Modified Newtonian, Dream Hypergraph Telescope

This page last updated July 23rd, 2026.

gen V 16" f3.5 Dream Hypergraph

fully corrected & optimized (no vignetting) for a 55mm focal plane diameter and small pixels

This paper compares the installed performance efficiency of one original gen I 16" f3.75 Dream Astrograph telescope compared to four 18" f2.8 prime focus telescopes. The new gen V Dream Hypergraph will be substantially higher in quality and installed performance compared to the gen I.

Dream will no longer offer different options in this aperture, so we can focus on the new gen V 16" f3.5 Dream Hypergraph.

The only athermal instruments in the world that use such a high percentage of carbon fiber supporting structures (95% of the telescope weight without optics). These cutting edge low-mass, high stiffness athermal structures are mated with Dream's highly engineered, thin-featured lightweight zeroDELTA™ mirrors, which have no print through. The entire system is optimized from the ground up for remote/robotic use and the highest installed performance, eliminating countless areas of performance loss. Dream's technologies have unrivaled consistent, long-term installed performance and the lowest possible maintenance.

IMX461 CMOS: 3.76µm pixels, 11656 x 8742, 55mm image circle.

Field Of View (f3.5): 79.3' x 105.6' (2.326 deg²)

Arc-seconds/pixel: 0.54

OTA diameter - OD
length
focal length

CFSC™ HybridTube™: 20.0"
~60"
1422mm - f3.5

lightweight secondary mirror
weight - pounds
single unit pricing

6" (36.5% central obscuration)
~65-70
contact Dream

100% illumination of 55mm image circle. No vignetting from secondary mirror or the corrector.
this weight includes focus, the new large corrector and FAST.
clamshell rings are not required for mounting, only a dovetail plate

The new gen V 16" f3.5 Dream Hypergraph has unrivaled optical design performance. Dream spent three years refining this optical design to be at the leading edge. Because the performance can't be improved upon, it will allow Dream to focus on this model long into the future. To learn more about understanding a spot diagram, please read Shane's published article from the January, 2024 issue of Laser Focus World.

The gen V system has the same 82mm of back focus as our original 16" f3.75 Dream Astrograph.

The gen V uses the same telescope tube, the same spider assembly, the same secondary mirror support and the same thin-featured lightweight zeroDELTA™ secondary mirror as the original 16" f3.75 Dream Astrograph.

There is no vignetting from either the corrector or the secondary mirror on this telescope, even when using a IMX461 detector (55mm diameter focal plane). The gen V telescope has less vignetting than the original, slower telescope because the gen V corrector is shorter.

May 12th, 2026: The first batch of corrective lenses (the finished and coated lenses themselves) are now finished. The largest diameter corrective lens is shown to the left and right. As of July 20th, 2026 the titanium housing has been started at the machine shop.

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Dream continues to work on the main structures (see photos further down on this page), including the most complex and precise portion of the puzzle: additional lightweight primary mirrors, finished using our 4D Technology PhaseCam 6010 dynamic interferometer. This is the same technology used to test the James Webb Space Telescope mirrors.

June 1st, 2026: Martin received the first few PCB boards he designed for the new Dream controller. He's wired up one of the precision linear actuators and its dedicated absolute encoder, as shown left.

June 4th, 2026: Martin tested the new control board with one of the precision linear actuators. He tested all three actuator ports on the board, verifying they all work properly. Martin previously tested one of the actuators, receiving data from the encoder at a rate of ~14K/sec, which will never be needed for our purposes.

Dream receives the 30 precision linear actuators on July 3rd, 2026.

The PCB controller board will control each actuator and receive data from each absolute encoder. This system will be ASCOM/ ALPACA-compliant so the user can control focus on the gen IV (2 units) and gen V (future units) telescopes. The board also provides power for the fans on the back of each Dream telescope.

July 6th, 2026 - Martin received the other two actuators recently. He now has all three actuators wired in and has tested them with the control board. Everything is working well.

Each precision linear actuator has an absolute encoder and a small battery backup. If both power and the firmware fail, position data for each actuator will be maintained.

The ASCOM driver has been completed and the basic ALPACA driver is operational as well. He's now working on the calibration table for each actuator and finishing the simplified final user configuration tool that will allow users to adjust tip/tilt of the primary mirror.

A detailed document about this gen V optical design/instrument can be viewed here.

Click here to watch a video showing the scale of Dream's in-house figuring work to the first zeroDELTA™ lightweight primary mirror for this gen V telescope.

