Milky Way Tuesday 2 August

Sconesbie (Scott) · #1 05-08-2016, 10:03 AM

Tuesday night in Northern Tas was absolutely sensational (cold though). I decided to go for a drive about 10 minutes away from home where there were no lights. The sky was as black as I have ever seen it. Crystal clear and absolutely superb.

I found a road to pull up on and start having a go. A horse in the paddock frightened the life out of me.

Anyway, the result is as you can see.

I am still learning how to take star photos but I quite like these ones. Any assistance in how I can make them better is appreciated. Please use English terms only!!

Camera is Pentax KM. ISO 3200 (tried 1600 but no good), F3.5 and 30 seconds.

thegableguy (Chris) · #2 05-08-2016, 11:21 AM

Nice work! What I'd give for skies that clear... mine are pretty good, but they sure ain't that good. Lovely capture of the small & large magellanics too.

I'll be interested to see what others say, but I kinda think you're at the limit of your camera there and there's not much to be done. To get more detail you'd need a) longer exposure times, b) higher ISO, or c) a faster lens.

Longer exposures will make the stars into lines instead of points, so not a great option.

Higher ISO will make the images really noisy, which no-one wants.

A faster lens and/or a new camera with low noise levels at high ISOs will produce the best results, but I expect it's probably not worth $3k+ to you!

Best suggestion would be getting a Star Adventurer:
http://www.bintel.com.au/Mounts---Tr...oductview.aspx

It's a little tracking mount that enables much longer exposures. They're a great, relatively cheap & easy way to get into long exposure night photography. Best for widefield shots but I've seen them used with zoom lenses to great effect too.

omegacrux (David) · #3 05-08-2016, 06:33 PM

Hi Scott
Another option is the Pentax astrotracer if your camera supports it , makes you sensor track the stars , another member here has posted pictures of what it can do , can't remember who though.

David

OzEclipse (Joe Cali) · #4 05-08-2016, 08:13 PM

Hi Scott,
I am one of the people who has posted astrotracer images.

This is the astrotracer page and the KM isn't listed. The model is getting a bit old now. I did a bit of photography with my 2006 model K10D which I think had the same 10.2Mpx sensor as the KM. You can use it but you will struggle a bit. If I remember, I used lower ISO's and tracking.

http://www.ricoh-imaging.co.jp/engli...trotracer.html

The astrotracer is not compatible with your camera body but this is not a great loss. The astrotracer is very convenient when travelling but a small tracking mount such as the Star Adventurer mentioned elsewhere, or a homemade barndoor drive is much more versatile.

Your camera does seem to have a lot of noise (Purple/green background).

This can be reduced with combinations of some basic techniques :
1. longer exposures
2. lower ISO's
3. by taking multiple images and stacking them to average out the noise.
4. capture in raw and use noise reduction software

I did a bit of noise reduction and a reprocessing of a copy of your image downloaded from this thread. See attached.

Did you capture in raw or jpg? The raw file processors have very good noise reduction software. Even if you don't have photoshop or lightroom, you should have received a version of Silkypix included with your camera.

If you want to upgrade cheaply, you can pick up mint Pentax K5's for about $300-$400 on ebay from Japanese dealers. The K5 is now a bit dated and not the best camera on the market but for $300 you can have a lot of fun with it. You don't have to spend $3k as someone suggested.

For comparison, there is a picture in Nightscapes called Moonrise on Golden Pond
http://www.iceinspace.com.au/forum/s...d.php?t=146519
Taken on a fixed tripod, no tracking with my Pentax K5 (2011 model)
I took 4 exposures at 15s each with a 12mm f4 at ISO6400. The four exposures were stacked. I have deliberately left the image a bit small to de-emphasise the noise.

Also here are some aurora pictures I took in Norway last year
All the exposures were at ISO 6400 for between 3s and 10s also with the K5 and 10mm f3.5 fisheye.
http://www.joe-cali.com/eclipses/PAS...ora/index.html

Hope this helps

Joe

Sconesbie (Scott) · #5 06-08-2016, 01:24 PM

Thank you Joe, David and Chris.

The shots would have been taken using JPG I'd suspect. I'll try again next time using RAW.

I don't have any software from the camera but will download your suggestions. I have the latest edition of Aus Sky and Telescope and noticed there are some good hints and tips in there too as was the last issue.

It's great fun and I was like a kid again. I couldn't wait to come home and show my wife.

