Recent content by Andy Resnick

Catching up with the backlog... Currently my GM-8 mount is under repair- the quadrennial replacement of the declination gearbox- this is as much time on target (18 hours total) as I could get before the gearbox completely failed: This is the full frame- the prominent galaxy is NGC 7331...

I couldn't see the moon this morning- I don't have a clear sightline to the horizon and the moon is too close to the sun (new moon). Last night was (supposedly) peak Draconid meteor shower, so I tried imaging (using a non-motorized tripod) with my now trusty Vivitar 28/2.5 lens. I realized...

This morning was also clear: Nikon Z7 + 800mm lens, 0.5s ISO 800. Lower ISO = less noise = :) ISO 64, 1/20s exposure. At 200%, along the border of Oceanus Procellarum: Prominent craters from lower right: Grimaldi, Hevelius, Cavalerius (located approximately in the image center).

Melteigite (Ijolite) intrusion adjacent to fenitized country rock (telemark gneiss), Fen complex. The intrusion consists predominately of a dense mat of anhedral augite prisms, some zoned, with abundant euhedral titanite (sphene) and fine-grained mixtures of muscovite and (likely) aegirine...

Thanks again! Another significant advantage of using 'live view' is ease of focusing- once upon a time I shot a roll of Ilford SFX Infrared and had to adjust focus to account for chromatic aberration. Because (at the time) there is nothing to see and focus on through the viewfinder, the lens...

This post was incredibly helpful- thanks! Just wondering, have you done any testing like, for example, trying to see if you can image the light from a tv remote (or some other remote that uses IR LEDs)?

Yesterday morning's moon and Jupiter: Nikon Z7, 800mm lens, ISO 64, 1/15s (IIRC). I shot this RAW because I hoped I could pull out the Galilean moons of Jupiter with tone mapping (200% zoom): The aberration is expected since this part of the image is located near the very edge of the...

Just saw your reply, this is a little more interesting. If I understand the patent description correctly, what I need is a wavelength-dependent polarization ellipse azimuthal angle 'θ'. My magic book ("Ellipsometry and Polarized Light, Azzam and Bashara) has some information on how to do this...

Thanks for this- I stumbled outside early this morning and was wondering about the bright dot next to the Moon!

This guy: I'm not joking. Watch the whole 30 minutes. For those with shorter attention spans:

I highly recommend checking out a few textbooks, including: Physical Biology of the Cell (Phillips et. al) Bioenergetics 3 (Nicholls and Ferguson) An Introduction to Systems Biology: Design Principles of Biological CIrcuits (Alon)

Field trip today and I challenged myself to shoot 28mm tilt-shift by hand (no tripod). The lens also has a polarizer, so the sky looks x-tra blue. This one is no shift or tilt, I just tried to keep all the horizontal and vertical lines staying horizontal and vertical: Mostly successful, but...

Hydrothermally altered ultrapotassic fenite, Fen complex. Rock is almost entirely K-feldspar. K-feldspar grains are dusty in PP, anhedral, with highly convoluted grain boundaries. In places, the K-feldspar grains have an irregular rim of albite. In other places, occasional patch perthite...

I wonder if the more interesting version of your question is, "are there non-separable solutions to the 3D wave equation?" Standing waves typically are separable in space and time. However, there does appear to be a case (irregular boundary conditions), when the solution cannot be...

Same flowers, same tilt-shift, different lens- 15mm, my widest: With this lens, I increase perspective distortion, so nearby objects are WAY larger than distant objects. One drawback, because this is a retrofocus lens there is vignetting, so I cropped that image as well as this...