has any one used one of these?

[Daniel-K]

http://www.altairastro.com/product.php?productid=16485&cat=108&page=1

it says it helps to sharpen mono pictures, im planning on using my mammut mono ccd for a few weeks untill i get my dedicated ccd will this help?

[Cornelius Varley]

I'm going t move this one tpo the imaging section.

Peter

[NickK]

It's a filter lol.. basically the narrower the band, the easier it is to make a sharper image.. although you need pretty small sensor pixels.

[riklaunim]

IR/UV filters are used to block infrared and ultraviolet when doing color planetary imaging. It keeps the colors (IR would make colors more redder) and cuts out UV that would quite likely by out of focus or quite fuzzy due to seeing. In pure mirror telescopes it's a smaller problem than in scopes with glass in the path.

For DS imaging you could use light pollution rejection filter like Astronomik CLS. I use it for such imaging with a mono Atik.

[Daniel-K]

do i need a filter for a mono cam for imaging? such as LP

[NickK]

Sorry Daniel, my earlier comment could have been taken in a different way than it was meant.

I use a IR/UV cut filter all the time. It's on the nose of my filter wheel. The other filters then cycle through behind it. As a mono cam can't tell IR from red, green or blue wavelengths then it's appears as additional brightness. However most refractors suffer from some form of aberration where the lens can't focus all of the different wave lengths to the same point. Usually IR will be out of focus and thus causes a softening or blurring of the target.

A LP filter will remove the sodium band and does help. For moon shots I use IR/UV + Neodymium (an LP filter). The Baader LRGB filter set has a dip where it blocks the sodium.. although from experience it's not brilliant at it!