Advice on IR filter

[teokf]

I saw some very impressive IR pixs and would like to try my hands on it. I realised the HOYA R72 is a popular IR filter. I have googled and came up with the below from a seller.

720nm IR filter is suitable for all visible light under 720 nm
760nm IR Filter is suitable for dawn or under faint light .
850nm IR filter is suitable for indoor and weak light.
950nm IR Filter is suitable for outdoor and strong light use.

Could someone enlighten me about IR filters as I have no idea where to begin.

Thanks in advance
Steven

[rpcrowe]

Shooting IR using an IR filter presents a problem. Since the filter cuts so much of the light, exposure times tend to be too long to hand hold...

Shooting with a camera that has been converted to full time infra-red allows flexibility in that you can shoot at exposure times which can be hand-held.

I modified an old Canon D60 (not he latest 60D) DSLR camera which was not worth much for anything else into a full-time infra-red camera.



However, if I were to do this again, I would shoot IR with a good P&S camera. That way I could carry the camera in a pocket of my photo vest and always have IR capability handy. The D60 and lens is a relatively large solution and I often leave it at home unless I specifically am going out to shoot IR.

In fact, I have a Nikon Coolpix 5400 camera which I just might get converted to full time IR. That way I can bring an IR camera with me when I travel without the burden of the weight and bulk of my D60 plus lens. I can get it modified for $105 at

http://www.ebay.com/itm/ws/eBayISAPI...:X:RTQ:US:1123

There are usually quite a few P&S cemeras which have been converted to IR avaiable on eBay. Some are about the price of a good IR filter alone...

[Kris V]

Shooting IR using an IR filter presents a problem. Since the filter cuts so much of the light, exposure times tend to be too long to hand hold...

Shooting with a camera that has been converted to full time infra-red allows flexibility in that you can shoot at exposure times which can be hand-held.

I modified an old Canon D60 (not he latest 60D) DSLR camera which was not worth much for anything else into a full-time infra-red camera.



However, if I were to do this again, I would shoot IR with a good P&S camera. That way I could carry the camera in a pocket of my photo vest and always have IR capability handy. The D60 and lens is a relatively large solution and I often leave it at home unless I specifically am going out to shoot IR.

There are usually quite a few P&S cemeras which have been converted to IR avaiable on eBay. Some are about the price of a good IR filter alone...

Richard, that's such a great picture...
I have a Kodak Z8612 that I don't use very much anymore. Can it be converted for IR?
Currently I try to get some IR results (not yet suitable for posting!) in PP, but I haven't been able to get it like I want it, regardless of all the on-line information available.
I checked Amazon for the price of Hoya IR filters.....cost almost as much as my camera!

[Manfred M]

First of all, I rather suspect that you will need to modify your camera to do so. Sensors do not have the same restrictions as our eyes and see off both ends of the visible light spectrum, i.e. infra-red (IR) and ultra-violet (UV). This means that camera manufacturers build filters into the camera to ensure that these wavelengths are filtered out and have permanently installed filters in place to do so. You need to have these filters professionally removed to properly to IR work and there are some companies out there that will do so for you; but is not inexpensive and is irreversable.

When I did a bit of IR work in film, I used a 25A (red) filter for B&W work. It essentially let the red and IR side of the spectrum in while blocking all shorter wavelengths (blues and greens) and cuts off all wavelengths below 580nm so yellow, orange and red get through. The filters you list are all filters that cut off visible light and get into cutting most visible light (the 720 lets a bit of red light; up to 750nm through). The others cut off at different IR wavelengths (IR goes from 750nm through to 1mm wavelengths).

The other issue that you will be looking at is that IR focuses differently than visible light. My old film cameras had a little red IR focusing mark so I could focus manually and then offset for IR; modern digital cameras have dispensed with this, so you are on your own here; and smaller DOF will be the easiest thing to do. Remember also that these are going to be low light shots.

[rpcrowe]

Some companies that convert standard digital cameras (either P&S or DSLR) to infra red ask you to send in the lens which you will be shooting with so that they can modify the camera to get a sharp IR filter with that specific lens. The guy, I don't remember who it was, who converted my D60 to full time IR did not ask for a lens to be sent in. Instead, he recommended that I shoot at f/11 or f/16. This is fine since I will often shoot at ISO 200 or 400 to aintain a hand-holdable shutter speed.

