mikeDnight

I've had my FC100DZ for four years now, and I felt it was about time I gave the objective its first clean. Many tread cautiously when cleaning such a precious lens, and that's wise, but there's no need to be overly fearful, because the design of the FC100D lends itself to easy cleaning, even if there's dust or condensation marks on the rear element. So because of this I thought I'd include some informative pic's that may help. It's also good to know that none of what I'm showing here, affects the collimation of the telescope in anyway. With the DZ version the first pic's show the removal of the retractable dewshield. But other than that, all the FC100D series are identical in their lens cell construction. So here we go - Pull dewshield forward and unscrew anticlockwise, holding the silver slider firm at the same time. With other versions just unscrew from the silver back cell. Next, gently unscrew anticlockwise the shiny front section of the lens cell which contains the objective. At this stage you could check the scope tube for dust and blow it away if there is any. Placing the cell on a clean surface blow dust off it using a bulb blower. Takahashi warn about using compressed air blowers as they can blast dust scratching the lens coatings, but more importantly can cause thermal shock to the rear fluorite element due to the refrigerants they contain. I've misplaced my Caloclean lens spray that would be sprayed onto the lens cloth, so in my case, after I'd blown any free surface dust from the surface of the front lens, I simply used my breath to dampen the lens before gently wiping from centre to edge. Once happy with the lens I turned the lens over and repeated the procedure on the rear element. I did not attempt to dismantle the elements! It may be necessary to hold the lens cell up so you can check the lens against the light, after which and if you are happy with the clean, gently screw the lens cell back onto the tube cell and replace the dewshield. Happy Tak for another few years! 😁

Some folk think you have to be off your rocker to pay so much money for an apo refractor. Well here I am, off my rocker!

I had a 8" Newtonian & a 10" for a while thinking it would give me a great advantage, but rarely used it. Too bright for Venus, good on Mars had it been easy to use, but the 10" was on a horrible Dob mount. I might enjoy an old style 10 or 12 inch Newtonian with rotating rings and a strong Equatorial! It would need to look like one of those old Parks Newtonians to win me over. Observing through Dob's hurts my back! Why are rotating rings not compulsory!? The 8" F6 barely revealed anything on the moon or planets that I couldn't already see through my FC100DC, so off it went. While the 10" mainly gathered dust.

Well you wouldn't need a barlow John. I suppose the problem that some binoviewers may face would be rotation of the diopter's.

Clear again for a while this evening, and used nothing but the SvBony 3-8 zoom. In the FS128 the Moon, despite being near full, was an absolute joy to observe with this eyepiece. The view was clean of any CA around the limb and sharp to the edge at any power. It was only right at the edge of the field against the field stop did the eyepiece show any hint of colour. Moving my eye to the opposite side of the eye lens countered the colour. The relatively large eye lens made observing at the 3mm (347X) setting very comfortable and without eye strain. I don't normally wear glasses to observe though I need them for sketching. So I tried observing with them on to see how the eyepiece would feel from a spectacle wearers point of view. I could see the entire field once I'd folder the rubber eye cup down and the view remained sharp.

FS128 on GPDX. It was clear a short time ago honest!

He did! I believe he used a 6" refractor. I'm sure I have pic's of his scope's and observatories. What a great and funny guy!

Good grief Michael, how did I miss this one!? That's a superb sketch of Jupiter even though you used a Newtonian. Sorry, I can't help myself! 🤐 The detail is beautifully rendered and both your observing skill and sketching skill is tops. You mentioned needing to wear reading glasses to sketch. Often I do too. May be consider half cut glasses. It helps to make you look more intelligent, or at least I think it does in my case.

