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Lunar and Astro Photography (7)

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Howard_S View Drop Down
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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 22 July 2020 at 21:36
Thanks, Fred.

That rule or guideline would suggest 1 sec as the exposure to aim for with my 500mm lens on a full frame camera.

That is 4 stops less exposure than what I used, so to get the same sort of overall exposure at fixed F8 I could have used ISO 32000 - but the better practical solution would have been to stack more frames. Perhaps a 1-sec frame would have been more amenable to stacking and using say ISO8000 I could have overcome noise and pulled something more attractive out of the sensor. (I did take 18 frames, but I didn't want to manually stack them all by hand.)

As it was I was struggling in the dark - I couldn't see the comet with the naked eye, and I barely could see where the end of the lens was. I used binoculars and the Stellarium app to locate where the comet was (though by now I'm beginning to recognise nearly all the visible stars in that corner of the sky!), take an exposure, look for a comet, adjust, and repeat. What a life!

Still we'll see the back of this thing in a few days, not to be repeated for 7 millennia.
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Fred_S View Drop Down
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Post Options Post Options   Quote Fred_S Quote  Post ReplyReply Direct Link To This Post Posted: 22 July 2020 at 21:47
Howard, I completely recognize your struggle but also the learning of the stars! Initially I was almost shooting in the blind after spotting it with binoculars
Not sure how useful that rule is with longer FL's. I have shot FF with 400mm at 8 or 20 secs but without trails appearing.
Maybe the more experienced star shooters can shine a light on this.
I know Neowise is still around for a few days, but I think I am done.
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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 22 July 2020 at 22:50
In my quick read around the subject, pixel density is a factor, so an A7r series camera might be more sensitive to star movement than say an A7s series camera.

I’m grateful for the cloud forecast for the next few evenings!

Howard Stanbury Instagram | Flickr | Web
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Post Options Post Options   Quote alpha_in_exile Quote  Post ReplyReply Direct Link To This Post Posted: 23 July 2020 at 00:58
Originally posted by Hans Brinkel Hans Brinkel wrote:

Great shots, like the milky way

Thank you, Hans. I echo Howard's sentiment to say: I really enjoyed your windmill shot. Having buildings or trees adds good context to the shots.

Which, I should say, I keep forgetting. I took some more shots of the comet at 200mm, and forgot again to try some wider shots.

Anyway, here's my latest attempt: several shots, including dark frames, stacked in DeepSkyStacker, which I'm slowly learning how to use. A900, Tamron 70-200/2.8 at 200mm and f/3.2. Various ISO speeds (2000, 2500 and 3200) and exposure times in several stacked images (lost track of how many and how long).



Best single-frame capture, 6s at ISO 3200, some NR in Lightroom:



Edited by alpha_in_exile - 23 July 2020 at 23:56
-- Matt
A900, Min 24/2.8, Min 50/1.4, Tam 90/2.8 Macro, Tam 70-200/2.8 | Nex5N & some MF lenses
my web gallery
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Micholand View Drop Down
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Post Options Post Options   Quote Micholand Quote  Post ReplyReply Direct Link To This Post Posted: 23 July 2020 at 17:09
Here's another image of the comet from Monday night, July 20.


"Comet C/2020 F3 (NEOWISE) - 20 July 2020"

a7 + Minolta AF 500/8 Reflex
/Michael

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Post Options Post Options   Quote Dena Quote  Post ReplyReply Direct Link To This Post Posted: 24 July 2020 at 00:28
My comet photos. It's been hard getting a clear night here. a77ii + Minolta 50mm f2.8 macro RS.




 



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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 26 July 2020 at 11:57
Dena, I love the reflection in the second picture - well caught!

To my great surprise we had a clear night last night, and I managed to get a couple of sets - this time 25 lights with 8 darks. I used the A7 III and the new firmware intervalometer.


Farewell to Neowise /1

As the comet retreats it is no longer visible to the naked eye, having dropped in brightness from 6 to 7 (if I understand these things correctly; I certainly couldn't see it last night, but Stellarium pointed to its location). This was taken with the Samyang 35mm AF F2.8, more detail at Flickr.

I tried a sequence with a Hexanon F1.4 but alas my focusing was not good enough. So I then used a MC-Rokkor 135mm F2.8:


Farewell to Neowise /2

I was going to try with the 70-210 F4, but the comet by then had slipped behind the tree, never to be seen again.
Howard Stanbury Instagram | Flickr | Web
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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 27 July 2020 at 17:30
I expect you've seen the image by a person with the Instagram and Twitter name Bray Falls (@astrofalls): Link. I was amazed to see the ion and dust tails separated like that.

So I tried to do some more processing of my source files for the picture taken with the 135mm F2.8 Rokkor, and cropping in I managed this in colour:


NEOWISE detail /1

This negative black and white version reveals detail more clearly


NEOWISE detail /2

The two parts of the tail are visible here.

For comparison (and inspiration in my case) a local amateur astronomer produced these images a couple of nights before my image (when the comet was an order of magnitude brighter), Link.

As a neophyte I'm glad to be making some progress, but the post-processing with Photoshop after image stacking is the next challenge for me. And how many years until the next comet?! Plenty of time to practise, I imagine.

But the photo by Bray Falls is something else! (I imagine telescopes were involved ...)
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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 28 July 2020 at 14:22
A change of tack now. We have skies rated at Bortle Scale 6 in our neighbourhood. Yesterday evening the skies cleared yet again and rather than pointing my camera to a rapidly receding comet I thought I'd try a Milky Way photo (my first):



A7 III / Samyang 14mm F2.8 / 10 exposures @ 20s F2.8 ISO 1600 / 5 darks

I forgot to switch the SteadyShot off, so I think the foreground is blurred as a result
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Post Options Post Options   Quote Micholand Quote  Post ReplyReply Direct Link To This Post Posted: 28 July 2020 at 17:51


"Comet C/2020 F3 (NEOWISE) and ISS"

a7 + Voigtländer Macro APO-Lanthar E 65/2
/Michael

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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 28 July 2020 at 21:59
Bravo!
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Post Options Post Options   Quote digiton Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2020 at 09:17
No Neowise this time, just a picture of the galaxy



Sony ILCE-7M3
E 10-18mm F4
12.0 mm
20sec
iso3200
A7III and A6500 with glass from 10mm to 600mm my flickr
I use google translator to translate
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Howard_S View Drop Down
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Post Options Post Options   Quote Howard_S Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2020 at 16:52
That's lovely, using the light pollution to good effect.
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Micholand View Drop Down
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Post Options Post Options   Quote Micholand Quote  Post ReplyReply Direct Link To This Post Posted: 30 July 2020 at 15:37
Originally posted by Howard_S Howard_S wrote:

Bravo!
Thx
/Michael

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