Thanks Nuge and Clastro for your follow up posts.
I used Sky Safari to determine the separation and PA of the 35 Aurigae Clastroiana (aka HD 20762/20743) pair in Camelopardalis. It works like this, zoom in so that the two stars are somewhat apart in the field of view. Select the "primary" or brighter star. Then from the Selection menu, choose the Measure From option. Then click the secondary or fainter star. A line is displayed connecting the two stars and the separation/PA are calculated and displayed next to the line. I've only done this with stars, but I'm guessing it would work for other objects too.
Agreed about the Maven binoculars being workhorses. Somewhat unexpectedly, the Maven b.5 10x56 has increased my appreciation for the Oberwerk 10x50 Ultra, a binocular I have always loved. My issue with it has been that the edge performance isn't as good as that of the Fujinon 10x50 FMTR-SX. But it is reasonably sharp to about 80% of the FOV, at least for my corrected vision and the softening/distortion from there to the edge isn't distracting or annoying. Similar to the Maven edge performance, honestly, at about 1/5th the price. Which is darn impressive when you think about it. Even more so considering that the Swarovski 10x56 SLC is something like $1000 USD more(!) than the Maven and has similar edge performance. The truth is that darn few 10x50/56 binoculars are sharp past 80% of the FOV. Those include the Fujinon, the Vortex Razor 10x50 UHD, and the Swarovski 10x50 EL. Maybe a few others. The Nikon 10x70 SP is sharp to nearly the edge with a smaller FOV. The Canon 10x42L IS is sharp to the edge with a 6.5 degree field. Honestly the best edge performance of any 6.5 degree FOV binocular on my team.
What the Maven helped me understand is that while I appreciate good edge performance, being sharp to the very edge of the field is not as critical to me as other characteristics, particularly excellent optical performance in the center of the field (sharpness, brilliance, and color rendition) as well as viewing comfort and ease of use.
Clastro, what star charts are you working from? To learn star hopping it's important not to rely on an application like Sky Safari but to work from actual star charts that provide good detail and consistent star sizes and DSO symbols covering the sky. My absolute favorite atlas for binocular star hopping is the Sky Atlas 2000 black laminated field edition. It includes stars down to 8.5 magnitude on the main charts. A few detail charts at the back may go deeper. The Jumbo Pocket Sky atlas isn't bad, but doesn't plot enough stars for my taste -- to enable pinpointing DSO positions. For more detailed charts I use the Uranometria 2000, now available again since Sky Publishing picked up the Willmann Bell inventory and rights. I use Sky Safari and like it a lot, but it is very much a supplement to print atlases. And in my opinion it is difficult to learn star hopping from an app like Sky Safari because zooming in and out changes the star symbol size, spacing, and limiting magnitudes of the stars seen. This doesn't matter so much when zooming in to a very small area to pinpoint the location of something like, say, M1, but to learn star hopping it can be a confusing impediment. Really a tool that works better for accomplished star hoppers than neophytes.
Regarding separation estimates based on the actual field of view, I never think of it that way. For any given binocular, I have a sense of what a specific separation should look like, and the magnitudes involved which aids identification and resolution. For a 10x50 binocular, 40" is close -- a mounted (or Image Stabilized) instrument is required to resolve it satisfactorily. Handheld, it is possible to see that a 40" double, if the components are not too dissimilar in magnitude, actually is a double star but the individual components cannot be held steadily, which does not make for an enjoyable observation. A 10x50 binocular can resolve evenly matched doubles down to something like 18", but that definitely requires a mounted instrument. Also, when observing any double star, whether it's a planned observation or one I stumbled across and then need to identify, I almost always use either the Sky Atlas 2000 or the Uranometria 2000 to determine the precise position of the star, which I then look up with Sky Safari. I have learned not to rely on Sky Safari data, however. Once I have the catalog designator for the star, Like STT 128 (35 Camelopardalis), I get precise multiple star data from stelledoppie.
Edited by Fiske, 25 January 2022 - 02:21 AM.
