Description
Tracking Is the Whole Discipline. A mount can be perfectly polar aligned and a camera perfectly focused, and the image still walks if nothing is watching the stars while the shutter is open. Guiding is that watchman, and the guide scope is the eye it uses. The SV165 is built for the job rather than adapted to it: thirty millimetres of aperture, a 120mm focal length, an f/4 light path that finds a guide star quickly in a crowded field.
The mechanical side is where small guide scopes usually fail, and this one is specified properly. The body is aluminium alloy and glass with a sandblasted oxidation finish, 92 by 56 by 78 millimetres and 342 grams on the scales, light enough that it does not strain a small mount or fight the imaging train for balance. Back focus is adjustable at 26mm, the helical focuser travels 45 millimetres, and the dovetail carries a 1/4 inch screw hole for a standard shoe or bar.
Connections cover the cameras people actually guide with. A 1.25 inch interface and an M42 by 0.75 male thread accept the SV305, ZWO, Orion, QYH and comparable auto guiding cameras, and the fully broadband multi-coated optics keep the star field bright enough for the guide software to hold a lock on a dim target. For a rig that images at a long focal length, this is the difference between round stars on a five minute exposure and a night of deleting frames.
A guide scope does not take pictures. It decides whether the pictures are worth keeping.
What the Optics Give You
- ✦30mm aperture with a 120mm focal length and f/4 light path for fast guide star acquisition
- ✦Fully broadband multi-coated optics with an aluminium alloy and glass body
- ✦Front part helical focuser with 45mm of travel
- ✦Adjustable 26mm back focus for camera spacing
- ✦1.25 inch interface and M42 by 0.75 male thread for SV305, ZWO, Orion and QYH guide cameras
- ✦1/4 inch dovetail screw hole for standard finder shoes and guide bars
- ✦342 gram weight and a 92 x 56 x 78 mm footprint that leaves mount capacity for the imaging train
Optical Record
- ModelSV165
- Objective lens diameter30mm
- Focal length120mm
- Aperture ratiof/4
- CoatingFMC, fully broadband multi-coated
- Back focus26mm, adjustable
- Tube travel112.2mm, helical focus stroke 45mm
- Focuser typeFront part focuser
- Camera interface1.25 inch or M42 x 0.75 mount
- Body size92 x 56 x 78 mm
- Net weight342g (0.75 lb)
- Material and finishAluminium alloy and glass, sandblasted oxidation
- Dovetail1/4 inch screw hole
Who Guides With This Scope
Deep sky imagers add a guide scope when their mount tracks well enough for the short exposures but not well enough for the long ones, which describes most portable set-ups. Narrowband photographers use a small guide scope because the guide camera has to hold a star for twenty minute sub-frames. Travelling astronomers choose it for the weight and the footprint, since every gram removed from the top of the rig buys tracking stability below it. It is also the sensible first guide scope for someone stepping up from unguided imaging, because the 1.25 inch and M42 interfaces accept the camera they probably already own, and the f/4 optics make the search for a usable guide star quick rather than fiddly.
Astrophotography Questions
Q: Which guide cameras will fit?
A: The scope accepts 1.25 inch mounted cameras and cameras with an M42 by 0.75 thread, which covers the SV305, ZWO, Orion, QYH and comparable auto guiding models. Message us with your camera if you are unsure.
Q: Do I need a separate guide scope at all?
A: If your mount holds round stars for the exposure length you use, you do not. If you are deleting frames because the stars are elongated, guiding is the fix, and a guide scope is where it starts.
Q: How do I focus it?
A: Focus with the front part helical focuser, which provides 45mm of travel. Set back focus at 26mm and adjust from there, then lock it down before the session, because the focus point barely shifts once the camera is seated.
Q: Will it fit my finder shoe?
A: The dovetail includes a 1/4 inch screw hole, so it mounts on a standard shoe or a guide bar. If your rig uses a different bracket, tell us what you are mounting to and we will confirm the fit.
Q: Is it suitable for guiding a long focal length scope?
A: The 120mm focal length and 30mm aperture are designed for guiding rather than for imaging flexibility. For long focal length imaging, use the guide software settings to suit the guide scale, and keep the scope firmly mounted so flexure does not enter the system.
Q: What is included in the box?
A: The guide scope as listed. Send us a message with the model and we will confirm the exact contents for the variant you are ordering, so that nothing you need is a surprise.
The EastSupplier Promise
Every unit in this listing is inspected and packed by our own cross-border team in China before it leaves the warehouse. We hold the stock, we handle the export paperwork, and we answer technical questions directly rather than routing you through a marketplace resolution desk.
Orders ship with tracking, and quantities above ten units are quoted individually so that shipping and duties are confirmed before you pay. If you are buying for a workshop, a studio, a fleet, or a service bay, tell us what you need and we will confirm availability, lead time, and landed cost.
Wholesale, OEM, and multi-unit inquiries: service@eastsupplier.com
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