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The world's sharpest 250mm telephoto lens ever made for full frame cameras, at Apochromatic specification with Strehl Ratio >0.97+.
The world's sharpest 250mm telephoto lens ever made for full frame cameras, at Apochromatic specification with Strehl Ratio >0.97+.
129 backers pledged $79,978 to help bring this project to life.

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Ultra Versatile Telephoto Lens, Redcat 250mm f/4.9

$79,978

129

© James Y Taipei, Taiwan > Click here for Original <  Shot with REDcat 51
© James Y Taipei, Taiwan > Click here for Original < Shot with REDcat 51

Click here to download this test footage lRAW shot with GH5 HLG, 10 bit, 4:2:2

Please download the file then try some color correction by stretching from LOG Gamma into linear picture.

 From the beginning, the goal was to create the best possible design for an affordable, small, lightweight, and fast Apochromatic refractor for astrophotography needs. The unique optical design includes the highest quality glass for the best possible color correction and flat-field.  The result is a 51mm objective lens, in a sleek Petzval design, for a full frame flat field image.  The optical quality provides for exceptional performance at a fast focal ratio of F/4.9.

51mm objective lens, in a sleek Petzval design, using Synthetic Flouride ( FPL53 and FPL51 ) glass for a full frame flat field image.  The optical quality provides for exceptional performance at a fast focal ratio of F/4.9.

A7RIII + NINJA V + REDCAT 51 f/4.9
A7RIII + NINJA V + REDCAT 51 f/4.9
Plumbeous water redstart with Redcat 51
Plumbeous water redstart with Redcat 51
©Redcat 51 Witch Head Nebula courtesy of Mehmet Ergün from Germany
©Redcat 51 Witch Head Nebula courtesy of Mehmet Ergün from Germany

The only lens that has the most interchangeable camera mount compatibilities, with future proof full frame design. Customers are only allowed to pick one camera mount in the Kickstarter's survey at the end of the funding day. All mounts will be available to purchase at William Optics website after release.

Removable Reversible CAT Sunshade
Removable Reversible CAT Sunshade
All metal construction, 0 Plastic Part
All metal construction, 0 Plastic Part
Add-on Long Plate, available at William Optics website.
Add-on Long Plate, available at William Optics website.
Lumix GH5 + Redcat 51
Lumix GH5 + Redcat 51
Sony A7III with smallRig, Atomos NINJA V Recording Monitor
Sony A7III with smallRig, Atomos NINJA V Recording Monitor
© Bearizona, USA - Redcat 51
© Bearizona, USA - Redcat 51
Erecting Prism + EYEPIECE funding GOAL!
Erecting Prism + EYEPIECE funding GOAL!

Erecting Prism is UNLOCKED retail $125!

Add $99 on top of your pledge amount to get a Erecting Prism.

 HOW TO CHANGE PLEDGE AMOUNT?

EYEPIECE is Unlocked Retail price $129!

Add $99 on top of your pledge amount to get a Cat Eye 25x.

REDCAT 51 250mm F/4.9 MTF
REDCAT 51 250mm F/4.9 MTF



© Syntrend, Taipei > Click to view Original
© Syntrend, Taipei > Click to view Original
© William, Taiwan > Click to View Original Photo
© William, Taiwan > Click to View Original Photo
© Rick, Taiwan > Click to View Original Photo
© Rick, Taiwan > Click to View Original Photo
© Renai Township, Taiwan > Click to View Original Photo
© Renai Township, Taiwan > Click to View Original Photo
© Starry House, Taiwan > Click to View Original Photo
© Starry House, Taiwan > Click to View Original Photo
© Hehuan Mountain, Taiwan > Click for Original <
© Hehuan Mountain, Taiwan > Click for Original <
© 杉林溪, Taiwan > Click for Original Photo < A7RIII
© 杉林溪, Taiwan > Click for Original Photo < A7RIII
© Pygmy Owl, Redcat 51
© Pygmy Owl, Redcat 51
A7R3 Continuous Shot REDCAT 51
A7R3 Continuous Shot REDCAT 51
Courtesy of Wang, Wei Hao > Click for original photo <
Courtesy of Wang, Wei Hao > Click for original photo <

Shot on Nikon D800 provided by Dr. Wang Wei Hao :

> RAW Photo for editing test/ optical test <

Courtesy of Wang, Wei Hao
Courtesy of Wang, Wei Hao
Courtesy of Wang, Wei Hao
Courtesy of Wang, Wei Hao
© Hehuan Mountain, Taiwan > Click for Original Photo <  Rosette Nebula Hubble Palette with ASI 1600
© Hehuan Mountain, Taiwan > Click for Original Photo < Rosette Nebula Hubble Palette with ASI 1600

