GSO 8" f/4 Parabolic Primary and 70mm Secondary Telescope Mirror Set
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.
For years, GSO has made dobsonian telescopes sold under various labels. Users of these scopes know the excellent quality of the optics included, and they have a well-deserved reputation for being the finest mirrors in their price range. We are now pleased to offer virtually the entire line of GSO's Newtonian optics in the US market.
GSO's parabolic primary mirrors are perfect for those who want to build their own telescopes or replace mirrors in older ones. Ranging in aperture from 6” to 16” and offered in various f-ratios, these mirrors are made from optical grade BK-7 glass. All mirrors have a reflective aluminum coating with a reflectivity of 92-93%. The aluminum coating is protected by a silicon oxide (SiO2) over-coating. GSO's elliptical flat mirrors have the same high quality as their parabolic primary mirrors.
GSO uses high-volume, state-of-the-art, high quality manufacturing and test lines. GSO guarantees diffraction limited performance, but their mirrors typically have a mirror surface quality of 1/16 wave RMS at least, and often better. This very smooth mirror surface results in excellent optical performance with practically no light scatter.
Please Note:
Most parabolic mirrors will have 2-4 minor uncoated areas along the edge of the mirror. See photo 3 above for an example. These are caused by the clips used to hold the mirrors in the coating chamber. Note that these are not defects. A couple of these uncoated edge strips will typically be covered up by the clips in your mirror cell anyway.
Additional Information:
Q. Is a test report included with each mirror?
A. No. GSO tests each mirror via laser interferometry before shipping, but does not provide individual test reports.
Q. Is the primary center-dotted?
A. No – the GSO primary mirrors we offer are not center-dotted.
You can easily center-dot the primary yourself following instructions readily available on the internet. If you want a free center-dotting sticker, just request one from us at the time you place your order. However, we do not offer center-dotting services.
| Specifications of GSO Primary Mirrors | |||||||
|---|---|---|---|---|---|---|---|
| Part Number | Aperture | Focal Ratio | Mirror Diameter | Focal Length | Mirror Thickness | Mirror Weight | Suggested Secondary Size |
| AD096 | 6" | f/4 | 153mm | 600mm | 20mm | 1lb-14oz (847g) | 62.5mm |
| AD046 | 6" | f/5 | 153mm | 750mm | 20mm | 2lb-1oz (941g) | 50mm |
| AD045 | 6" | f/6 | 153mm | 900mm | 20mm | 2lb (921g) | 50mm |
| AD011 | 6" | f/8 | 153mm | 1200mm | 20mm | 2lb (921g) | 31mm |
| AD048 | 8" | f/4 | 200mm | 800mm | 24mm | 3lb-15oz (1794g) | 70mm |
| AD049 | 8" | f/5 | 200mm | 1000mm | 24mm | 4lb-1oz (1831g) | 62.5mm |
| AD082 | 8" | f/6 | 200mm | 1200mm | 24mm | 3lb-13oz (1717g) | 50mm |
| AD094 | 10" | f/4 | 250mm | 1000mm | 34mm | 9lb-2oz (4126g) | 88mm |
| AD081 | 10" | f/5 | 250mm | 1250mm | 34mm | 8lb-9oz (3891g) | 62.5mm |
| AD095 | 12" | f/4 | 304mm | 1200mm | 38mm | 14lb-8oz (6574g) | 88mm |
| AD017 | 12" | f/5 | 304mm | 1500mm | 38mm | 14lb (6348g) | 70mm |
| AD015 | 16" | f/4.5 | 406mm | 1800mm | 45mm | 28lb-14oz (13092g) | 88mm |
| Specifications of GSO Secondary Mirrors | ||||
|---|---|---|---|---|
| Part Number | Minor Axis Diameter | Approx. Major Axis Diameter | Approx. Thickness | Mirror Weight |
| AD041 | 28mm | 38mm | 5mm | 0.3oz (9g) |
| AD012 | 31mm | 43mm | 8mm | 0.7oz (20g) |
| AD064 | 46.5mm | 65mm | 10mm | 2.1oz (60g) |
| AD007 | 50mm | 70mm | 10mm | 2.3oz (65g) |
| AD047 | 62.5mm | 88mm | 12mm | 4.5oz (128g) |
| AD091 | 68mm | 95mm | 15mm | 6.7oz (190g) |
| AD009 | 70mm | 97mm | 12mm | 5.5oz (156g) |
| AD092 | 74mm | 104mm | 16mm | 8.2oz (232g) |
| AD093 | 80mm | 114mm | 18mm | 11.5oz (326g) |
| AD037 | 88mm | 122mm | 20mm | 14.5oz (411g) |
| AD018 | 104mm | 145mm | 17mm | 18.2oz (515g) |
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
For years, GSO has made dobsonian telescopes sold under various labels. Users of these scopes know the excellent quality of the optics included, and they have a well-deserved reputation for being the finest mirrors in their price range. We are now pleased to offer virtually the entire line of GSO's Newtonian optics in the US market.
