I have compared my two objectives - the achromatic and the apochromatic lens - both of 80/480mm how they perform. Clearly, the apochromatic lens shows a bad error. It is by far not as sharp as it should be.
On the 3 May 2023 the Moon was much brighter compared to 30 April, lightening up the sky background a lot more.
As we live so far in the North of Germany nights are bright with not reaching astronomical darkness after 10 May until end of July.
All images are unguided so far. Polar alignment I made as good as I could do. As the "Littlefoot" controller does not work anymore, I have to use the old SD-1 controller, which does not have a really good precision.
An image of the M13 cluster with the apochromatic lens. Dark frames subtracted but no flats.
The stars are not really round - but the colours are nice :-)
30 April 2023 - 2033UT - ISO2000 - 42*30s - LUMIX G110 - NH-APO with FPL53 triplett apochromatic lens 80/480mm
An image of the M13 cluster with the achromatic lens. Dark frames subtracted but no flats.
Here the stars are much better - but brighter stars have blue fringes despite the dedicated "fringe-killer" filter.
03 May 2023 - 2050UT - ISO2000 - 81*30s - LUMIX G110 - NH-original with achromatic (less colour corrected) lens 80/480mm
This is a full resolution part of a single image (not stacked) with the misaligned APO.
Stars are elongated in one direction.
NH-APO with FPL53 triplett apochromatic lens 80/480mm
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This is a full resolution part of a single image (not stacked) with the Achromat. Stars are much rounder.
NH-original with achromatic (less colour corrected) lens 80/480mm
This is a full resolution part of the first image above. Stars are elongated in one direction.
NH-APO with FPL53 triplett apochromatic lens 80/480mm
This is a full resolution part of the second image above. Stars are much rounder.
NH-original with achromatic (less colour corrected) lens 80/480mm
Equipment
Optics : NH StellarVue Nighthawk Achromatic Refractor d=80mm f=480mm (f=1/6)
: Intes MK-67 Maksutov Type Reflector d=150mm f=1800mm (f=1/12)
: APM Finder Scope 50/205mm with star diagonal and 24mm eyepiece
: Chinese Guide Scope 50/205 and 24mm eyepiece or guide camera
Camera : NIKON D7000 DSLR unmodified (from 2011)
: Panasonic LUMIX G110 MFT System (from 2021)
: The Imaging Source DMK21AU4.AS monochrome USB highspeed camera
Filter : IR/UV Cut, Astronomik H-Alpha, Astronomik LRGB
add. optics : ED 2x Barlow lens, eyepiece projection
: 35mm, 50mm, 135mm and 200mm NIKON lenses available
: 2.8/60mm Sigma, 12 .. 60mm Leica for MFT system
Mount : VIXEN GP with MT1(RA) & MT1(DEC)
Controller : Littlefoot Controller (selfmade but defective) -> SD1 Controller
Guiding : PHD
Aquisition : DELL Notebook (Windows 10)
Image Processing : ImagesPlus, NeatImage 7, Registax 6, DeepSkyStacker, Gimp
latest list update : May 2023