IDAS LPS2

[Bill R.]

I've been using the Hutech IDAS LPS P2 filter nearly all the time. It works quite well, but imaging time is increased.

[Kevin Galka]

Do you have any images you could post? Not being able to get out to a dark site that often, I'm curious about how well some of these filters work.

Kevin

[Bill R.]

Hi Kevin, I have three pics posted right now. All were taken with the IDAS LPS P2. None were from heavy light polution like I have in suburban St. Louis County, but it wasn't a real dark sky spot either. I do have to take longer exposures to get out of the noise, but when I am processing I have much less sky background to nuetralize.

[John O'Neal]

That's right, Bill. Imaging time is increased because less light is getting through the filter. That's the downside of an LP Filter.
The upside is that the signal you DO capture is desirable light with all the nasty wavelengths filtered out. This dramatically reduces luminosity and color gradients inherent to urban astrophotography.

[John O'Neal]

Hi, Kevin,almost every single image on my site was taken with a light pollution filter. The light pollution is so bad at my observatory location that I reach 1/3 histogram and begin fogging at about 30 seconds at ~ 500mm f/5.0.
The Orion Skylight Filter I use blocks common light pollution sources (mercury vapor, etc) and allows me to increase my exposure times up to around 3 minutes.

Maybe you can borrow one from a fellow club member to try out. If you're in an urban setting, you will be impressed with them.

[John O'Neal]

That's exactly right, Bill. But the upside is that only the light you want to pass through, is the only light that is passing through. All the extraeneous light you DON'T want is getting blocked by the filter.
This also makes focusing much more difficult, because the image is darker.