Telescopes & Binoculars

Question:

How does one distinguish Lumicon nebular filter types from each other?

Answer:

For those who have inadvertently lost track of the identities of their Lumicon filters, follow these guidelines:

The traditional Deep Sky Filter (Visual & Photographic) will make the daytime sky or fluorescent lights appear a deeper blue than will the Ultra-High-Contrast Filter. Its reflection from one side of the filter is silvery, and from the other side, green-yellow.

The new Deep Sky II Filter (Visual Only) appears silvery on both sides.

Between the Oxygen III Filter and the Deep Sky Filter, the filter that shows the Orion nebula best is the Deep Sky Filter.

The Oxygen III Filter will make the daytime sky or fluorescent lights appear green. The reflection from both sides of the filter is green-yellow.

The Ultra High Contrast Filter will make the daytime sky or fluourscent lights appear light blue. The reflection from both sides of the filter is silvery.

The Hydrogen-Beta Filter will make the daytime sky appear red as seen through it. The reflection from both sides of the filter is a very light blue.

The Comet Band Filter will make the daytime sky or fluorescent lights seen through it appear green. Tilting the filter sixty degrees will make the daytime sky or fluorescent lights seen through it appear pink. The reflecton from both sides of this filter is silvery if the angle of illumination is high.

Lumicon Deep Sky Filters

Qestion:

What is the transmission of the Lumicon Neutral Density Filter?

Answer:

Lumicon’s Neutral Density Filter is available in three transmissions: 13%, 25% and 50%. This means that they are blocking 87%, 75% and 50% of the light across the visible spectrum.

Lumicon Neutral Density 13 (ND13) 2″

Lumicon Neutral Density 25 (ND25) 2″

Lumicon Neutral Density 50 (ND50) 2″

Lumicon Neutral Density 13 (ND13) 1.25″

Lumicon Neutral Density 25 (ND25) 1.25″

Lumicon Neutral Density 50 (ND50) 1.25″

Qestion:

Why is the Deep Sky filter the only nebula filter recommended for photography?

Answer:

We recommend the Deep Sky filter because it has the widest band-width among Lumicon’s nebula filters. The wide band-width of the Deep Sky allows for shorter exposure times, which makes for easier astrophotography of deep-sky objects. This is not a recommendation against narrower band-width filters, such as the UHC or OIII, which can be used to produce higher-contrast pictures. These narrower filters are more “challenging,” however, because they require longer exposure times. If you are new to astrophotography–a difficult art–start with a Deep Sky filter. In terms of exposure time required, from shortest to longest, Lumicon’s nebula filters progress as follows: Deep Sky

See Details:

Lumicon Deep Sky Filters 2″

Question:

I am new to astronomy. What is the all-around best filter?

Answer:

Unfortunately, there is no all-around best filter for everyone. The optimum filter depends on your telescope / equipment, seeing conditions and objects wanting to view. There are three basic categories of celestial objects that can be enhanced with filters: lunar viewing, planetary viewing and deep sky objects (faint objects like nebulae). There is no filter that will do it all.

For observing the moon, the primary requirement is to reduce the light intensity and enhance contrast for easy viewing. This can be done with a Neutral Density or Polarizing filter.

For planetary observing, color filters bring out the most detail because planets are naturally colorful. Different colors bring out different details of the planet you are viewing.

Always remember that you want to use the darkest filter your telescope will handle. Most small telescopes up to about 5″ in aperture use the light colors. The larger the telescope, the darker your filter can be.

Color filters can sometimes be used in conjunction with a Neutral Density or Polarizing filter to aid in glare reduction. The more you use your filters the more you appreciate them and their affect.

Lumicon Filters

Question:

Can you help?  I have a 2″ eyepiece and want an adapter so I can fit 1 1/4″ filters to it.  I realize that my field of view will be restricted.  Do you have such an adapter?

Thanks, John

Answer:

John,

Because of the severe vignetting that would result, no one makes such an adapter. However, we know a way around it:

We do have a 2″ female, 1-1/4″ male eyepiece adapter (it allows the use of 2″ eyepieces in 1-1/4″
holders) which is threaded on the bottom for 1-1/4″ filters.

You would sacrifice over 50% of your field of view to use this adapter, but it is on our website,
part number 735-49020. It is usable with 2″ eyepieces that have shorter focal lengths.

Note: if using this adapter in a newtonian scope, it will require an additional 2″ of in-travel in the focuser to come to focus. With any catadioptric scope  having a moving mirror focus (SCT or MCT), it is  more easily  usable.

Don

Lumicon 1.25″ Male - 2″ Female Adapter: