Explore Scientific AR152 6" f/6.5 achromatic doublet refractor optical tube


Availability: More on the way

This 6" Explore Scientific AR152 achromatic refractor optical tube is a sensational value - a big 6" (152mm) and fast f/6.5 refractor that's priced like an 80mm scope.
Our Product #: ES152D
Explore Scientific Product #: DAR152065-01

Product Description

This Explore Scientific AR152 6" achromatic refractor has:

  • big 6" aperture fully multicoated achromatic doublet refractor optics
  • collimatable objective lens cell for fine-tuning the images
  • dual-speed 2" Crayford focuser with 10:1 ratio fine focusing 
  • 2" dielectric star diagonal with 2" and 1.25" brass compression ring eyepiece holders
  • big 8 x 50mm finderscope
  • tube rings with carry handle and Vixen-style dovetail plate
  • bright high contrast deep space views, plus excellent performance inside the solar system
  • extended lifetime warranty

This large aperture 6" Explore Scientific ES152D achromatic doublet refractor optical tube is a big scope (41" long, with a weight of 23.5 pounds), with big performance to match. It has a 152mm (6") diameter multicoated doublet objective lens (988mm focal length f/6.5) that gathers 44% more light than a 5" scope. Its diffraction limited optics are sharp and well suited to serious deep space observing of binary stars, star clusters, and faint nebulas and galaxies, in addition to excellent high contrast planetary and lunar images. The objective lens cell is fully collimatable, so you can optimize your image quality.

The 6" Explore Scientific ES152D is good enough optically to be the heart of a reasonably-priced serious observing system when mounted on one of the many equatorial mounts and go-to altazimuth mounts from Celestron, Meade, iOptron, and others.

Some chromatic aberration is visible on stars and objects of 2nd or 3rd magnitude and brighter, as you would expect in a big achromatic refractor with such a fast focal ratio. However, the spurious color is well controlled and not unreasonable, thanks to careful optical design, and has little effect on deep space observing. Most observers feel the relatively limited amount of chromatic aberration visible is a small price to pay for the scope's many other virtues of portability, sharpness, contrast, and optical clarity.

Details About This Optical Tube . . .

  • Achromatic refractor optics: 6" (152mm) aperture, 988mm focal length, f/6.5 air-spaced crown and flint glass doublet lens. Tube diameter is 6.21" (157.7mm) and the tube length with dewshield installed is 41" (1041mm). Scope weight is 23.5 pounds (10.7 kg).

  • Collimatable lens cell: The 6" Explore Scientific lens is precision collimated at the factory to give optimum performance. Although you may never need to adjust optical alignment, the ES152D allows for collimating the lens set should the telescope ever require it due to a fall or very rough handling.

  • Multicoated optics: Fully coated on all surfaces with multiple layers of antireflection materials for high light transmission and good contrast.

  • Internal light baffles: Multiple internal knife-edge baffles in the optical tube mask and deflect unwanted stray light for improved contrast.

  • Dew shield: The removable dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves visual and photographic contrast by shielding the lens from off-axis ambient light (the neighbor's yard light, moonlight, etc.)

  • Dust covers: Front and rear dust covers are provided.

  • Dual-speed Crayford-style focuser: 2" focuser, with adjustable tension and lock knobs. The 2" eyepiece holder uses a non-marring brass compression ring to hold the supplied 2" star diagonal in place without scratching the diagonal barrel. The precision-made 2" focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with 10:1 ratio reduction gear microfine focusing. This provides exceptionally precise image control during high power visual observing or critical DSLR or CCD imaging. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.

  • Dielectric star diagonal: 90° viewing angle first surface mirror 2" star diagonal with 1.26" eyepiece adapter. The diagonal uses durable 99% reflectivity for maximum light transmission and long life.

  • Finderscope: 8 x 50mm straight-through achromatic design, in a dual-ring six-point adjustment bracket with a quick release mounting shoe. Focuses by loosening the trim ring behind the objective lens cell, screwing the lens cell in or out to focus, and tightening the trim ring to lock in the correct focus.

