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Post by jimcurry on Jun 13, 2014 6:08:09 GMT -5
I owned a Tak FS102. When I finished my Istar 4" f/12 build I did several same night, same object comparisons. I did not notice a difference although perhaps if the atmosphere had been perfect the Tak might have shown less color. In any case my focuser and overall build quality far surpassed the Tak so the Tak was sold... Jim   |
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Post by Ales - iStar Optical on Jun 13, 2014 15:10:40 GMT -5
Thanks for the very nice report Brian, good info and excellent results. As far as the yellow tinge, as mentioned, some people 'can't see the forest because there are too many trees in the way'. They become fixated at the anomaly and don't see the big picture. What I would like to see is how the 150/5 or 204/6 perform on deep space objects when imaging. Unfortunately those are few and far between. A camera imaging DSOs really doesn't capture too much CA, except for some violet fringing on brighter stars. Even that can be tamed by filters or by using a couple more glass elements in the form of a reducer/corrector. A perfect example of that can be seen in the following image, which was taken with a Borg 50mm/f5 achromat (2 element) and a .85 reducer (2 element):  Messier 33 w/50mm by Astronewb2011, on Flickr So, judging by that picture, an ota with three or more times the aperture would make an excellent imaging system for DSOs? Ales, the 150/6 or a 180/6 could be fitted with a Borg .65 4 element super-reducer for some mind boggling images...  Best regards...Paul Paul, Ive been asking iStar refractor owners to experiment with deep space photography but most are not interested. Personally I believe that our R35 LD doublets are more than capable of APS format imaging without field flattener. For sure I would love to see some photos made with our newly introduced Ares WFX 150-5. Regular achromats are not suited for photography unless you shoot separate RGB or use narrowband filters. So I will wait for someone to use iStar Rx optics for imaging. Very unfortunately I don't have time to do this myself. Best regards Ales |
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