[UncleVanya]

Eclipse images - all taken on A7R III - cropped well beyond APSC.

Pentax FA* 300 f4.5 mounted on LA-KE1:
First best images were NOT made with manual focus. I tried manual focus and found it hard to nail. The A7R III was able to leverage the integration with the LA-KE1 and lock excellent focus virtually every time - these locks were not always without a miss and retry much like using a macro lens in autofocus is on the native Pentax KP I use.








Tamron 70-300 f4.5-6.3 RXD E mount zoom lens

[cooks333]

First best images were NOT made with manual focus. I tried manual focus and found it hard to nail.

I'll second that. Manual focus was the only option I had available and man, was it tough. The Night Vision (red) LCD Display helped some, but still felt like I was guessing/hoping most of the time.

Great shots!!

[UncleVanya]

I'll second that. Manual focus was the only option I had available and man, was it tough. The Night Vision (red) LCD Display helped some, but still felt like I was guessing/hoping most of the time.

Great shots!!

Thanks. I shot a few using manual focus and they were ok but the exact focus is hard to nail in that light. The red mode lcd on my KP is way more useful in starscapes - with this moon it was pretty bright even with an eclipse. The Sony lacks a dedicated lcd mode for Astro.

[K-Three]

with this moon it was pretty bright even with an eclipse

Yes, I'm amazed you got stars to show, with the moon, Nicely done,

[kwb]

Weather wasn't cooperating, didn't nail the (manual) focus either, but I like how this one turned out. K-3III, DA*300 and HD DA 1.4x telecon. Oh, this was somewhat after the total lunar eclipse.

Blood moon behind clouds by k kwb, on Flickr

[bicycle]

My attempt at a shot of the eclipse. Surprised that a 2 sec exposure gets such elongated stars. Things are really moving up there. Will have to try the moon some other time, was nice to be out at night with the camera.




Bob

[UncleVanya]

My attempt at a shot of the eclipse. Surprised that a 2 sec exposure gets such elongated stars. Things are really moving up there. Will have to try the moon some other time, was nice to be out at night with the camera.




Bob

I was a little surprised myself until I did some math. The moon was far from the North Star and this meant the stars would be moving more relative to my camera position. The “rule of 500” is more like the rule of 300 when used in that direction. With my shots I got away with up to 1 second using a 300mm lens. Anything slower started to show blur which is why I was using iso 3200.

https://photographylife.com/500-rule-vs-npf-rule/amp

You appear to have used a 300mm with the 1.4x for about 420mm. In that case am exposure close to 0.7 seconds was probably needed to tame the star trails and keep the moon surface details as crisp as possible. The shot is still good - I wouldn’t beat yourself up over it.

[MossyRocks]

The “rule of 500” is more like the rule of 300 when used in that direction. With my shots I got away with up to 1 second using a 300mm lens. Anything slower started to show blur which is why I was using iso 3200.

I have found that one really wants to be using the rule of 200 with digital cameras. The rule of 500 made use of the reciprocity failure in film to paper over trailing. Even using 200 you will end up with out of round stars but not my too much. I have a couple ready to post and a lot more to slog through as I was running 4 cameras during the clipse.

[UncleVanya]

I have found that one really wants to be using the rule of 200 with digital cameras. The rule of 500 made use of the reciprocity failure in film to paper over trailing. Even using 200 you will end up with out of round stars but not my too much. I have a couple ready to post and a lot more to slog through as I was running 4 cameras during the clipse.

300 seems to have worked for me. 300/300 = 1 second which I had good results from without (to my eyes) didn’t result in oval stars.

[MossyRocks]

300 seems to have worked for me. 300/300 = 1 second which I had good results from without (to my eyes) didn’t result in oval stars.

Well there is only a 50% difference there and depending on the lens and how it was run won't produce noticeable trails or there may be aberrations that paper over the trails. I am usually pixel peeping for astro things and will make up for short exposure times with lots of exposures but then I am mostly shooting deep sky objects so having those really pinpoint stars helps a lot with getting proper alignment when doing the stacking. With the eclipse I was doing 1/4s untracked shots with my 800mm setup but for my smaller lighter stuff (a 200mm and 300mm) I had them both on my equatorial and that did 30s shots no problem and in the case of my wide setup (28mm) I just had it on a tripod and ran at 8s.

For longer glass to nail the focus I use a bahtinov mask and point at a bright star to get the focus perfect and then reframe. The nice thing is that it also allows for one to easily check the focus and adjust as the temperature changes.

