Maco IR820c Speed Rating? Your experiences? General Discussion...

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Ran my 1st roll of Maco IR820c last weekend and ended up with thin negatives (thin by my standards anyway) One negative was somewhat closer to my comfort zone (all other negs were consistant density) and that was one I'd put my camera on 1/2 sec exposure rather than the 2secs I intended, so I added an extra 2secs to that frame (camera was on tripod and I figured more exposure was better than less!) maybe I just metered this scene a whole lot better than the others! Always a possibility!

The packaging of the film states 100asa so I figured that that was a good place to start. I only have an orange filter for my Mamiya 645 lenses so I used that and set my meter to 25asa. Mostly metered shadows and decreased exposure by two stops. Processed the film in Rodinal 1:100 for 20mins @ 20C. Looking at the negs, there is some detail in the shadow's of some frames but I can see frames where I have no shadow detail. The next roll I use I will do a bit of testing, rather than wandering around snapping things, however I'm going to add at least another stop of exposure. (this stuff is getting slow!)

Other observations:

I loaded it in the shade of a large tree during the middle of the day (bright sunny one at that). I can't see an sign of fogging other than some edge fog that I can get on any 120 roll film. The frame markings are somewhat fuzzy... is that normal?

Orange filter not strong enough to get any IR effects. I haven't printed any frames, but the couple I've scanned didn't show much, some plants and skys look IR like but I'm not putting much faith in the scanned version cause I had to tweak the scanner so much to get any image from the very thin negs. A new filter will be under the Xmas tree I feel.. good guy that Santa!

The Maco website only lists two developers (the Massive Development Chart has a couple more - I didn't check Ed's site to see if there's any suggestions there), pity they couldn't spend a little time offering a few other suggestions! What's everyone using?

Anyone got anything to say about this stuff? Own experienses, suggestions...

-- Nigel Smith (nlandgl@unite.com.au), December 18, 2001

Answers

Greetings Nigel,

I have a previous post re. this film, but from recollection...

I use an EI of 6 for this film with an 87 IR filter. I develop it in full strength XTOL for 6 minutes at 20C (rotary processor) and get negs that print easily.

Regards,

-- Pete Caluori (pcaluori@hotmail.com), December 18, 2001.


I wrote a larger posting about the film, speed and development on this listserve. Maco informed me that they now recommend either using Ilford Microphen or Tetenal Ultrafin Plus as developers. You will definitly have to move to a IR filter to get the full effect. The speed will be very low though. I got ISO 0.25 with a Wratten 87 filter. The film though is absolutely superb, beyond compare to Kodak HIE.

-- Volker Schier (Volker.Schier@fen-net.de), December 19, 2001.

You refer to the "infrared effect" or "wood effect" that you do not get with an orange filter. What most people do not realize is that the "yellow father" cheats a little in this respect. If you use different filters on HIE you will always notice very light or white foliage on the negs, mostly not depending on the spectrum band of visible light you remove by filtering. Physically this phenomenon does not make much sense, since the IR spectrum is only a minimal portion of the wavelength the film records. HIE has a heigthened blue and green sensibility and much what people consider "IR" effect comes through this. With an IR film that has a more or less panchromatic rendition (which the Maco 820 has) you will get a very different response depending on the wavelength you actually record on the film. This is one of the points that makes the Maco so superior, since you have much more versatility and control over the situation. With a Wratten 87 filter you will have a totally different realisation than with a red filter. I see this with infrared reflectography, for which I use the film. By using different filtration I get very different results in penetrating the colour layers of paintings and by comparing these differing results I get a far better "picture" of what is going on. The results with HIE and different filters often very, very similar. Also the grain and resolution speak for the Maco.

-- Volker Schier (Volker.Schier@fen-net.de), December 19, 2001.

Thanks Volker, good info! Looks like a new filter is in order. I did notice that Maco state the different effects that each filter produces. Now I'm off to find your other posting regarding Maco IR820c

-- Nigel Smith (nlandgl@unite.com.au), December 19, 2001.

Another tip: Use your search engine for "Orwo, infrarot, filter". This should get you to the page of a photo shop in Berlin that is selling a wide array of ORWO infrared gels cemented between glass and mounted in filter rings. These are left overs from GDR days. These filters are very accurate in their cutt of frequencies and cheap in comparison to many other IR filters. For your purpose this may not be of special importance, but if you want to use IR for sciencitific use you want to make sure that the filters are accurate, so that you can determine the spectrum you actually record. Many filters sold as IR filters -- even when they state equivalent Wratten numbers -- are not. The ORWO filters are often a little denser than others, but their quality is superb. ORWO was the main supplier for high quality IR products for the whole Eastern Block and their IR plates (they had a variety of to 900nm) were a class of their own.

-- Volker Schier (Volker.Schier@fen-net.de), December 19, 2001.


I've had excellent results with MACO 820 in 120 size. I use the sunny 16 rule with an EI of 4 with either a R72 or 87 filter. I develop in Diafine and get 6x6 and 6x7 negatives that print to 16x20 with acceptable grain and decent shadow detail (for IR Film).

There is no IF effect with the visible light filters such as an A25 dark red. I recently got an 3x3 87 gel filter for $12 from B&H and fit it to a 77mm UV filter. Works great and a lot less expensive than a glass one ($200+). I also have found that I can load 120 in the shade with no fogging.

Be sure to presoak the film for 1-2 minutes to remove the anti- halation backing before developing.

-- gene Crumpler (hassieguy@att.net), December 20, 2001.


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