[Wingincamera]

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I am thinking about using one of my KP's for Infrared Photography. Would this good camera for infrared? If I do this, I will probably use an infrared filter first before making any physical changes to the camera. I also have a KS-2 and a K1000 film camera that is unused,

[stevebrot]

Would this good camera for infrared?

Probably as good as my K-3, meaning that exposures will be long and that a quality filter such as the Hoya R72 would be a good idea.

From a small experiment this last summer using the Hoya R72 with my unmodified K-3 mated to an S-M-C Takumar 28/3.5 (click through to Flickr for full details)...



Serious work usually requires conversion of the camera for IR, however.


Steve

[kypfer]

I am thinking about using one of my KP's for Infrared Photography. Would this good camera for infrared? If I do this, I will probably use an infrared filter first before making any physical changes to the camera. I also have a KS-2 and a K1000 film camera that is unused,

The KP, as with all Pentax cameras with CMOS sensors, will have limited sensitivity in the infra-red.
An R72 filter, as mentioned by Steve above, is about as "dark" as you can reasonably go and retain anything like "sensible" exposure times.
The KS-2 has the same limitations, unmodified.
For a "better" effect, IMHO, you might be advised to look for one of the older (6 or 10 M'pixel) cameras with their CCD sensors. These have much greater sensitivity to infra-red, unmodified, but unfortunately don't have the advantage of LiveView, though most of them have Digital Preview … quite important when the filter fitted to the lens is so dark you can't see anything through it





Taken with my unmodified *istDL2 and a Lee 87 filter

[tuco]

I use a R72 filter on my CCD sensor camera and get much shorter exposure times for equivalent f-stop and ISO than newer CMOS cameras I've tried. My shutter speeds are like using a 9 or 10-stop ND filter. While that's still a long shutter speed (typically 1/2 to 1-second, f11, ISO 200), it's much shorter than I've seen from my unmodified CMOS DSLR cameras using the R72 filter.


Maryhill, WA by tuco, on Flickr



57' Chevy Bel Air by tuco, on Flickr



Old Ford by tuco, on Flickr

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Last edited by tuco; 01-10-2022 at 02:25 PM. Reason: Add Photo

[Bob 256]

It wasn't mentioned so far, and you may already know, but you can have one of your cameras "converted" for infrared (and ultra-violet) use by having the UV/IR blocking filter which sits in front of the sensor, removed. This vastly increases sensitivity to IR light and allows you to use faster shutter speeds and/or smaller lens openings. The latter can further sharpen your shots by providing increased depth of field which is hard to obtain with the blocking filter in place since you need to run the lens wider open for more light.

There are several places you can have conversions done. Your camera can still be used for regular photos but you need an external UV/IR blocking filter for all of the lenses used (without such a filter, colors will be rendered incorrectly).

Here are a couple of sources for conversions and conversion information:

Isaac Szabo

https://kolarivision.com/?utm_source=bing&msclkid=f9dea1e018a...d0c03c4182792d

[Michail_P]

I use a R72 filter on my CCD sensor camera and get much shorter exposure times for equivalent f-stop and ISO than newer CMOS cameras I've tried. My shutter speeds are like using a 9 or 10-stop ND filter. While that's still a long shutter speed (typically 1/2 to 1-second, f11, ISO 200), it's much shorter than I've seen from my unmodified CMOS DSLR cameras using the R72 filter.


Maryhill, WA by tuco, on Flickr


57' Chevy Bel Air by tuco, on Flickr

Never touched the subject. These are some great shots!

[MossyRocks]

Probably as good as my K-3, meaning that exposures will be long and that a quality filter such as the Hoya R72 would be a good idea.

From a small experiment this last summer using the Hoya R72 with my unmodified K-3 mated to an S-M-C Takumar 28/3.5 (click through to Flickr for full details)...

I use a R72 filter on my CCD sensor camera and get much shorter exposure times for equivalent f-stop and ISO than newer CMOS cameras I've tried. My shutter speeds are like using a 9 or 10-stop ND filter. While that's still a long shutter speed (typically 1/2 to 1-second, f11, ISO 200), it's much shorter than I've seen from my unmodified CMOS DSLR cameras using the R72 filter.

Something I want to try now. Looks like I need a couple of IR filters. How painful are they to the wallet.

[tuco]

Never touched the subject. These are some great shots!

Thanks.

Something I want to try now. Looks like I need a couple of IR filters. How painful are they to the wallet.

It's like purchasing a CPL filter. A lot depends on the filter size. I tried it to see if I wanted to convert one of my cameras. I haven't done that yet. IR pictures are something I only do now and then. But having normal shutter speeds with an IR converted camera is a more versatile camera for taking IR shots no doubt. Now they have lots of wavelength choices you can convert to instead of the typical 720nm.

[MossyRocks]

It's like purchasing a CPL filter. A lot depends on the filter size. I tried it to see if I wanted to convert one of my cameras. I haven't done that yet. IR pictures are something I only do now and then. But having normal shutter speeds with an IR converted camera is a more versatile camera for taking IR shots no doubt. Now they have lots of wavelength choices you can convert to instead of the typical 720nm.

thanks. I figured on an unconverted camera it would be long exposure but it is good to hear that they are ballpark CPL cost

[stevebrot]

How painful are they to the wallet.

I spent $49 USD for my Hoya R72 49mm.

I might mention that I also have an off-brand 720nm filter that bleeds visible light like a pig.


Steve

[MossyRocks]

I spent $49 USD for my Hoya R72 49mm.

I might mention that I also have an off-brand 720nm filter that bleeds visible light like a pig.

So the lesson there is don't skimp on quality as you will be let down but I learned that many times over in my life. Most of my lenses are 49mm filter or either 58 or 52 (I forget which one) and need to pick up a CPL for the non 49mm ones at some point but keep forgetting. At ~$50 that is something I can afford to play with.

[Wingincamera]

WOW, thanks for all the information. I think I might try it with the Hoya R72 49mm filter first. I was thinking of landscapes so a long shutter speed shouldn't matter. And I should be able to focus & compose the scene first and then attach the filter, correct?

[tuco]

Also note that some lenses can cause a so-called "hot spot" when using a R72 filter. Maybe search and see if any you plan on using fall into that category. I experienced that with some of my modern DSLR lenses to various degrees. But the images I posted here were done on an older design manual focus lenses which did okay.

[Bob 256]

Zomei makes a range of lower cost, reasonable quality infrared filters. I've used their brand before with good results although for most of my IR photography, I stick with Hoya IR filters which can cost considerably more. This eBay listing lists a range of sizes and cut-on wavelengths.

Zomei 49/52/55/58/62/67/72/77/82mm 720-950NM Infrared X-RAY IR Filter for Camera | eBay

[stevebrot]

Zomei makes a range of lower cost, reasonable quality infrared filters. I've used their brand before with good results although for most of my IR photography, I stick with Hoya IR filters which can cost considerably more. This eBay listing lists a range of sizes and cut-on wavelengths.

Zomei 49/52/55/58/62/67/72/77/82mm 720-950NM Infrared X-RAY IR Filter for Camera | eBay

Zomei is is the brand of 720nm filter that I have had trouble with in regards to visible light "leakage". In reviewing their product page, it appears I might have had better luck with the 680nm.

https://www.zomei.com/ir-filter_p0117.html


Steve