[travelswsage]

Could you share which ones you tested? I have noticed a mild hotspot on the FA31mm with a 720mm filter on an unconverted K-1 and haven't tried others yet.

I'll check later tonight -- I think I still have the results somewhere in Lightroom. I remember the biggest disappointment being the 70-200 f2.8.

[travelswsage]

Here is a thread I had started a while back with examples from the 67 lenses: Pentax 67 55mm, 120mm; TiltRokr; Infrared - PentaxForums.com


I unfortunately didnt keep the best of notes but the lenses I tested were the dfa 70-200 f2.8 (by far the worst performer), dfa 100mm macro 2.8 -- good at 2.8 and 4, ok at 5.6, useable at f8 not so great beyond. Dfa 28-105, lensbaby 56mm and 85mm, Zeiss zk 25 2.8 and 35 2.8 all ok at 2.8 and 4, none all that great beyond. The 67 lenses I used were the 55mm, 75mm, 100mm macro, and 120mm soft -- all were good stopped down to f16 and useable at f22. I was testing with an 850nm filter on a Sony a7rii and in between 30 and 45 degrees to the sun so pretty harsh conditions to try to elicit hotspots and see what I could get away with. Lower spectrums and other angles will increase useability range. Note that Medex who responded in the thread had better results than I did but I think they were at 640nm.

[JensE]

Kolari has a database of what lenses work well and what doesn't. They list the 18-135 as a poor performer but I have a friend that uses one exclusively on his K-01 without issues.

Lens Hotspot Database - Kolari Vision

I found the Kolari list not necessarily reliable - as noted, the FA 31mm does produce a hotspot when stopped down. Maybe it's more useful to look at the 'poor performers' - I can confirm that the DA*55mm is only usable fairly wide open (720nm filter).

I unfortunately didnt keep the best of notes but the lenses I tested were ...

Thanks a lot, your recollection already helps to figure out which ones to try next.

[lmd91343]

Serendipity!

I got my K10 in 2009 converted by ProCamera in San Diego. I have been happy with their work. However, I lost the dust removal.

I want to convert a K3 Mark II now and I am undecided between using Spencer's and Kolari Vision for the work. There is discussion here about hot spots and having a coated filter would be important to me, as I have several lenses that have hot spots on my K10. I'll be watching this thread and calling Kolari and doing more research.

[lmd91343]

I just spent some time in conversation with both Kolari Vision and Spencer’s Camera about converting a Pentax K3 mark II to infrared 720nm.

I am an experienced IR photographer using film in years past and my converted K10 over the last 12 years.

Both companies can convert a Pentax K3 mark II with the pixel shift, composition adjustment, astrotracer, and shake reduction functions retained. Both also offer 720nm filters. The 720nm allows in only a small bit of red that can be dropped in post processing or used for false color.

Kolari Vision’s base price is $350.
Adding antireflective coating costs $100.
Anti smudge coating costs $50.
Dust removal is taken out and cannot be reinstalled.
Normal processing time is two weeks.
Focus calibration would be done via the menu system.
Rush processing can be ordered online for an additional $75-$125.
KV can send you a box to ship your camera for $50 or camera and lens for $75.

Sending my K3 mark II for an anti reflective 720nm conversion where I shipped in my own box, where I would wait for two weeks would cost me $450 plus one way shipping.

I would not use the Kolari prepaid shipping box nor would I get the anti smudge coating.


Spencer’s Camera base price is $250.
The 720nm filter comes standard with anti reflective coating.
Normal processing time is two and one half weeks.
Spencer’s does not offer anti smudge coating.
Spencer’s removes dust removal and will reinstall it for $50.
The normal processing time is two and one half weeks.

Focus calibration is done by some process “internal” to the camera. A special lens should be sent in for the calibration.
EDIT--- superseded by below -----EDIT

EDIT---
Spencer's calibration is three part: 1)a mechanical adjustment is made to the extant sensor plane 2)additional firmware is downloaded ??? 3) sometimes the focus screen is reshimmed.
------EDIT

Sending my K3 mark II for an anti reflective 720nm conversion with my 20-40 Limited for calibration where I shipped in my own box, where I would wait for two and one half weeks would cost me $300 plus one way shipping.


