Exploring The B+W 403 (UG-1) Filter For IR


Alternative Infrared Filters

It is time to return to the roots of this BLOG!  Enough (for now!) with the touchy, feelie posts and back to the technical discussion of Infrared Photography!

If you have a Full Spectrum Infrared converted camera (like the Olympus E-PL1)  that has an electronic based viewfinder then you have the ability to photograph with Infrared filters that are opaque to normal human sight.  What this means is that you can see through the filter by using the cameras electronic viewfinder.  This is a VERY important distinction.  There are a lot of really unique filters out there that cannot easily be used on any other type of IR conversion.

 

Common Infrared Filters

I am going to discuss the B+W 403 (UG-1) dual band (UV/IR) filter today. This filter is a lot like LDP’s XDP filter but slightly narrower on the UV side.  If you take a look at the frequency response chart on the right (a comparison of the most common IR filters) for the UG-1 filter (dark purple) you will see that the filter passes light energy in the UV end from 300nm to 375nm that is very sensitive (allows a LOT of light in that frequency range to pass through).  This is dark blue/purple colored light.  It also allows a little light (less sensitive) from 710nm to 775nm before it falls off to nothing.  This end is in the Near Infrared end of the spectrum but at a much reduced amount. In fact, compared to the rest of the normal IR filters shown in the chart, the UG-1 does not allow much light through it at all!

 

Detailed UG-1 Response Chart

What this means to us is that with this filter you will get VERY dark blue/purple skies and very white foliage. This filter was NOT designed for Infrared photography in mind, but pay that no head. It will generate very ethereal images that have a dark blue sky and very white leaves and takes full advantage of the Wood effect!  Take a closer look at the response line on the chart to the left.  Only what is above the blue line is actually recorded on your camera!  This means that the leaves will be stark white and seem to be surrounded by a slight halo!  This makes for very pleasing images that really draw the viewer into the image.  Most of the image will be monochromatic except for the sky and sky reflections in water.

 

UG-1 Filter On E-PL1 Full Spectrum Camera

To make good use of this you need to concentrate on compositions that have a good sky with scattered clouds, lots of leaves and hopefully a little water for reflections. Remember, leaves are the primary subject of interest for this filter. The sky will give a good contrasting area of dark blue and the rest of the normal 720nm compositional items will add supporting structure.

There will be very little to NO red information in your LCD display if you have properly white balanced your camera with the filter installed.  In fact it should be totally monochromatic except for a beautiful blue sky!

White Balance is extremely important in order to get good images here.  I suggest that you try different targets for WB.  Green grass or leaves, the sky and so on.  Experiment until you find what works well for you and your equipment. The image to the right and above had its WB set on the leaves on the left side of the picture.

I will talk about this filter a lot more in the future.  But for now I want to leave you with the following points for your consideration if you decide to try this filter:

  • There is about a 4 stop loss of light when using this filter. This means that you will have longer shutter speeds.
  • There will be no reds recorded that will be usable for Faux Color Post Processing.
  • There is NO CHANNEL SWAP needed to use this filter.  The image (above) is basically what you get right out of the camera!
  • Compositions with lots of green plants, blue sky and water will generate a very ethereal image that makes full use of the desired Wood Effect.
  • This filter B+W 403 is on the expensive side (as are all opaque filters).

Obviously, this filter would not be your normal choice for normal (is there such a thing?) Infrared photography. BUT it does have a place in your bag of tricks.  If you do decide to give it a try, please come back and let me know what you think!

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10 comments on “Exploring The B+W 403 (UG-1) Filter For IR

  1. Hello, I have just discovered your blog and am in love! My summer/autumn project is to assemble a basic kit to delve into the world of UV/IR/IRR photography of fine art for forensic purposes. When looking at the specs for this B&W 403 I am worried that the IR leak will “taint” UV photography/reflectography. My test camera is converted to full spectrum and I’m attempting to do as much research as possible ahead of time to eliminate the dreaded noob tax. Would this be the case? Or would this filter be fine for such purposes?

  2. I have just come across one of these filters, and would like to know if I’m thinking correctly 🙂 I have a G9 converted to full spectrum – will this filter give me similar results to what you show providing I use the correct custom white balance? I do all sorts of things with cameras converted to 720nm, 550nm, and they seem to work well with slightly over exposed custom white balance. Maybe this is a stupid question to ask you, but as you have so much experience it seemed to me you wre the guy to ask!
    Jen

    • Yes, this will give the same results that I show on the blog! IR (590, 630, 665 and 720) have the tendency to overexpose on the red channel. You have to usually watch your exposure when shooting in these bands. If your camera can show the individual rgb histograms just watch the red and adjust the exposure down to ensure it is correct!

      • Thank you so much, I will definitely watch the red channel carefully when I use my Canon 500D as I shoot RAW with that one and I can view the histogram. Not sure about the G9 – time to go out and play if I get a suitable day – autumn is not the best for IR landscapes!
        Been having a look around now that I have remembered your blog, and the action you have on another page works in CS6 you might like to know! I love it, saves me thinking a lot and then I can tweak it to whatever I like best.
        Might be interested in your DVD, but wonder what UK postage would be?
        Thanks
        Jen

  3. Pingback: Foveon-Falschfarben durch Dualband (UV+NIR) Passfilter - Sigma - Bilderforum.de

  4. Hi Mark
    I have heard that a dual profile filter like the XDP or BW 403 produces IR-like images that seem sharper than an ordinary IR image due to the addition of the 300-400nm spectrum. Is this your way of thinking too?
    And have you used the U-330? Judging by the graphs it looks like the BW 403 on steroids! What are your experiences with this lens?

    Cheers

    Peter

    • Yes this is indeed true! I have not used the 330 but it is really close to the others out there! I REALLY like the B+W 403 and have them in several sizes! It is a unique filter that gives unusual results and is a fun play filter. BUT, my main everyday filter is the 630nm B+W 091!

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