Description
eShel III Objective lens (Manual focuser)
2 700,00 € incl. VAT - 2 250,00 € excl. VAT
This very specific lens will transform your eShel II into an eShel III
It incorporates a new 122mm focal length optical system, specially designed to improve the focusing of each order and extend the spectral range to between approximately 370 and 910 nm.
You must use a camera with a SONY IMX 571 sensor (we recommend the ASI 2600 MM Pro).
Achieve your goal with the products below:
Recommended acquisition cameras
Recommended cameras: technical specifications
| Description | Shelyak ref. | Included |
Acc. type
|
Cooled
|
Comment
|
| Camera Atik 460EX Mono | SE0124 | Camera Science | yes | The standard CCD camera for the eShel II | |
| Caméra ASI2600MM-Pro | EL0271 | Camera Science | yes | New generation CMOS camera |
All about the product:
Description
This objective is custom-designed for the eShel III and extends the spectral range covered by the instrument
Spectrum of Sunlight
Orders #22 through #61 are uniformly focused.
Spectrum of Chi Oph Be star
This allows us to process orders #25 through #60 and extend the usable spectral range from approximately 370 to 910 nm. 
The manual version of this lens comes with a helical focuser, enabling precise focusing of the spectrum.
Specifications
- 122mm focal length Petzval lens @ f/2.2
- Manual helical focuser
- Requires a SONY IMX571 sensor (we recommend the ZWO ASI 2600 MM Pro)
Composition
- The optical system and its manual focuser
- 2 plastic protective covers
- 3 screws for mounting the optical assembly on the eShel spectrograph
- 1 interface board for an ASI 2600 MM Pro camera
Documents
Articles related to this product:
eShel III: An Improved Version of eShel II
By Olivier Garde The eShel II spectroscope features an 85-mm focal-length camera lens that is no longer manufactured; an alternative had to be found, so Shelyak Instruments designed its own 122-mm focal-length Petzval-type lens. This “custom” design has made it...
Demetra tutorial
You'll find all our Demetra video tutorials on this web page. Demetra is a free software package for processing spectra from the ALPY 600, LISA and eShel spectrographs from the Shelyak Instruments range. Playlist of Demetra tutorials Tutorial #1 Introduction to...
