Why Purchase from All-Star Telescope?
Free Expert Support
Whether you are a first timer needing help with setting up or an enthusiast that can't quite make that one thing work, our expert staff are ready to support your needs. With decades of knowledge and first hand experience we've been there and we can help you through it!
Stress Free, Secure Transactions
You can trust purchasing and delivery with All-Star Telescope. All of our transactions are 100% secure and Level 1 PCI DSS compliant thanks to Shopify's ShopPay platform. For additional protection, we insure 100% of the value of every shipment we make. If it get's lost during shipment, we replace it. If it gets damaged during shipment, we repalce it. We make sure your product arrives exactly as you would expect it to; we promise.
We also ensure privacy protection. We never keep any of your credit card information on file and any of your personal data is stored accordign to our policies.
30 Day Return Policy
Buy with confidence knowing that we accept returns up to 30 days after purchase. We want you to have something you will actually use and we are confident that we keep good quality products in our store with No Junk.
Price Match Promise
Shipping around for the best price is tough, we make it easier by offering the best pricing in the market. But if you find a better price on an in-store item somewhere else we will match it!
Product Description
The CLS (City Light Suppression) broadband filter is designed to improve the visibility of various deep sky objects. By selectively reducing the transmission of wavelengths of light pollutants, specifically those produced by artificial lightings including mercury vapour lamps, both high & low pressure sodium vapour lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). Together with the highly transparent in main nebula emission lines at OIII(496nm and 500nm), H-beta (486nm), NII(654nm and 658nm), H-alpha(656nm) as well as SII(672nm), the filter is suitable for enhancing the contrast and details for both visual and photographic purpose at sub-rural area.
Suitable for colour CCD cameras and unmodified DSLRs.
CLS with wider pass-band than UHC and hence is more favoured when observing under mild to moderate light pollution.
Light pollution filter do not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.
WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Optolong CLS Spectrum and Characteristic
- Substrate: Optical glass
- Thickness: 1.85mm
- Tave: T>90%
- Blocking range: 400-700nm
- Blocking depth: light pollution line blocking >99%
- Surface quality: 60/40
- Transmitted Wavefront RMS: λ/4
- Parallelism: 30s
Coating Technology
- Multi-layers anti-reflection coating
- Non-cementing optical substrate coating
- Optolong filter adopts precision coating based on Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change.
- Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band.
Warm Prompt
- About colour: due to the influence of ambient light, colour difference of the display and flash photography, the colour of the product may have some colour difference. Detailed colour is in accordance with the final product.
- About coating: the interference filter will show different colours under different light, which is a normal phenomenon. Please refer to the material object.
- About the style: in order to improve the product, the change of design/appearance/parameters has not been updated in time. Please see the subject produce.
- About the description: the series of this product have the same material, technology and design, different sizes only, please note.
Additional Articles, Videos, and Links
Astrophotography for Beginners Step 4: Shooting Deep-Sky Images
Taking deep sky pictures can be daunting, luckily there is an easy process to follow to allow you to get great shots! Here is the typical process for actually taking deep-sky images in the field.
Astrophotography for Beginners Step 3: Choosing Gear for Deep-Sky Imaging
Using a star tracker gains you experience with the fundamentals of deep-sky imaging. Shooting the Moon gains you experience focusing and framing through your telescope. Through your sessions you’ll...
Astrophotography for Beginners - Start Here: Getting into Astrophotography Step by Step
Shooting the night sky has never been more popular, nor easier. The choice of equipment has also never been better, or more affordable. However, as per the advice given by Dickinson and Dyer in the...
Astrophotography for Beginners Step 1: Using the Star Adventurer Tracker
By far the most economical and easiest way to capture beautiful images of the Milky Way and large deep-sky objects like the Andromeda Galaxy (shown here) is to use a star tracker. Here are steps an...
Astrophotography for Beginners Step 2: How to Shoot the Moon
Close-ups of the Moon are rewarding, and an easy way to learn to shoot through your telescope. While good results are possible with a phone camera clamped to an eyepiece (as shown below), this tuto...