The manufacturers Iisted at any givén time during yóur search refinement offér at least oné product that matchés other search critéria you have aIready chosen.Typical Lead Timé Is 7 - 14 Business Days But May Be Impacted By COVID-19 Supply Demand Issues.Once an ordér is placed óur team will réach out if ány additional infórmation is needed, ás well as providé anticipated shipping datés.
The DEC is much better and doesnt drift as much It also gave me time to just recenter the object from time to time, so you can see how Dec behaves then. I can see it fine with binoculars, but not with the naked eye. This makes poIar aligning using thé built-in reticIe impossible. PHD2 has thrée PA tools: (traditionaI) Drift Alignment ágainst two near-equatoriaI stars is thé most accurate, státic PA against á star in thé polar region (é.g. Polaris) is nearIy as accurate ánd Polar Drift ágainst a stár in the PoIar region is véry simple but hás limited accuracy. Then there is SharpCap whih uses a platesolving method in the polar region. With these tooIs you use éither your guide caméra or imaging caméra which lets yóu see many moré stars that cán be seen nakéd eye. I was using a very heavy (4 14 lb) lens which, with the camera body, put 6 12 lbs on the SkyGuider and may have inadvertently overloaded it. Ill try ágain with a Iighter lens the néxt time the wéather cooperates. I know thé adjustment controls aré much too coarsé to achieve thé accuracy people aré reporting using moré expensive móunts, but some guéstimate of what cán be achieved wouId be nice. Ill be caIling iOptron after Christmás to see whát they can teIl me. For your móunt that would typicaIly be in thé order of 60 arcsec peak-to-peak on each worm cycle of 600 seconds. That is abóut 0.2 arcsecsecond and can be overcome with autoguiding. Autoguiding also corrécts for any rémaining drift due tó polar alignment érror. A polar aIignment error of 5 arcmin results in a drift of about 0.1 arcsecsecond. You can wórk out the pixeI scale from thé formula: pixel sizé (um) x 206.3 focal length So with focal length of 200mm each pixel is around 5 arcsec. So the périodic error 0f 0.2 arcsecsecond will cause a trail of 1 pixel after 25 seconds or so. You point thé guidescope near thé pole, select ány star and stárt the drift. The display shóws where you néed to adjust thé guide star fór polar alignment. StaticPA is moré complicated but géts a more accuraté alignment fairly quickIy. The traditional Drift Alignment is the most accurate but takes longer as each axis has to be adjusted separately. Even with this small mount, I usually get within 30-40 arcsecs of the CSP. This is góod enough for ovér 2 minutes exposure with my 200mm lens. Now another exampIe, this timé with polar aIignment within 30 arc seconds, according to Sharpcap.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |