[lotech]

While checking my photo album I found some interesting old photos I took with my K7, I shot infrared with it ! I prefocus the lens, I put an IR760 filter over it, and pump the ISO up to 1600 which is the max usable ISO on the K7 and then I fire the shutter, although under bright sunlight the shot still took 15 seconds to complete ! Since the camera unable to focus in IR I stopped down quite a lot to make sure a reasonably sharp image, the sensor can barely pickup the light escape from the internal IR blocking filter, the images are not clear and blurry due to high ISO and long exposure, it took some post to restore the image to usable state. It is interesting to see the sky is dark, the leaves are white, people faces doesn't look unusual though. I am yet to test my K3 w/o the IR blocking filter, I expect much better image from it. If you are new to this you can start easy with your cell phone, I read that some uses exposed color negative as filter I've not tried, but I believe it is not strong enough to block visible light to make IR stands out, but whatever method you use please share your photos and your tricks to IR photography with us !

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Last edited by lotech; 07-27-2018 at 11:02 AM. Reason: Correction

[Medex]

There are many people shooting infrared. The best solution is modified camera when hot mirror is replaced with IR filter. Then you get short exposures and maximum quality. I shoot landscapes and portraits. The results can be stunning after postprocessing.

Examples are here:
https://www.efoto.lt/nuotrauka/640_nm

[kypfer]

I did a few quick tests a few years ago, comparing my then recently-acquired K-5 with my long-standing *istD S. Results showed that the older camera was very much more infra-red sensitive than the newer camera, both cameras being un-modified.


I've only got two "infra-red" filters, the gel supplied by Ilford for use with their SFX film, equivalent to a Wratten 89B, I believe, I can just about make out an image through this with the naked eye when viewing a light bulb, and the Wratten 87 which appears totally opaque.


The K-5 couldn't "see through" the 87 at all, for any practical purposes, but the *istD S managed quite successfully!


My net results of the comparison tests were of little photographic value. For use of the 87, I choose an appropriate lens to match the external viewfinder (ex r/f) that I fit into the hot-shoe, when/if using the K-5 + 89B I find Live-View to be perfectly adequate!

[Kelvin 5500]

... please share your photos and your tricks to IR photography with us !

I tried using a 720nm infrared filter with my Pentax K20D eight years ago. The requirement for high ISO and long shutter speed produced results that were way too noisy for my taste. Now that I have a K-1 Mark II, I plan on trying again. I just have not gotten around to doing a test as yet.

For your interest, here is a link to a Pentax K-1 review article written by Joe Farace in which he states: "Yes, the Pentax K-1 is infrared sensitive and performed flawlessly when shooting using IR filters." The sample photo in the article was done with an unmodified Pentax K-1 and a Cokin 007 infrared filter (650nm).

Pentax K-1 DSLR Review by Joe Farace | Jun 3, 2016

Dennis

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Last edited by Kelvin 5500; 07-27-2018 at 08:44 PM.

[fwwidall]

I've been playing around with IR for quite a few years now.

I started out with an unconverted istDS, which requires longish exposures to produce an image. If I recall correctly I used to start off a IS0 800, F8 and 1/8s and adjust from there based on the results. Then I'd mess about with the image in Photoshop, usually swapping the red and green channels to get a false colour image. Some times the results were pleasing - for example:




Then I picked up a Sigma SD14 which has an IR/UV blocking filter which is removable, making it into a full spectrum camera. Using an R720 filter I was able to get some very nice B&W IR images. I could never manage to use it for decent false colour images.





The Sigma been sitting, unused since I bought a converted istDL2 from a forum member a few years ago. I can use all my Pentax lenses and its much easier to use, and to process the images.






Sometimes the shots work, and some times they don't. It takes me back to the old days when you were never sure of what you had until you processed the film.

If you'd like to see some more images check out my Digital Infrared album on Flickr

Fred.

[Kelvin 5500]

If you'd like to see some more images check out my Digital Infrared album on Flickr

Great! Thanks for posting. While I like them all, I find those that have been converted to grayscale particularly appealing.

Dennis

[lotech]

Wonderful pics thanks for sharing ! they looked like taken with IR film, btw what's the best filter to use, I simply pick one I found in shop, is it 760 or 720(nm ?) or else best for pictorial shots ? I also want the sigma, actually I dropped the idea of getting a SD QH due to the very limited and low ISO and dynamic range.

I've been playing around with IR for quite a few years now.

I started out with an unconverted istDS, which requires longish exposures to produce an image. If I recall correctly I used to start off a IS0 800, F8 and 1/8s and adjust from there based on the results. Then I'd mess about with the image in Photoshop, usually swapping the red and green channels to get a false colour image. Some times the results were pleasing - for example:




Then I picked up a Sigma SD14 which has an IR/UV blocking filter which is removable, making it into a full spectrum camera. Using an R720 filter I was able to get some very nice B&W IR images. I could never manage to use it for decent false colour images.





The Sigma been sitting, unused since I bought a converted istDL2 from a forum member a few years ago. I can use all my Pentax lenses and its much easier to use, and to process the images.






Sometimes the shots work, and some times they don't. It takes me back to the old days when you were never sure of what you had until you processed the film.

If you'd like to see some more images check out my Digital Infrared album on Flickr

Fred.

[RuiC]

Somewhat offtopic, I apologize, but any suggestions on where to modify a istD for IR , in Europe ? Or any thread dealing with the matter.

Thanks,
Rui

[fwwidall]

Wonderful pics thanks for sharing ! they looked like taken with IR film, btw what's the best filter to use, I simply pick one I found in shop, is it 760 or 720(nm ?) or else best for pictorial shots ? I also want the sigma, actually I dropped the idea of getting a SD QH due to the very limited and low ISO and dynamic range.

I use a cheap generic 720nm filter on the Sigma. I tried 850nm, and 950nm, filters but didn't like the results. The Sigma SA mount is close to Pentax K so I have successfully used my M42 lenses with a Pentax adapter. I picked up a Sigma 28-200mm in SA mount which is what I use now - albeit very infrequently. I probably should sell the Sigma and let someone have fun with it, rather than leaving it unused, and unloved, in my closet.

Fred.

---------- Post added 07-28-18 at 09:43 AM ----------

Somewhat offtopic, I apologize, but any suggestions on where to modify a istD for IR , in Europe ? Or any thread dealing with the matter.

Thanks,
Rui

I've never used a conversion service but a quick google search found this link which has details on several services in Europe. Whether or not they would convert an istD I don't know. Hope that helps.

I did notice that there's currently a converted K01 on Ebay selling for US$349. Conversions seem to run US$200-250 so it might be worth just buying one that has been converted. Just a thought.


Fred.

[pentax360]

I have a bunch of old floppy disks which act as IR pass filters (or so I've read) I'll have to give it a try.

[RuiC]

I use a cheap generic 720nm filter on the Sigma. I tried 850nm, and 950nm, filters but didn't like the results. The Sigma SA mount is close to Pentax K so I have successfully used my M42 lenses with a Pentax adapter. I picked up a Sigma 28-200mm in SA mount which is what I use now - albeit very infrequently. I probably should sell the Sigma and let someone have fun with it, rather than leaving it unused, and unloved, in my closet.

Fred.

---------- Post added 07-28-18 at 09:43 AM ----------



I've never used a conversion service but a quick google search found this link which has details on several services in Europe. Whether or not they would convert an istD I don't know. Hope that helps.

I did notice that there's currently a converted K01 on Ebay selling for US$349. Conversions seem to run US$200-250 so it might be worth just buying one that has been converted. Just a thought.


Fred.

Thanks Fred.

[VoiceOfReason]

I found that a converted camera is much easier to use, and gives less of a chance of IR hotspotting. I had my K1 converted and use filters on the lens when I want to do IR stuff, bets part it is all handheld and autofucus.

[lotech]

Please excuse my ignorance what is "IR Hotspotting", does it apply to IR only or a general optical distortion/effect ? and why K1 needs conversation it does not have the low pass filter ? and what about the Sigma camera ?

I found that a converted camera is much easier to use, and gives less of a chance of IR hotspotting. I had my K1 converted and use filters on the lens when I want to do IR stuff, bets part it is all handheld and autofucus.

[VoiceOfReason]

Please excuse my ignorance what is "IR Hotspotting", does it apply to IR only or a general optical distortion/effect ? and why K1 needs conversation it does not have the low pass filter ? and what about the Sigma camera ?

IR Hotspotting is where the center of the image gets overexposed and it is hard, if not impossible to fix in post. Some lenses contribute more to it, others don't do it at all.

[fwwidall]

Please excuse my ignorance what is "IR Hotspotting", does it apply to IR only or a general optical distortion/effect ? and why K1 needs conversation it does not have the low pass filter ? and what about the Sigma camera ?

With regard to the filters my understanding is (please correct me if I'm wrong) that digital cameras generally have a low pass filter and a IR/UV cutoff filter in front of the sensor.

The low pass, or anti-aliasing, filter is there to reduce 'moire', but can reduce sharpness. The K1 does not have this filter as anti-aliasing is achieved by moving the sensor instead. Interestingly the Sigma SD14 doesn't have one either due to it using a Foveon sensor, instead of the more usual Bayer sensor.


The IR/UV filter restricts the light reaching the sensor to the visible spectrum, The filter is usually affixed to the sensor and in an IR conversion it is physically removed. In the Sigma SD14 the filter is located just behind the mount, and can be popped out with a finger. There was an old article in Popular Photography which discusses the Sigma SD14
.

Hope that helps,

Fred.