The budget doesn't have room for the camera tracker or a new camera (just yet) as we are heading overseas but will have it on my list of goodies to chase.

I'll also keep playing outside and seeing what else I can capture. I'm fairly impressed that I can even get these but now want to start being a bit more creative with the shots.

Thanks again.
Scott

Atmos (Colin) · #6 06-08-2016, 01:48 PM

I have found that with my camera (Nikon D700) it just goes down hill quickly after ISO 1600, dynamic range is reduced, becomes noisier but doesn't actually improve the image itself. Sometimes what shows on the back of the camera is not a good indication of what is actually in the image. I have found that at ISO 800&1600 my camera (30s images with a 24-120mm @35mm @F/4) do not look crash hot but far better after some processing. This in comparison to ISO6400 images which look great on the back of the camera but not so much when processing.

I have found that a good website is http://www.sensorgen.info/ , it may not always been 100% accurate with results but they're close enough to give an indication.

Your camera, http://www.sensorgen.info/PentaxKM.html

It shows that after ISO 800 you do not actually get an improvement in image quality, actually gets worse.

Cimitar (Evan) · #7 06-08-2016, 01:49 PM

Quote:

Originally Posted by Sconesbie

I am still learning how to take star photos but I quite like these ones. Any assistance in how I can make them better is appreciated. Please use English terms only!!

Hi Scott, congrats on your first batch of images!

You've got some great hidden detail in your images and with some extra processing it really begins to show. Hope you don't mind, I had a play with one of your images (#4) in an effort to draw out the detail via extra processing and see if there was a difference to the final result. The noise is beginning to show with the extra enhancements, but it just depends on how far you push the image. Generally speaking I used a combination of curves, layers and masks in photoshop, some automated astronomy enhancement plugins, enhanced the colour using LAB and soft light, and finally rotated your image to frame it with a different perspective (now peering into the core) and added a star spike. Included below is a rotated version of your image + the one I edited. Happy to explain further details if you have any questions.

Looking forward to seeing your next round of pics

Cheers, Evan

Cimitar (Evan) · #8 12-08-2016, 04:48 PM

Hi Scott, I'm back from my break and just processed your South looking (Carina Nebula) images. I decided to stitch the 2 together and this was the result. The processing brought out some good underlying signal that was evident in your images

The star spikes were added randomly just to add a bit of flare. For reference purposes the Southern Cross is near the centre of your image.

Cheers, Evan

OzEclipse (Joe Cali) · #9 12-08-2016, 05:22 PM

Quote:

Originally Posted by Cimitar

Hi Scott, I'm back from my break and just processed your South looking (Carina Nebula) images. I decided to stitch the 2 together and this was the result. The processing brought out some good underlying signal that was evident in your images

The star spikes were added randomly just to add a bit of flare. For reference purposes the Southern Cross is near the centre of your image.

Cheers, Evan

Evan,

That enhancement is fantastic. Great job. I had a go at them and couldn't do nearly that well. Can you elaborate a bit more on what you did?

regards

Joe

Sconesbie (Scott) · #10 12-08-2016, 07:36 PM

Wow! Thank you very much.

It certainly has enhanced the image. I haven't tried any of your hints yet but will certainly give it a go.

They look awesome. I didn't know something I thought looked good for my standards could look even better with a bit of fidgeting.

To say I'm happy is an understatement.

Regards
Scott

Cimitar (Evan) · #11 16-08-2016, 06:57 PM

Quote:

Originally Posted by OzEclipse

Evan,

That enhancement is fantastic. Great job. I had a go at them and couldn't do nearly that well. Can you elaborate a bit more on what you did?

regards

Joe

Hi Joe, happy to describe the process. Sorry it's taken me a little while to come back to you.

Below are 5 images of the key steps in the processing that I did. The bulk of the work was done in Photoshop, and for bits and pieces I used the Astronomy Tools Actions Set by Noel Carboni. The other software I used was Fitswork4 & Google Nik. Note - I have no affiliation with any software provider, just a happy end user

The first image is the stitch (I merged the 2 images using mspaint, then used Fitswork4 to remove the horizontal banding). The 2nd, 3rd and 4th images were enhanced using light curves and LAB/Soft light layers in Photoshop. The biggest change is between images 4 & 5. This improvement was achieved by running "Enhance DSO and reduce Stars" and I also used the "Increase Contrast" action. Finally I used the Google Nik collection, specifically Color Efex Pro 4 to draw out some extra detail in a new layer and then merged this into the final image.

Cheers, Evan