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Experiments with IR

Started May 13, 2019 | Discussions thread
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mike earussi Veteran Member • Posts: 9,440
Experiments with IR
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I decided to try my hand again with IR using the SD1M after having poor focusing issues earlier with the SD15.

Using a Hoya R72 I found that the SD1M's offset setting can compensate (to some extent) for the IR shift in focus. Using older EX lenses can be a problem though because even at -20 one of them (specifically the 50-150 OS) still didn't achieve correct focus. But using A lenses is no problem because they also can be offset using the USB Dock.

I tested the 50A, 85A and old 150 EX macro which required a -20 to almost achieve correct focus. The first two were fine and the 150 was "good enough" when used as a pano stitch as maximum magnification was not required.

This is the Columbia River Gorge (Oregon) taken with the Sigma 150 f2.8 EX macro at f8:

Sepia toned (20 shots two layers)

Any questions or comments welcome.

 mike earussi's gear list:mike earussi's gear list
Sigma SD1 Merrill Sigma 105mm F2.8 EX DG Macro Sigma 17-50mm F2.8 EX DC OS HSM Sigma 50mm F1.4 DG HSM | A Sigma 24-35mm F2 DG HSM Art +2 more
Sigma SD1 Merrill Sigma SD15
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