I shoot with several lenses including a 12-24mm f/4 Tokina and an ancient 28mm f/1.8 Sigma. Since the Sigma will not work on any camera more recent than the 10D and since Sigma will not or cannot upgrade it for a modern camera; it lives on my D60.

Here is a conversion for point and shoot cameras...

http://www.ebay.com/itm/Infrared-IR-...item43a99c04f0

[teokf]

wow! thanks for all the replies

Richard, thanks for the input of getting a P&S instead of a dSLR. But, at this point I am thinking through the workflow to see if I would finally go into it full swing. So I have gotten myself a filter and I would like to go from there and see how things would work out and thanks for the eBay link. Now is to understand what they meant "The picture to the right is also a full spectrum photo straight from the camera, taken with a custom white balance (most cameras will not set WB like this for a full spectrum shot)"

BTW, that's a very lovely pix

Manfred, thanks for your input. Just a question. What do you mean when you said; "Remember also that these are going to be low light shots."?
I read somewhere that the best time to shoot IR is between 10am - 2pm

[Manfred M]

wow! thanks for all the replies
Manfred, thanks for your input. Just a question. What do you mean when you said; "Remember also that these are going to be low light shots."?
I read somewhere that the best time to shoot IR is between 10am - 2pm

The reason I say this is that that those heavy duty IR filters you have listed remove all visible light; and you will be relying only on the IR component of the spectrum for your exposure. Even the relatively wide spectrum 25A required an increase of 3-stops in exposure. Less light = means you will have to increase exposure through the usual means. The information out there is a bit sketchy regarding filter factors (because of the variability of IR sensitity of devices, I suspect). As an example; I found:

http://www.jackspcs.com/filters.htm

Quoting one of the line items:

"#89B, R72 (092, Schott RG 695)
Visibly Opaque used for infrared photography, especially aerial. Transmits wavelengths greater than 700 nm. This Dark red filter is for black and white infrared film and filters out light below approximately 650 nm. It allows pictures of a pure read image while making good use of relatively low sensitivity of infrared films.
The filter factor is approximately 20-40."

In layman's terms - your exposure with this filter will be 20 to 40 times longer than without it. Sounds like low-light work to me.... But again, my IR experience is with film, not digital, so I'm going out on a bit of a limb here.

[rpcrowe]

Here are a few more shots done with my Canon D60 DSLR camera converted to full-time IR.









I have decided to get an old Nikon Coolpix 5400 (which I was given years ago and have never used to any extent) converted to full time IR. I had wanted to do some IR shooting on an Alaska trip and then again on a China trip but, because of the weight and bulk of the converted D60, I left it home. Since I can get the Coolpix converted for $125 USD, I am going to do it and be able to have a pocket camera with IR capability...

[Kris V]

Here are a few more shots done with my Canon D60 DSLR camera converted to full-time IR.










I have decided to get an old Nikon Coolpix 5400 (which I was given years ago and have never used to any extent) converted to full time IR. I had wanted to do some IR shooting on an Alaska trip and then again on a China trip but, because of the weight and bulk of the converted D60, I left it home. Since I can get the Coolpix converted for $105 USD, I am going to do it and be able to have a pocket camera with IR capability...

Just awesome! PP doesn't even come close to these results.

[Momo]

I bought a Hoya R72 a while back. I found that it was too much of a PIA with the long exposure times. I eventually had my old Sony a-100 converted to 590nm SuperColor by LifePixel. I touched the R72 only once since then... and that was to screw it onto the front of my Sony. That works like a charm as well and no slow shutter speeds. You just point and shoot.

Here's what you can get with a 590nm filter. This filter is also excellent for converting to B/W.

[jcuknz]

I would make a note of caution about buying a P&S/Bridge camera for IR... it does depend on the camera.
I have a Nikon 5700 which is quite good when a Wratten 87 is added but when I got a Panasonic FZ20 it was no good.
The test is to see, with live view, if you can see an IR remote activated and pointing at the camera. If it is bright go for the expensive filter, if not forget it. This ignores the approach of converting a P&S but aimed at those with just the one camera for IR and regular.

