Aug 6 2017

Testing the New Kolari Vision AR 720nm Screw On Filter


720nm Medium Format Film Photography with Rollei IR400 Film

 

Tomotley Plantation in 720nm Infrared with Rollei IR400 film and the Kolari Vision 720nm Filter

Infrared FILM photography has always been on the difficult side, but not because of lack for film because there are several films on the market.  Rather it is due to the poor quality of the available 720nm filters on the market.   

Kolari 720nm FIlter

Recently Kolari Vision www.kolarivision.com has come out with a new series of infrared filters with their AR (anti reflection) that stop or greatly reduce hot spots in the center of your film or digital sensor.  These hot spots are due to the various coatings, paint and other reflective coatings on the glass elements and coatings on inside of your lenses causing the light to bounce back and forth several times then hit the film dead center causing the hot spot.    

The main filter on the market has been the Hoya R72 filter which works but gives a low contrast washed out image.   Along come the new Kolari filter and now I am getting more contrast and even images with greatly reduced hot spots.  AMAZING!

So lets take a look at the image above.  This is the Tomotley Plantation about 20 min west of Beaufort, SC and  was taken with the Rollei IR400 film rated at 720nm.  Without a IR filter the ISO is 400 and the emulsion generates a very good likeness of Kodak TriX 400 film.  If you add the 720nm filter the ISO drops down to 12 or 6  but you get the amazing whites on the grass and leaves.  You even get the Wood Effect where the green items BLOOM  out with an etherial soft white energy on the image!

Few things beat a beautiful sunrise photographed in color when you want to create a dramatic image. The same scene photographed in infrared may be disappointing unless there’s some  IR reflective subject matter (we’re talking about deciduous trees here) to add interest. That’s because of the “Wood Effect,” which is the bright, white reproduction of the chlorophyll layer of deciduous plants. The effect is named after infrared photography pioneer Robert W. Wood (1868-1955) and not after the material wood which does not strongly reflect infrared.

Normally the Wood Effect is difficult to achieve at 720nm and is better seen at 800nm and and above.  I have been very happy with this new filter from Kolari in combination with the Rollei IR400 film because I am constantly getting the effect plus deep contrasty images.  It simply works as expected which is way more than I can say for others on the market!

Technical Data:

  • Fuji GF 670 Medium Format (120) folding Rangefinder with a Voigtlander 85mm Color Scopar lens.  
  • Kolari 720nm AR filter
  • ISO at 12 and 6, both are close to perfect because they are only 1 stop apart.
  • Aperture: f/32
  • Tripod mounted

Development:

  • Ilford Perceptol Stock mixture 1:0, 20c, 14 min with 5 seconds of agitation every min.
  • Water Rinse
  • Stop Bath
  • Ilford Quick Fix for 5 min with 5 seconds of agitation every min.
  • Water Rinse
  • Clearing Wash
  • Water rinse for 10 min
  • Distilled Water rinse with 3 drops of wetting solution
  • Dried overnight in filtered Mistral Drying Cabinet.
  • Wet mount scanned on a Epson 850 pro at 6400dpi.

If you are considering working in 720nm whether in film or digital I highly recommend this new filter from Kolari!

 

2 comments on “Testing the New Kolari Vision AR 720nm Screw On Filter”

  1. I just found your two blogs. I got a digital IR camera conversion by Kolari last year, which led to me to trying the Rollei IR film this year. I’m using a B+H 092 IR filter. It has a max at a slightly higher wavelength. I’ve been shooting at and EI of 6, with +- bracketing of one stop. Develop with F76+.

    I also had a hard time getting the “wood” effect (never knew it was named after someone named wood). I found that there is a slight difference between using the R72 and the 092 filter, but what helped the most was over exposing to increase contrast. That led me to the EI of 6.

    Reply

    • Good, I am glad to hear that you are trying the film. Honestly, You have to shoot at 6 or 12 ISO depending on the subject and light. You will only get the Wood effect on bright green leaves, NOT pines! I would go with a true 720nm filter like the R72 or the new one from Kolari!

      Reply

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