Christine,
Thanks for your comments here, both regarding M27 and double star observations. I also have an FC100 and am wondering about trying out this eyepiece. I do enjoy observing double stars, but am most often using higher power than what the 12.5mm TPL would provide…and your comment about FOV and eye relief taking your experience down got my attention. Comfort is as important to me as optical quality, to a point….
I have a 14mm Delos that I really enjoy, and my color perception is not great in general…I guess what I am wondering is, in your experience, what was different viewing M27 that the FOV/eye relief were less an issue?
Alan
Hi Alan,
While you probably have your favorite DS setup...I do use my FC-100DF for DS and almost exclusively use the Tak TOE 3.3mm eyepiece. I have mentioned this before, if I could only take one eyepiece with the FC100, it would be the TOE 3.3. I got the 12.5 TPL to fill a hole in focal lengths. It was great for Venus at inferior conjunction (but so is my ES15 Plossl), however, Saturn and Jupiter are too small. The Sun is too small, but great detail regardless, but it's not special. The TPL is very enjoyable with the moon, however. I think again contrast was its strong point. So certainly some of those mentioned are FOV important objects.
I get eyepieces for specific scopes and travel with a whole set up. As opposed to getting groups of eyepieces. So I have a very eclectic collection. Parfocal is cool, but since I only view with one or two EPs in a night, it's not very important to me. (Plus I have 3D printed parfocal rings for many of my EPs). The 12.5 TPL filled a focal length hole for me for the FC100DF. Mind you, the eye relief is not bad, it is only about 8 or 9mm. For M27 I fold down the eyecup to get the full field, which is easy enough and it is not uncomfortable at all. Indeed this is how I generally used it through the night. By way of comparison, with a TOE, I leave the eyecup up simply because for doubles the FOV is not really a concern for me. Indeed, I can back off considerably with the TOE and loose FOV at a much smaller rate. I can't do this with the TPL. The FOV gets small fast, and plus with the TPL that is a mid power eyepiece in FC100, so FOV is more important.
It is an excellent eyepiece, I will be keeping it. As for the drop off in sharpness on the outer edge, that that is Takahashi's way of saying, it's not sharp for us, but for every other scope/eyepiece combo, we still have you beat. I couldn't detect any decrease in sharpness. (see my comment below about a 25" f/3.5 dob)
To be fair, wide eyepieces are not a priority for me, even for general viewing in faster larger aperture scopes. I prefer to see the field stop(s), I know other's prefer wide EPs. So, if you do, this is not your EP of choice.
I would rather get more time with the TPL before I really comment, trying it in my dob and BTs and with a barlows as well. I did try it with my clubs 25" dob on a couple of Globs. Well wow...we have a dedicated set of Ethos for that scope and I preferred the TPL to the 13mm Ethos. But to be honest, a coke bottle bottom is pretty good in that scope too...lol. But is was more contrasty. We have a couple of Mewlons in the club, so I would like to try with them and see how it holds up in deeper scopes especially for color.