I love learning, expanding my toolbox, in all areas of my life besides photography. It’s been a summer of just that. Here in New Jersey (USA), due to the close proximity of the Gulf Stream off the coast, the summers are tropical in nature — hot and humid — with afternoon thunderstorms that leave the atmosphere still humid but take the edge off the heat. This summer has been no different which means I hibernate indoors from mid-June until September 1, only venturing out on those days that our dear Canadian friends send us cold fronts so that we can shut off the air conditioning and open the windows for a couple days.

So what have I been learning about infrared? Lots.

First I made the switch from LifePixel sensor filters to Kolari Vision on both my Nikons. Not sure why it suddenly dawned on me this summer, but KV’s head offices are located a mere 40 miles from my house: no time difference, no expensive shipping (and insurance) costs, no downtime without a camera body for a month (ship time is a week each way), and best of all, an enormously friendly and educational atmosphere, one that is open to sharing information and in-the-field experiences both ways. Best of all, it is a family-run local business. I am all about supporting local small businesses when it is an option for me.

Did I find a difference in the sensor filters between the two manufacturers? Oh my gosh, yes!

As Kolari’s Illja Melentijevic (just call him Illja — like actor David MacCallum’s role, Illya Kuryakin, in the mid-1960’s television show The Man from U.N.C.L.E.) explained to me, KV’s infrared sensor filters are designed specifically for each camera make/model so as not to take away anything from the sensor’s capabilities.

I’ve found that images are very, very sharp from both my Nikon D800 (720nm) and my Nikon D750 (850nm). Illja explained that the design of their sensor filters is for optimal sharpness. Here I thought all along that “infrared” was suppose to produce a “soft” image (even using Live View, zooming in, and tweaking the focus). After all, in looking at IR film images, IR film did not produce a wicked sharp image. I learned that “softness” from a converted digital camera, actually has everything to do with the sensor filter.

It took me a couple weeks of shooting with KV’s conversions in different types of light to dial in my processing workflow. These images are simply different and I am at a loss to explain in which way. They aren’t better than before — simply different. I need to further work with the cameras… looking forward to a couple days next week up at Cape Cod so I can totally submerse myself in shooting IR.

I am guilty of being human — I did not embrace this new change easily. After all, I had worked for years to develop my IR processing workflow that yielded my style. I admit I was incredibly frustrated until I realized that what I was going through was important for me to experience — it will make me a better educator and now understand that not all sensor filters are the same. Who knew?

That brings me (finally) to the point of the blog. I was down at KV’s offices, picking up my cameras and Illja was educating me about their line of lens filters. When he asked me if their IR ND 5-stop circular lens filter was on my radar, I became very curious. A neutral-density filter designed specifically for IR?

I told him that I used Singh-Ray’s ND 10-stop and 15-stop frequently on the IR cameras, as I love shooting long-exposure with water and clouds. I told him that I had used my Singh-Ray ND 6-stop once but I found that it really didn’t seem to block a lot of light. As a rule, I always start with my 10-stop.

Illja took the three Singh-Ray filters to his lab and had them analyzed. We chatted a bit while the results came back to us. And this was what I learned.

I’ve long preached the fact that our cameras and lenses are built for visible light. So when converting a camera to IR, we are many times at the mercy of changing our capture workflow (such as shooting in manual mode instead of aperture preferred to be able to override the shutter speed beyond the exposure compensation options).

Foolishly I assumed my visible-light ND filters would not be affected when the camera was converted to infrared. Ha!!

The Singh-Ray ND 6-stop filter (when used on any IR converted camera body) specs out to approximately 3.5 stops.

The Singh-Ray ND 10-stop filter (when used on any IR converted camera body) specs out to approximately 6.67 stops.

The Singh-Ray ND 15-stop filter (when used on any IR converted camera body) specs out to approximately 11.5 stops.

Light bulb moment. No wonder the Singh-Ray rep could not believe I was using their 15-stop lens filter happily all throughout the day for long exposures under one minute. Infrared changes everything.

Disclaimer: I have no idea what the lab test results would be with ND filters made by other manufacturers. I only was able to ask Illja to test filters that I owned — and every single filter (circular filters or 100x150mm ND grads) is made by Singh-Ray. I’ve been a Singh-Ray user since I moved to digital photography in 2009.

It is important to note, that as of last year, I am a Singh-Ray affiliate, and have no intention of giving up my ND filters (I do still shoot with my “color” / visible light Nikon D810) as I am familiar with how they work in the field and am very comfortable with them.

I hope this education (thanks Illja!) makes it easier when trying to calculate long exposure time when ND filters are used with your IR camera bodies.

I did take the Kolari IR ND 5-stop — the filter is the closest equivalent to my Singh-Ray ND 10-stop — for a drive this week and the lead image is the result: 20 second exposure (Nikon D750, 850nm) under a bright but high overcast sky at approx 9am in the morning. Summer sun was pretty high in the sky by that time.

I did not find any color cast at all when comparing the RAW files side by side in Adobe Bridge (comparing the “at meter” no-filter image to the 20 second exposure with KV IR ND lens filter image).

The Kolari Vision (new to me) IR ND 5-stop has a home in my bag. I am filling up Illja’s in-box with almost daily requests to develop a 10-stop IR circular lens filter too!