digital slr / infrared photography

i am going to buy a digital slr (stuck between a nikon d60 & pentax k200d) i'd

like to try experimenting with IR photography. if i got one of those hoya r72

red filters would i be able to take IR photos in the black & white capture mode

or does it involve a whole lot of messing around iwith imaging software? or is

it even possible at all to do without sending the camera away for modification?

There is an IR blocking filter sandwiched on the sensor. There are a couple of places that will remove it for you, approx $400 to have it done. Not sure what you will get with only an IR transmissive filter on the front, but probably not much.

Even with the internal infrared filter in place it is still possible to take infrared pictures, it just takes longer exposures.

 

An older, but mostly still valid site on this is at

 

http://folk.uio.no/gisle/photo/ir.html

 

 

Some lenses do not work well for infrared because they have internal reflections creating 'hot spots' when they are used, but the article has a list of the older lenses that are unsuitable.

 

The pictures you get will be color infrared, where growing vegetation is red. You can convert to B&W with color corrections, etc. to get the white leaves and so forth of non-color infrared.

Once your camera is converted to IR, you won't be able to do anything else. When using a IR filter, a tripod is needed (exposures vary between 2 and 20 seconds) a remote control is best to abvoid any shakes. Be aware that the focusing distance with IR is different. I bought a D70 with an IR filter a few months ago and I had quite good results. Make sure the camera you buy can take decent IR pictures, the lens is also important (primes are usually better).

I've never done this myself, but I've read that a quick and simple test to see if your camera is sensitive to IR is to point a TV remote control at it and take a picture. If the camera records a point of light coming out of the remote, then it is sensitive. If it doesn't, then it isn't.

 

IR filters are expensive, so this might be a cheap way to find out if it is worthwhile to even try IR photography with your camera. One of these days, I'm going to remember to try this with my K10D.

 

I'm not sure how IR affects autofocus. In the old days, lenses were marked with a focus point for IR. On my old Super Takumars, it is a little red R. In practice, you would focus normally, using visible light, and then shift the focus point from the normal one at the top of the lens, to the red R.

 

Paul Noble

The Hoya R72 is not an infrared filter but a deep red filter. Though lots of folk go this avenue taking 'Deep Red' photos not IR :-)

 

You should get yourself a Wratten 87 or equivalent filter for true IR. Your results will come out in B&W tones with camera set to B&W or color. A cheapish way for me was to buy a six inch sheet, quarter it and onsell three to freinds, and mounted the remaining quarter onto a UV filter I had spare .. you need to make sure it is absolutely light tight with narry a pinhole to let light seep in during the long exposures .. took me awhile to achieve this :-) I started by slotting it into a Cokin holder ... disasterous!

 

The TV Remote test is a reasonable way of detirmining if your camera, un modified, will give you a satisfactory result but I'm not sure how it works with a DSLR becasue the way I have applied the test is through the electronics of pro-sumer's EVF or LCD. If the DSLR has 'live view' {I hope that is the right description] it will work AOK. You need to see a nice bright burst of light for the camera to be usefull and even then the exposures are likely to be on the long size such as one second f/2.8 at 100ISO in bright sunlight.

 

AF seems to sense the IR, after a little time, and find focus AOK. Some of the delay I guess is becuase of the low level of non-visible light coming through the Wratten87 filter and the amount of adjustment the electronics have to make to display an image in the EVF. A similar delay occured when I shot a solar eclipse through the Wratten 87 as the camera coped to give me a 1/4000 shutter at f/8.

An astronomer freind was interested in my result becuase I recorded different sunspots to those our local press guy got by photographing a projected image at the local observatory.

 

If you can afford to have a dedicated IR camera that is the best way to go, removing the caamera's filter and inserting your own Wratten 87.

<i>The Hoya R72 is not an infrared filter but a deep red filter.</i>

<p>

That is flat out wrong. Look up the transmission traces of this filter before misleading others as well. <br>Also, check to see where near IR begins.

<p>

Here is the link:

<br>

http://www.hoyaoptics.com/color_filter/ir_transmitting.htm

I use a Canon G9 IR Converted camera. To repeat what another posted stated: the biggest benefit (and it is a huge advantage) over a digital camera with a R72 IR filter is that I can handhold my camera when taking IR photos in sunlight vs using a tripod or using very high ISO's for the non converted camera.