GSO's parabolic primary mirrors are perfect for those who want to build their own telescopes or replace mirrors in older ones. Ranging in aperture from 6” to 16” and offered in various f-ratios, these mirrors are made from optical grade BK-7 glass. All mirrors have a reflective aluminum coating with a reflectivity of 92-93%. The aluminum coating is protected by a silicon oxide (SiO2) over-coating. GSO's elliptical flat mirrors have the same high quality as their parabolic primary mirrors.
GSO uses high-volume, state-of-the-art, high quality manufacturing and test lines. GSO guarantees diffraction limited performance, but their mirrors typically have a mirror surface quality of 1/16 wave RMS at least, and often better. This very smooth mirror surface results in excellent optical performance with practically no light scatter.
Please Note:
Most parabolic mirrors will have 2-4 minor uncoated areas along the edge of the mirror. See photo 3 above for an example. These are caused by the clips used to hold the mirrors in the coating chamber. Note that these are not defects. A couple of these uncoated edge strips will typically be covered up by the clips in your mirror cell anyway.
Additional Information:
Q. Is a test report included with each mirror?
A. No. GSO tests each mirror via laser interferometry before shipping, but does not provide individual test reports.
Q. Is the primary center-dotted?
A. No – the GSO primary mirrors we offer are not center-dotted.
You can easily center-dot the primary yourself following instructions readily available on the internet. If you want a free center-dotting sticker, just request one from us at the time you place your order. However, we do not offer center-dotting services.
| Specifications of GSO Primary Mirrors | |||||||
|---|---|---|---|---|---|---|---|
| Part Number | Aperture | Focal Ratio | Mirror Diameter | Focal Length | Mirror Thickness | Mirror Weight | Suggested Secondary Size |
| AD096 | 6" | f/4 | 153mm | 600mm | 20mm | 1lb-14oz (847g) | 62.5mm |
| AD046 | 6" | f/5 | 153mm | 750mm | 20mm | 2lb-1oz (941g) | 50mm |
| AD045 | 6" | f/6 | 153mm | 900mm | 20mm | 2lb (921g) | 50mm |
| AD011 | 6" | f/8 | 153mm | 1200mm | 20mm | 2lb (921g) | 31mm |
| AD048 | 8" | f/4 | 200mm | 800mm | 24mm | 3lb-15oz (1794g) | 70mm |
| AD049 | 8" | f/5 | 200mm | 1000mm | 24mm | 4lb-1oz (1831g) | 62.5mm |
| AD082 | 8" | f/6 | 200mm | 1200mm | 24mm | 3lb-13oz (1717g) | 50mm |
| AD094 | 10" | f/4 | 250mm | 1000mm | 34mm | 9lb-2oz (4126g) | 88mm |
| AD081 | 10" | f/5 | 250mm | 1250mm | 34mm | 8lb-9oz (3891g) | 62.5mm |
| AD095 | 12" | f/4 | 304mm | 1200mm | 38mm | 14lb-8oz (6574g) | 88mm |
| AD017 | 12" | f/5 | 304mm | 1500mm | 38mm | 14lb (6348g) | 70mm |
| AD015 | 16" | f/4.5 | 406mm | 1800mm | 45mm | 28lb-14oz (13092g) | 88mm |
| Specifications of GSO Secondary Mirrors | ||||
|---|---|---|---|---|
| Part Number | Minor Axis Diameter | Approx. Major Axis Diameter | Approx. Thickness | Mirror Weight |
| AD041 | 28mm | 38mm | 5mm | 0.3oz (9g) |
| AD012 | 31mm | 43mm | 8mm | 0.7oz (20g) |
| AD064 | 46.5mm | 65mm | 10mm | 2.1oz (60g) |
| AD007 | 50mm | 70mm | 10mm | 2.3oz (65g) |
| AD047 | 62.5mm | 88mm | 12mm | 4.5oz (128g) |
| AD091 | 68mm | 95mm | 15mm | 6.7oz (190g) |
| AD009 | 70mm | 97mm | 12mm | 5.5oz (156g) |
| AD092 | 74mm | 104mm | 16mm | 8.2oz (232g) |
| AD093 | 80mm | 114mm | 18mm | 11.5oz (326g) |
| AD037 | 88mm | 122mm | 20mm | 14.5oz (411g) |
| AD018 | 104mm | 145mm | 17mm | 18.2oz (515g) |
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
GSO 8" f/4 Parabolic Primary and 70mm Secondary Telescope Mirror Set