ukskies

Excellent picture, well done and thanks for sharing.

Well said Stu. As I always say guys let's just play nice. I felt I took the thread off topic asking about sharpness which I thought at the time was an interesting point, however I then felt I should have begun a new thread. I haven't posted on this thread since until now. I also notice a lot of post on here taking the mickey and I personally like a bit of banter so I personally enjoy these tho some may not but it's a forum and sometimes things get misunderstood because text isn't the same as speech. When you are face to face and say something to someone they can fully understand your meaning instantly from your expression and tone. When you write exactly the same words some people will read and ask themselves what exactly does he mean by that, it is the weakness of the written word I think. I personally read through stuff twice before posting to try to see if there's anything that sounds offensive but still I'm always concerned how my posts will be received. It's sad that Michael has felt so strongly that he needs to leave the forum for a rest, I for one hope he returns soon as his contributions will be sorely missed. Come back soon Mr Spock.

Sunday late afternoon the clouds began abating opening up to lots of clear patches. I was getting ready for a session. I set the tripod and mount out in the garden in the full daylight performing a rough polar alignment and got the FC100 case and the eyepiece case also out in the garden to acclimatise. I waited, what seemed like forever for Venus to appear in the still blue sky and then I was finally away. I am not a skilled Venus observer hence I am only reporting what I actually noticed in the eyepiece. Since I first posted this thread I have been mulling things over and forming a plan of attack. This was to simplify the issue by limiting the eyepieces initially to only two and the Barlows to just the Baader 2.25. I also decided to refer to the BBHS prism as T-2 and the clicklock mirror as 2". Venus at 148X, 5mm BST with the T-2. Very luminous, faint purple glare/flare around the planet nothing too bad tho. Gibbous phase was very easy to see plus occasional hints of darker patches/shading in the cloud tops. Atmosphere unstable at the low altitude of Venus, the planet appeared quite sharp but wobbled a little at times. Quick swap to the 2" plus 5mm BST showed a liitle darker shade of purple in the flare around the planet but not a lot different plus a very noticeable red flare to the South Pole. In with the 3.2 BST For 231X, the planet obviously appeared larger and so did the flare but only in the same proportion as in the 5mm, more of the same just bigger with more obvious movement to the image due to the atmosphere. The darker shading in the Venusian cloud tops appeared to be slightly more elusive though, not being visible for most of the time. Back in the T-2 went and the story was unsurprisingly the same, a faint purple flare but the red South Pole was not there, same as the 5mm exhibited. I really preferred the image scale at 231X but the low contrast detail was more easily visible at 148X this particular night. I persevered with Venus whilst waiting for the increasing darkness to reveal other targets and concluded that the T-2 showed slightly less chromatic aberration than the 2" however it wasn't by a lot and the view though either one was fine and showed pretty much a similar level of low contrast detail. Eventually i could see an extremely low Sirius so swung the Tak onto it. Same order, 5mm for 148X with the T-2 focused on the airy disc and the star showed two (I think) diffraction rings which were constantly moving and breaking up and spoiled the view a bit. Swap in the 2" and again the view was more similar than different but more so than on Venus to the point that it was difficult to see any difference but careful study swapping diagonals twice more revealed a very slight one the T-2 was ever so slightly cleaner. Same story with the 3.2 but the image in both diagonals was more alike than different. A quick look at the ever diminishing Mars sitting quite high to the south, The Red planet in the 2" at 148X was small, sharp and very red. No glare or false colour was visible. Changing to the T-2 the view appeared identical, if there was a difference I could not detect it. 3.2 for 231X revealed the same story. The moon was up by now but I could not view it as it was still too Easterly and obscured behind the house next door. I looked up at the Twins, they were sitting very high above me so I thought the view would be less affected by the seeing and I quickly located Pollux. It appeared yellowish white in focus in the 3.2, the faint companion was not visible. The star showed a nice tight airy disc with a single unstable diffraction ring, breaking away from the star. In with the 2" and again a very similar view presented. On to Castor and the double star rewarded me with a very pretty view, the fainter companion showed a tight airy disc with a single diffraction ring that didn't break away whereas the brighter components diffraction ring was breaking up quite a bit. The view was the same in the T-2 except it looked a tiny bit cleaner/clearer. I swapped a couple of times to double check but it was definitely slightly preferable in the T-2 in my eyes. I picked up the whole rig now and moved it as far away from the house as I could to view the moon. The T-2 was already in so I slipped in the 5mm and the view was very bright and bleached of detail. I slewed to the south and then used the high contrast shadows to focus accurately, the focus popped and so did the detail. I don't think I'll ever stop gasping at the Lunar views through this scope. In with the 2" and very much the same view. I swapped diagonals again several times and same with the 3.2 and the views were extremely close but the view in the T-2 was just, for want of a better word, nicer but not by a lot. There was no trace of false colour when i viewed the limb of the moon in either eyepiece or diagonal. It was getting late so I quickly popped in the 2.25 Barlow with the 5mm for 333X and the 2" was just as sharp as the T-2 but again the T-2 was ever so slightly nicer maybe prettier? I can't think of a descriptive term that would explain the difference as it was very subtle but something about the T-2 view just made it appear nicer to my eyes. 4 hrs I had been out by this point and it was very cold by this time after 11 o'clock so I called it a night. As I did not notice any false colour slewing around the limb of the moon in either eyepiece or diagonal I went indoors rather pensive. By the next morning (Monday) I was convinced that I had not re-created the conditions which produced the false colour on my previous outing and planned a second session for that very night.

