Ts optics photoline 72mm f 6 fpl5311/28/2023 ![]() On paper this is an old design but he takes great pictures with it. One of our regular guests has a TEC140, which is obviously a brilliant scope, but he also swears by his TeleVue 85 doublet. In the real world, when you are on a budget, a simple optical design is likely to beat a complex one because it is more likely to be supplied in good working order. (Takahashi have been guilty of supplying an alarming number of miscollimated FSQs in the last few years.) And refractors must be collimated to work well. There also good and bad lens cells which can pinch the optics or be impossible to collimate. There are plenty of examples of focusers which slip or sag, introducing the problem of tilt. I think it's important to know that the mechanical quality is very important in imaging scopes. I saw RedCat or similar scopes, i don't want that much 250mm, i can use my Canon 70-200mm f/2.8 with 1.4x and can be at 250mm, but i prefer a scope, last results i made by Nov-Dec last year made me to change my plan entirely cause of FOV, in fact 300mm is the sweet focal length i want, so with my ST80 and 0.8x as test i've got 320mm and i was blown away with FOV, so something like Esprit 80mm and reducer will do, but those are expensive, i am trying to make the second scope below $1000 if possible, and if i buy reducer that will add to the price also.īottom line is, the options i gave i can all use at 275mm-400mm, Redcat is a fixed Petzval 250mm that i don't want, i prefer to be more flexible with many FL using flatteners and reducers, i ordered a new model of TS 90mm F/6 triplet which will be available after March since they changed the date from end of Jan this year, or even longer than March, it is 540mm scope, i am planning to buy APS-C color camera and buying 0.65x reducer so it can give me almost 300mm FOV, a second scope next to it as dual i can't buy exactly the same again, i already have 3 mono cameras all with 4/3", have to use them at least one of them, i already have 0.8x, but i don't mind buying their 0.7x to go much wider than 360mm or even wider than 300mm very slightly, but not 200mm-260mm. Mosaic is not in my mind at all to do, i will not do it or go for it, so he only option is wider scope. ![]() It is a bit more involved - but it is cheap and it let's you go even wider - at 217mm (3x3 panel and x3 bin) or 162mm (4x4 panel and x3 bin). This also preserves total pixel count of your final image bin 2x2 each of those panels to recover lost SNR because you imaged each panel for only 1/4 of the time. Well, you can then look at 60mm scopes with field flatteners / reducers, or you can do mosaics instead?įor example little RedCat has only 250mm of focal length:Įven simple 130PDS will act as 325mm FL scope if you: So, for example, will you choose this one It is proper imaging scope with no issues with CA. People that use it as visual instrument are very happy - no trace of CA, but for imaging purposes - it shows CA. By the specs it should be excellent scope - FPL53 and Lanthanum glass. I've seen couple of images made with this scope - and it has very pronounced blue halo around stars. TS even markets this as being part of their PhotoLine series of scopes. Take for example this scope (and line of similar scopes from Altair Astro or StellarVue): Optical quality is only important when doing planetary imaging, and there you want your telescope to be sharp, but for long exposure - atmosphere just dominates and if telescope is not sharp - no one will be able to tell at resolutions that we use for long exposure. There are a lot of imaging scopes that are not diffraction limited and would pass as rather poor optically. Often, for imaging purposes (not the same for visual) - triplet with "lower quality glass" will give better color correction than high quality ED doublet. ![]() Optical quality is really not that important when discussing imaging scopes.
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