Post by arnaud on May 1, 2021 3:05:53 GMT -5
Hi, My name is Arnaud van Kranenburg
I live in the Netherlands under a Bortle 9 sky, so mainly my interest in astronomy was to image the planets, Moon Sun and the occasion comet.
I have recently gotten into narrowband imaging and was suprised at the quality of images I could obtain. I'm currently using a 60CB takahashi telescope. If I want to upgrade to a bigger aperture I have to choice to spent my money on a limited aperture expensive APO, visually well corrected, or an expensive high aperture telescope, with a higher resolution, but limited spectral correction.
Since I'm into narrowband imaging by necessity, I prefer the latter. Istar seems the best choice for a modern large achromate telescope, so here I am. The new perseus telescope looks very promising. The idea of doing deepsky imaging through a 8 or 9 inch achromat is tempting, so I want to keep informed.
There are some things I'm interested in and I hope to get some answers reading the posts on the forum, or perhaps someone could reply to this thread.
- most modern telescopes are completely focused on the visual part of the spectrum. Mirrors are coated with AR coatings that exchange a few percent in reflectivity for an almost complete blocking of the IR and UV. For me, an achromate is interesting because, once you accept the limitation in spectral range, you can use it freely on every wavelenghth from UV to IR, with acceptable results. For example, is imaging Venus in the UV possible with Istar achromates? What kind of sharpness can I expect? What are the characteristics of the lens coating? Our camera's are capable of imaging from UV (350 nm) to IR (1200 nm), giving us a range of possibilties!
- are there flatteners available for the achromats of Istar?
Thank you for reading this and I'm very interested in the future development of the perseus type telescopes!
Regards,
Arnaud
I live in the Netherlands under a Bortle 9 sky, so mainly my interest in astronomy was to image the planets, Moon Sun and the occasion comet.
I have recently gotten into narrowband imaging and was suprised at the quality of images I could obtain. I'm currently using a 60CB takahashi telescope. If I want to upgrade to a bigger aperture I have to choice to spent my money on a limited aperture expensive APO, visually well corrected, or an expensive high aperture telescope, with a higher resolution, but limited spectral correction.
Since I'm into narrowband imaging by necessity, I prefer the latter. Istar seems the best choice for a modern large achromate telescope, so here I am. The new perseus telescope looks very promising. The idea of doing deepsky imaging through a 8 or 9 inch achromat is tempting, so I want to keep informed.
There are some things I'm interested in and I hope to get some answers reading the posts on the forum, or perhaps someone could reply to this thread.
- most modern telescopes are completely focused on the visual part of the spectrum. Mirrors are coated with AR coatings that exchange a few percent in reflectivity for an almost complete blocking of the IR and UV. For me, an achromate is interesting because, once you accept the limitation in spectral range, you can use it freely on every wavelenghth from UV to IR, with acceptable results. For example, is imaging Venus in the UV possible with Istar achromates? What kind of sharpness can I expect? What are the characteristics of the lens coating? Our camera's are capable of imaging from UV (350 nm) to IR (1200 nm), giving us a range of possibilties!
- are there flatteners available for the achromats of Istar?
Thank you for reading this and I'm very interested in the future development of the perseus type telescopes!
Regards,
Arnaud