Hi, thanks David. Bill P found the BBHS mirror to be an amazing experience reporting seeing details on Jupiter if memory serves, that he'd never seen before. Anyway I will test again and report back soon. Thanks everyone.

Hi bosun. Yes I realise now that sentence wasn't complete and seems out of context when isolated. I read, as I wrote above, that Baader claim that dielectric coating a mirror diagonal is no easy trick because as the layers build up it is difficult to control surface irregularities because the many layers of coating required can build up in an uneven manner. What I didn't post above is that their 2" clicklock however does not have this issue because they claimed to be the first to crack the problem of how to control the build up of layers. I was also aware that Baader claim one tenth lambda surface accuracy for their mirrors as that's the reason I chose that particular diagonal.I have however read both of Bill P's diagonal reports on CN which gave me food for thought and led to my purchase of the prism diagonal as I couldn't seem to a clean image at high power with the mirror at low and even medium powers it was fine. Skies are clearing here right now and I have to attend a birthday party otherwise I would have more input from further testing.

Yes, my thoughts exactly and another clear night will be needed before I can make any conclusions, if then. Is it not however possible that as I am quite sensitive to false colour and maybe the objective is producing a little off axis colour that the mirror is amplifying it whereas maybe the prism is muting it. Many people have noted more light scatter with dielectric mirrors than with prisms I've read recently. Correct me if I'm wrong here but doesn't dielectric coating involve getting something like 100 ultra thin layers of coating? From memory a process Baader say is extremely difficult to achieve without surface irregularities? That said I wanted the 2" mirror primarily for lower powered widefield views with 2" eyepieces, it seems fine for this purpose but I will be looking harder from now on.

Thank you Michael, I'm in total agreement with you here. Sharpness, like beauty is in the eye of the beholder and limited by many other factors.

To me two scopes of equal focal ratio, side by side a night of great seeing with the same eyepieces AND same eyes is required to "prove" which is sharpest. I also believe that during the test one will go soft at a given magnification and one will exceed this level by a margin. I also believe that scopes could be the same make and model and this will still hold true in many cases, even seemingly identical high end instruments have sample variations. That is extremely interesting and I would love to discuss this in more detail however I'm thinking I maybe should have started a new thread as we're veering off topic here now. 😬

Hi Gerry thank you. Ha the yoga straight through position is no longer on my available options list, if I got there I may not be able to get out of it. I also appreciate your comments about my Tak being a fine optic, I believe you are right and I'm a mixture of pleased and relieved at this. 😆 Finally eyepieces, yes, well, the plan is to purchase some top end eyepieces to go with my top end scope but I have to budget for these so I hope to acquire a few as this year progresses and as funds allow. (It never ends doe it?) For the moment I have as my main collection a Baader mark IV zoom with associated 2.25 Barlow and a 30mm UFF plus a couple of BST Starguiders in 5mm and 3.2mm and a Celestron 2X barlow. I'm sure the Tak objective is likely begging for better and capable of more but I will have to be patient to test that theory out. I have a few old Plossls but rarely use these nowadays.