Photos taken with my Canon G9 IR converted handheld

 

http://d6d2h4gfvy8t8.cloudfront.net/7065326-md.jpg

 

http://d6d2h4gfvy8t8.cloudfront.net/6934491-md.jpg

<p><i>"The Hoya R72 is not an infrared filter but a deep red filter."</i> Really? </p>

 

<a href=" title="Untitled by Trevor Hare, on Flickr"><img src="http://farm3.static.flickr.com/2304/2450982869_9ae840f153.jpg" width="500" height="333" alt="" /></a>

If you are interested in IR, you may want to consider the Sigma SD-14 DSLR - the IR

filter is easily removed by hand (it's also the dust protector) meaning you can hand-

hold IR shots with near-normal exposure times. And of course putting back in the filter

means you have a full color DSLR again (detail similar to around a 10MP DSLR).

<p>

If you use an IR filter like the R72 on a normal camera you are looking at exposures in

the range of a second or more to capture detail, and it will not work quite as well.

<p>

Take a look at some of the work here by a friend of mine:

<p>

<a href="http://www.flickr.com/photos/seng_merrill/collections/72157601132465988/">

http://www.flickr.com/photos/seng_merrill/collections/72157601132465988/</a>

<p>

(some of those are from an IR converted DP-1, but it has a very similar sensor to the

SD-14 so you could expect similar results if you used the same filters and took out the

IR blocker).

<p>

One of my own (not as impressive) examples from the SD-14 is included with this

post.

<p><div></div>

It is really very simple .. with a true IR filter you get a black and white image .. if you get a red result them obviously you are recording some, however small, amount of visual light. And yes I am well aware of the postion of IR on the spectrum. The Wratten 87 and equivalents are true IR filters while the others are obviously not selective enough in cutting out visual light. I think I prefer to trust my Kodak filter booklet rather than Hoya.

<p>In this old thread the problem is mentioned, that one can use only an IR-filter or the normal filter inside the camera. So the decision is, if a camera only for IR work will be ok.<br /> And if one decide to do that modification, the next answer is, which filter is to use.<br>

I had the same thoughts, and got a solution:<br /> In my Canon (I know it is a Pentax thread) EOS 350D / Digital Rebel XT I have enough room in front of the shutter to place the filter with ~ 2 mm thickness there. And so I could change the filter in just 2 minutes. The main problem is dust - but for me it is the possibility to change the filter more valuable that dust free pictures.<br>

Up to now I have the following filters modified:<br /> B&W 093<br /> Hoya R72<br /> UV-Filter<br /> Grey Filter factor 1000<br /> Original Canon IR-Cut filter (with some problems)<br>

Here are the first DIY instructions for this work:<br /> http://4photos.de/camera-diy/exchangeable-filter-dslr.html</p>

<p>I just sent my 20D off to have it converted to a permant IR camera.They will replace the IR blocker with a IR pass filter. They say they have reduced the fee from $400 to $250 for this off season. It will cost $20 for the return shipping. The company is named LifePixel and located in Washington state. You could save some money. You could do it yourself if you have the nerve!</p>

<p>I just purchased a Opteka 72 720nm IR Filter from Amazon a few days ago and just received it. I did a few test shot and I got the deep red image, I haven't tweaked it in PS yet but will do once I get a capture more images. I very excited to go out and shoot.<br>

Gear: Canon 5D MrII</p>

<p> </p>

<h1 > </h1>

<p>I have a Kodak DCS 720x with an easily removable IR filter - it comes out with removal or three screws. I no longer use this camera for daily work and have removed the filter. I have experimented with some IR, but find the results a little indefinite. Does anyone else have any experience with this camera, either with a deep red or a true IR filter?<br>

Test shot made yesterday using a 720nm filter...<br>

<img src="http://myweb.cableone.net/abbysm/images/ir720x.jpg" alt="" /></p>

 

<p>It's not strictly true that you can no longer use the camera for anything else after an IR conversion... I have a Kodak DCS560 with the IR filter removed and have taken many daylight photos with it (though they say that after removing the filter the reds are a bit stronger). With more modern digital cameras the effect of removing the IR filter may be stronger, but you could still tone down the red channel in post-processing or make black-and-white pictures in daylight. Perhaps there is a 'visible light only' filter you can attach to the front of the lens to filter out infrared there?</p>