Teleskop-Service is very quick, 24H chrono!
I received yesterday afternoon and undertake some verifications, the period being clear at the sky.
First: verification of the alignment and the collimation with the GMK collimator.
The net patch of the 4 light spots were at final well at the center of the FOV, the images of the 3 images of the 4 spots well collimated: no need for additional adjustment on the sky.
The focuser is only decent and need to be replaced by a better one with amplification to be more acurate on the focus point. Anyway it does the job.
The OTA was received without a finder, a dovetail plate for mounting, a diagonal mirror (the OTA is designed for receiving a 2" diagonal).
The focuser tube is very long sothat this may diaphragm the aperture, I have to verify that.
I could use it on venus in order to apraise the contrast level of the banding patern appearing.
Hereafetr is a report of venus performed last 18th of march with the new 102mm refractor F10.Conspicuous features at the eyepiece with 111x were met, reduced by the seeing.Very more one hour later when the seeing level was at his best, 7/10, anyway this was not modifying the collected data.
AL was not there, bright spot as well.Polar caps were observed with all filters, banding pattern also.
At the focus point the blue halo is not there, commencing to appear with a 7.7mm ortho eyepiece.
The filter use cancelled this color residue.
I was disapointed of the overall results with a blue RG435 filter where the halo was conspiscious (that was not so proheminent in the meade 90F1000 OTA). Anyway the banding pattern appeared as shown.
This mean the lens aspherisation on that deep blue segment is not a significant help.
This mean also, to be verified the thickness spacers betweeen lenses of the doublet are not optimised in this view.
The yellow-green and deep red segments gave perfect results. The edge of the planet moving with the seeing kept sharp ondulations without filter and with the W11 filter, not blured. A good sign.
On the dark sky, the observation of stars m2.0 to M4.0 confirmed the very good collimation with 250x (ortho 4mm kasai).
The 1st diffraction ring was observed circular without light condensations, the airy disk was well clear and circular.
The ronchi exhibited almost straight bars (less than 1/8 curvation).
Intra extra focus images exhibited spikes of moderate amplitudes suggesting some rough lens surfaces, evaluated to be L/20 +/- rms, rather average.
In fact this is here the limiting point that lower the contrast levels. A pitty.
With a 20mm plosl eyepieve, FOV 1°, pinpoint stars were nored on all the FOV.
This must be also evaluated on jupiter, mars, saturn, mercury for a clear completion.
For 320€ this is not a bad figure, but smoother optical surfaces would be welcome for improvement, spacing the lenses as well.
Globally for a comparison, a 102F10 vixen or an istar 100F12 are making similar performance (but little better) on the yellow-green and red color segments, but perform superiorly on the deep plus segment.
Even my 150F6.6 refractor with aspherised lens performs better on the blue segment, but is more sensitive to seeing.
To be followed.
Thanks for reading.