Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing

Pages: 1
sternenhimmel
super member


Reged: 06/06/13

First Light 50mm @ Vega, Need Pointers new
      #5993988 - 07/28/13 01:04 AM

I have finally achieved first light of the barn door tracker I've been working on for some time now. I don't know how good my polar alignment was, but the subs I took were looking sharp at 2 minutes. I also nailed the focus (I think).

The problem is, I was shooting from a backyard location in a small town, with a half-phase moon about 45 degrees from my target. I chose to shoot at the zenith to minimize atmosphere/light pollution.

I need some advice. I was mostly just testing the ability of the barn door tracker to, well, track, but I also feel like the results of this shoot could be more interesting if only I knew how to process the stacked photo in Photoshop. Following some articles I found, I did some levels and curves adjustment, but am still thinking that there is more detail in this image than I am currently extracting.

Do I just need more subs because of the sky fog, or is it just a matter of post-processing? In the future I'll be shooting from a darker site, but I think this will be good practice.

Camera: unmodded T1i with 50mm 1.8 lens, stopped down to f5.6, ISO800
Light frames: 17 @ 2 minutes = 34 minutes
Dark frames: 13 @ 2 minutes

Example Sub:

http://i.imgur.com/D34aRjI.jpg

Stacked Image:

http://i.imgur.com/DJk0Ijs.jpg


Post-Processed image:

http://i.imgur.com/y0LxZ5O.jpg

I've identified M56 and The Ring Nebula in this photo as fuzzies -- otherwise, the most interesting thing about this portion of the sky is probably the dust..

Edited by sternenhimmel (07/28/13 01:05 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Erskin71
professor emeritus


Reged: 12/13/10

Re: First Light 50mm @ Vega, Need Pointers [Re: sternenhimmel]
      #5994012 - 07/28/13 01:31 AM

Looks like the tracking is good. More subs will always help of course. For 34 minutes of data that's pretty good. Pick up GradientXTerminator when you get a chance. It's a nice tool.

Post Extras: Print Post   Remind Me!   Notify Moderator  
mmalik
Postmaster
*****

Reged: 01/13/12

Loc: USA
Re: First Light 50mm @ Vega, Need Pointers new [Re: sternenhimmel]
      #5994176 - 07/28/13 05:47 AM

Quote:

Do I just need more subs




More subs will definitely help but that's not all; bit longer subs will help also. Using modded camera will help a great deal. LPS filter is also highly recommended, an example here.... Thx


On a side note, some image processing instructions here....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Chris_H
Post Laureate
*****

Reged: 11/24/03

Loc: Norway
Re: First Light 50mm @ Vega, Need Pointers new [Re: mmalik]
      #5994223 - 07/28/13 07:23 AM

For widefield imaging like this, a modded camera really is a must. There is so much faint detail out there that a stock cam just wont pick up unless you go somewhere really dark. And even then you'll struggle

Post Extras: Print Post   Remind Me!   Notify Moderator  
RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: First Light 50mm @ Vega, Need Pointers new [Re: Chris_H]
      #5994412 - 07/28/13 09:53 AM

Any (or all) of a Baader mod, a CLS filter or judicious application of flats (allowing for more severe post-processing) would make a difference.

Tracking looks excellent, though!!! Well done.

Grant


Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: First Light 50mm @ Vega, Need Pointers new [Re: RedLionNJ]
      #5994963 - 07/28/13 03:29 PM

Ya I agree more subs always help and perhaps slightly longer subs may help in this particular case. You look to have good tracking out of your barn-door mount and good focus.

I suspect there was some colour lost in processing, so as you improve your processing you will be able to pull a bit more character into the image.

As you said the largest object of interest in that view is the dust lanes in the milky way showing in the lower-right. A bit of a different framing choice and you could focus on the band of the milky way with it's dust lanes.

As far as the Mod goes, yes the mod will help for those areas with H-alpha emission light, but you can still do some nice wide shots like this of areas without much Ha and produce some good images so don't let the lack of mod stop you!

Really nice first light!


Post Extras: Print Post   Remind Me!   Notify Moderator  
sternenhimmel
super member


Reged: 06/06/13

Re: First Light 50mm @ Vega, Need Pointers new [Re: Falcon-]
      #5994981 - 07/28/13 03:40 PM

As always, good advice and awesome links!

Modding my camera is something I've been thinking about, however I use it extensively for other types of photography as well. What I would probably do is replace my primary camera, and assign the t1i to pure astrophotography. I've got an old 300D that is sitting in a box in my closet. Is it even worth trying to mod this camera? Or should I just move on?

