Astro-Tech 24mm illuminated reticle eyepiece


Availability: In stock

The economical Astro-Tech #AT24IL illuminated reticle 1.25" eyepiece helps you align your go-to telescope on the sky, check your polar alignment for astrophotography, center guide stars in an photoguide scope, and more . . .
Our Product #: AT24IL

Product Description

This Astro-Tech #AT24IL illuminated reticle 1.25" eyepiece is the perfect eyepiece for aligning go-to telescopes on the sky each night when you go out to observe. It is also ideal for checking your scope's polar alignment for long exposure astrophotography, for centering guide stars in an off-axis photoguide scope for astrophotography, or for testing the accuracy of your computer pointing or the periodic error of your tracking system. Priced as much as 40% less than competitive illuminated reticle eyepieces, the #AT24IL is yet another example of the Astro-Tech philosophy of "more performance for less money."

Most conventional illuminated reticle eyepieces have a short focal length and limited eye relief, which can make for uncomfortable viewing, particularly if you wear eyeglasses. In comparison, the Astro-Tech #AT24IL has a long 24mm focal length for a wider field that makes it easier to locate guide stars. This virtually eliminates the need to swap out a high-power illuminated reticle with a lower power eyepiece to locate or center objects.

Its very long 20mm eye relief and soft roll-down rubber eyecup make it very comfortable to use, whether you wear glasses to observe or not. You can use this Astro-Tech 1.25" eyepiece with any make or model of telescope or off-axis guidescope.

The eyepiece reticle has a single etched crosshair precisely centered in eyepiece field of view for accurate results. A ribbed ring at the top of the eyepiece rotates to focus the crosshairs sharply to match your eyesight. The five-element optical system is fully multi-coated on all air-to-glass surfaces with high transmission anti-reflection coatings for bright, crisp views. The edges of the lenses are blackened for high contrast. The barrel is threaded for standard 1.25" filters.

The metal-body cordless red LED (light emitting diode) crosshair illuminator has a rotary on/off switch with an integral brightness level control. Two supplied 1.5V watch/camera/calculator button batteries will power the illuminator for many hours of use. The supplied batteries are model GPA76, but you can also use the Duracell, Maxell, National, Panasonic, Sony, or Toshiba LR44; the Eveready or Philips A76; etc. When replacing batteries, be sure the battery - signs face the LED portion of the illuminator and the + signs face the on/off switch.

Please note: While the manufacturer normally supplies batteries at no cost with this product as a convenience, the battery charge or useful life is not guaranteed. The batteries may arrive with their charge depleted or very low. In such a case, you will have to purchase replacement batteries locally, as battery life is not covered by the manufacturer's warranty.

Tech Details

Eye Relief 20mm
Field of view 50
Focal Length 24mm
Weight 4 oz.
Warranty 1 year


Review by:
This is a very nice eyepiece. It does exactly what I needed it to in that I use it to assist with polar alignment on my CGEM II. It is well made, true Astro Tech quality and I have not had a bit of problems with it. I should have bought one of these quite some time ago.

The reticle is clear and fine enough so that it doesn't block whatever star I am using. The brightness adjustment is solid and sure and just the overall build and quality is awesome. It really makes my polar alignment and go to setup so much quicker and easier. I had researched many like this one and I am happy that I bought the Astro Tech. (Posted on 5/12/2024)
Review by:
Five stars for the optics, 2-3 for the illuminator. The image is clear and bright and the eye relief is excellent. The reticle focusing mechanism is smooth and the reticle is a very fine cross that shows nicely when illuminated.

The illuminator has two chambers that open by unscrewing the barrel, one for the batteries and one for the electronics. The instructions say not to open the electronics chamber or you'll damage the electronics and void the warranty, but that chamber doesn't close securely and the dimmer rides on its threads. It seems to open every time you turn the dimmer to "off" due to the detent between min-brightness and off. As a result, the brightness of the illuminator jumps around and isn't a smooth gradient from min to max brightness.

Making it easy and inevitable to do something that'll void the warranty rubs me the wrong way, especially since this issue could have been easily remedied at the factory with some red Loctite or a set screw. (Posted on 1/15/2024)
Review by:
I personally did'nt need the illuminator and I'm also no expert either. But the eye relief on this eyepiece is amazing, I wear glasses and I live in Georgia. My glasses foggy if I need to squint and get up close to an eyepiece. But the astro-tech reticle eyepiece is comfortable and clean. (Posted on 9/9/2021)
Review by:
I use it on my SkyWatcher 72ED. Works well. Helps a lot for alignment with the main scope.
Price is good. (Posted on 7/22/2019)
Review by:
Works great when completing polar alignment. I use this reticle to run drift alignment routines and able to get within 1" of accuracy which is sufficient enough for my autoguider to manage. Nice to have the ability to dim the brightness as to not overpower the star you are tracking (Posted on 11/6/2018)
Review by:
I use this eyepiece when I setup to align my guide scope to my imaging scope. It works really well with the variable intensity control. The price is reasonable and delivery was fast. (Posted on 10/17/2018)
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