness.

 

[Throttle]

i have read about modifying the camera sensor to make it ir specific but i used a cheap ir filter in my lee filter holder as i just wanted to try it out. I think removing the filter in the camera can also reduce problems focusing shots. Thanks for the link D.P. i will check it out

 

[D.P.]

i have read about modifying the camera sensor to make it ir specific but i used a cheap ir filter in my lee filter holder as i just wanted to try it out. I think removing the filter in the camera can also reduce problems focusing shots. Thanks for the link D.P. i will check it out

its just something to think about. The reason the exposure times are long is because the camera tries to block IR, the filter on the lens tries to block visible light but let IR come through, so it makes sense to remvoe the IR filter on the sensor but this ruins the camera for other purposes.

this company does the modifications for you at a price:
http://www.lifepixel.com/infrared-faq

But you can sometimes buy older second hand cameras that have already been modified for not much more.



One thing that is cool about IR photos is that you can often get more details through haze which is great for summer black and white landscape shots. They are also great for portraits, IR light gives a much softer look on human skin and shows less blemishes etc.

 

[Derek W]

There's a guy on here Johnny Lucidcomposure who did a nice IR shot or two about 5yrs ago. I did a search for him but his image host / website has lapsed so his shots aren't available. I did however find his facebook photography site! https://www.facebook.com/pages/Alldepth-Photography-Uk/203038146389663?sk=photos_stream There's only a selection of 4 IR images (you'll need to scroll down to find them)

From memory I think he used a Canon for those shots (forget which model) possibly modded but he also had his own IR action in Photoshop to tweak the end result.

 

[CGrieves]

If you remove the IR filter from a camera, you can still use it for normal photography- just screw IR filters onto your lenses.

The Canon 60Da has no IR filter from the factory (as did the 20Da). Both also work in most situations for visible-light photography as they are calibrated to do so from the factory. There still an advantage to using an IR filter in some situations though.