Is B+W 092 Filter Still Good With New Rollei Infrared Film???

[Andre Noble]

Is anyone else upset with the discontinuation of Macophot IR820C film?

It appears that the new replacement, 'Rollei Infrared ', requires a different filter, but I'm not sure if the old B+W 092 and 89B deep are no longer useable.

Does anyone know from testing the new Rollei Infrared film, if you still can use a B+W 092 Deep red filter (89B) with good results?

These IR glass filters are expensive. Did Rollei considered this when they reformualted the film?

[Ralph Barker]

I haven't tried the Rollei 820c, but the fact that they left the designation of 820c would suggest the same IR cutoff point of 820nm. Thus, the B+W 092, which has a cutoff of 650nm, or an 89b (720nm) should be OK.

Here's a table with the relative IR cutoffs: http://www.rbarkerphoto.com/IR-wratten-tbl.html

[Michael S. Briggs]

The B+W 092 filter transmits wavelengths longer than 700 nm (approx. 50% point), and the Rollei IR film has response to wavelengths above 700 nm, so the filter should work. I haven't tried this film yet, but I am expecting that the results will be different from the Maco IR820 film. Stating that both films have the same cutoff wavelength of 820 nm gives a very incomplete picture -- the Maco film has an approximately flat spectral sensitivity to about 800 nm, while the response of the new Rollei film is steeply falling above 700 nm.

[Marko]

I just started getting used to Maco and they disconnected it... Oh, well. OTOH, if the new Rollei film really maintains the 820nm cutoff point, it might be even better deal, since they raised the ISO number... If that all holds up in testing, I would definitely hope they keep producing it longer than Maco did.

As far as filters are concerned, it's all just a matter of physics. The light "stops" being Red and becomes Infrared at about 680-700nm, depending on one's eyesight and all the infrared filters do is transmit light longer than 700nm and either absorb or reflect anything shorter. So yes, if the film really goes deep enough, your filters should work just fine.

They'll even work with infrared-enabled digital, so when they stop producing film altogether some day in the future, we'll still be able to use our filters, we'll just have to buy new cameras and convert them to "see" infrared in case of digital slrs.

Speaking of which, I did experiment a bit with a Canon D30 while I had it and a 89b filter. It's sensitivity without any modification to the body was very similar to Maco with the same filter, perhaps a stop slower. Newer digitals have much more efficient hot mirror so if one wants to shoot ir, best route is to have a cheap digital body modified for that purpose.

Makes me wonder though, why is it that none of the digital makers has an option for infrared - there are enough infrared shooters out there to warrant at least one such model. Sony had something like that until last year, but they went out of their way to make it as impractical as possible. Even with film cameras, very few 35mm ones were/are ir safe, save for Canon's very top model.

Anybody else notices this?

[Donald Qualls]

Originally Posted by Marko

Makes me wonder though, why is it that none of the digital makers has an option for infrared - there are enough infrared shooters out there to warrant at least one such model. Sony had something like that until last year, but they went out of their way to make it as impractical as possible.

IR has always been a small specialty market. With digital, it's complicated by the fact that, to give accurate color rendition (that matches pretty closely what your eye sees, assuming your color vision is normal), you have to block IR from confusing the color filtered sensors -- in a conventional "Bayer array", there are a lot of sensor elements, each with a color filter over it, but like most color filters, these pass some wavelengths outside their design range (especially in IR); the result is that if you don't have or disable the IR block filter in a digital, you get really wonky colors -- IR passes the green filters more than blue, and red more still, but IR added to red doesn't look too strange, while IR added to green most assuredly does.

So, an IR conversion needs to record the image in B&W or compensate the colors in software (which has its own problems, such as over-range green when trying to get enough light for blue, and no way to tell if the green sensors are seeing real green or IR) to produce some reasonable analog to visual color (for most non-scientific purposes, anyway), and not many folks are willing to pay for a specialist B&W digital camera.

And since digital cameras are affordable only due to mass production, making tiny quantities of a specialty item also pushes the pricing through the roof -- which makes them even harder to sell, of course.

Bottom line, digital is hard to sell in IR because digital chips do IR so well natively they have to be prevented in order to do visible light photography well -- and it's expensive to undo something that's applied at a low level. It'd be relatively easy, starting from scratch, to design a B&W, IR-only digital camera or DSLR body variant -- the problem would be selling enough of them to pay for the R&D and retooling.

