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 | 2 | (show all)
jsines
sage
*****

Reged: 09/06/11

Loc: Berkley. Michigan
Re: Light pollution filter for astrophotography? new [Re: smithers3]
      #5648379 - 01/28/13 02:41 PM

Quote:

I have an unmodified Canon t3i. I'm wondering which light pollution filter would be the best. Orion has a skyglow that is specifically designed for astrophotography. However, I'm not sure how different it is from their regular skyglow (other than the fact that it's far more expensive).

But, are there others that would be better? I don't have a lot of light pollution now, but I'm going to be moving in the next year to a place with more, and I'd hate to stop astrophotography just when I'm getting going.

Thanks!




When you say "regular skyglow", I'm assuming you're referring to their SkyGlow Broadband LP filter. There is a difference between the two. Take a look at their transmission graphs - the Broadband LP filter blocks everything from about 540-625, while the Astrophotography LP filter doesn't block everything between 540-625.

I bought the Orion SkyGlow astrophotography filter, and it's constantly attached to my t-adapter. I shoot from a white zone, but I'll keep it on even when shooting from a dark zone, per Jerry's suggestion. I did a lot of research, read Samir's article, and decided on the Orion rather than the more expensive filters because it has about the same transmission graph as the more expensive filter, and I could always return it if I didn't like it.

It has allowed me to image at least twice as long - I was getting washed out at about 60 seconds, 400 ISO before, now I go to 2-3 minutes at 400 ISO. I don't see a strong blue cast to the image like I've heard from other filters. I'm very happy with it.


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

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Light pollution filter for astrophotography? new [Re: jsines]
      #5648883 - 01/28/13 06:16 PM

Until I started using a light pollution filter color imaging from my red-zone back yard was pretty much a waste of time. Boadband filters designed for visual weren't much better; they pulled down the skyglow, but whacked the color. The Hutech IDA LPS2 made a tremendous difference, reducing sky glow and preserving the color information. The Orion imaging sky glow filter gives similar excellent performance. I now use both the Hutech and Orion filters in their 1.25" format and I just bought a 2" Orion filter.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Dan Watt
scholastic sledgehammer
*****

Reged: 10/13/09

Loc: Oceanside, Calfornia.
Re: Light pollution filter for astrophotography? new [Re: jgraham]
      #5649439 - 01/28/13 11:00 PM Attachment (124 downloads)

Another comparison with my CLS-CCD filter from a almost dark site (green zone). This is a 180sec exposure @ 1600ISO without the filter. Camera used is a full spectrum modded Canon T3 on my 8" f4 newt.

Edited by Dan Watt (01/28/13 11:02 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Dan Watt
scholastic sledgehammer
*****

Reged: 10/13/09

Loc: Oceanside, Calfornia.
Re: Light pollution filter for astrophotography? new [Re: Dan Watt]
      #5649440 - 01/28/13 11:01 PM Attachment (119 downloads)

And here is a 300 second exposure @ 1600 ISO with the CLS-CCD filter in place. Quite a difference.

Post Extras: Print Post   Remind Me!   Notify Moderator  
avarakin
Carpal Tunnel
*****

Reged: 07/13/09

Loc: Parsippany NJ, USA
Re: Light pollution filter for astrophotography? new [Re: Dan Watt]
      #5658945 - 02/02/13 09:19 PM

To OP:
I suggest getting 12nm Ha Astronomik Clip In. Even though your camera is not modified, it does have some sensitivity to Ha, so you will be getting much better Ha signal.

Here is a thought which would be interesting to prove or disprove: assuming that your image S/N is limited not by noise of sensor but by Light Pollution, then it does not really matter if camera is modified or not modified: the in-camera filter will be reducing both Ha signal and LP signal, thus keeping S/N ratio the same. The only drawback of non-modified camera with Ha filter would be that one needs much longer exposures.
It would be interesting to test this theory.

Alex


Post Extras: Print Post   Remind Me!   Notify Moderator  
Samir Kharusi
Carpal Tunnel
*****

Reged: 06/14/05

Loc: Oman
Re: Light pollution filter for astrophotography? new [Re: avarakin]
      #5659421 - 02/03/13 06:54 AM

Narrowband filters ain't cheap, so I do not understand why all the recommendations for pursuing filters before modding. All these unmodded DSLRs are extremely lousy when we try to shoot in Infra Red (like 10x or more slower than in visible light), yet with heroic efforts one CAN take IR photos with them. This is fairly similar to trying to image H-alpha nebulae with unmodded DSLRs. One CAN do so, but after spending $100 to $200+ on a filter and having to struggle hugely to coax the Ha image out, it all seems rather quixotic when having the camera modded first makes such a huge difference. Let's bring science into it. This is the response of an unmodded Canon DSLR (1Ds):


Note: Ha is at 6556A. See how little gets through? Now here's the response of a full spectrum modded DSLR (Canon 20D):



I know where I would spend my $ first. If the filters cost only $25 then the priority might reverse. Just IMHO.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Toxic Coolaid
professor emeritus


Reged: 10/01/11

Loc: NorthEast Tennessee
Re: Light pollution filter for astrophotography? new [Re: Samir Kharusi]
      #5659550 - 02/03/13 09:09 AM

Quote:

why all the recommendations for pursuing filters before modding.




I agree. I would not bother with a Ha filter yet. All you would get is red. Stick with a LP filter. All I've ever had are the Astrinomik clip in CLS and CLS-CCD and they are great.


Post Extras: Print Post   Remind Me!   Notify Moderator  
guyroch
Vendor (BackyardEOS)
*****

Reged: 01/22/08

Loc: Under the clouds!
Re: Light pollution filter for astrophotography? new [Re: Toxic Coolaid]
      #5659646 - 02/03/13 10:04 AM

I agree with Samir... I wouldn't dare otherwise

However, I remember my first DSLR, a Canon 40D back in 2008. It was my $2000 baby. I was just getting into astronomy back then and I could not wrap my head around cracking open my new (and only) DSLR to have it modified. Fear took over, what-if the mod is a failure, what-if I send it over to a stranger to get it modified and I never see it again. I'd be $2000 in the red. Fear was just overwhelming. So I bought filters, the expensive ones! It barely made a difference.

Then I woke up. No risk, no reward.

Got the 40D modified and I never looked back. I now have 7 Canon and 4 Nikon. Five are modified and a brand new D5100 is currently being MONOfied.

So, the conclusion his... we've all spent some $$$ and made mistake along the way. Some were based on fear and some were based on budget. Do what feels right for you at this time... and time will tell you if you made the right decision for you. But if it were me... I'd modified it first knowing what I know now.

Just my 2 cents.

Guylain


Post Extras: Print Post   Remind Me!   Notify Moderator  
avarakin
Carpal Tunnel
*****

Reged: 07/13/09

Loc: Parsippany NJ, USA
Re: Light pollution filter for astrophotography? new [Re: Toxic Coolaid]
      #5660883 - 02/03/13 11:10 PM

Quote:

Quote:

why all the recommendations for pursuing filters before modding.




I agree. I would not bother with a Ha filter yet. All you would get is red. Stick with a LP filter. All I've ever had are the Astrinomik clip in CLS and CLS-CCD and they are great.




After I modded my camera, my CLS is hardly used, so I wasted the money on it. Also I noticed that sometimes it give some strange aberrations with lenses.
There are some folks who modify the cameras for $100. Another option is to look for used modified cameras in the S&S section, sometimes they are pretty cheap. This way you can keep your original camera for terrrestrial only.

Alex


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


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

Moderator:  Dave M, WOBentley, tecmage 

Print Thread

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


Thread views: 3131

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics