LP filter for William Optics 71

[Datalord]

Having recently finally found a way to polar align and take longer exposures I run into a new problem: At recommended ISO for the Canon 6D (1600 according to "graphs"), a 2 minute exposure totally blows out the image. I had to reduce to ISO400 and it was still very lit.

So, my assumption is that I had way too much LP. The full moon was blasting the sky, among other things.

Question: what filter should I buy? I assume it goes between camera and lens? 2.5" something? I have no clue what to search for.

[MARS1960]

The full moon is a killer, i'm lucky if i can go above ISO 100 and even at that i'm hard pressed to get even a 4 min sub and that is with a good quality LP filter.

When there is no moon however and i use the ASP-C equivalent of this, it works brilliantly.

http://www.365astronomy.com/Astronomik-EOS-XL-CLS-Visual-Clip-Filter-for-Canon-FULL-FRAME-Cameras.html

[Datalord]

So for a filter like that I have to install it directly on the ccd? That would make me nervous... 

[Davey-T]

Nowhere near the sensor, just clips in and out.

Dave

[geordie85]

You could always get an idas-p2-light-pollution-suppression-filter. They work wonders for light pollution. 

You can unscrew the very end of your focuser and there will be a thread for it to screw into.

[MARS1960]

13 hours ago, Davey-T said:

Nowhere near the sensor, just clips in and out.

Dave

Exactly and it also helps keep dust off the sensor datalord.

[Datalord]

Ah, calms my nerves. Thank you! 

[Datalord]

Ah, calms my nerves. Thank you! 

 

Follow up question : the one linked in the first response says "for B&W photography". Is that true? 

[Davey-T]

5 minutes ago, Datalord said:

Ah, calms my nerves. Thank you! 

 

Follow up question : the one linked in the first response says "for B&W photography". Is that true? 

Ignore that bit of confusing info doesn't apply to astro use.

Dave

[Datalord]

So, bought the Astronomik filter. This is a comparison with and without filter side by side. ISO1600 120s shot on both sides.

Currently the scope is taking the final dark shots after 3 hours on the whirlpool tonight. Going to be interesting if the final stack gives me the result I want.

[Datalord]

Totally worth it. I made a mistake on the camera, so I only got 1h10m exposure with 120s frames. Yet, this is definitely my best shot to date. This filter really works!