Kolari Vision introduces a NEW Anti Reflective IR coating for their conversion filters!
I LOVE shooting IR and have a long history with it in both Film and Digital. I have had over 25 conversions from ALL of the big conversion companies around the country! But, once in a while I would get a camera that no mater how hard I tried, I will get a hot spot with it or the lenses I used. You learn how to deal with this by selective use of the aperture but once in a while you would just not be able to get around the problem and loose the shot….
Well about 3 weeks ago Ilija from Kolari (http://www.kolarivision.com ) sent me a note telling me about a new coating process for his conversion filters. I have a long history with Kolari, LDP and Lifepixel but I have never heard of this till now. Ilija offered to do a free conversion with this newl IR AR coating for me in return for evaluating it in the real shooting world! So I told him that I would send the X100s off as a test camera and that I needed it back fast in order to allow others to play with the camera also! Off it went on Tuesday. Imagine my surprise when I got it back in hand the following Wednesday!
Here is what Kolari says about this new AR IR coating:
- Uncoated glass has a reflection of around 4-5% at all wavelengths, and we found that this reflection off the sensor filter was bouncing off the glass and reflecting back from the lens housing and aperture blades to cause the hotspots. We developed this anti-reflective coating that is centered around the IR wavelengths that cause hotspots, and reduced the 5% reflection down to <0.5% (see the attached graph for reflection % by wavelength scan, and the picture of the IR filters for the visual difference of IR reflection).
- The coating does not reduce visible light reflections as much, and does not reduce blue reflections at all. This gives the glass we use a blue shine, since that is the only range that is fully reflected still (see picture of black filters).
- I am getting ready with a new website which I hope to launch in 1-2 weeks, so I have not put the coated version of the conversions online yet, but they will be offered on our Full spectrum, two spectrum, 590, 665, 720, 850, and Blue IR/NDVI conversions. There will be a $50 optional upgrade on all of our conversions at this point.
- I plan on offering only the coated version eventually, but the batch runs are expensive and I cannot coat our full inventory at once. I’m not sure if you are aware, but we stock custom made custom thickness filters for all our camera/filter combinations so that each conversion gets a piece of glass that maintains the original optical distance (refractive index x physical thickness) as closely as possible, which changes for each filter material. Other companies use a few general size pieces of glass, glue them directly to each sensor, and calibrate the focus for an arbitrary lens, which reduces what they have in inventory. Our design choice means that we have around 200 unique pieces of glass in inventory for DSLR and mirrorless cameras, and another 200 for point and shoot models, so you can imagine the challenge in getting them all coated. – Ilija
So as you can see they are up and almost ready to start filling orders for these new filters.
I have to tell you that with my test conversion on the Fuji X100s to AR 850nm that ALL of my hot spot issues simply went away. This camera has always had a tendency for IR hot spots. I have converted, tried and sold so many IR systems in the past that I have lost count. I could not, would not sell this one as it is one of my most prized IR systems. To say that I am pleased with the results of the Kolari IR AR Coating is the understatement of the year!
Remember, if you decide to order from Kolari, give them my name for a $15 discount!
very interesting. So, does this mean the original infrared blocking filters that are in all cameras have a similar coating? I’m wondering about this since the cameras/lenses don’t hot spot until they’ve been converted and that glass is replaced. Also, is this a similar coating to what goes on the outside of lenses? So, what Ilija and you are saying is a lens that used to hotspot in infrared at say any stop beyond f8 will now be good. Is that correct?
Not at all. The chances of a hot spot are greatly reduced. There are no coatings like this on normal cameras and lenses because the hot mirror blocked all ir even hot spots and only allowed visible to pass. With an ir conversion all sort on new players are affecting your image like lens coatings and Barrell paints, things that never affected color.
Ah, I see. Well it is all fascinating. I wish Ilija had created this coating before I did my most recent conversion there a year or so ago. Every one of my lenses behaves differently. It’d be nice to have uniformity. Well, there’s always the next one.
frankloosephotography talk to them about updating your filter…if i am not mistaken Kolari offers a discount for previously converted cameras
Mark, great post. This got me thinking about converting an X-Pro2 to IR. I do a lot of street stuff and have had this idea of using IR at night on the street. With that in mind, you know of anyone making an IR flash? I know I could just filter a normal flash but I would think it still would make some visible light. Thanks
Brian, all flash units create ir light along with VISAbLE You can put a ir filter gel over it so that is not as noticeable. I believe that LDP ( max max.com) makes ir only units.
Thanks for the info, I’ll have to check out LDP. I already have a bunch of flashes, so maybe I can just find something to filter it with.
You can get a deep red Rosco gel from Amazon (Rosco Gel Sampler) and tape it over the flash lens also.
Here, check these gel packs out! http://www.amazon.com/Rosco-Lux-Small-Swatchbook/dp/B0002ER2YG/ref=sr_1_1?ie=UTF8&qid=1461282851&sr=8-1&keywords=rosco+gel+swatch
Mark, this is exciting news. I see it as a goundbreaker for the IR community. Potential to open up an entire suite of previously unusable lenses is or will be revolutionary. I can’t help but question image quality, however. Is there any degradation, even at close pixel-peeking level noted with the coating?
No my images are sharp and clear
Fantastic. I have a mirrorless I will have to send for this conversion. Very exciting!
Thanks for the info, I wish is could see a 590nm image with ar coating, is there a url with samples
Not yet Randall. Keep checking in their web page.
I placed my order today, I trust ilija and kolari
I have a Fuji X100 in 850nm with the AR coating and love it. You will do well with them.
nice art you have here mark…and thanks for the info!
Thanks for the kind comments.
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Nice blog post!