Digital RF and Infrared Photography..

[gdi]

A question for the IR gurus...

I realized today that an M8 requires a significant amount of focus shift for IR Photography. The R-D1 does not require that and seems fine if I just go with the RangeFinder. (It looks like the R-D1 may be one of the best non-modded IR cams there is.)

Is this due to a greater amount of visible light making it through on the R-D1? I am using a R72 filter on both.

Thanks
Gary

 

[pfogle]

A question for the IR gurus...

I realized today that an M8 requires a significant amount of focus shift for IR Photography. The R-D1 does not require that and seems fine if I just go with the RangeFinder. (It looks like the R-D1 may be one of the best non-modded IR cams there is.)

Is this due to a greater amount of visible light making it through on the R-D1? I am using a R72 filter on both.

Thanks
Gary

My experience (with R-D1 and R72 filter) is that there is a focus shift on the R-D1. It's dependent on the lens, of course, so are you using the same lens on both cameras?

One thing - I tend to only use the green channel for IR b/w as the results show better definition and contrast than if the red channel is included. It's possible the fact that the R-D1 is less sensitive than the M8 to IR means that, as you say, some visible light is affecting the result, but perhaps it only is affecting the red channel. The green channel is a couple of stops less sensitive than the red, so I think it represents a truer IR rendering of the scene.

Try using the b/w option with the green filter (in jpg mode, of course - the picture options have no effect on the RAW files themselves) and see if the focus shift is similar on both cameras.

 

[gdi]

Thanks Phil - I think I have been using the R-D1 always at F8 so that may be why I didn't notice the shift.