How necessary are the IR filters, really?

[barnwulf]

The IR requirement and the coding thing really put me off about the M8. I wanted a M9 really badly and tried but just couldn't come up with the money. I bought a used M8.2 with the primary intention of shooting B&W. I get the color DNG and convert it with either Silver Efex or Lightroom. I have tried a little bit of Infrared and I want to do more of that so as it turned out the camera is just fine for me. I don't have any Leica lenses and haven't tried to code my lenses. I do have a couple of IR filters and do use them if I am shooting something that I want to shoot in color. I may be missing something but everything seems to be working out fine for me. Jim

 

[Rob-F]

I picked up a used lens that came with a 49mm Leica IR filter. I was surprised that the filter didn't look so obviously red as I had expected. I just see a little hint of red at certain angles. Have they changed the filter since the very red looking ones I've seen in the photos here? Or maybe they photograph redder than they look when viewed directly? Or what?

 

[Doug]

Rob, IR filters we know from use with film are IR Pass filters, which filter out most or all the visible spectrum, allowing the IR to pass through, so appear either dark red or black.

What you have is surely the UV/IR Cut filter for use on the Leica M8, which has insufficient IR-absorption in the sensor cover glass, and needs help. 🙂 This UV/IR Blocking glass filter has a completely colorless glass carrier coated with a number of extremely thin, partially reflecting layers with precise thicknesses, similar to multi-coating.

It does not block by means of absorption, but by interference of the unwanted UV and IR radiation that is repeatedly reflected between these layers affecting the wavelengths on both sides of the visible spectrum with a steep cut-off.

As you observed, holding the filter at some angles will show a visibly red reflection that is near-IR visible light. The stronger the IR light source, the brighter the reflection will appear.

Edit: That 49mm Leica UVA/IR filter goes for $129.95 ($95 used) at B&H, a significant goodie with your lens!
http://www.bhphotovideo.com/c/product/483708-REG/Leica_13412_E49_UVA_IR_Glass_Filter.html

 

[Rob-F]

Doug: yes, it is the IR filter for the M8. Your explanation about the IR light source making a difference is what I was missing. No doubt there was not that much IR light when I looked at the filter. I just tried reflecting the light from the gas fire logs. Now the filter looks red! Funny, it didn't look red from the light reflected from an incandescent bulb when I tried it that way. But that's the answer, though.

 

[ramosa]

Good question. I use the IR filter for IR, but also as simple protection for lenses.

 

[AncientCityPhoto]

To be honest, coding is not really that big a deal. It takes 10 seconds and you only do it once generally. I can't imagine coding would be an issue to keep someone from such an amazing camera.

The IR filter is not as big a deal on strictly black and white. I kind of prefer the IR look anyways.

However, I use multiple cameras on set so the IR filters are absolutely necessary. This allows me to take color profiles and calibrate my Leica with other brand cameras to have consistent color in a shoot. The IR filter is totally necessary for accurate color work.

I don't see how there is any "management" of the filters. I normally shoot with a UV/IR filter on my glass. Since my lenses for the M8 don't go on any other camera, they each have a dedicated IR filter. I use this instead of a UV/IR filter. So they never come off. Just like coding, it's done once and I don't think about it again.

I personally found that once I took the plunge and ignored all the "negatives" people rant about online, the M8 and its glass are the best camera move I ever made.