 Must have Astronomy Filters

Astro Duo Narrowband (Example shot with Redcat 51 by Jack Tsai)
Astro Duo Narrowband (Example shot with Redcat 51 by Jack Tsai)
D850A H alpha
D850A H alpha
© Taiwan > Click for Original Photo < REDCAT 51
© Taiwan > Click for Original Photo < REDCAT 51
© 杉林溪, Taiwan > Click for Original Photo < REDCAT 51
© 杉林溪, Taiwan > Click for Original Photo < REDCAT 51

The Company - William Optics - Telescope Company for 21 years

Story of William Yang 

William Optics is the best refractor telescope, lens and wildlife sporting scope manufacture from Taipei, Taiwan; perfecting all kinds of refractor from binocular to a super large telescope for 21 years. William Optics was formed by the team of experienced astrophotographers, lens designer and an external art designer - William Yang himself. To create the best possible lens for the strict specification astrophotographers needs the Redcat is borned. As an appreciation of your support, we will ensure every REDCAT's optical quality is superb before sending out to all of our supporters on this project.

WO Quality

Warranty

The REDCAT 51 offer 2 year warranty, and lifetime service.

Estimated Delivery

Each reward levels may have a different estimated delivery date. We will provide updates if the estimated delivery date changes.

International Shipping Disclaimer

We currently ship the lens worldwide free of charge for kickstarter backers by UPS carrier.

Risks and challenges

No project is without risk nor challenges; however, William Optics is determined to minimize them. We have done all the necessary preliminary work, and production run before coming to Kickstarter. We are an experienced team in this industry for over 21 years. We already started the manufacturing run early, and quality control to ensure our Kickstarter backer can receive their Lens earlier after the funding goal is reached.

Learn about accountability on Kickstarter

Questions about this project? Check out the FAQ

Support

  1. Reward no longer available

    Pledge $498 or more About $498

    1 x Redcat 250mm f/4.9 Package

    Get Redcat Package at the 71% of the retail price.

    Includes:
    • Redcat 51 f/4.9
    • Soft Carry Case
    • (Nikon F/Canon EF/ Sony E) Mount
    • Patented Bahtinov Mask
    Less
    Estimated delivery
    Ships to Anywhere in the world
    Reward no longer available 5 backers
    $
    Kickstarter is not a store.

    It's a way to bring creative projects to life.

    Learn more about accountability.
  2. Reward no longer available

    Pledge $598 or more About $598

    Redcat 51 Package (EARLY CAT)

    Get Redcat Package at the 83% of the retail price.

    Includes:
    • Redcat 51 f/4.9
    • Soft Carry Case
    • (Nikon F/Canon EF/ Sony E) Mount
    • Patented Bahtinov Mask
    Less
    Estimated delivery
    Ships to Anywhere in the world
    Reward no longer available 20 backers
    $
    Kickstarter is not a store.

    It's a way to bring creative projects to life.

    Learn more about accountability.
  3. Reward no longer available

    Pledge $609 or more About $609

    Redcat 51 Package (Limited Time)

    Get a Redcat Package at $609 for a limited time only.

    Includes:
    • Redcat 51 f/4.9
    • Soft Carry Case
    • (Nikon F/Canon EF/ Sony E) Mount
    • Patented Bahtinov Mask
    Less
    Estimated delivery
    Ships to Anywhere in the world
    Reward no longer available 8 backers
    $
    Kickstarter is not a store.

    It's a way to bring creative projects to life.

    Learn more about accountability.
  4. Reward no longer available

    Pledge $628 or more About $628

    Redcat 51 Package (Garfield CAT)

    Get Redcat Package at the 90% of the retail price.

    Includes:
    • Redcat 51 f/4.9
    • Soft Carry Case
    • (Nikon F/Canon EF/ Sony E) Mount
    • Patented Bahtinov Mask
    Less
    Estimated delivery
    Ships to Anywhere in the world
    Reward no longer available 30 backers
    $
    Kickstarter is not a store.

    It's a way to bring creative projects to life.

    Learn more about accountability.
  5. Select this reward

    Pledge $648 or more About $648

    Redcat 51 Package (Kickstarter Special)

    Get Redcat Package at the 93% of the retail price.

    Includes:
    • Redcat 51 f/4.9
    • Soft Carry Case
    • (Nikon F/Canon EF/ Sony E) Mount
    • Patented Bahtinov Mask
    Less
    Estimated delivery
    Ships to Anywhere in the world
    61 backers
    $
    Kickstarter is not a store.

    It's a way to bring creative projects to life.

    Learn more about accountability.

Funding period

- (30 days)