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-   -   Milky Way (http://e-group.uk.net/forum/showthread.php?t=48142)

wornish 27th June 2018 02:00 PM

Re: Milky Way
 
Quote:

Originally Posted by chris (Post 449816)
Whatched a tutorial on a free Milky Way stacking program called Sequator, looks user friendly with good results.

Thanks for the heads up on Sequator its a new one for me.

I have just watched the video and it looks very promising. I will give it a go when the skies get a little darker.

skids 30th June 2018 01:38 PM

Re: Milky Way
 
Here's one of my efforts from a trip to Lundy in Nov 2016. I'm sure it could look more impressive if my processing skills were better.

EM1 mk1, 7mm, iso 1600, f/3.5, 41 seconds (had my Polarie Star Tracker with me so not much to worry about regarding trails as long as I align things properly).

Went back in Nov 2017 but no clear nights.

https://farm1.staticflickr.com/446/3...5725c02b_b.jpgLundy Milky Way 2_25112016_181505 by jonskids, on Flickr

Petrochemist 1st July 2018 09:59 PM

Re: Milky Way
 
Quote:

Originally Posted by freewheeler (Post 449603)
Thanks Dave, my logic is if I look at the moon through say a telescope, it would look considerably larger so the effect should be the same with a lens. I don't notice too much enlargement with the 70-300 either and thought it was some setting I have wrong in the camera.

The effect is the same with a lens, but a decent telescope will have a much longer focal length than your 200mm. Even my little one is over 500mm without an eyepiece, with an eyepiece it's total can be as high as 16000mm IIRC

birdboy 2nd July 2018 10:52 AM

Re: Milky Way
 
Chris the key to all astophotography is clear skies and as low light pollution as possible. Currently the night sky is polluted everywhere in the UK because the suns light is still scattering its rays over the night sky. You will only get to astro dark from about August onwards. Clear Outside is a good place to start as a forecast and understand dark skies. You need to be in the black astrononimcal darkness zone.

http://clearoutside.com/annual_darkness/53.22/-1.68

Planning is everything and the best piece of software to use is Stellarium, its free. Set up your lenses so you can see what field of view you will get and set the location, date and time of year you plan to take images. This software will tell you where to point your camera. You can set up what level of human light pollution and it will also show the effects of the sun and moon on the clarity of the milkyway.

As for settings it is impossible to say (other than wide open aperature and shutter speed that does not show star trails) without knowing what level of light pollution you get from your location. Without a tracker I have never liked the 500 rule but would reduce it to about 400 which gives very short exposures. Stacking images works better but you then need to do some trickery with software to blend in images of landscape which will show rotation. I have heard that some folk use these low cost trackers and set the tracking speed to half rate and that enables them to double shutter speed without too much blurring of the stars and landscape.

Sorry I cant give any examples in the UK but its not for want of trying. I did get one when in Peru in 2015. This was taken with EM1 MK1 12-40 lens at 17mm f2.8 Iso 1600 10secs taken raw converted to tif and processed in Startools. This was at the start of my astrophotography journey.
http://e-group.uk.net/gallery/data/5...s_Milkyway.jpg

wornish 2nd July 2018 12:37 PM

Re: Milky Way
 
+1 for Clear Outside. I have been using for two or more years now.
The current day and 5 day detail forecasts for you location get updated daily and are very useful. The UK weather is the biggest challenge.

birdboy 2nd July 2018 02:34 PM

Re: Milky Way
 
Stacking has been mentioned a few times so I thought I would revisit my images I took from Peru these were the 17mm fl 10 sec f 2.8 ISO 1600 images.
The ealier one was a single frame without a crop.
I took a total of 30 frames at the time I have stacked these in Deep Sky Stacker and selected the best 50% and then processed the fits file in Star Tools. There is some cropping because of the rotation of the frames. I don't know how accurate the colour is but I used the default settings in Star Tools with a bias of green to yellow.

http://e-group.uk.net/gallery/data/5...ay_stacked.jpg

chris 2nd July 2018 07:13 PM

Re: Milky Way
 
Thanks for all the input folks, much appreciated

blu-by-u 5th July 2018 01:43 PM

Re: Milky Way
 
Quote:

Originally Posted by birdboy (Post 450255)
Stacking has been mentioned a few times so I thought I would revisit my images I took from Peru these were the 17mm fl 10 sec f 2.8 ISO 1600 images.
The ealier one was a single frame without a crop.
I took a total of 30 frames at the time I have stacked these in Deep Sky Stacker and selected the best 50% and then processed the fits file in Star Tools. There is some cropping because of the rotation of the frames. I don't know how accurate the colour is but I used the default settings in Star Tools with a bias of green to yellow.

http://e-group.uk.net/gallery/data/5...ay_stacked.jpg

I was just thinking of the stacking techniques to reduce the noise.