Hi John thanks for your input, it is appreciated. I'm actually wondering at this point if my particular 2" clicklock might be not be up to snuff. I too was surprised at the false colour, my first light with the Tak was on Jupiter and mentions the purple halo I observed. Bear in mind it was from my town garden with houses in all directions and central heatings on as it was a very cold night so the seeing wasn't inspiring hence I didn't worry too much. As time has gone on though I do notice some false colour on most bright objects so began to suspect the eyepieces or even my own eyesight, I mean a £200+ diagonal was not likely to be the issue was it? I know the remove the diagonal and view straight through advice that is oft quoted but I believe my days of being capable of getting into position for this have long gone. Maybe a proper observing chair might assist. However the T-2 Zeiss BBHS does appear to give me completely colour free views albeit on only one occasion so far and only on the Moon.

Now that's very interesting your saying Starfield Apo was extremely sharp yet wouldn't handle high magnification like your 102 Achro? That brings me to a question of how we define sharpness and I believe this to be an individual thing affected by what and how we view and influenced by our own eyesight as well as atmospheric conditions. To me for example, due to light polluted skies at home I am mainly a Lunar, planetary and double star observer and I'm visual only. Most of the stuff I do from home is at higher magnifications and often pushing or exceeding the "acceptable" limits of magnification for the instrument and mostly pushing the limits of our wonderful atmosphere. If I take my 100mm Tak to 200x mag I am at the acceptable maximum for a 100mm scope and I do view in the 150X to 200X range a lot of the time. At this level I can pronounce my scope is very sharp . This however is where it begins rather than where it ends because on my last night of better seeing and a different diagonal (not sure which made the difference) I have taken the little Tak to over 333X on the moon and then on to just above 400X and the image was still just as sharp and contrasty. This little Tak will go to double and maybe more of the accepted limit for it's aperture and still maintain it's sharpness. This I would describe as "super sharp" as it is way above the accepted limit. Maybe in the future on a night of excellent seeing and with top quality eyepieces I may find out the scopes full capability but it has already proved it's an extremely sharp instrument capable of anything I would wish to do with it. Please understand everyone this isn't me bragging about how great my scope is, I'm merely making a point about perceived sharpness from my own perspective. Though I am speaking from my own experience I have also read many reports of exceptional optics on test by skilled and acknowledged observers exceeding the 50X per inch rule and getting to 100X per inch and beyond with no loss of sharpness. It isn't limited to refractors either, I once read an observing report by Rick Singmaster with a 14.5 inch Zambuto/ Singmaster that he and Carl took to stupidly high magnifications on one exceptional night. So the question is then, what is "sharp"?

I thought it meant the last telescope you read a great review of and now want. 🤷‍♂️

When I purchased my Takahashi DF just before Christmas I decided to buy a quality 2" diagonal for it. Many choices were out of stock so limited my options but FLO had the excellent 2" clicklock dielectric in stock so I ordered one. All my early viewing has been done with this diagonal. I read the reports by Bill P on several diagonals tested and following this I felt that a prism diagonal might suit the FC100 more than the mirror one. In particular I fancied the T-2 Zeiss prism diagonal but FLO showing no stock. I tried RVO not expecting anything but my email was answered with a yes in stock. I ordered it immediately. Now I've only managed one short session with it so far due to the ever present clouds and on that night a veil of thin cloud was covering the entire sky. The Moon and Venus were visible through this however so I set up to try the new prism on the Moon. I scanned the Lunar surface for quite a while at 150x and it was beatiful and sharp, loaded with high contrast details. I swung to the limb of the moon and suddenly noticed there was no false colour.I usually can see a very tiny yellowish green halo at the limb but it wasn't there. I decided to try more power and still could not provoke any false colour so I turned to Venus very low to the horizon and turned the focus wheel, it did have a little false colour but it was a tiny amount much less than I expected. There were larger low level clouds by now making a viewing a hit and miss operation requiring patience however I stuck at the eyepiece and went back to Luna. As I increased power to 333x the highest I'd been to this point I noticed that the details still stayed sharp as a razor, the view was dimmer but the contrast and sharpness remained. I eventually got to over 500x times before the sharpness was not there it held up at over 400x very well indeed. I decided to grab the 2" clicklock to compare but the clouds had increased and obscured everything. I plan a side by side comparison as soon as I get a clear night and will update this thread once I have but the prism on this night showed no false colour where previously there has been and allowed me to go to higher powers than the mirror has allowed before.

Mine was a retirement present even tho I still work part time, I'm not sure about this last telescope thing though. 😉 My advice would be not to wait Steve I wish I hadn't. I

When I was a young boy and through my teen years my Mother always bought the best and taught me the value of doing so. The old "buy cheap buy twice" phrase became ingrained in me. As a boy "cheap" was anything with made in Japan (yes Japan not a typo) labelled on it. I remember the old metal toys from Japan with thin cheap metal and often sharp edges that would cut your hands. Japan though soon began to produce high quality cameras, good enough to rival the German stuff that dominated the market in those days and you could be confident that Japanese glass was in the top tier as regards quality. I've seen the Chinese glass go from OK to extremely good and the early cheap focusers have also now become very precise and a pleasure to own, things keep progressing. I believe nowadays the "buy cheap buy twice" phrase has much less importance and some of the less expensive stuff is indeed extremely worthy. That said I once saw and looked through a Takahashi many years ago and it's cost was way beyond my reach at that time but I promised myself that one day I would get myself one and once I reached retirement age I decided I could it was time.

Wonderful drawings @mikeDnight thanks for sharing. The detail you sketch is amazing, I wish I could draw detail like that.

Thank you for taking the time to do this comparison Michael it's really nice to know how good the lower priced scopes are. There's something about owning a Tak that I can't explain (apart from having no money of course). I open the case just to look at it quite often, it's so beautiful, small and light. There is something about the view through my DF that just keeps making me gasp. It's not the level of detail my 12" dob reveals far more but the Tak view is just so pretty I really do gasp at the view especially on Luna. My Tak is also super sharp and stays sharp well over 400X on the Moon. I have never tried a Starfield though I was very tempted whilst waiting for a DZ for 10 months, in the end I bought a DF and the DZs came into stock a couple of days later. I have no regrets tho I have a great scope and I've wanted one for many years so I now feel privileged to own such a beautiful hand crafted instrument.

1. Another pic of the misaligned arms. In this pic it doesn't look anywhere near as bad as it was tbh. 2. The two halves of the cell aligned properly and taped in place then pilot drilled with a vertical pillar drill. These holes were then drilled out to the correct size for the 6mm tap and then the thread was tapped into them. 3. The 6mm bolts threaded through the top half of the cell (looking from underneath). I countersunk the bolt heads and used countersunk bolts to keep the heads flush with the top of the cell. 4. The springs fitted over the bolts prior to re-assembling the cell halves. 5. The re-assembled cell ready for the primary. WE actually this didn't happen as I decided I might as well improve the 3 point mirror support screw arrangement.

The arms of the two top and bottom parts of the cell were not lined up and this caused a twist in the cell which put the mirror off centre in the tube. I decided to strip the cell, align these outer arms and then re-drill and tap for the collimation bolts out on the arms for more mechanical advantage thus making them less sensitive.

1. the open ended tube arrangement. 2.The primary on first inspection. 3. The original date stickers. 4. The cell showing mirror supports (more later) and you can also see the misaligned assembly just about. 5. The bottom of the cell showing the position of the collimation screws.

I had hoped to update this thread a little sooner but life had other plans. The mirror cell had 2 issues that I felt needed resolving. 1. It hadn't been built square causing the mirror to not sit centrally in the tube. 2. the screws for adjusting collimation were close to the centre of the mirror making them very sensitive. First jobs then were to square things up and move the collimation screws to nearer the edge of the tube. the tube is an open ended affair so there was nothing to hamper access to the screws.

