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01-23-2019, 07:08 AM   #16
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QuoteOriginally posted by clackers Quote
Your shutter speed was way too slow.

The moon is much faster across the sky than the stars (20 seconds would be fine for them).
See, now that's what I thought. Thanks for lay-manning it.

01-23-2019, 07:11 AM - 1 Like   #17
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QuoteOriginally posted by jawats Quote
See, now that's what I thought. Thanks for lay-manning it.
Now that's why I said what I did about your shutter speeds should have been at least 1/200s or 1/400s. Not 2s. I guess you missed what I said.
01-23-2019, 07:15 AM   #18
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QuoteOriginally posted by photolady95 Quote
Now that's why I said what I did about your shutter speeds should have been at least 1/200s or 1/400s. Not 2s. I guess you missed what I said.
Nope! I saw it. This last was in the context of understanding what the previous, more science-inclined comment, said. Your advice was and is good.
01-23-2019, 07:18 AM - 1 Like   #19
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QuoteOriginally posted by jawats Quote
Nope! I saw it. This last was in the context of understanding what the previous, more science-inclined comment, said. Your advice was and is good.
Moon moves faster than we think it does. No science-inclined to it. We just know it does. LOL Learned that in science in primary school. Plus a little common sense helps too.

01-23-2019, 07:24 AM   #20
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QuoteOriginally posted by photolady95 Quote
Moon moves faster than we think it does. No science-inclined to it. We just know it does. LOL Learned that in science in primary school. Plus a little common sense helps too.
See now, I always thought the reason the moon moved fast was due, similarly to the stars, to the earth's rotation. I mean, the earth rotates at 15 degrees per hour. The moon travels roughly 13 degrees per day. So, most of the speed is, similarly to the stars, due to the earth's rotation, no?
01-23-2019, 07:30 AM - 1 Like   #21
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Yes,

And since you have that knowledge, you should have known 2s was too slow a shutter speed to capture the moon, right?

A google search on how fast the moon orbits earth:

The Moon orbits Earth at a speed of 2,288 miles per hour

Last edited by photolady95; 01-23-2019 at 07:38 AM.
01-23-2019, 07:38 AM   #22
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QuoteOriginally posted by photolady95 Quote
Yes,

And since you have that knowledge, you should have known 2s was too slow a shutter speed to capture the moon, right?
Oh, absolutely. My thought was to whether 2s was the cause of the lack of focus, or the ice, or some other issue. Hence, my original thought "I couldn't get wide enough to capture the moon and color without motion blur." I still think I would've been able to speed the shutter with (1) a wider lens, and / or (2) Taking into account your original suggestion of turning SR off.
01-23-2019, 07:51 AM - 1 Like   #23
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QuoteOriginally posted by jawats Quote
Oh, absolutely. My thought was to whether 2s was the cause of the lack of focus, or the ice, or some other issue. Hence, my original thought "I couldn't get wide enough to capture the moon and color without motion blur." I still think I would've been able to speed the shutter with (1) a wider lens, and / or (2) Taking into account your original suggestion of turning SR off.
Turning of SR would have probably helped but taking off the 2x TC would have helped more because you lose light when you add one of those to a 300mm lens, when your f stop is low. I don't know what your f stop is on that lens at 300mm. On mine it's usually f6.3, so two steps down would make it f11, I think.
Adding a 2x isn't giving you 900mm it's only giving you 600mm. It's 2 x 300mm, not 300mm x 300mm.

01-23-2019, 08:39 AM   #24
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QuoteOriginally posted by photolady95 Quote
Turning of SR would have probably helped but taking off the 2x TC would have helped more because you lose light when you add one of those to a 300mm lens, when your f stop is low. I don't know what your f stop is on that lens at 300mm. On mine it's usually f6.3, so two steps down would make it f11, I think.
Adding a 2x isn't giving you 900mm it's only giving you 600mm. It's 2 x 300mm, not 300mm x 300mm.
I suspect you're correct as well. My 60-300 is at f/5.4 at the long end. With the 2X TC, it's 2-stops loss, I think. So, f/8 if wide open.
01-23-2019, 10:03 AM - 4 Likes   #25
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QuoteOriginally posted by clackers Quote
Your shutter speed was way too slow.

The moon is much faster across the sky than the stars (20 seconds would be fine for them).
Living in mythical Australia with your upside down moon has confused you!

As any flat-earther knows:

The sun orbits the earth every 24 hours.

The stars orbit the earth about every 23 hours 56 minutes (the constellations rise about 4 minutes earlier each day).

The moon orbits the earth about every 24 hours and 49 minutes every hour (the moon rises about 49 minutes later each day).

Thus, the moon moves about 4% slower than the stars.

P.S. This implies that Pentax astrotracer (which moves the sensor to track the stars) overcorrects slightly for moon motion. The over-correction amounts to about 2.7 microradians per second. That implies astrotracer does help stabilize moon shots but not for as long a duration as it does for stars. With a 600 mm lens, astrotracer should do a decent job of stabilizing the moon for up to 10 seconds depending on the quality of the calibration, quality of the lens and atmospheric conditions, and whether the shooter pixel-peeps.
01-23-2019, 10:35 AM - 3 Likes   #26
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QuoteOriginally posted by jawats Quote
Also, Brian, here are a couple more, same equipment, on other nights:

One from earlier in the eclipse, and two from late Dec.
Much better, so the lens & convertor are definitely capable of more! Going from my own failures looked I do think it's more than motion blur that's the issue though, but I could be wrong.

I do notice that the exif of your photo shows 1/3s?

QuoteOriginally posted by clackers Quote
The moon is much faster across the sky than the stars (20 seconds would be fine for them).
20 seconds would be very noticeable star trails, at 600mm they would be about 4% of the width of the frame. Please correct my lack of astronomy skills, but the moon takes about 27 days to orbit around the earth, or 2*pi/(27*24*60*60) ~ 2.7 micro radians per second across the sky. The rest of it's apparent motion from where I'm standing is from the earth spinning, which the stars get too. So the stars are about 72 microrads/sec and the moon is 72-2.7 microrads/sec or about 69 microrads/sec (it's orbiting opposite with the earths rotation I think?).

---------- Post added 01-23-19 at 12:38 PM ----------

QuoteOriginally posted by photoptimist Quote
Living in mythical Australia with your upside down moon has confused you!

As any flat-earther knows:

The sun orbits the earth every 24 hours.

The stars orbit the earth about every 23 hours 56 minutes (the constellations rise about 4 minutes earlier each day).

The moon orbits the earth about every 24 hours and 49 minutes every hour (the moon rises about 49 minutes later each day).

Thus, the moon moves about 4% slower than the stars.

P.S. This implies that Pentax astrotracer (which moves the sensor to track the stars) overcorrects slightly for moon motion. The over-correction amounts to about 2.7 microradians per second. That implies astrotracer does help stabilize moon shots but not for as long a duration as it does for stars. With a 600 mm lens, astrotracer should do a decent job of stabilizing the moon for up to 10 seconds depending on the quality of the calibration, quality of the lens and atmospheric conditions, and whether the shooter pixel-peeps.
Oh sigh. Beat me half an hour. I'm blaming the snow/sleet that kept disrupting my hillbilly internet connection that prevented me from posting before lunch.

Last edited by BrianR; 01-23-2019 at 10:50 AM.
01-23-2019, 11:33 AM - 2 Likes   #27
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QuoteOriginally posted by clackers Quote
The moon is much faster across the sky than the stars (20 seconds would be fine for them).
If I am thinking correct the moon moves a bit slower across the sky than the stars do by about 4% or so but for most things that doesn't matter much. A 20 second exposure for stars with 300mm on a 2x teleconverter would show a lot of trailing. Generally when shooting stars people follow the rule of 500 (full frame) or rule of 300 (APS-C) to avoid having visible star trails. To get point stars going to the rule of 400(full frame) or 200(APS-C) will produce much better results. Since the moon's movement across the sky isn't that different from the stars these work well enough if one isn't using an equatorial to track for a long span of time. Basically these rules are (Number)/(focal length)=Max shutter length.

Using the rule of 300 that 600mm (300mm plus the 2x converter) would mean that the maximum exposure one could use to get a fairly sharp image would be .5 seconds and going to the rule of 200 would mean an exposure of up to .3 seconds would produce a nice sharp image. I got fairly good results using a 300mm f/4 lens stopped down to f/5, at .5s and ISO 1250 (I think that is what I was using)

If you have a pile of images of it in totality I would almost suggest stacking them in a tool like Autostakkert, RegiStax, or even photoshop and then using the wavelet feature in RegiStax to bring out the detail. You may be pleased with the results although if you haven't worked with wavelets before there is a learning curve to understand them. I am having to do that with my shots as I got to shoot through high level clouds and with the one I finished last night was fairly pleased with what I managed to pull out.

So at 2 seconds there is some motion blur from the moon moving. The 2x converter on a long zoom lens isn't helping much either. If the lens was set at f/8 then the 2x converter means you were really shooting at f/16. Add in that the zoom at the long end may not have super sharp to begin with and the converter only magnified that unsharpness.