H-alpha filters have also been on my mind. I'd be sacrificing color, but I love the way they can bite through light pollution and moon light... H-alpha wide field though?

Edited by sternenhimmel (07/28/13 03:51 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: First Light 50mm @ Vega, Need Pointers new [Re: sternenhimmel]
      #5995908 - 07/29/13 01:57 AM

Quote:

Modding my camera is something I've been thinking about, however I use it extensively for other types of photography as well. What I would probably do is replace my primary camera, and assign the t1i to pure astrophotography. I've got an old 300D that is sitting in a box in my closet. Is it even worth trying to mod this camera? Or should I just move on?



I would not put money into the 300D by paying someone to mod it - the 300D is much higher noise then you get with the T1i/500D (or even the 350D!), it has strong amp glow, you will need a serial long-exposure-adaptor cable to get longer then 30s, and you can not use software like BackyardEOS to control it. However that said with well matched darks it can still perform and you DO already own it. I would say give your 300D a try as-is and if you are not put off by the (relative) difficulty in operation then see if you can get the replacement filter you need for low cost and do the mod yourself. Here is an image I got with a unmodified (stock) 300D and a 50mm lens.

Long term a newer camera (450D+ or 1000D+) will be easier and a better performer.

Quote:

H-alpha filters have also been on my mind. I'd be sacrificing color, but I love the way they can bite through light pollution and moon light... H-alpha wide field though?




Depends on what you define as "wide" but I have used my clip-in H-Alpha filter with my 300mm lens too good success and will certainly be trying it with wider lenses in the future. I seem to recall some filters do not work well with very fast focal ratios, not sure if that applies to any specific Ha filter or not though...


Post Extras: Print Post   Remind Me!   Notify Moderator  
sternenhimmel
super member


Reged: 06/06/13

Re: First Light 50mm @ Vega, Need Pointers new [Re: Falcon-]
      #5996098 - 07/29/13 08:19 AM

Beautiful photo. I remember when I bought my T1i years ago, it already felt that it was a purchases much overdo. I've taken some good photos with my 300D, but it's an incredibly noisy camera. You mentioned something about sensor read noise. I've only ever made one attempt at astrophotography with my 300D piggybacked on an 8" Newtonian, and 8 minute exposures showed significant read noise.

A big part of me wants to make a camera upgrade soon. I might be going full-frame, and I would be extremely tempted to use my new camera for astrophotography. However, I'll start with either the T1i, or, if I don't make a purchase, the 300D.

I'm attracted to the H-alpha clip in filters and may be going down this road. They're expensive, but it looks like they're interchangeable across the EOS platform? It might be smart to start by buying an H-alpha filter, doing the 300D IR filter removal (myself), and seeing what I can get before investing more $$ on a student budget .

Edited by sternenhimmel (07/29/13 08:21 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: First Light 50mm @ Vega, Need Pointers new [Re: sternenhimmel]
      #5996488 - 07/29/13 12:38 PM

Quote:

I'm attracted to the H-alpha clip in filters and may be going down this road. They're expensive, but it looks like they're interchangeable across the EOS platform? It might be smart to start by buying an H-alpha filter, doing the 300D IR filter removal (myself), and seeing what I can get before investing more $$ on a student budget .




I have a couple of cautions to keep in mind:

- the Clip-in filters will not work on a full-frame camera
- the Clip-in filters will not work with most EF-S lenses (they do work with EF lenses and any converted older lenses). This is because most EF-S lenses stick further into the camera body leaving no space for the filter.
- The simplest mod, simple removal of the UV/IR filter in the 300D to create a "Full Spectrum Mod" will likely end up creating a situation where you can not focus to infinity with most camera lenses. Not a problem for imaging through telescopes, but for a barn-door tracker that is somewhat of a non-starter. You will need a astro UV/IR or clear filter to replace the stock UV/IR filter to retain focus distances.



For a bit of context I have an Astronomik 6nm Ha EOS-Clip filter, I have both an old 350D and a new(er) 1000D that I use for astro, both have had their stock UV/IR filter replaced with a Baader UV/IR filter. I also do lots of imaging wide with 28mm, 50mm, 135mm, 200mm and 300mm camera lenses.


Post Extras: Print Post   Remind Me!   Notify Moderator  
sternenhimmel
super member


Reged: 06/06/13

Re: First Light 50mm @ Vega, Need Pointers new [Re: Falcon-]
      #5997644 - 07/30/13 12:59 AM

Oh interesting. What are options for full-frame cameras then?

Anyway, fortunately most my lenses are EF L-series. I've invested in my lenses because the quality of the lens, in my experience, really does make a difference for certain types of photography.

