Southern skies following the constellation Scorpius (this helps to keep me humble)

[Brian W]

The skies cleared and this newbie went out to try various settings. These ones worked the best: ISO 12800 ~ Shutter Speed Six s. ~ F/3.2 ~Sony Alpha a58 ~ Tamron 90mm 272E.

Next time I will use a shutter speed of 5 s. for better stars.

I can't seem to post the image so here's a link (https://theoldmansshotsandthoughts.blogspot .com/2017/07/from-deep-space-southern-sky-following.html)

[Brian W]

I am nmot sure that this will work

[Benjamin]

I really like the photo in the context of your blog. Knowing where you are when taking it (the side of a volcano in the Philippines!) gives the silhouetted palm a nice significance. Look forward to hearing about and seeing more from your part of the planet :-)

[Brian W]

Thanks. I have a lot to learn and Ice in Space is one place I turn to for my education. About September a tracking mount and a bit of gear will hopefully allow me to reach the next level. I went out tonight to test some settings and as Vega was the only star visible I used it to do some aperture testing on star trails. I was pleasantly surprised to find that I had split the Double Double into the first double with my Tamron 90mm 272E.
Brian

[DarkKnight]

Hi Brian,

I'm not sure dropping your shutter speed from 6 secs to 5 secs will show much improvement with your elongated stars.

As an exercise why not try about a dozen shots at 1 sec, then pop your lens cap on and take say four Darks, then stack them all in something like DSS (it's free), assuming of course your camera allows you to turn off in-camera noise reduction, otherwise you will be doubling up on the Darks as your camera will take them automatically (and load up it's buffer).

Looks like you have a nice dark sky to work with.

[Brian W]

if the clouds cooperate I'll try that tonight. Yes i can turn off my in camera noise reduction. And I do have dark skies.
Brian

[Brian W]

I went out last night and did as you suggested. First thing I noticed was that there are a lot less stars in a 1 s. exposure. Second thing was that I can't get DSS to work on my computer with W-10. I end up with a shot of vertical thin colored lines as the program freezes.

But try and try again is my motto.
Brian

[Brian W]

Hmm my message didn't show up another finger malfunction! Okay I did figure out DSS and here are two shots.

The first is of Saturn shot at 1s. Not so good because DSS could only find enough stars in 1 frame so the stacking didn't do anything.

The second was shot right after the first but at 4s. Antares and M4 With the Oph nebula. DSS used at 10 frames and the difference is rather noticeable.

Lessons learned: For my camera/lens 4 seconds works well. I need to get on a first name basis with DSS. I can do short exposure stacking without polar alignment.

The games afoot. Thanks for suggesting the test.
Brian

[Brian W]

Being a reasonable sort of person I often take the advice I go looking for. Since posting here I have been reading, thinking, experimenting and just all around enjoying myself. Which means I have refined my question.



When I was doing visual astronomy my greatest pleasure was in finding faint fuzzies. I truly enjoyed M42 and other bright and beautiful objects but seeing a faint fuzzy was my great joy. I spent many an enjoyable hour gazing at the Veil Nebula first in a 4.5" short tube reflector and then an 8" dob.



Which brings me to my refined question: Is there a lens I can attach to my Sony that will allow me to see the Veil Nebula or will I need to attach my camera to a telescope.



If the answer is a telescope what would be the minimum aperture from a dark site?

Brian

[DarkKnight]

Try googling 'Veil Nebula with DSLR'

[Brian W]

A perfect lunch time pastime:)

[RB]

Hi Brian,

I imaged the Veil with a 130mm scope and a DSLR in 2009.
See link below with all the details.

Veil Nebula (West) - NGC 6960 (http://iimagespace.com/page/ds/veil-west.htm)

The Veil is a magnificent object and I was very happy to 'bag' this one.

Cheers
RB

[Brian W]

If you consider the Veil 'relatively faint' what's a faint nebula?

It took me about four years to become competent with my Sony Alpha a58 in our garden. I'm under no delusions about simply hooking up my camera to a telescope and getting the same results you do. However you are certainly where I would like to be in time.

Am I right that a 6" reflector on a pier with a properly aligned mount is where I start?
Brian

[sil]

Ok I'm assuming you're shooting on camera tripod (not tracking) and found the "500 rule" somewhere. But at least you didnt whine about it like others I've seen and realised its a close starting point.

Yes, go outside and take photos at 5sec exposure, 4sec, 3.5sec down to about 2sec. Basically one or two test shots of the sky at every shutter speed from 6sec down that your camera can be set to. Try pointing the camera due east or west in the sky so the star rotation will be most apparent. Now inside on your computer look closely at the stars in the shots, ignore the difference in brightness completely. You can view the EXIF information of each photo to read the exposure settings, what you want to do is find where the stars are as round as you deem ok, before they football then streak. This value becomes your shutter speed limit and you should note it and never exceed it. Once the stars start footballing they can be difficult for software to align and stack. Round stars are good and it is a factor of your camera, its pixel size and the exposure time (shutter speed), so ignore number anyone tells you. Take the above test shots and see for yourself.

Note this gives you the limit for that camera body and focal length. So if you change lenses or zoom it will be different. But always 500 divided by the focal length gives you a good ballpark exposure time to try your first exposure test at, then drop it down by increments on the camera to find the exposure limit, it'll be close. How round the stars are is up to you to decide what looks best for your needs, but trailing will effect software being able to align shots to stack.

Then because the shots will be underexposed grab DSS and take a dozen or more shots using not exceeding the shutter limit and some darks as suggested and get DSS to stack them for you and learn to use the sliders to bring up the milky way in the shot etc. Its all learning

[Brian W]

I'm getting there. Next good night it will be 3.2s, F/3.5, ISO 6400. I've tried higher DSO but unless I shoot at 1s or less it is seriously over exposed. I'm working on DSS.:)
Brian