  • Dovetail tube mount: The optical tube comes with two split and hinged tube rings for installing the optical tube on your mount. The rings are connected to a dovetail mounting plate that slips into the standard dovetail groove on Explore Scientific, Celestron, Meade LX80, Vixen, and similar mounts. A carrying handle is conveniently fitted to the top of the tube rings

  • Extended lifetime warranty: This individually serial numbered Explore Scientific telescope is backed by a limited one year warranty, which will be extended to an Explore Scientific transferable product lifetime limited warranty when its warranty card is registered with Explore Scientific within 60 days of purchase. Full details on this unique transferable lifetime warranty.

Tech Details

Aperture 6"
Binary and Star Cluster Observation Great
Focal Length 988mm
Focal Ratio f/6.5
Galaxy and Nebula Observation Good
Highest Useful Magnification 282x
Lunar Observation Great
Weight 23.5 lbs
Planetary Observation Great
Resolution 0.76 arc seconds
Telescope Type Refractor
Visual Limiting Magnitude 13.4
Warranty Limited Lifetime


Review by:
I purchased this scope several years ago. I find it to an excellent value and a fine instrument. It came with an excellent diagonal and a 50 mm finder scope. It gives great views of deep sky objects and also has excellent resolution, easily spitting close double stars. It also comes with a built in handle, which helps with transport. The only negatives are chromatic aberration on bright objects like Jupiter, the limb of the Moon, and first magnitude stars. This is to be expected in short focal length achromatic refractors. Otherwise, the false color is not noticeable. It is also heavy, but this is to be expected in any 6 inch refractor. I highly recommend it. (Posted on 3/5/2024)
Review by:
I've owned this scope for about eight years now and I'm still in love! You just can't beat the contrast and sharpness of a refractor. I use it with the ES 82deg eyepieces and love the effect of the scope going away and feeling like you're seeing space directly. There is some CA on brighter objects like Jupiter and the moon, but it's only an issue at high magnification. Best solution for that is to stop it down to four inches. I use a paper plate with a four inch diameter hole cut in it and place it over the dew shield. There is no CA when viewing most deep sky objects with the exception bright stars. There are reviews out there that claim this scope compares closely with APO's costing them times as much on DSO's. I believe it. (Posted on 2/7/2023)
Review by:
Hello, my vocation is professional photography, I understand optics and point of diminishing returns. This achromatic refractor is a beauty. Very functional with crisp. Contrast, focused images, and no cooling period required. I have tried numerous eyepieces on this scope and found that the televue deletes worked the best in regards to weight and balance. This is a fantastic scope equivalent to a 8" reflector. Reflectors have a central obstruction therefor making the objective smaller. I do not have the formula handy but I can assure you a 6" refractor supersedes a 7" reflector and on par with an 8" reflector. Google online professional reviews:this scope is a winner especially for the price. Enjoy. (Posted on 5/31/2021)
Review by:
I purchased used the Bresser labeled scope, which is the same as this one. I have had it for several months, and also own some other scopes including an SCT and 8" Newt. I do use it on a permanent mount; it weighs about 25 pounds. To date my best photos have been taken with this scope. They are pinpoint sharp. The scope is well built and I find the Crayford focuser adequate. Best of all the 1000 mm focal length at F7 gives a good compromise between lens speed and focal length. The Newts are faster, but do not provide as much magnification, and the SCTs are much slower at F10 or F11. I highly recommend this scope. (Posted on 10/4/2019)
Review by:
I have had this scope for about 5 years now. Wonderful scope with very little CA. It is a bit on the heavy side so it does not get out as much use as it probably should. It puts up great views and mechanically is very good. Lunar, planetary, DSO and wide views have all been great for me in this scope.
Very good achro for the price. You will not be disappointed. (Posted on 8/22/2019)
Review by:
I purchased this scope two years ago and have had great view with it. I have also taken photos of pack man, whirlpool, and the dumbbell nebula in H alpha. A good performing scope. It provides the increased magnification for smaller objects with it's 988 mm focal length. It comes with a diagonal and finder. As a refactor it is very forgiving in high humidity and moderate to poor observing conditions. Good quality and a joy to use. (Posted on 7/31/2019)
Review by:
Always wanted a 6" refractor thus purchased this. Well built with beautiful paint job. Optics are collimatable which is a huge plus! Focuser is a duel speed and pretty decent. A bit of CA which is expected but well controlled but being a wide field scope the CA is not there observing DSO's. Bought a Baader Semi Apo filter which works great controlling CA on brighter objects with this scope. At 23 pound a bit heavy but with all that comes with the scope at a decent price, I really can't complain! (Posted on 7/22/2019)
Review by:
Much larger scope in person than pics show. Fit and finish on mine wasn't quite 5 stars. A few minor blemishes in the paint on dew shield and "fish eye" on the optical tube. Otherwise a very nice scope for the price. Some color around bright planets and the moon to be expected with an achro. Really don't like the straight thru finder. But only use it for initial alignments anyway. (Posted on 1/14/2019)
Review by:
I purchased this scope as a Christmas gift to myself on Black Friday directly from the manufacturer at a deep discount. Brand new. It came well packaged with no dent to the box, much less damage to the content of it. It is my second 6" achromat, first one was Meade's AR6AT, which was medium FL refractor (f/8). I had that one for some 7-8 years but its bulkiness, weight and overall awkward appearance made me use it less and less. So I sold it and after 3-4 years with no "big cannon" I couldn't resist a call of a large-lens instrument so I bought this telescope. I must say I agree with pretty much everything that others here wrote about it. It is "shorter" (lengthwise) and "faster" ( a bit more CA than the Meade, obviously) and I'd say made for deep sky. Yes, it's a RFT that can be used for the moon, planets, solar (with a proper filter)... but I wouldn't recommend it for anything but DSOs. Filtering purple fringe causes some other problems with a fast achromat like this so use it for what is meant to be used and you will be quite happy with it. Be prepared to use a solid mount/tripod with it - I can tell you that my Meade LXD75D is ok for visual (not perfect but usable, with 2-3 seconds of vibrations) but I wouldn't use it for astroimaging. Something like Orion Atlas-class or better - there are many choices these days, Sky-Watcher, iOptron and Celestron, for example, sell some good ones but be ready to spend quite a bit more than you did for your AR152! - would be required for taking decent pictures/images. As far as focuser is concerned, it is pretty good for a stock 2-speed 2" one. I don't like the supplied finder and I use strictly laser (as well as the Go-To mount). The handle is very useful and a smart move by ES to supply it with the scope. But, above all, be aware of its weight! It is on the heavy side. It is kind of bulky too with a significant arm movement when it slews across the sky mounted some 4-5' high. I have a 6" reflector OTA which is more than twice lighter and I'd say for 1/3 shorter and, needless to say, it doesn't necessarily requires as capable mount. Is it worth for you for that much money? No one can answer that question but you. It was definitively worth what I paid for it and the next big refractor will be at least an ED doublet. That would be also the way to go for imaging though one can image even better with smaller but top quality triplet APOs combined with top mounts. (Posted on 1/4/2019)
Review by:
Bought this scope within the last month. Optics were well made and collimated. Fit and finish is excellent. The focuser is extremely smooth and well made. The finder scope is fair and does the job. The cradle is heavy duty as it should be. This scope is a "beast," and weighs in at 23 lbs. by itself. With dslr and other equipment you are at 25-26 lbs. I mounted it on a twilight 2 AZM. mount and it held it for a temporary evening out. This is a little to large of an instrument for a permanent mounting. I ended up ordering a Bresser heavy duty equatorial mount for it. It's not a, easy grab and go portable instrument, but it's views of deep sky is razor sharp and impressive. I like many other reviews, were impressed by the optics considering this was an acro. and at a price point most could reach. Some quick deep sky photography yielded decent results as long as your targeting deep sky. Yes, there is CA around the moon, but I didn't purchase this particular scope for that type of photography. The non retracting dew shield doesn't bother me at all. It kept the dew off and optics clear as a bell one night. All in all, get one if you have wanted a 6 inch refractor. It's worth the money and has some photographic deep sky capabilities. Clear skies everyone........ (Posted on 12/29/2018)
Review by:
The ES AR152 was my choice for a first time refractor. I've done many spec and hands on evals to get to this point. My first impression was "very good fit and finish". This was a referb but appeared brand new. 14 inch Vixen dove tail is very helpful. Along with this and the large range of adjustment with the tube rings, balancing the awkward length/mass of the scope is no problem. I have mine on a LX90 mount for a Meade 12 " SCT. The DIY cradle I have is fitted with a vixen saddle so the long adjustment is critical for such a setup. The non adjustable dew shield is a negative but OK. The mount location of the spotter scope makes it practically unusable (too close to main diag/EP). I will add diagonal or laser. The focuser is very nice compared to almost any SCT setup I have had. It is buttery smooth both coarse and fine adjustment. The two screw tensioner underneath for compensating weight such as camera or heavy EP is adequate but not perfect. The weight/length of the instrument is at the tipping point for me as far as usability. I would not want to handle anything larger than the 6 inch. The performance of the optics meets my expectations for a refractor. the open clusters I have viewed are pleasing to the eye and the strength of the instrument. I will use it for clusters, doubles, brighter galaxies and some nebulae. I've done a shootout with 6 large refractors including a Meade 7 inch and a Celestron 6 inch- high to low quality). My observations from that experience would be that the AR152 performs very well in direct comparison to those scopes (all but the Celsetron 6 were APOs). I'm very pleased with my first refractor. It's a great value! Thx. WEK. (Posted on 12/26/2018)
Review by:
Purchased this on sale here in 2015 and enjoyed it enormously till I moved overseas and had no way to effectively bring it with me. I miss having it! Always a big hit at outreach events for the Austin Astronomical Society. Why? The uninitiated look at it and this is exactly what they expect a telescope to look like. The test report I got with this after registering showed it to be above average. Stunning low-power views of the sword handle in Perseus with the ES 40mm 82-degree eyepiece. It pushed a Celestron AVX to the limit, but was fine as long as it was calm with no wind. Like other comments, the whole package is an unbelievable value with rings, finderscope and the shipping box did just fine toting this about. The usual, bearable, shortcomings of a fast achromat. I tried to remediate chromatic aberration (violet fringing) with various filters, then just accepted it for what it is. You get 80% plus of a triplet APO for 10-20% of the price. Had it up at TSP and a proud owner of an Astro-Physics 6" marvelled at what this inexpensive instrument delivers.
(Posted on 10/16/2018)
Review by:
I bought this scope three months ago and use it for solar work. I am very satisfied with it, you can easily image granulation and sunspots at high resolution. (Posted on 10/8/2018)
Review by:
This is my second Explore Scientific telescope. I bought this couple of years back and purchased the 4" scope this last winter, for a more portable telescope. These are finely crafted telescopes and a real joy to handle. I felt like a kid again when I first opened the shipment box and was surprised by the beauty and clean looks. But, most important the optics are excellent. These are hands down the best bang for the dollar that you can find. The optics are very clear and with absolutely no distortion. Each detail of the scope is obviously carefully constructed and tested. I'd highly recommend this Scott Helgeson (Posted on 8/4/2017)
Review by:
I am very pleased with my purchase of the Explore Scientific 152mm refractor. This is a big refractor and gathers alot of light. I have had this several months and the optics are excellent. I have observed a number of Deep Space Objects. They were so bright and sharp. The contrast is excellent. Observing the moon and Jupiter and Saturn were all treats. The colors were great and images sharp. The improved longer dew shield makes a big difference in preventing dew on the lense. This Ota comes with an excellent 2" enhanced 99% reflectivity diagonal. This is a high quality diagonal so you wont have to replace it. The focuser is a 2" duel speed Crayford focuser and is smooth and has no problem handling my large 2" eyepieces. I wanted to buy the largest refractor I could afford and I have no regrets I don't even use my smaller refractors anymore. This large refractor is just what the doctor ordered for my aperture fever.
Neilson (Posted on 8/4/2017)
Review by:
I bought this telescope about a year ago as my first scope with the intention of doing mostly astrophotography (AP). It works great for AP when using a monochrome camera and filters (especially narrowband filters). Using a one-shot-color camera the chromatic aberration is obvious, resulting in bloated blue stars, but this is to be expected from an achromat. If you want a larger field of view, I've used the Astro-Physics CCD-T67 reducer (0.67x), and it works very well. The scope is very easy to collimate, and the lens cell also allows for lens centering adjustments. Overall this has been a very enjoyable imaging scope for me. (Posted on 8/4/2017)
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Supplied Accessories

  • Dual tube rings with Vixen-style dovetail and carry handle
  • 8 x 50mm straight-through finderscope
  • 2" dual speed Crayford focuser
  • 2" dielectric star diagonal with 2" and 1.26" brass compression ring eyepiece holders
  • Removable dew shield
  • Dust covers