I found this discussing a 300D mod that replaces the IR filter with a piece of glass from Edmunds:
http://ghonis2.ho8.com/rebelmod.html

That explains why the clear glass was needed, and does make some sense. Sounds like a little more work, but will still be the cheapest option for a first go.

I'm wondering what focal lengths I can push with a barndoor tracker. Currently the entire construction is entirely too delicate and needs fortification and redesign. It appears to work fine with no wind and a super light 50mm lens, but I know it will be a different story as soon as I throw a big hunk of glass on the end of my camera.

The more and more I refine my design, the more and more tempted I am going to be to machine my own GEM. I've seen it done on these forums, and it looks like a fun project...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: First Light 50mm @ Vega, Need Pointers new [Re: sternenhimmel]
      #5997837 - 07/30/13 05:11 AM

Quote:

Anyway, fortunately most my lenses are EF L-series. I've invested in my lenses because the quality of the lens, in my experience, really does make a difference for certain types of photography.



Nice! AP is certainly one of those places where the quality of a lens makes a diffrence. In my early AP I was fortunate enough to be able to borrow a friend's EF 300 L f/4 IS USM - that is about the only lens I have been able to personally use that worked perfectly for AP wide-open. Hopefully a few of the various lenses you have will be equally good performers.

Quote:

I'm wondering what focal lengths I can push with a barndoor tracker. Currently the entire construction is entirely too delicate and needs fortification and redesign. It appears to work fine with no wind and a super light 50mm lens, but I know it will be a different story as soon as I throw a big hunk of glass on the end of my camera.

The more and more I refine my design, the more and more tempted I am going to be to machine my own GEM. I've seen it done on these forums, and it looks like a fun project...



Would you be willing to post up a picture of your Bard Door? I am curious about it's construction now....

Given how well the tracking seems to have worked for your 2min 50mm exposures I would not be surprised if you could get to 100mm easily enough. Perhaps further depending on what part of the sky and how much the tracker tends to flex. This is purely making-it-up guessing though

If you DO decide to machine your own GEM make sure you let us know! Would you be thinking of a DSLR/Lens sized GEM or something for a scope? If DSLR-sized (unless you wanted to be able to guide in DEC) you would only need to do up the RA axis and use something like a ball head to get pointed in the sky. There are already commercial systems like that such as the Losmandy Starlapse (basically the RA axis of a G8 mount with various accessories instead of a DEC axis)


Post Extras: Print Post   Remind Me!   Notify Moderator  
sternenhimmel
super member


Reged: 06/06/13

Re: First Light 50mm @ Vega, Need Pointers new [Re: Falcon-]
      #6000815 - 08/01/13 12:06 AM

I used to own Canon's 70-200 F/4 lens, but it was stolen from my apartment years ago. It probably would have made a decent lens for this kind of photography. Getting my hands on the 300mm, even if just for testing, would be pretty sweet. There is no way my current setup could handle such a massive lens though. I would need to build a support platform for the lens and mount the camera/lens assembly closer to the center of mass. This setup probably doesn't have the tracking accuracy to take advantage of that lens.

The current assembly is in the prototype stages only. There are jumper wires everywhere, alligator clips hanging out, and unfinished, uncut wooden pieces. Rest assured, when I work out what I want the final design to be, and functionality, it will be much more attractive .







As for my DIY equatorial mount, I was really inspired by this post:
http://www.cloudynights.com/ubbarchive/showflat.php/Cat/0/Number/1924110/page...

But that's over ambitious for my technical skill set. I have basic lathe and milling operations down, not much more.

It will probably be a camera-only mount, but I like the idea of it being able to accommodate a scope. I have an 8" F/4 Newtonian at my parents' place that I've been contemplating bringing up here...


Post Extras: Print Post   Remind Me!   Notify Moderator  
shawnhar
Postmaster
*****

Reged: 06/25/10

Loc: Knoxville, TN
Re: First Light 50mm @ Vega, Need Pointers new [Re: sternenhimmel]
      #6001770 - 08/01/13 05:37 PM

I think it looks completely awesome just the way it is!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: First Light 50mm @ Vega, Need Pointers new [Re: shawnhar]
      #6001825 - 08/01/13 06:06 PM

That is cool - great idea on using rubber bands as tensioners to remove the "backlash" in the bolt threads!

As for that link to the home-made EQ.... wow - even doing gears and bearings....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1


Extra information
18 registered and 31 anonymous users are browsing this forum.

Moderator:  Dave M, fishonkevin, WOBentley, tecmage 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 625

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics