Best Precise Focal Length

Donegan OptiVISOR LX Binocular Magnifier-Lensplate #4 Magnifies 2X At 10 Focal Length

Please note: number on the lens designates the diopter, not the magnification.
Matched set of Lenses prismatically ground and polished to precise optical standards.
Lens conveniently flips up and away when not in use.
Ergometric soft genuine leather headband backed with wool felt designed from natural material to help wick moisture away.

...eniently be stashed in an accessory case between uses. "Dovetail guide scope bracket installs on virtually any astrophotography telescope quickly and easily..
The sturdy metal housing made of black anodized aluminum. Looking out not only solid, but is also very robust. A milled and knurled ring allows easy and precise fine focus adjustments. It comes with matching pipe clamps and a Synta-style mounting plate to make assembly and installation as easy as possible..
Have a built-in worm-focuser with Brass Compression Ring and 2 thumbscrews,45mm focusing range (10mm focusing range with micro-focusing Helical focuser, the rest is by a fixable, scaled drawtube) is made possible by an extremely precise focus adjustment. The mechanism has a determined orientation: This is mounted cameras or eyepieces - and thus also the area with your guide stars - not rotate during focusing..

Compact Deluxe Mini Guide Scope with a built-in helical focuser for precise focusing of guide stars.
Designed for use with the Orion StarShoot AutoGuider (sold separately), and astrophotography telescopes up to 1500mm focal length.
Non-rotating camera collar will not cause the attached autoguider to rotate during focus adjustments, ensuring the field of potential guide stars will....
Adjustable-aim dovetail guide scope bracket installs on virtually any astrophotography telescope quickly and easily.

Focal length and maximum aperture: 35mm 1:2.
Lens construction: 10 elements in 8 groups.
Rear focusing system with USM focus adjustment.
Closest focusing distance: 0.24m/0.79 ft,Focal Length : 35mm Comparable APS-C 1.6x Focal Length: 56 mm.Lens Construction:10 elements in 8 groups.

Focal length and maximum aperture: 35mm 1:2.
Lens construction: 10 elements in 8 groups.
Rear focusing system with USM focus adjustment.
Closest focusing distance: 0.24m/0.79 ft,Focal Length : 35mm Comparable APS-C 1.6x Focal Length: 56 mm.Lens Construction:10 elements in 8 groups.

75mm equivalent focal length on APS-C cameras, 80mm equivalent focal length on Canon APS-C cameras.
Ring-type ultrasonic-type AF motor with full-time manual focusing.
77mm filters. 77mm filters. 0.4m/15.7" minimum focus. Please use a USB dock for calibrating the focus.

7.5x high magnification zoom/ 27-202.5mm (35mm equiv.) focal length. Lens Groups / Elements : 12-16.
Outstanding sharpness from 1x aspherical and 2x ED glass elements.
7-blade circular aperture contributes to beautiful bokeh. Hood Type:Petal shape, bayonet type. Minimum focus distance- 0.45 m (1.48 feet).
Optical SteadyShot image stabilization for sharper stills and video.
Fast, precise, quiet AF for high-speed stills and impressive video.

【STANDARD 0.8 MOD】SmallRig Seamless Focus Gear Ring 3292 is designed to fit lenses for precise and stable focal length adjustment. It features standard 0.8 MOD and allows you to add 0.8 MOD gears to a compatible lens for use with cine follow focuses..
【FITS LENS PERFECTLY】Moderate stiffness, SmallRig Φ66-Φ68 Seamless Focus Gear Ring 3292 fits lens perfectly. This 66mm to 68mm size fits virtually all lenses of the same outer diameter..
【SUPPORT 360° ROTATION】It makes less noise and no distortion, allowing 360º smooth rotation and precise focus adjustment..
【SEAMLESS SWITCHING】The ring is made by elastic material, suits lens seamlessly and evenly. (Please Note: Gear slippage or jam may occur when mounted onto lenses larger than Φ66-Φ68mm across.).
【RELATED ACCESSORIES】The ring 3292 can work with SmallRig Mini Follow Focus 3010 and other follow focus systems, such as Seamless Focus Gear Ring 62.5 to 64.5mm 3291, 72 to 74mm 3293, 75 to 77mm 3294, 78 to 80mm 3295, 81 to 83mm 3296..

...ction adapter for 1.25-inch eyepieces of up to 38mm outside diameter, also can be used as a focal adapter with a T2 thread..
Two adapters in one: The projection and focal adapter consists of two parts - the projection part and the focal adapter. The projection part is used with an eyepiece for achieving a long focal length with small objects, e.g. for individual craters. Use the focal adapter without the use of an eyepiece so employing the focal length of your telescope - for taking photos of the entire Moon, gas nebula or galaxy..
Zooming into the night sky: Use the sliding rear part of the adapter to zoom - pull out to magnify the image - without needing to change your eyepiece. Connect this adapter to each telescope with a 1.25" eyepiece connection. You can use an eyepiece of any focal length - and you can achieve high-magnification images of lunar craters and planets. All you need is a T2 ring (Not Include) and a suitable camera with a bayonet connector..