[UncleVanya]

Well there is only a 50% difference there and depending on the lens and how it was run won't produce noticeable trails or there may be aberrations that paper over the trails. I am usually pixel peeping for astro things and will make up for short exposure times with lots of exposures but then I am mostly shooting deep sky objects so having those really pinpoint stars helps a lot with getting proper alignment when doing the stacking. With the eclipse I was doing 1/4s untracked shots with my 800mm setup but for my smaller lighter stuff (a 200mm and 300mm) I had them both on my equatorial and that did 30s shots no problem and in the case of my wide setup (28mm) I just had it on a tripod and ran at 8s.

For longer glass to nail the focus I use a bahtinov mask and point at a bright star to get the focus perfect and then reframe. The nice thing is that it also allows for one to easily check the focus and adjust as the temperature changes.

I agree that different use cases may require different numbers. 300 seemed ok for my shots but I’m no expert.
Does that kind of mask work on the moon also?

[bicycle]

The shot is still good - I wouldn’t beat yourself up over it.

Thanks for the encouragement, and I am fine with the photo. I had inexpensive telescopes in the past and I know it is always a trick to keep stars in view due to the relative motion.

On the other hand I gave the type three astrotracer a try just for the heck of it and I was quite impressed. It was just my first try and I was able to pull it off without the instructions and in the dark (of a very light polluted location). Also even with all the light pollution there are way more stars in the photo then to be seen with the naked eye.

So the little jaunt out the back door for an eclipse is likely to get me out at night to try some photography. Might just be the regional park north of my place but at least there won't be a gas station within my view.

Bob

[MossyRocks]

I agree that different use cases may require different numbers. 300 seemed ok for my shots but I’m no expert.

When I am doing some night landscapes with my wide and ultra wide lenses I will often use a value closer to 300 since the stars a small in the frame and I am more after having the sky over the object so with my 28mm I will use 8s exposures and with my 12mm will use 20s, so in the general ballpark of 300.

Does that kind of mask work on the moon also?

I use it to obtain a proper infinity focus for shooting the moon but if you use it against something with a resolvable disk (moon, planets) you don't get the nice thin spikes but fat rays coming out of the resolvable disk. That is why I focus using a star and recompose on the moon.

On the other hand I gave the type three astrotracer a try just for the heck of it and I was quite impressed. It was just my first try and I was able to pull it off without the instructions and in the dark (of a very light polluted location). Also even with all the light pollution there are way more stars in the photo then to be seen with the naked eye.

Type 3 astrotracer seems to be very capable of finding and using stars even in very light polluted locations. One night I really wanted to see what it could do so I tested it out in the park behind my house. First I shot into the "dark" area which is into some skies that are bortle 7 (pretty light polluted), then did a few shots straight up (bortle 8. so really bad) and then into the bortle 9 light dome (might as well shoot star pictures at dawn) with the camera just above the horizon. This was on a full moon night just to make things harder for it. In all cases it didn't have a problem finding stars to figure out tracking. Then because I could I placed the full moon just outside of the frame to see if it would choke on that and it still managed to find enough stars to figure out tracking. However for some reason it seems to choke with my 400mm sometimes and when it does I get a data processing error. That error is what cause me to undertake the test of it but I wasn't able to replicate the error with my 200mm or 50mm. I did find that it is rather optimistic in the maximum estimated tracking time it gives but so long as you ignore that and instead learn what it actually will give with a given lens you will be fine. For example with my 400mm lens I can get great tracking along the celestial equator if I use 40s but at 60s I find the results unacceptable. Another error I have gotten was tracking time too long but that is after it takes the pre shot and does its calculations and when I got that error it was because I was just being dumb with things to see what happens if I said to take a 10 minute shot of things along the celestial equator with my 200mm. In all my tinkering the only times I have been able to replicate the data processing error is if I enter a focal length that is not correct, yes I did this as part of the testing, so I wonder if the SMC A* 400/2.8 isn't exactly 400mm when focused at infinity and instead is something like 390mm or 410mm.

So the little jaunt out the back door for an eclipse is likely to get me out at night to try some photography. Might just be the regional park north of my place but at least there won't be a gas station within my view.

I'm also in Minnesota (south metro) and with experience one can get some good astro shots even from the core 7 county metro area. If one ventures out to some real dark locations you can get some really good shots.

[shiner]

Tonight with KP, DA300, 1.4x

[MossyRocks]

Tonight with KP, DA300, 1.4x

Nice. I may waste some electrons on it here soon if the clouds ever clear out. This reminds me that I should post my eclipse shots.