Recent content by Andy Resnick

Jealous = me! This is one of the lenses I'd like to play with, for sure. It seems we are in a 'new golden era' of lens design, with Laowa offering some really off-the-wall lenses (10mm rectilinear full frame! Macroprobe!). Nikkor has recently introduced a 58/0.95 (for the Z mount). Sigh...

A second example of a carbonatite: Carbonatite. The literature on carbonatites is generally too advanced for me (for now), so I will simply quote some relevant sentences from a recent review (Annu. Rev. Earth Planet. Sci. 2022. 50:261–93) that may be open source: “Carbonatites are igneous...

Moving on from Fenites, I have several samples of carbonatites- the source magma for fenitization. Carbonatites are still the subject of active research, and I confess I'm way out of my depth. But, the optical properties of carbonates make the samples fairly photogenic. Here's the first one...

Thanks, but these don't address the problem that spatially varying hue causes. For my other lenses, I've had excellent results by placing the lens against a flat panel display monitor: there is no problem correcting for the spatial brightness. Again, as you can see from the image I posed, the...

Just on the off chance you have some ideas... I have a good example of the underlying problem I am having with trying to use flats flats when imaging with my 400/2.8 lens. Below is a single-night stack, representing an average of 353 individual frames taken over a 3 hour period: The problem...

I think this will be the final example of Fenite: Fenitized gneiss. This sample was been classified as having strong fenitization-1 (45% rock volume) and strong fenitization-2 (15% rock volume). Strongly fenitized-1 rocks contain clear, euhedral alkali feldspar crystals forming a matrix of...

Wow.... just, wow. The computational tools (for example, Postshot) that are available now... it's really amazing.

Coming up on the end of Fenite samples, only a few more to go: Fenitized gneiss. This sample was been classified as having strong fenitization-1 and moderate fenitization-2. Strongly fenitized-1 rocks contain clear, euhedral alkali feldspar crystals forming a matrix of chessboard albite and...

Tonight: Rabbit in the moon

sure? I have no idea.

It is a fantastic lens for low-light level work, and vanishing depth-of-field images. Fully open, tho, the image is a little soft for astrophotography.

Thanks! The reflected distorted vertical lines originate from the reflected building's structure. The windows are not perfectly flat. Along the left side could indeed be vertical blinds inside the room(s). I liked the distorted patterns....

Weekend trip to Cincinnati, Ohio and while there, took a riverboat cruise. Straight jpgs (some cropped) from the camera, all shot using either a 105mm or 55mm lens:

A cropped and downscaled image of the Veil nebula and NGC 6940, taken using a 105mm lens: Deets: Nikon D810 + 105/1.4 (shot at f/2) on Losmandy GM-8, 30s subs, 8.75 h total integration time. Stacking etc. using APP. As it happens, for whatever reason(s) flat frames worked really well with...

More fenitized gneiss samples: Fenitized gneiss. This sample was been classified as having strong fenitization-1 and moderate fenitization-2. Strongly fenitized-1 rocks contain clear, euhedral alkali feldspar crystals forming a matrix of chessboard albite and microcline without preferred...