What word's that Stu? TAKAHASHI? 😂

This is not a review, just my experiences when comparing the views through four beautiful, top class, eyepieces. There's nothing scientific, just ubjective waffle. Hope it's of use. Initially desperation sent me out in less than favourable conditions, because just as with many others, my skies have been cloudy for ages. A few nights ago however, there appeared to be a chance through gaps in the clouds to get a reasonable look at the night sky. On that first night I used my 100mm refractor to check out some old & some new eyepieces that I have, while on the second night I used my 128mm refractor. So what four eyepieces were being compared and why? Well the "Why" part of the question is easy to answer. All four cover a similar high power range, and all four have already got or are rapidly acquiring a fine reputation as being top class planetary eyepieces. Here are some: left a 4mm TOE by Takahashi, centre a 3.5mm XW by Pentax, and right a 3.4mm High Resolution eyepiece by Vixen. Not exactly new kids on the block I know, but they are all top class in their field, so how did they compare and "Where's the fourth one!!!"? Night one with the 100mm was plagued with fast moving cloud, the edges of which played havoc with the star images and lunar detail. However, some things that stood out as being notable were that out of all the eyepieces, it was the multi element Pentax XW that gave a significantly brighter image than any of the others. Possibly this was because the XW has the widest apparent field out of the group; it having a 70° apparent field. So more elements don't necessarily mean a dimmer view. The XW was very sharp showing high power wide field vistas of the lunar surface, and sharp across the field. Star images were textbook perfect at 229X on what was at best an average night of Antoniadi 2 to 3 variable. The 4mm TOE gave wonderfully detailed lunar views as did the 3.4mm Vixen HR, but clouds brought my session to an early end. It was at that point I suddenly remembered I had a fourth eyepiece that had somehow slipped my mind. What I needed was another clear night, and preferably one without cloud. I could hardly believe it when the following night was clear. This time I used the 128 instead of the 100, which at 1040mm fl, meant the magnifications on all four eyepieces would be higher and so would offer a more critical comparison. I would rate the seeing when I began as 3 Antoniadi & later 2, so the night got better as it went along. The Pentax as a joy on the moon, and revealed intricate fine detail at 297X. Turning to the 4mm TOE, I felt there was some subtle improvement but couldn't quite say what it was for certain. Perhaps the narrower field plus the slightly lower power of 260X played a part, or perhaps it was the eyepiece design? The TOE is not a minimal glass design though it has been designed with high definition viewing in mind. Whatever it was it was subtle, yet I prefered the lunar views through the TOE more, because there was less distraction in that it concentrated my attention on a narrower, yet still highly detailed area of the Moon. The Pentax gave more of an eye full! The TOE also gave a somewhat dimmer, though still very bright, view of the Moon. Star images in the TOE were also perfect yet for some reason presented themselves in a more pleasing way than in the Pentax. At first I reasoned that this was likely due to the lower magnification, but that thought soon changed. The 3.4mm Vixen HR gave a magnification of 304X in the FS128, yet out of all the four eyepieces it gave the most aesthetically pleasing, almost 3D view of the Moon. It also gave the narrowest true field and had the sharpest field stop I've ever seen. May be these things together led me to like this eyepiece the most? The TOE's excellent star images were not the result of it giving lower magnification, or at least that's what I concluded, because the Vixen HR just blew me away on the stars. The pure white and subtle pink hues of Castor were mouth-watering (Not a scientific term!), and to me at least the HR was and is the eyepiece to beat. At this point I had to back track a little because I wanted to compare the colour hues of Castor in the XW and the TOE. With the XW the hues were least noticeable although they were there. The TOE rendered the star colours more vividly and I'd like to say on par with the HR? More experimenting is needed between these two on the stars. But now comes the surprise eyepiece. A surprise because I haven't mentioned it until now, but an even bigger surprise because of how it performed against these three world class eyepieces. It's the SvBony 3 to 8mm Zoom! What a beauty this turned out to be! I don't intend to discuss the eyepiece mechanics, just how it compared to the other three. Having a constant 56° apparent field the lunar views were bright and razor sharp to the edge throughout the zoom's range of 130X, 142X, 173X, 208X, 260X, & 347X in the FS128 refractor. It's worth remembering that the telescopes used are among some of the finest refractors ever made, so these eyepieces gave their best possible performance, with only the seeing conditions and my eyesight being the questionable variables. The Zoom was put through all the same paces as the other three, with seemingly endless direct comparisons which meant changing eyepieces dozens of times to get a clear feel for what the zoom could and couldn't do. What it couldn't do was match the Pentax in image brightness, though it was brighter than both the TOE and the HR. When it came to viewing the Moon it was a joy to watch the invisible detail at 8mm become obvious and highly detailed at 3mm. Comparing all four eyepieces when observing finer lunar detail the SvBony 3 to 8 zoom kept pace with them all, which considering the pedigree of the competition, was quite something. Star images in the zoom were also a big surprise, as the zoom even at its maximum magnification in the FS128 of 347X were exquisite. Perfect Airy disc's with perfect diffraction rings possibly equalling that of the Vixen HR, and showing the subtle colour differences between doubles on par with the TOE and HR. It has been implied that the SvBony 3 to 8 Zoom is a poorer version of TeleVue's 3 to 6 zoom, - It is not! If the SvBony 3 to 8 can keep pace with the TOE and Vixen HR, it can easily be considered every bit as good as good optically as anything TV has ever produced. There is no point in trying to compare the Sv to longer focal length eyepieces as some U-Tube reviews have done. As similar as possible is the only meaningful way! So in conclusion I would say the XW was the one I least enjoyed, as it was the least comfotable due to long eye relief and occasional kidney bean. That however doesn't mean I didn't still love this eyepiece. The XW's are some of my favourite eyepieces! The TOE gave great views yet the body of the eyepiece felt like it got in the way as it felt bulky against my eye socket. It was subtle but I was aware of it more than with the others. The Zoom was a little more comfortable to use than the TOE, or at least that's how I felt. But other than that I'd place these two eyepieces in the same high end category. My favourite at the end of the evening was still the HR, but for me I felt it was a very close compare. I hope someone buys me a 3.3mm TOE!

Thanks Magnus, With the first one I used a binoviewer. The night was poor and clouds brought the observation to an end before I'd completed recording all the detail. I used 18mm Ultima eyepieces with a 2X barlow on the binoviewer giving 4X amplification. The magnification was 231X. I

The White Spot on Saturn c 1990/91, can't remember, but it will be in my notes somewhere. Saw it, didn't report it, then a couple of weeks later someone shouts "I've discovered a white spot on Saturn. Slippery Big Fish!

Well since the SVBony arrived, it has been cloudy. But over the last two nights I've been able to compare it with three other amazing high power eyepieces. I was hoping to do a write-up soon. I just need to get my thoughts together! It won't be a review as such, just my experiences with these eyepieces and how I felt they compared on two less than perfect nights. I'll get round to it soon, but not giving anything away at this point! 😊

Observing is like fishing. When I see fishermen sitting at the bank of a lodge or along the canal when walking my dog, I can relate to the pleasure I believe they get. They go fishing, but don't necessarily catch any fish, and yet thoroughly enjoy themselves. Well that's me when I observe. It's just relaxing and enjoyable, and if I see something new, I've caught a fish, but if I don't, then it doesn't matter because I've had a nice time playing with my telescope. A number of years ago I was watching my next door neighbour spend ages patiently rearranging his fishing tackle box while sitting in his garden. He must have sat there for over an hour just playing and enjoying himself, and I thought how similar we were. I mess around with my eyepieces, rearranging, cleaning, and generally just passing my time doing exactly what my neighbour did, except I play with bits of glass instead of fish hooks, flies and floats. It's all just for fun!

No!

I could, but my granny told me "Neither a lender nor a borrower be"! There you go, I've saved you from being enslaved to debt! 😊

One of the problems with any kind of communication that isn't face to face, is that things can be so easily misinterpreted - especially humour. What may be funny while writing may not be funny when reading. But over time we begin to understand the personalities on here. Similar to being at an astronomy club in person you'll gel with some personalities more than others, but it doesn't mean you don't get along with those you don't feel you gel with. I can't remember how long I've been on SGL but its been a while, yet I've never known anyone intentionally make anyone feel unwelcome. There's no hurt here, just different personalities all passionate about the same hobby. Stick around a bit longer, I'm sure you'll find your comfort zone. ☺️

It would depend on who made the 4" achromat! I had a 4" F13 Vixen achromat back in the mid 1980's that was an absolute dream. One evening I took it with me when visiting a local astronomer (John Coates) and set it up alongside his 8.5" F6 Newtonian. We aimed the scopes at Saturn and compared the views. John, a life long and very experienced planetary observer, who is sadly nolonger with us, was in utter disbelief at just how good the Vixen achromat actually was. I discerned this because of the barrage of colourful expletives he used in quick succession over a considerable length of time as he compared one scope with the other. All this finally culminated in John kicking his garden gate off its hinges and walking back into his house. I stood there for what seemed like ages wondering if he was coming out again, but he didn't. So I went into his house to see if he was ok, and all he could say, while making us both a brew was - "That's a bloody good telescope! Bloody good scope that is!!" I never let him look through my 4" after that! Personally I would choose a "good", long focal length achromat over even an 8" reflector every time. Sadly they are hard to come by these days!

Peppermint tea sounds a bit too posh for me. If I ever take a drink out with me it would generally be coffee or hot chocolate. Sometimes I'll take Ovaltine, but then I have to sing the song "We are the Ovaltinies, Little girls and boys,........" with a slight warble in my voice as if I'm on a WWII radio. It's embarrassing! I do the same thing with chocolate bars. My family refuse to buy me Toblarone anymore! You're probably too young to remember these old adverts, but they've stuck with me throughout my life, and once in your head, they'ed keep you awake at night. When I was younger, the two older astronomers I used to go on field trips with would take flask's of OXO. It may sound a strange thing to drink, but honestly, when you're cold and tired it's a god-send!

The APZ is able to use motor drives and Star Book I believe . All at extra cost of course. Its also most likely better engineerd too, but "twice as good"? It's prettier!

We should have an Off Topic section. I expect we'd then stay on topic, but how boring would that be! But here I am going off topic!

I've used an AZ4 on several different tripods, and I've used it at high powers. For me the worst thing about it is that if you don't move it for a while the motions stick and cause the movement to jolt slightly. Once in motion it will flow easily providing its moved regularly. As the Rowan 75 has been mentioned, which does not have slow motions, I'll throw another option into the mix which does have slow motions - the Vixen APZ from Bresser UK.

Exactly the same reason I sent a Sightron back too!

You can always use a 2X barlow and turn your F7 into an F14. Often I will use a 2X barlow on my binoviewer, but because of the extended light path the amplification factor is closer to 4X, which means I can get high powers while still using long focal length eyepieces. I rarely ever use anything shorter than 16.8mm in my binoviewer.

In the past I've owned a Vixen 102mm F13 and a Antares 105mm F14, and I can tell you that those scopes, although being great scopes, had nothing over a modern apo or ED other than being long and needing heavier mounts. What I remember most, especially regarding the Antares, is that I found it uncomfortable to use because of the varying observing angle the focuser made. To observe the zenith I had to observe on my knees. On the positive side, they looked awesome as an ornament and turned heads in the field. Comfort when observing can mean the difference between seeing finer or fainter detail, or not seeing it.