[captainbert]

i've been dabbling in landscape astrophotography using the O-GPS1 and haven't really driven out to a place with dark skies; so far contending with massive light pollution.

I do shoot one with the tracer on and then a second shot with it off at the same exposure and then blend the two with a layer mask. This is easy and fairly effective.

I use both lenses you mentioned, the Sigma 10-20 and the DA15. I usually stop down a few clicks, but you should be able to get decent results at wide open apertures.

Mike, amazing!! Thanks so much for sharing sir! Those are incredible results to say the least. That has well and truly put the Astrotracer on the shopping list!

[Docrwm]

sure Doc,
this was the night of the meteor shower (Aug 13th). I went east toward the mountains to find a darkish sky. Unfortunately, upon arriving at this row of towers around 10pm, the glow from Sacramento was really lighting up the sky and there was a heavy bank of clouds rolling in. Ended up waiting til 3am before it started to break up. There were many meteors, but i didnt manage to catch much.
This is the Sigma 10-20 at 10mm and wide open, ISO 2500. It is a 2.5 minute exposure. I shot one with the O-GPS on and then clicked it off and shot another without any tracking then did a layer mask in Photoshop. This was was trickier to do than most because the star trails were very evident in the gridwork of the tower and my masking was a little sloppy. Rather than keep the black sky that was recorded, I boosted the exposure to reveal a few more stars and lighten the sky. This tower is bathed in red light from the blinking red light atop the adjacent tower.

Mike, first - thank you, second - as usual you are a mensch!

-Robert

Mike, amazing!! Thanks so much for sharing sir! Those are incredible results to say the least. That has well and truly put the Astrotracer on the shopping list!

Mike is one of the good guys. I like his style and he is always willing to share how he got the shot.

[Stone G.]

I can only share the admiration of mikeSF's great images. I don't do much landscape astrophotography myself, living in a heavily lightpolluted area. But Mike's work inspired me to do a quick and dirty test to see the difference between wideangle photos with and without astrotracer so here goes (with excuses for the light polluted sky - one has to look at the larger versions to really see the stars):

With Astrotracer:



Without Astrotracer:



Images were 25 second exposures at ISO 400 taken with an SMC DA 18-135mm lens at its widest setting and at full aperture, f/3.5. The 18-135 isn't ideal for astrophotograhy due to its lack of a fixed infinity setting but it will do for this demonstration.

Differences are hard to tell with these downsized images. You may click on images to see larger versions, but these are still only 1/4 of the original. Hoever, the 100% non-resized crops below reveal the differences:

The Sky:


In all examples crops to the left are with Astrotracer and crops to the right are without.

Background:



Foreground:



Obviously, stars are much better recorded with Astrotracer than without, but that comes at the expense of blurred objects on the ground. Hmmmm......before I get a decent wide angle lens for Astrophotograhy I'd better take some lessons from mikeSF on his layering technique!

[captainbert]

Mike is one of the good guys. I like his style and he is always willing to share how he got the shot.

He sure is! Ive asked Mike's advice before about the DA 15 and he was most helpful and probably the reason why i went for it. Ive seen a lot of his photography on here and it is nothing short of spectacular! One of the good guy's, he most certainly is (and talented into the bargain).

[captainbert]

I see what you mean Stone G about the sacrificing of foreground detail when using the Astrotracer though that still looks pretty darn good! I'm going to do some online hunting on the Photoshop technique but i'd better get out and shoot some stars before i do anything!

[pixelsaurus]

This is a good general starter. Techniques on both image capture and processing Catching the Light: Astrophotography by Jerry Lodriguss

[captainbert]

This is a good general starter. Techniques on both image capture and processing Catching the Light: Astrophotography by Jerry Lodriguss

Some reading would be well in order so thanks for that!

[mikeSF]

you are most welcome, friends. Believe me, if you do a search with my name and O-GPS1, you will find at least a couple of threads full of my own frustrations in using the device, at least early on. I thought i would just stick it to the camera and go and find there is some technique involved. That said, definitely practice with it, IN THE DARK, before setting off for that once in a lifetime shot.

[captainbert]

you are most welcome, friends. Believe me, if you do a search with my name and O-GPS1, you will find at least a couple of threads full of my own frustrations in using the device, at least early on. I thought i would just stick it to the camera and go and find there is some technique involved. That said, definitely practice with it, IN THE DARK, before setting off for that once in a lifetime shot.

Thanks again Mike! I have actually done a fair amount of initial experimenting using my current set up and i'm going to continue experimenting before i buy the device although i'm definitely going for it in a month or two (funds permitting). Thanks very much for all the advice from everyone here. I really appreciate it very much! These are my first attempts although they are not great nor have i managed to get the stars looking well rather than fuzzy but it's a start so thanks a lot!

[VTerlakyPhoto]

Good start there captainbert! To me the first one looks the best both compositionally and also in terms of sharpness. The other two are looking soft all across the frame, so maybe you have to do a few more practice shots to get the focus just right. The first one looks sharp in the middle but soft along the edges - maybe stopping down the lens a stop or two would help with that. Which lens did you shoot it with? I tested both the 15mm ltd and the 10-20mm Sigma the other day, and found both to be pretty soft along the edges wide open...

[captainbert]

Good start there captainbert! To me the first one looks the best both compositionally and also in terms of sharpness. The other two are looking soft all across the frame, so maybe you have to do a few more practice shots to get the focus just right. The first one looks sharp in the middle but soft along the edges - maybe stopping down the lens a stop or two would help with that. Which lens did you shoot it with? I tested both the 15mm ltd and the 10-20mm Sigma the other day, and found both to be pretty soft along the edges wide open...

Yeah that's the problem i'm finding for sure! I used the Sigma 10-20 for the first and last and the DA 15 for the middle one. With the DA 15 i shot wide open but found the foreground in all cases to be soft and mushy. I shot the Sigma on the second night stopped down to f5 or f5.6 i think and the foreground was certainly a bit better but still not great at all! I taped the Sigma at infinity before i left the house. When you see the images at full size, stars look quite fuzzy and not great either. I have been looking and it seems a lot of post processing in Photoshop or other software is the way forward and adding dark frames and whatnot. I simply adjusted these in Lightroom.

[pixelsaurus]

Nice job Cap'n. If you want to spend a small sum, there are some photoshop/PSElements actions you can get. These seem to have a good rep as they are mentioned often in astroforums and the like. You can make them bloated stars a lot slimmer plus other goodies. I do have them installed but haven't really got around to using them seriously yet.
Astronomy Tools Actions Set by ProDigital Software

[captainbert]

Nice job Cap'n. If you want to spend a small sum, there are some photoshop/PSElements actions you can get. These seem to have a good rep as they are mentioned often in astroforums and the like. You can make them bloated stars a lot slimmer plus other goodies. I do have them installed but haven't really got around to using them seriously yet.
Astronomy Tools Actions Set by ProDigital Software

Thanks very much Pixelsaurus! I'll definitely invest in those!

[Dr_who]

captainbert I like your 3rd picture with Pleiades in it.

pixelsaurus I'll have to check out those actions

I have a O-GPS unit but almost never use it, mainly cause recently I'm been doing deep sky targets rather then wide milky way type shots. I'll have to dig it up and give it a go again.

[Stone G.]

- - - - - - -


I have a O-GPS unit but almost never use it, mainly cause recently I'm been doing deep sky targets rather then wide milky way type shots. I'll have to dig it up and give it a go again.

You should take a look at stephp's recent Astrotracer images in the 'K-5 for Astrophotography' thread. They are quite convincing - to put it mildly understated:

https://www.pentaxforums.com/forums/pentax-k-5/143409-k-5-astrophotography-11.html#post2134702