MLAstro 10mm Quartz Slit
The wait is over
$120.00
For SHG 700 owners (regardless of you buy it from me or anywhere else), Just use the 20SHIPPINGOFF code to have shipping waived on your order.
Overview
The wait is over!!! MLAstro 10mm Quartz Slit is the extended-length upgrade for the SHG 700, built for solar spectroheliographers who want to capture the entire Sun in one pass on longer focal length telescopes. Designed with a premium heat-resistant quartz substrate and MLAstro’s OD7-rated coating (on VIS), this slit can now handle unfiltered scopes up to 130 mm aperture at f/7 or slower. To achieve this, we need a complete rethink of the slit coating/lithography process and even the glue that attaches the slit to the slit mount has to be beefed up too.
Key Features
Full-Disk Reach up to 1000 mm FL
Extended 10 mm slit length enables full-disk solar scans on scopes up to 1000 mm focal length.Enhanced Thermal Resistance
Survives direct solar exposure without an ERF on telescopes up to 130 mm aperture at f/7 or slower.Precision Quartz Optics
Built with a 7 µm slit width for ultra-high spectral resolution and perfectly parallel, microscopic clean edges made from a patent pending photolithography process that MLAstro developed just for our slit.Improved Maintenance Access
The large rear opening allows for easier cleaning if dust settles on the slit. And the slit coat also has been improved with a hardener coat that allows direct cleaning with a cotton Q-Tip.Quick DIY Upgrade
Compatible with all SHG 700 units. Swap in minutes using just a 2.5mm Allen key.
Performance Considerations
Vignetting on Longer Scopes
On telescopes over 850 mm FL, you will experience severe vignetting that artificial flats cannot correct – a physical flat is required (see demonstration video).Field Curvature at Extreme FL
At ~1000 mm FL, expect mild softening near the poles due to field curvature. See this image under, taken from the SHG 700 with the 10mm slit and a Takahashi TOA 130mm at F/7.7 and physical flat. Notice the slight blur in the N-S poles (top-bottom).
Compatibility
Works with all SHG 700 production batches.
No other modifications required.
Price
$120 USD (plus shipping)
Recommended camera
For the 10mm slit, we recommend using the MLAstro IMX183 COLDMOS
Q: When will my order of the 10mm slit ships?
A: It'll take until late Aug 2025 for the 10mm slit to start shipping.
Q: Anything else?
A: If you have the early version of the 7mm slit and eligible for a free upgrade, you can have the new version of the 7mm slit shipped along with the 10mm slit for free. Just let me know in the order comment.
Q: Will replacing the 7 mm slit with the 10 mm slit and using a longer telescope improve image quality?
A: Possibly, but not guaranteed. The SHG is highly sensitive to astronomical seeing, and longer focal lengths magnify seeing effects. If your local seeing isn’t decent, the gain in detail may be offset by atmospheric blur.
Q: Can I buy the SHG 700 with only the 10 mm slit (no 7 mm slit)?
A: No. The 10 mm slit is only offered as an optional accessory for the SHG 700 due to compatibility considerations and certain limitations (such as vignetting and slight softness at the poles).
Q: Can the 10 mm slit be installed as the default on my SHG 700?
A: Unfortunately, no. Installing the slit is extremely easy, but pre-installing it would add unnecessary complexity to assembly. Since MLAstro is still a one-man operation, keeping production simple is essential. If you want the 10 mm slit, you’ll need to install it yourself — it only takes a minute with a Phillips screwdriver.
Q: Do you recommend the IMX678 sensor with the 10 mm slit?
A: You can use it, but you won’t see the slit edges, which makes collimator focusing trickier. The official recommended camera for the 10 mm slit is the MLAstro IMX183 COLDMOS — and yes, we sell it at the lowest price you’ll find anywhere.
Q: How long is the warranty on the 10 mm slit?
A: 1 year.
Q: I already own an SHG 700 — do I get any promotion when ordering the 10 mm slit?
A: Yes! You’ll get free shipping. Just email trong.minh@mlastro.com for the code. The offer applies whether you purchased your SHG 700 directly from MLAstro or through a dealer.
Q: When will my order of the 10mm slit ships?
A: It'll take until late Aug 2025 for the 10mm slit to start shipping.
Q: Anything else?
A: If you have the early version of the 7mm slit and eligible for a free upgrade, you can have the new version of the 7mm slit shipped along with the 10mm slit for free. Just let me know in the order comment.