Chroma OIII (3nm) Imaging Filter Optimized for f/2.8-f/3.6 - 31mm Round Unmounted
Ships by Next Business Day
Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.
US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.
International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.
This Chroma 31mm round unmounted 3nm O-III filter will fit inside virtually all filter drawers/holders and filter wheels on the market. However, please verify this with your accessory before purchase. The glass substrate thickness is 3mm.
OIII Filter for Narrowband Imaging - Optimized for f/2.8 to f/3.6
Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when imaging nebulae. Chroma’s f/3.0 filters are designed to minimize spectral shift and hold their shape better in an f/3.0 beam.
About Chroma Filters
Chroma manufactures the highest quality astronomy filters with durable, sputtered hard coatings using single substrates of the best glass, eliminating the need for laminations. All primary filter coatings are applied on the front surface and anti-reflection coatings on the rear surface to prevent ghosting and to maximize transmission. Highly precise and accurate, the passbands of Chroma filters remain spectrally stable and do not drift in response to extreme temperature fluctuations or changes in humidity. All filters may be used with focal ratios of f/4 or slower.
Cleaning, Handling, and Orientation
Handle Chroma filters by the edges only. Clean gently only if necessary. Loose particles should be removed with a bulb puffer or filtered, pressurized air cleaner. If necessary, gently wipe surface using anhydrous alcohol and lint-free lab towels. Use new surface of towel with each wipe.
- AVOID TOUCHING OR WIPING A/R COATED OR METAL MIRROR SURFACES
- AVOID HANDLING EXPOSED COATINGS WITH BARE FINGERS
Proper orientation of the filter is recommended for maximize performance. These filters should be mounted with the coated surface toward the light source and the AR-coated side towards the camera sensor. The AR-coated side can be easily identified because you can look right through the AR side into the filter. The front side, on the other hand, is highly reflective to prevent unwanted light from passing through.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
This Chroma 31mm round unmounted 3nm O-III filter will fit inside virtually all filter drawers/holders and filter wheels on the market. However, please verify this with your accessory before purchase. The glass substrate thickness is 3mm.
OIII Filter for Narrowband Imaging - Optimized for f/2.8 to f/3.6
Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when imaging nebulae. Chroma’s f/3.0 filters are designed to minimize spectral shift and hold their shape better in an f/3.0 beam.
About Chroma Filters
Chroma manufactures the highest quality astronomy filters with durable, sputtered hard coatings using single substrates of the best glass, eliminating the need for laminations. All primary filter coatings are applied on the front surface and anti-reflection coatings on the rear surface to prevent ghosting and to maximize transmission. Highly precise and accurate, the passbands of Chroma filters remain spectrally stable and do not drift in response to extreme temperature fluctuations or changes in humidity. All filters may be used with focal ratios of f/4 or slower.
Cleaning, Handling, and Orientation
Handle Chroma filters by the edges only. Clean gently only if necessary. Loose particles should be removed with a bulb puffer or filtered, pressurized air cleaner. If necessary, gently wipe surface using anhydrous alcohol and lint-free lab towels. Use new surface of towel with each wipe.
- AVOID TOUCHING OR WIPING A/R COATED OR METAL MIRROR SURFACES
- AVOID HANDLING EXPOSED COATINGS WITH BARE FINGERS
Proper orientation of the filter is recommended for maximize performance. These filters should be mounted with the coated surface toward the light source and the AR-coated side towards the camera sensor. The AR-coated side can be easily identified because you can look right through the AR side into the filter. The front side, on the other hand, is highly reflective to prevent unwanted light from passing through.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Chroma OIII (3nm) Imaging Filter Optimized for f/2.8-f/3.6 - 31mm Round Unmounted # CT-27066-31D