This is common with small aperture refractors when they want to do away with quality control. Presumably this aperture stopper tactic is to remove the need to maintain quality control, but is such a waste when they apply it on Tanzutsu objective lens.ĭo a torch light test even if the baffle is set just in front of the findscope housing screw, in case the width of the baffle ring is such that it still truncates the light path and reduce its aperture. The loss is to operate these units at 50mm instead of 60mm, and is a massive and inexcusable loss when light gathering is quintessential on such small units on the astronomical front. Not sure why Tasco moved the baffle to restrict the aperture to 50mm for their 9Fs, other than to increase f ratio from 13 to 16, which is to increase sharpness of the objective lens when they don't bother with rotating the crown and flint objective lens elements to ensure their alignment and remove astigmatism. Hope everyone is keeping safe and well with COVID-19 being house-bound. Thanks for your posts and my apology, have not been back to the site until today.
#Red tasco telescope professional
PS: I haven't check yet if the objective lens on this second unit requires rotation to eliminate astigmatism, hope not as the aluminium retainer ring looks hard to remove without professional lens ring openers. It makes a huge difference for such small aperture scopes! You can see how much large the circle is at 60mm versus at 50mm.
#Red tasco telescope full
They should not be set to perform at 50mm, and should be deployed at its full aperture at 60mm instead. Hope everyone can make the most of their Tasco 9 F by unscrew at the objective end and push down the baffle, as the Tanzutsu objective lens is very good. Third photo shows the full opening at 60mm after the baffle got pushed down the tube towards the eyepiece end.įinal photo shows the light test with the opening at 50mm. The new location of the baffle can be seen in the crescent slit looking down the tube, now sitting right in front of the two screws that house the flip prism finders cope casing. The second photo shows inside the tube, the ring is where the baffle used to be located, with no matt black paint after I pushed towards the eyepiece end, so bare unpainted metal shinning thru.
I acquired another second hand Tasco 9F 60mm scope in better condition than the first.Īgain, the baffle on this unit acts as an " aperture stopper" from 60 mm to 50mm, so the Tasco 9Fs are all set to operate at 50mm on manufacture.Īttached are photos of the scope with light test showing it is operating at 50mm due to baffle being set too forward towards the objective lens.
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