Improving the periodic error and guiding ability of a Losmandy GM8 mount
Why bothering about improving Losmandy's GM8 mount Fig. 1: Losmandy GM8 guide star drift while auto-guiding. Overall the mount produces round star images and guiding works. However, the guide star drifts are relatively large (compared to seeing). As mentioned ...
Using an MGEN v2 Autoguider on a Losmandy mount with 492 Digital Drive System
Why I bought a Losmandy GM8 mount Figure 1: Analysis of guide star positions when using the MGEN autoguider on a Skywatcher EQ5 Pro mount. The green circles indicate the offsets in arcsec of the guide star in RA, while blue diamonds show the offsets in DEC. The ...
Nikon D90 astromod VS. Nikon DF unmodified
It is fact that Nikon's DF is among the most sensitive camera's available on the market today. Its FX format CMOS chip offers 16.2 million pixels. The corresponding pixel size of 7.3μm is thus large compared to most other state-of-the-art cameras (with typical sizes of ...
Testing Nikon TC-17E II and TC-20E III with Nikkor AF-S 70-200 1:2.8 ED VR and Nikkor 200-400 1:4 ED VR
For more than one year I am now carrying Nikon's 2x teleconverter TC-20E III in my camera bag. I bought it from a local store in good used condition, with intent to get more reach with my Nikon D300 (which is APS-C sized) and the Nikon AF-S 70-200mm f/2.8 VR lens. Since ...
Nikkor Lens Comparison for Astrophotography AF 80-200 f2.8 ED vs. AF-S VR 70-200 f2.8 ED
I bought two used Nikon lenses, both very similar in their specifications, which is not surprising as the Nikkor AF 80-200 f2.8 ED is a precursor of the Nikkor AF-S VR 70-200 f2.8 ED (see Ken Rockwell's history page). With the highest bid, I got the 80-200mm for 280 EUR + ...
Measuring Linearity, Readout Noise and Gain of a ATIK383L+ CCD camera
Today I did some tests with my 2-year old ATIK383L+ CCD camera. I am using the camera regularly and you can find some results at my astrophotography page. The camera uses the well-known KAF-8300 17.6mmx13.52m CCD chip with a resolution of 3362x2504 pixels and a pixel size ...