MacUser2

I have been using High Sierra Beta for several months, have experienced no problems using my Wacom tablet.

Have you considered a monopod?

Sorry, I did not address your second question.  As long as you get enough time to move from one pixel to the next, stacking improves the Signal to Noise (IQ) by a factor of the square root of the ...

Contrary to what is written on a great many web sites, the crop factor must never be used in calculating the exposure time.  The crop factor does not actually change the focal length, it is ...

Nice composition and very good foreground exposure. I might have moved the sharp peak from the center, but that is just my thing. The lens is exhibiting vignetting (unless you added the vignette in ...

I grabbed the wrong image.  This is the one when he came back again and I was ready with my flash.

Significantly cropped.  I am doing a mental recap and I seem to recall that I was about 75 feet from the bird.  Here is the original (out of the camera) In later version I reduced the contrast ...

You do not need a perfect sky, all you need to test you lens is a reasonable clear sky with enough stars distributed across the scene.  Since Coma is usually worst in the corners try to take ...

Your exposure time of 25 seconds is much too long, there are obvious star trails (I estimate about 9 pixels). An exposure time of 3 seconds would potentially result in a perfectly round star, but ...

I expanded the image to 100% and two things jumped out. 1. I saw star streaking toward the center and the streaks were "fat".  This suggests tangential astigmatism.  If it was due to sagittal ...

There is considerable variability reported in the Rokinon lenses. One guy reported, on this site, that he went through four copies until he finally gave up. A friend of mine has this lens and his ...

I have been running LR 6.12 on High Sierra (Beta) for several months.  No problems encountered.

There are six third order Seidel aberrations, they are: Chromatic Aberration, Spherical Aberration, Comatic Aberration, Astigmatism, Field Curvature, and Geometrical Distortion. These aberrations ...

It is going to be tedious, but did you try content aware and then touch-up with the clone tool?

Thank you. I use a Harbor Digital Flash extender.  I originally used the BB, but I am such a klutz that I kept knocking out of alignment or off the flash as I stumbled through the woods.  The ...

He came back, this time I was ready for him and used my flash extender.  It was getting on to dusk, so I used the flash as main light (minus 1 stop)

He came back today.  Heavy overcast and in the woods and of course I did not have my flash extender; ISO =1250, hand-held.

The artifacts do not appear to be do to tracking errors or bad focus. Unfortunately, your lens exhibits some of the worst examples of coma  (limited number) that I have seen.  Look at the brighter ...

Chromatic aberration is not Coma but Comatic aberration is absolutely coma. If you do not believe me look at the following quote from wiki, "In optics (especially telescopes ), the coma , or comati ...

I went back and looked at your last posting.  I did not see significant Coma, so it appears that you got a good one.