The choice is clear. Spencer’s is $150 cheaper including reinstalling the dust removal system. The two competitors offer identical (by specification) 720nm anti reflective coated filters. Spencer’s reinstalls the dust removal system, Kolari won’t. The only con for Spencer’s is that it takes 3 days more processing.

P.S. The people at Spencer’s said that modern Pentax cameras make excellent conversions!

[kolari]

I found the Kolari list not necessarily reliable - as noted, the FA 31mm does produce a hotspot when stopped down. Maybe it's more useful to look at the 'poor performers' - I can confirm that the DA*55mm is only usable fairly wide open (720nm filter).




Thanks a lot, your recollection already helps to figure out which ones to try next.

We try to update our list regularly, if you find any discrepancies we are happy to update to keep the resource as up to date as possible. We cannot test all lenses ourselves and rely on community feedback which can involve different shooting conditions and often different assessments.

[JensE]

... if you find any discrepancies we are happy to update to keep the resource as up to date as possible.

Thanks, I'll get back to you once I am more confident with my judgements - which will require more experience and data points (wavelengths, cameras).

[lmd91343]

I just got my K3 Mark II from a camera store in Tokyo today! Everything seems to function ok.

It will go off to Spencer's Camera for conversion tommorow! They want me to send my 20-40 Limited (my main IR lens) also. UPS here I come.

I am also dyeing my white Domke strap "scarlet red" so I can tell my IR K3 Mark II from my unaltered K3 Mark III.

[mattb123]

I just got my K3 Mark II from a camera store in Tokyo today! Everything seems to function ok.

It will go off to Spencer's Camera for conversion tommorow! They want me to send my 20-40 Limited (my main IR lens) also. UPS here I come.

I am also dyeing my white Domke strap "scarlet red" so I can tell my IR K3 Mark II from my unaltered K3 Mark III.

Cool! Looking forward to hearing and seeing how it goes!

[Ishpuini]

Perhaps a bit late, but I had my K-3 II converted to full spectrum by Kolari Vision. Great service and great result. Despite having a new K-3 mark III, I find myself going back to the older converted camera over and over again.

I picked full spectrum with their Pro AR coating. Full spectrum allows me more options, but that comes at the cost of lens filters. I'm using a lot of Hoya R72 and Kolari's IR Chrome especially depending on the subject. I have both 49mm and 77mm versions, but I'm using the 49mm versions more because I dug up some of my old Pentax glass. That seems much less prone to infrared hotspots than more modern glass. I'm loving the cheap M28/2.8 that I purchased in the days of the *istDS when we didn't have menu options. That and the lovely FA43/1.9 limited of course.

[Mbaez]

I just got my K3 Mark II from a camera store in Tokyo today! Everything seems to function ok.

It will go off to Spencer's Camera for conversion tommorow! They want me to send my 20-40 Limited (my main IR lens) also. UPS here I come.

I am also dyeing my white Domke strap "scarlet red" so I can tell my IR K3 Mark II from my unaltered K3 Mark III.

Wondering how the conversion went.

[cdd29]

I'm still waiting on my camera. Spencer's was supposed to finish and ship it last week.

[mtkeller]

I'm still waiting on my camera. Spencer's was supposed to finish and ship it last week.

They have my K-50 right now, too.

[lmd91343]

I am still waiting. They expect to finish mine by Monday. That would make it exactly three weeks since they received the camera. Initially, they told me two and a half weeks. There are twelve ahead of mine.

I've taken the time to dye a Domke tan strap red for my converted K3-II (IR), so I can easily tell my K3-III and K3-II(IR) apart. My K3-III sports a black Domke strap.

[Ishpuini]

When I had my conversion done by Kolari Vision they also ran into considerable delay. It seems the current situation has a lot of people go back to their hobbies exploring new possibilities in the limited space they are living in. Hence a lot more conversations are requested and these companies are struggling with considerable backlogs.