The SkyWatcher has recently launched a new tool, dubbed as Black Diamond. In this new series Black Diamond can be found by the refractor 80 mm to 120 mm apochromatic all, the Maksutov 150 and 180 mm, the Newton 200, 250 and 300 mm and 190 mm Mak-Newton.
I already had the opportunity to try the Mak-Newton 190 and I found it to be optically excellent, now I have recently purchased the 250-newton mm. The Black Diamond
Skywatcher 250 is a configuration tool in Newton with a focal length of 1200mm. F.4, 8 dedicated to the observation and the resumption of deep sky objects, but also lends itself well to those planets. Mechanically is very good about finishing high enough, a Crayford focuser by 50.8 mm. with reduction of 31.8 mm. A note on the preparation for the installation of a cooling fan on the breech of the primary mirror. The primary mirror also has a reference collimating optics at the heart of it, very useful for collimating or quickly check the state of centering in any case is perfectly collimated and came after several nights of use was perfect, for adjusting the collimation of the primary mention the screws are well made and easy to use. The secondary mirror is supported by a spider with very thin strips and activated by the same three screws.
in support tube is sold with the 9x50 finder, quick-release that allows a very fast thanks to the alignment of the spring adjustment screws and a 28 mm Plossl eyepiece with a field of fifty-eight degrees with graft by 50.8 mm. The rings of support and dovetail bar allow you to quickly mount on frames dedicated.
tube, despite its size you can still call portable with its weight of about 15 kg with all accessories installed, and still suitable for class EQ6 mounts.
I got to try this telescope in several nights so far and with different seeing conditions, always pointing very impressed. The Moon
the large size of the mirror gives a lot of light and thus images are very bright, I am in poor seeing conditions, I managed to get to 320x noticing many details.
Unfortunately this period is only visible in Jupiter, and so my tests are limited to this planet gas giant, but still offers spectacular detail the large diameter of the planet, with images ever recorded and contrasted, mainly due to lower secondary mirror obstruction , approximately 28%.
But where the 250 is comfortable and secure in the deep sky objects, I observed several objects from the M27, The Dumbbell Nebula, noting many fine details, including which the central star to the nebula. M57, The Ring Nebula, looked fine in his classic oval shape with a high contrast. The globular cluster M13 was also amazing, bright stars and rose up in the middle. The observations were all made by a suburban sky, and not in the best conditions for observing the deep sky, and then I dare not imagine the pictures below can give a clear dark sky of the mountains.
For astro photography is certainly a necessary correction of coma, a problem that affects all working newton because of the primary mirror, but I noticed that with this option the SLR or CCD camera can not reach the accurate fire due to excessive height of the focuser, which is well done with very fluid movements, but has no necessary or back focus that allows precise control of the fire. Note that without the use of fire spell you can go well with both a CCD and with the SLR, thanks to the joint photographic kit that replaces the nose and from 50.8 to 31.8 mm and then decreases with the height of the focuser. To work around this problem I am doing to make my friend a nose 50.8 mm low-profile that should allow me to use the correction of coma and give me back focus of about 2 cm.
In conclusion, I can assure you that this 250 Newton is really good and despite the weight and the problem from the focuser (only in photo), surely Highly recommended for those looking for a tube of large diameter, but at prices much lower as long as we have a frame of at least grade EQ6.
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