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DeltaRho 350 Optical Tube Assembly

SKU# 140126Q

Price: $18,500.00


Introducing PlaneWave’s revolutionary Delta Rho 350 f/3 telescope. The Delta Rho 350 is designed for unsurpassed wide field imaging and ease of use in the field. Since the primary mirror is fixed in place collimation is quickly achieved by adjusted the tip and tilt of the secondary mirror. With the Delta Rho 350 your astrophotography experience will be second to none!

  • Corrected Cassegrain focus optical design
  • Aperture – 350 mm
  • Focal length – 1050 mm
  • Focal Ratio – f/3
  • 60mm Image Circle > 3 degrees
  • Fixed Primary Mirror
  • Collimation performed via 3 tip/tilt screws at the secondary mirror
  • Backfocus of 5.651” (143.535 mm) from mounting surface (without focuser and rotator). This distance includes refraction from filters.
  • Backfocus of 2.525″ (64.135 mm) with Series-5 focuser and Series-5 Rotator installed (with focuser at midpoint of travel range).
  • Built in primary and secondary dew heaters with temperature sensors
  • *L-350 mount seen in product photo is sold separately


Capturing the most stunning astrophotographs possible is something our team is passionate about. From design to manufacture, our goal with the DeltaRho 350 was centered around creating a game changing wide field telescope. The DeltaRho 350 is a Cassegrain optical design which means the imaging train is secured at the back of the telescope and does not block the light path compared to prime focus designs, which severely limit users ability to operate with filterwheels, or large cameras.

The DeltaRho 350 is an incredible breakthrough in telescope technology and ease of use. Operating at f/3 and 1050 mm focal length, the DeltaRho is a wide field telescope that is sure to revolutionize your astrophotography!

Additionally, the DeltaRho 350 provides a perfectly flat field so your astrophotographs will have stunning clarity from corner to corner of the image without field curvature degrading the photos. Offering the simplicity of single-mirror collimation, the stray light control of advanced baffles, structural performance created through finite element analysis (FEA), and decades of telescope design experience, the DeltaRho 350 is an exceptional diffraction-limited telescope. DeltaRho 350 users can experience pinpoint stars edge-to-edge and a 170 x 170 arcminute field of view when using large 16803/4040 size camera sensors. This field of view is nearly 3 times as large as our CDK14! When equipment fades into the background and simply performs, the astrophotography experience becomes even more fun and rewarding!



Optical System

Optical DesignCorrected Dall-Kirkham (CDK)
Aperture350 mm
Focal Length1050 mm (41.34 inch)
Focal ratiof/3
Central Obstruction56 % by diameter
Back Focus from Mounting Surface (No focuser/rotator installed)5.651 inch (143.535 mm). This distance includes refraction from filters.
Weight46 lbs (21 kg)
OTA Length23 inch (584 mm)
Optical Performance4.9 micron RMS on-axis, 6.2 micron RMS at 23 mm off-axis, and 7.6 micron RMS at 30 mm off-axis
Telescope CageCarbon fiber truss poles with carbon fiber shroud
Optimal Field of View60mm image circle

Secondary Mirror

Diameter190 mm (7.48 inch)
MaterialFused silica (quartz)
CoatingEnhanced aluminum – 96%

Primary Mirror

Optical Diameter13.78 inches (350mm)
Outer Diameter14.5 inches (468.3mm)
ShapeProlate ellipsoid
MaterialFused silica (quartz)
CoatingEnhanced aluminum – 96%

Lens Group

Diameter110 mm (4.33 inch)
Number of lensesThree
Coatingbroadband AR Coatings (less than .5% reflected from 400 to 700nm)

Standard Features

Corrected CassegrainThe corrected design yields a flat field free from off-axis astigmatism, coma, and field curvature.
Carbon Fiber Truss DesignMinimizes thermal expansion which causes focus shift with changes in temperature.
Dovetail Expansion JointAllows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss
Cooling FansThree cooling fans blow air inside the back of the telescope. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased.
Delta-T ReadyFor added dew prevention, the DR350 is internally wired with polyimide film heater pads and temperature sensor, ready to be controlled with the optional Delta-T controller.


Crated Shipping Weight 225 lbs
Crate Width 31 inches
Crate Height 26 inches
Crate Length 53 inches

Included Items

Included Items

Heating elements for dew preventionThe heating pads on the primary and secondary mirror require the 5-Series Controller sold separately
OTA CoverTo protect the primary mirror and inside of the optical tube
FlashdriveContains software and instructions for collimation and spacing the primary to secondary mirror
Wrench Set (5812A35)Standard hex wrenches (European orders only)




For warranty information please check our Standard Warranty Page.