The first graphic below left is PhaseCam data detailed in this video on Dream's YouTube channel. That u28 lightweight mirror was the first primary mirror finished for the gen V telescope. The Dream 16" zeroDELTA™ primary mirror is the only thin-featured, highly engineered, truly lightweight mirror with no print through on the market. It's 5-6 times lower in aerial density than the Hubble Space Telescope's lightweight primary mirror. No feature, including the face, is thicker than 3.2mm, on either the primary mirror or secondary mirror. The highly engineered zeroDELTA™ lightweight mirrors equalize faster than any other mirrors on the open market, which is one of many features that give Dream's telescopes their unbeatable installed performance.

The radius, and therefore the focal length, of a given primary mirror is less critical for a generic coma corrector used with a paraboloidal primary mirror. However, primary mirrors that vary by more than +/-0.125% in radius lead mass-market telescope companies to build large adjustments into their sub assemblies. This large adjustability of structures accounts for mass-market opticians' inability to hit a radius tolerance. This usually means the mirror mount structures are cantilevered and bend more than if the mirrors all came in within a tighter tolerance, eliminating the need for sub assemblies to move large amounts.

Now that Dream has taken over all work to our lightweight primary mirrors, we can finish the focal length to even tighter tolerances than we were promised by outside opticians. Outside opticians could never deliver on their promises and were often off by 0.8% or more. Back then it forced Dream to customize each and every telescope, one at a time, since our goal is high stiffness, to provide high installed performance and repeatability.

With our 2026 finishing developments we're able to achieve extremely tight control over the focal length of these hyperboloidal primary mirrors. This is a must when using this more optimized (hyper) optical design, since it requires the mirror to be more narrowly defined, as opposed to paraboloids. Details like this matter because cutting corners in a half a dozen places, to maintain a delivery-date-priority business, will produce soft installed performance. There are no free lunches in optics...

Each data set below is made from ~1.45 million data points quantifying the optical surface, tested in Dream's 5m vertical test tower, while on a carbon fiber athermal mirror mount.

gen V: 1st

finished end of November, 2025.

Radius: too long by 0.24% initially, but reworked to be long by 0.002%.

gen V: 2nd

finished March 3rd, 2026.

Radius: short by 0.0065%.

gen V: 3rd

finished March 29th, 2026.

Radius: short by 0.08%.

gen V: 4th

"U33" (unit 33) came out of casting furnace March 31st, 2026. It's now been cleaned out (upper left photo), the back plano ground, face and back flange OD's edged and the optical face fully ground to the correct face thickness and radius. It finished polishing and is halfway through figuring as of April 19th, 2026.

U33 finished figuring April 24th, 2026 with a Strehl of 0.959 over the entire 418.5mm optical surface. Over 406.4mm the Strehl is 0.967.

Radius: long by 0.018%.

gen V: 5th

Unit 34 came out of the casting furnace April 18th, 2026. It was cleaned out fully, then the back was plano ground and edging started April 24th, 2026.

May 7th, 2026 u34 has gone through all work prior to polishing and (at the end of grinding) is at the desired radius.

U34 finished figuring May 24th, 2026 with a Strehl of 0.965 over the entire 418mm optical surface. Over 406.4mm the Strehl is 0.976.

Radius: long by 0.05%.

gen V: 6th

Unit 35 finished casting and is shown to the left during early cleanout on May 7th, 2026.

Unit 35 finished the last stages of fine grinding May 25th, 2026. It started polishing on the May 26th and was finished with figuring on June 3rd, 2026. The Strehl is 0.936 over the full 418mm optical surface (shown to the left), while over 406.4mm the Strehl is 0.979.

Radius: short by 0.002%.

gen V: 7th

Unit 36 mirror mold is finished and will go in the furnace when the furnace is good and ready.

gen IV: 1 of 2

There will never be a gen III telescope because we're skipping generations to move to more known/quantified (not "qualified") optical surfaces. Only two gen IV's will be made. The lightweight primary mirrors are paraboloidal instead of the gen V's hyperboloidal, but these two gen IV primary mirrors were also finished inside Dream. The gen IV's will use the original 4" coma corrector, but will use the new actuator-based focus system of the Gen V's.

Radius: short by 0.0375%.

gen IV: 2 of 2

Both u29 and u30 data sets are showing the full (~418mm) optical surface. Both of these data sets have just over 1.5 million data points over the optical surface.

Radius: long by 0.04%.

Below are 10 units of the Dream zeroDELTA™ lightweight secondary mirror used for this telescope. We currently have less than 10 orders for this telescope design, but can cast more of this mirror in the future. All 10 of the below mirrors were here when Richard & Lew visited.

Four 6" freshly coated lighweight secondary mirrors came back from the coaters May 21st, 2026 (shown as four lower row uncoated in far left photo, then coated in the below photo). The five ground secondary mirrors (top row of far left photo) are at the finishers. Some are finished as of July 3rd, 2026, but others still need more work to meet spec.

July 6th, 2026 - To the left are 10 secondary mirror mount assemblies with integrated tube hub that sits inside the spider hub. These 100% carbon fiber assemblies have always been designed and made inside Dream and hold our 6" zeroDELTA™ lightweight secondary mirrors. These athermal assemblies hold the mirror without distorting as temperature changes and offer extremely high stiffness. These characteristics are a key part of Dream's market-leading all-sky installed performance. We currently have orders for 8 telescopes, so two of these sets are for future orders.

photo taken April 9th, 2026

The photo to the left (taken April 9th, 2026) shows 5 new Dream HybridTube™ structures, with a 6th existing tube in the foreground. Dream's unique tube has always used 1" thick honeycomb, for maximum stiffness, needed for this type of telescope design.

Below vintage photo illustrates the high stiffness of this tube, with two of us (~360 pounds) sitting on one tube with only the outer, bottom ends supported: 3-point bend "test."

vintage photo

On Friday, September 16th, 2022 the Royal Observatory Greenwich announced their astrophotography winners. The mosaic image to the right is the Galaxy category winner, taken with a gen II 16" f3.75 Dream Astrograph.

The main reason this image won the award was because the gen II Dream telescope captured the faint remnants of a previous galactic collision that Sombrero had in its past.

9.58 hours; 275min L, 100min each RGB.

"Hello Shane, I can't think of anyone who has delved as deeply into the mechanics of telescopes as you."

- Dream customer

"I went to bed at about 10PM and I let it run all night without focusing. I blinked through the images and focus did not change. Also, I did all of my other images by letting it run through the night without focusing."

- Dream Astrograph owner

Sombrero galaxy taken with a gen II 16" f3.75 Dream Astrograph by Utkarsh Mishra, Michael Petrasko & Muir Evenden.

Click on the photo to the left to see why this telescope does not need clamshell/mounting rings. A direct connection to the mount is superior because there is less flexure and it gets the CoG of the telescope closer to the mount - shorter lever arm means less bending and higher combined system performance.

The three links below show completely raw, unprocessed individual test images taken all-sky, without touching focus or collimation, with three different gen II 16" f3.75 Dream Astrograph telescopes while still here at Dream, using a luminance filter (400-700nm bandpass).

example 1

example 2

example 3

Click here to see processed images taken with a gen II 16" f3.75 Dream Astrograph.

"Within a temperature range of 10°C we see no measurable change in focus. Also, there was no change in focus as a function of telescope position."

- Michael Schwartz, Tenagra Observatories, 16" f3.75 Dream Astrograph owner.

M81/M82 image shows the efficiency and quality of the original gen II 16" f3.75 Dream Astrograph telescope. Image was taken in less than one full night, with a front-illuminated CCD detector.

16803 CCD detector: 9µm pixels, 4096 x 4096, 52mm image circle.

Field Of View: 83.0' x 83.0' (1.9 deg²)

Arc-seconds/pixel: 1.22

Dream's instruments are work horses that operate at the highest level; today, tomorrow and ten years from now.

One of Dream's gen II 16" f3.75 instruments (using old 16801 detector) was one of seven groups in a NASA NEO search & recovery project and found more objects than all other groups. At least one other group member was using a 1m telescope, showing the extreme power, throughput & reliability of Dream's philosophy of fully dealing with the traditional issues of low stiffness & mirror seeing.

The history of this telescope model -

gen 0

gen I		Abandoned years of work on the gen 0 open truss because even with a black shroud the light leaks were horrible. A HybridTube™ profile mold was created and we switched to a sandwich core carbon fiber tube using 1" thick honeycomb. This allowed us to develop other complimentary technologies around the tube.

gen II		Focuser platform open ribs instead of closed, small Dream logo on telescope and switched to lightweight mirrors for both mirrors in the telescope. Last model that used a 3" coma corrector.

gen II		Switch to larger 4" coma corrector, slightly larger logo and stripes added, but otherwise still lightweight mirrors finished by outside vendors.

gen II		Larger Dream logo, continuous red stripe but otherwise similar to above. Still used outside optician finished mirrors.

gen II	custom for US Air Force	No logos, etc., because of what these are used for.

Click either photo (left or right) to watch a video about the interferometry technology developed for JWST and funded by NASA. Dream uses this technology to finish its world-class lightweight mirrors in house.

Click here to see images taken with a 16" Dream Astrograph during test out at Dream around 2010, then over 10 years later.

pricing, availability and specifications subject to change without notice

space domain awareness (SDA), space Situational Awareness (SSA), Ball Aerospace, Lockheed martin, Boeing space, Airbus defence & space, planewave instruments, NASA JPL, NASA goddard, lightweight telescope, lightweight precision optics, lightweight precision mirrors