Friday, August 3, 2018

Ektachrome at GSSP 2018

Film astrophotography is not dead!


During the recent star party, I collaborated with Isabell Lin De La Cruz and worked through some targets on film.  She added her Pentax 67ii body to the tracking setup that I've been using and I swapped out the second 400mm lens for the shorter 165mm lens.

Because the darkness at this location in northern California is limited, I'd modified the estimate for exposures to use 40 minute durations at F4.  This meant running the 400mm EDIF wide open - a big risk.  On the other hand, it would be a cakewalk for the 165mm f2.8 lens.

The weather during the star party varied.  Some nights were clear and others had high haze.  All had good darkness and few airplanes, just that when the clouds came in, there were no stars!

We also shot some Portra and haven't gotten that developed yet.

I sent the Ektachrome film off to The Darkroom to get it developed and didn't preview the results until I had the film back in my hands yesterday.  When I saw them, I was pleased at the exposures and was glad that we'd opted for the settings and push.

When I did the deep scans on the Plustek Opticfilm 120 (5300 dpi) I found that all the images from the 400mm lens are out of focus.  This is frustrating, but expected, because even though we used the loupe and young eyes to check focus, I think that there's a need to do a more precise focus.  It may be time to learn to use a knife edge or ronchi grating (I have both).

The 165mm lens really shined.  Stars are crisp and there's very little vignette.


Cropped frame of M31

I've already scanned the rest of the images from the roll.  Will be uploading more.