As far as other pictures looking like they are slightly backfocused on the moon that is more an artifact of how the moon is illuminated. The depth of field (assuming you focused properly) at that distance will easily engulf the entire moon and everything farther out. You get the appearence of sharpness near the poles and edges because the illumination isn't as flat there as it is as you go towards the middle of the moon. The shadows from the craters create that contrast and depth, which is why moon pics near when the moon is half full look great as there is so much texture.

Frost on the lens barrel isn't an issue if that is only where it is and I frequently get that when I have been out. On the front element it is a problem but a hood will cure most of that and if that isn't enough you can always rubberband some of those air activated hand warmers around the extended hood which will cure it.
01-23-2019, 07:37 PM - 1 Like   #28
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QuoteOriginally posted by photoptimist Quote
Living in mythical Australia with your upside down moon has confused you!
Ugh, thanks for the corrections, guys!

20 seconds was fine for me with a 14mm prime, no good for the OP with their telephoto and converter.

I must give the Astrotracer on my K-1 a go, then I've already paid for the damned thing!
01-23-2019, 08:24 PM - 1 Like   #29
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QuoteOriginally posted by BrianR Quote

Oh sigh. Beat me half an hour. I'm blaming the snow/sleet that kept disrupting my hillbilly internet connection that prevented me from posting before lunch.
Wait. You're in Ontario. When exactly does snow / sleet not disrupt the internets?

---------- Post added 01-23-19 at 08:27 PM ----------

QuoteOriginally posted by MossyRocks Quote
If I am thinking correct the moon moves a bit slower across the sky than the stars do by about 4% or so but for most things that doesn't matter much. A 20 second exposure for stars with 300mm on a 2x teleconverter would show a lot of trailing. Generally when shooting stars people follow the rule of 500 (full frame) or rule of 300 (APS-C) to avoid having visible star trails. To get point stars going to the rule of 400(full frame) or 200(APS-C) will produce much better results. Since the moon's movement across the sky isn't that different from the stars these work well enough if one isn't using an equatorial to track for a long span of time. Basically these rules are (Number)/(focal length)=Max shutter length.

Using the rule of 300 that 600mm (300mm plus the 2x converter) would mean that the maximum exposure one could use to get a fairly sharp image would be .5 seconds and going to the rule of 200 would mean an exposure of up to .3 seconds would produce a nice sharp image. I got fairly good results using a 300mm f/4 lens stopped down to f/5, at .5s and ISO 1250 (I think that is what I was using)

If you have a pile of images of it in totality I would almost suggest stacking them in a tool like Autostakkert, RegiStax, or even photoshop and then using the wavelet feature in RegiStax to bring out the detail. You may be pleased with the results although if you haven't worked with wavelets before there is a learning curve to understand them. I am having to do that with my shots as I got to shoot through high level clouds and with the one I finished last night was fairly pleased with what I managed to pull out.

So at 2 seconds there is some motion blur from the moon moving. The 2x converter on a long zoom lens isn't helping much either. If the lens was set at f/8 then the 2x converter means you were really shooting at f/16. Add in that the zoom at the long end may not have super sharp to begin with and the converter only magnified that unsharpness.

As far as other pictures looking like they are slightly backfocused on the moon that is more an artifact of how the moon is illuminated. The depth of field (assuming you focused properly) at that distance will easily engulf the entire moon and everything farther out. You get the appearence of sharpness near the poles and edges because the illumination isn't as flat there as it is as you go towards the middle of the moon. The shadows from the craters create that contrast and depth, which is why moon pics near when the moon is half full look great as there is so much texture.

Frost on the lens barrel isn't an issue if that is only where it is and I frequently get that when I have been out. On the front element it is a problem but a hood will cure most of that and if that isn't enough you can always rubberband some of those air activated hand warmers around the extended hood which will cure it.
Thank you for the extensive comment! Whenever I can see the moon again, I will use these and others. I have Registax, but have the devil of a time doing much with it, but that's likely because I get something like 20 frames, which isn't nearly enough to work with in the stacking programs. I also considered using my telephoto and video recording, but that's for another experiment.

---------- Post added 01-23-19 at 08:27 PM ----------

QuoteOriginally posted by clackers Quote
Ugh, thanks for the corrections, guys!

20 seconds was fine for me with a 14mm prime, no good for the OP with their telephoto and converter.

I must give the Astrotracer on my K-1 a go, then I've already paid for the damned thing!
14mm Prime. One of the Rokinon / Samyang lenses?
01-24-2019, 12:56 AM - 1 Like   #30
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QuoteOriginally posted by jawats Quote
14mm Prime. One of the Rokinon / Samyang lenses?
Yeah, that's right, Jawats, I've got the 15mm Irix f2.4 for the future.
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