HOYA UV-IR filters.
These are specialized filters that cut BOTH UV rays below 390nm and IR rays above 700nm. This is important because the visible spectrum is between 400-700nm. Basically UV rays and IR rays both can diminish image clarity and sharpness. But by blocking them both before they get to the image sensor there is a noticeable increase in image quality.
I'd read that IR filters can sometimes work with cameras that haven't been altered for IR. I took a chance on this and have used it with my unaltered Canon EOS Rebel T1i. I have a lot more practising to do, but am very happy with the results from my initial tests with this lens. (Seems to work well in both color shots- where the results are the expected red tones and in shots taken in monochrome)
Used on my un-modified Canon 30D. Required a 30 second exposure to work, so make sure you have a solid tripod. Pictures turned out great...
With Kodak HIE gone, Maco/Efke and Rollie are the staple film for IR shooters. With this filter's ability to cut off IR light at 720 nm that leaves little room between what the filter works at and the film's peak sensitivity. I have got great results on Maco and HIE with this filter. Yes, you need to bracket, but the results are stunning.
I didn't realize it was red in color, so most of my photos come out looking Pink which i have to remove in a software program. It's a little bit to strong for what I wanted and it leaves a circular brightness in the middle of the photo.
I use it with an unmodified Pentax k200d. You must have the camera mounted on a tripod but the results are in my opinion better than samples seen on the internet.
I was a little worried about the ability of the E510 to take good infrared photos with the ir cut filter still in place. All of my worries were gone after I saw that first photo, the hoya rm-72 filter is a good match for this camera. I bright sun my exp time is anywhere from 4 to 6 sec. at f8 and an iso of 400. The other thing that I like about this filter, is that if you let your eye adjust for a few seconds you can see well enough to compose your shot though the view finder. Over all this product is a great value for the money.
Have not used it alot as yet. Due to its nature, it is best used when there is a lot of green folage. Sping is just starting here, so will be out with it alot soon. good results so far.
Perfect lens filter to gain the effect that I was looking for
The IR filter works just as I had expected. Interesting effects. I find I also need a ND (x4) filter with this in bright sunlight.