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Old 23-09-2020, 08:54 AM
kosborn (Kevin)
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kosborn is offline
Join Date: Mar 2018
Location: Canberra
Posts: 319
I have an Esprit 100 and bought the Starizona Apex ED 0.65x about 6 months ago. It's a great combination, giving roughly 357mm focal length and f/3.57. I ordered it direct from Starizona (and I previously ordered their autofocuser for the Esprit). Good service and quick delivery on both items. The reducer gives a very nice flat field across the entire sensor of my ASI1600mm and I understand gives the same flat field with larger sensors. It's as good as having a second wide field fast refractor. Having said that, I do have an ASI2600 on order currently...

Here is an example (ignore the poor processing mostly due to using old dark frames). There is some distortion of stars lower corners but the same appears without the reducer and also appears with my Newtonian so I assume it's due to sensor tilt within the camera. I also used it for a couple of mosaics of the Rho Ophiuchi region and the Vela supernova remnant.

Last edited by kosborn; 23-09-2020 at 11:26 AM.
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