First test of Rollei/Maco infrared film
Quick comparison
The three images below give a quick comparison of the results of exposing this film with no filter, a Kood Red filter (approx Wratten 25, I think), and an Ilford SFX filter. I did use other intermediate filters in addition, at a variety of exposures (see below).
I also used the Lee polyester 'infrared' filter, which is marked 87 on the envelope. Despite trying exposures up to EI6 (metered without the filter) the film for these exposures was completely clear, so I think the cutoff of this filter must be beyond the sensitivity range of the film. (Or its just too early in the year!) There ought to be a significant overlap between the pass band of a true Wratten 87 filter and the sensitivity of this film, so maybe the Lee filter doesn't have the same characteristics.)
Notes to help in reading the images
- The privet bush above the greenhouse clearly gets lighter in relation to the greenhouse with the red and especially the SFX filter
- The holly trees in the background get lighter mainly with the SFX filter, except where strongly shadowed.
- The aluminium greenhouse and green water butt just visible behind it change relatively little with the addition of a red filter, but are noticably darker with the SFX filter.
- The foreground grass changes in a similar fashion to the privet, except where shadowed
Although you can see that there is an effect with the red filter in these images, its not really strong enough to be easily observed in an isolated image. It might still be useful in separating some tones (eg deciduous and coniferous trees).
Red filter
Ilford SFX filter
Full set of results
Results of a quick test of the Maco/Rollei IR820 400ASA film, in early February, Northern Hemisphere.
Film developed in Prescysol, using partial stand development (normal recommended temperature and time). Camera used was a Minolta Dynax 7, autoexposure through the filters, bracketed. Negatives were scanned as slides (exposure set to -1 to move negative higlights back from pure white), inverted, converted to grayscale, and then adjusted simply using autolevels. In addition to the filters shown, I did use a Lee Infrared polyester filter (wratten 87 equivalent?) and this simply leaves the film clear, so the infrared sensitivity would appear not to extend far enough for this. (The yellow and orange filter results have now been removed, as they were of no great interest.)
| 400 ASA | 800 ASA | 200 ASA | 1600 ASA | 100 ASA | |
| No filter | 
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| Red filter | 
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| Ilford SFX filter | 
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