Should the ISO be reduced and time increased to compensate or should I increase the ISO and shorten the time?

Sent from my ASUS_Z00UD using Tapatalk

birdboy 5th July 2018 02:18 PM

Re: Milky Way
 
Quote:

Originally Posted by blu-by-u (Post 450451)
I was just thinking of the stacking techniques to reduce the noise.

Should the ISO be reduced and time increased to compensate or should I increase the ISO and shorten the time?

Sent from my ASUS_Z00UD using Tapatalk

For a non tracking mount such as tripod your shutter time is governed by how fussy you want to be over star trailing 500, 400 rule (shutter time =400/efl). Your ISO is then governed by your shutter time and the amount of light pollution you have in your sky at the time of imaging, more light pollution lower ISO. Dark sites will require high ISO. The more frames you take the lower the noise 9 frames gives 1/3 reduction 16 frames 1/4 and 25 frames 1/5 etc.

The other option is to use a tracker and longer shutter times but try not to go much more than 60 seconds. Above 60 secs I would favour increasing ISO over longer times even if my tracker coped with star trailing.

blu-by-u 6th July 2018 03:25 AM

Re: Milky Way
 
Quote:

Originally Posted by birdboy (Post 450454)
For a non tracking mount such as tripod your shutter time is governed by how fussy you want to be over star trailing 500, 400 rule (shutter time =400/efl). Your ISO is then governed by your shutter time and the amount of light pollution you have in your sky at the time of imaging, more light pollution lower ISO. Dark sites will require high ISO. The more frames you take the lower the noise 9 frames gives 1/3 reduction 16 frames 1/4 and 25 frames 1/5 etc.

The other option is to use a tracker and longer shutter times but try not to go much more than 60 seconds. Above 60 secs I would favour increasing ISO over longer times even if my tracker coped with star trailing.

Trying to digest the above.

Using the 7-14 at 7mm & taking the 400 rule, 400/(7X2) = 28s.
Can I use the Em1ii's stacking to do the stacking or should I use the desktop program like RegiStax?

If using out of camera stacking, should I use the LiveComp, LifeTime or just 28s?

Will be travelling to Mt.Bromo/Surabaya/Indonesia to try the milkyway on the 10th July.

Stay tune for photos..hopefully:o

Petrochemist 6th July 2018 08:54 AM

Re: Milky Way
 
If the in camera stacking can realign images that might be OK, but I suspect registax will be the better option.


Looking forward to seeing the results.

birdboy 6th July 2018 09:26 AM

Re: Milky Way
 
Star alignment stacking is not done in camera. I have tried Registax without success and my preferred stacking software is Deep Sky Stacker. But there is a problem if your frames include landscape and I am guessing that as you are going to Mt Bromo you will want some of the mountains in your frame.

Live Comp or Live time no good as your stars will trail just use the shutter speed at 25 secs nearest to 28 sec in manual take RAW and adjust ISO to your light conditions.

Your first task is to capture good frames with no star trailing and 25 sec exposures should do that at 7mm on a tripod. If you have Photoshop CC there are many helpful online tutorials to do the processing (including star alignment) of your images, but try not to worry about that while you are out there, you should be able to get stunning single frames and processed in Lightroom, you can do the stacking when you come back if you think it is required. I do not have Photoshop CC but have Adobe Elements and that does not seem to be able to do anything like I have seen with CC.

If you have a Mac Starry Landscape Stacker will do the stacking of stars and freeze landscape if you have a pc Sequator (free) should do a similar job.

Good luck and clear skies looking forward to seeing your images.

Phill D 6th July 2018 11:10 AM

Re: Milky Way
 
I'm looking forward to seeing the results too Henry.

birdboy 6th July 2018 11:25 AM

Re: Milky Way
 
Forgot to mention focus is critical for stars but I think the OMD EMmkII is the best to achieve this. Make sure you set Live boost gear D2 manual to On2. set up a front button for magnify. When setup at night use MF in manual mode the live boost will show a much better star picture use your magnify button and zoom into x14 on a small non bright star and carefully adjust the focus ring until the star appears the smallest roundest star. then make sure you do not disturb the focus ring. Better still is to use Olympus Capture in tethered mode if you can, I have a laptop I use, focus can be set really fine but make sure the focus ring is not in manual to remotely adjust focus.

blu-by-u 9th July 2018 06:17 AM

Re: Milky Way
 
Quote:

Originally Posted by Phill D (Post 450501)
I'm looking forward to seeing the results too Henry.

Please don't expect too much. After my Aurora lights failure, I am not keeping my expectations up too high. :D

And Birdboy, thanks for the tips. I leave tomorrow :o to start my milkyway adventure. :D


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