A question ... is that R72 a proper IR filter giving a black and white result or does it give you a red toned image? I'm suspicious of the 'R'

[Momo]

There will be some red with the R72. The trick it to mitigate that red and get as much contrast between the sky and foliage in the camera, not in post. This is done with a proper white balance. For my filter, I use a gray card. For the R72, you would set your WB on evenly lit grass/foliage. You bring up an important point that anyone shooting IR must know and that is getting the WB correct in the camera first. You can try to adjust it later in post, but it won't be the same. FWIW, Lightroom and Photoshop cannot come close to fixing WB issues. I have found that only Capture NX2 (Nikon) or Canon's equivalent software can get you close enough in post.

[teokf]

Thanks for all the replies.

Reading the responses made me relise it's not as straight forward as just putting on an IR filter or getting the camera modified. Now I have to come to grasp with physics and all that different wavelength thingy and what have you ... This reminded me of my early days of dSLR when I couldn't make head or tail of; aperture, speed, ISO, etc, etc.

Before I start asking about which wavelength filter (I am assuming that all those numbers with 'nm' are measurement for light wavelength) is good for which genre. How does one get a proper WB using a normal camera with an IR filter?

I guess Richard and Darren is not allowing me to change my mind on IR as those photos are just too poisonous

[rpcrowe]

I prefer my infra red captures in B&W rather than the false IR color so, I am going to select the 800 filter. I am looking forward to having an IR camera with me all the time...

Here is a link to the tutorials posted by the company from who I am going to get my Nikon Coolpix 5400 modified.

http://www.kolarivision.com/tutorials.html

Since I already have the camera, the $125 charge for modification is not very steep. That charge includes the shipping back of the camera from the company to me after the mod is complete.

I will post a separate posting later on on what I think of my new/old Nikon Cooolpix 5400 IR rig...

[Momo]

And, if you're looking for a second option with more than just B/W, check out LifePixel. These guys modified my camera. Do yourself a huge favor and take a moment to watch some of their videos. Especially the videos explaining each filter and how the images coming out of a Super* filter can be easily converted to B/W, thereby giving you more options in post. I highly recommend LifePixel and, no, I do not get any kick-backs. The guy in the video (forget his name at the moment) even called me at my office to explain and go over exactly what they did to my camera and also inform me there may be a bit of a hot spot on my lens. I really appreciated the straight forward and upfront talk. Oh, and it turns out my lens works fine so long as I am not shooting into the sun at a certain angle.

[drjuice]

To get some idea of things work with an IR filter, I found that fiddling with the IR filter function in a download and try out Tiffen's Dfx software was VERY helpful. In fact, I liked it so much that I ultimately didn't buy the filter and, instead, bought a legal copy of the software back at Version 1. Now, at Version 3, I just load my RAW image into the "boughten" copy of the software and it turns to gold! ;~)

v

[teokf]

Richard, Darren thanks for the websites. They are helpful and been reading them.

drjuice, thanks for the suggestion. Would it be possible to upload some of the photos post processed up by Tiffen's Dfx software?

[darekk]

Infrared pictures are similar to negatives or pictures taken in the moonlight.
Leaves are white, reflecting radiation not suitable for photosyntesis, but warm animals emitting infrared dark. Strange. Looks like cameras can see only "very shortwavelength" infrared, not more distant thermal radiation ?
Only polar bears should be dark, because of special structure of hair preventing heat loss:
http://www.thermotec-fischer.de/pdf/...r_IBA_2007.pdf

[xpatUSA]

Infrared pictures are similar to negatives or pictures taken in the moonlight.
Leaves are white, reflecting radiation not suitable for photosynthesis, but warm animals emitting infrared dark. Strange. Looks like cameras can see only "very short wavelength" infrared, not more distant thermal radiation ?

@darekk may nor be looking any more but I'll comment on his unanswered post anyway.

Cameras can only see up to about 1150nm. It's called Near Infrared (NIR). Warm bodies emit at about 9000nm and so can't be seen.

[Manfred M]

@darekk may nor be looking any more but I'll comment on his unanswered post anyway.

Cameras can only see up to about 1150nm. It's called Near Infrared (NIR). Warm bodies emit at about 9000nm and so can't be seen.

The last time Darius visited CiC was over four years ago.