[Marko]

Donald,

What you are saying makes a lot of sense, but here's what I'm thinking: There seems to be enough of an interest in IR photography to justify the existence of several outfits which specialize in such modifications. They will take your dslr, replace the hot mirror with either a band-pass filter or quartz glass to compensate for focus and charge you $300-$600 for that.

If it pays for them to do it, why wouldn't it pay for the OEM's to build an option in some models? I'd much rather pay extra to the OEM than to a third party. After all, Sony already did it with their 7x7 and 828 digicams - they enabled the hot mirror to be moved away at the flick of a switch and the software would then compensate for metering and focusing. But then they went out of their way to disable that same option as much as they could...

There was also another camera which had hot mirror mounted in such a way as to be easily removable/replaceable through the lens mount. I think it was one of the Sigmas, but I'm not sure. That was a very simple and yet usable solution - all one would need is to have an ir filter available in the same mount. That went nowhere as well.

All in all, it doesn't seem impossible at all nor even all that hard to do it. Colors wouldn't matter all that much because they would be false anyway, and shooting in RAW and post processing would take care of that for those interested.

What intrigues me is that none of the manufacturers show no interest whatsoever to accomodate this particular segment of the market. Ditto B&W, although that would be much harder to accomplish technologically.

[MJSfoto1956]

The Canon 20Da is available direct from Canon as an Infrared-capable digital camera. Companies such as Hutech and MaxMax will sell you new digital cameras modified for IR purposes.

J Michael Sullivan

P.S. for the last year I have been using a Hutech-modifed Canon 20d to complement my "Adventures in IR-land" series shot with the BetterLight back and Linhof Technikardan.

[Ron Marshall]

Here is a link to a comparison of photos taken with Rollei infrared using different filtration:

http://www.efikim.co.uk/macoir.shtml

[Ole Tjugen]

I've used a Heliopan 695 filter with the Rollei/Maco IR 820/400, and the results are great. Even better - the lightmeter in my Bessa-L is accurate when film speed is set to 400!

Edit: I know the Bessa-L is not LF, but it will also make a great lightmeter for ir photography...

[Donald Qualls]

Originally Posted by Marko

There seems to be enough of an interest in IR photography to justify the existence of several outfits which specialize in such modifications. They will take your dslr, replace the hot mirror with either a band-pass filter or quartz glass to compensate for focus and charge you $300-$600 for that.

If it pays for them to do it, why wouldn't it pay for the OEM's to build an option in some models? I'd much rather pay extra to the OEM than to a third party. After all, Sony already did it with their 7x7 and 828 digicams - they enabled the hot mirror to be moved away at the flick of a switch and the software would then compensate for metering and focusing. But then they went out of their way to disable that same option as much as they could...

There was also another camera which had hot mirror mounted in such a way as to be easily removable/replaceable through the lens mount. I think it was one of the Sigmas, but I'm not sure. That was a very simple and yet usable solution - all one would need is to have an ir filter available in the same mount. That went nowhere as well.

All in all, it doesn't seem impossible at all nor even all that hard to do it. Colors wouldn't matter all that much because they would be false anyway, and shooting in RAW and post processing would take care of that for those interested.

What intrigues me is that none of the manufacturers show no interest whatsoever to accomodate this particular segment of the market. Ditto B&W, although that would be much harder to accomplish technologically.

Actually, B&W would be *easier* to accomplish, and most cameras do it already, via in-camera conversion (they'll also do sepia). Of course, then you have the same pixel count you'd have in color, instead or 4x the count from the same chip (assuming the chip is capable of reading out single pixels rather than the Bayer array).

But let's say a manufacturer spends the money to make an IR version of a popular camera (perhaps a D20, just to pick one of the few model designations I recall). If you add $600 to the retail, you'd be paying 20% to 50% *more* for a camera that's only of use where you'd load a roll of IR film in a film SLR. I predict their marketing folks would squash that notion about ten seconds after it was brought up at a planning meeting. Given what it costs to retool and make a different version of a mass produced item, I wonder if they could do it for what the converters get -- though certainly, if they had the volume of the color model, they could sell it for the same price.

Or maybe it's just a conspiracy to force everyone to shoot in 24-bit color, and stifle creativity worldwide preparatory to some evil plot to enslave humanity.