As some of you may remember last year I bought a cheap used Orion Optics VX200L off ABS as a project scope as I was going to make it into a Dob. The mirror was covered in a thin layer of dust so I carefully washed it but many particles have become ingrained. As I bought it with a view to possibly re-figuring the mirror myself however I wasn't too worried. The secondary spider was an odd twin circle arrangement and I was undecided what to do with it and the mirror cell was badly assembled so the mirror did not sit centrally in the tube. All these little issues added up to a decision to shelve it until time would allow. It has since remained stored, stripped in my garage and been forgotten until two weeks ago when I decided I should really do something with it. I was thinking that my new Tak DF could do with a companion and that an 8" Newt might just make a good one. Also I have more recently picked up a mint 2004 Vixen Sphinx SXW mount with Starbook 1 from the original owner and an Orion Optics three legged pier (thank you Cliff if you are reading this), perfect for the newt and into the bargain it came with an I-polar adaptor and the I-polar scope and one very large counterweight. I took another look at the primary, quite a few marks are visible and it offends the perfectionist in me however it is still highly reflective and I've no doubt usable, the secondary mirror is fine and usable as is the finder. Why don't I simply rebuild it and use it a few times to at least assess if I actually want to own an 8" Newt? 🤔 The primary cell has to be re manufactured but then I would have a very usable scope! This then, 2 weeks ago is where this story begins: Hopefully in a few weeks time a first light report will be where this story concludes. Watch this space for the filling.... P.S Mods if this is in the wrong forum my apologies and please move it.

@SuburbanMak thank you.Wonderful first light report and you struck rather a few familiar notes with myself. I bought myself an FC100DF for Christmas and my first view was Jupiter, Mars some double stars and a bit of star testing. I was completely blown away then and it was a less than ideal night. I've observed the moon since on several occasions and I believe that the Tak does have a propensity to warp time as I too have been out for half an hour only to have the boss correct me that I've actually been out two and a half hours. Yes I'm, like you completely blown away by my little Tak. I too love the aesthetics of the scope, I keep opening the case in the garage and having an adoring look at it. It is truly beautiful, so gratifying to own and a dream to use. @mikeDnight recommended the Tak finder handle trick to me too and it really is an excellent idea if you can make use of it. It gives you a good grip on the scope when mounting and more importantly I find, when de-mounting Anyway I do hope you continue to enjoy your new scope and I'm fairly confident that it will become your most used scope too. All the very best and clear skies.

I was out last night with the little Tak DF quite early on. My location is poor in a housing site with houses on all sides meaning my seeing is affected by the heat rising from my neighbours until after midnight and light pollution is quite bad with 2 street lamps almost above me. Out early, first target Jupiter. I caught the Ganymede shadow crossing on the SEB and watched as it slowly moved off the planet's disc. Whilst observing and as the seeing fluctuated I realised I could also glimpse Ganymede itself further south and west from the shadow. I've never seen a moon in front of Jupiter before so I was quite excited and kept watching as the moon left the edge of the planet exactly where I expected it to prove to myself it was really what I had seen. There was quite a lot of detail on the equatorial belts swimming in and out as i watched, I could see some darker barges and swirls plus occasionally a few other belts. I do love Jupiter. By the time Ganymede had moved away from the planet Jupiter was getting lower in the sky so I turned to Mars. I could easily make out some darker markings but no polar cap, by now Mars was quite high but above a rooftop. I went in for a quick warm and a cuppa before coming out to see Orion was now in view. Had a quick look at Rigel, the star looked beautiful and bright in the refractor, somehow prettier than I remember in other scopes. The diffraction rings were broken due to the atmosphere but the companion was easy to see. I then spent some time with a 30mm UFF just cruising over the belt and sword. I've had more detailed views of the nebulae from darker skies in the past with bigger scopes but the little Tak didn't disappoint me, I could see 4 stars in the Trapezium at 150X. I popped in the Baader zoom and filled the eyepiece with M42 and it was a very nice view. By now I thought I'd take a look at Sirius, quite low in the sky so I didn't expect much, the super bright stars diffraction rings were dancing about at 231X but I watched it for a few minutes and suddenly thought I glimpsed the pup off to the right tho it disappeared immediately so i kept looking and I saw the same faint dot appear twice more and again disappear immediately. I later checked online the current position of the pup and it was off to the left so as my diagonal swaps left and right I'm still thinking I may have glimpsed the pup. What do you guys think, is it possible? If it is it's a first for me as I've never seen it before. After a bit I swung up to the Pleiades and again had a pretty view of the cluster. Back to Mars to finish but tho now very high in the sky and not over the rooftop the red planet didn't show me any more detail than my earlier look. 3.5 hours viewing and feeling cold I called it a night.

Second light (finally) plus an update. I had trouble with the mount power and stability first time out but the clouds have given me chance to take a good look what the issues were and to get a Talentcell 72 Watt battery with 9V and 12V outputs. As i have the DD1 paddle with the SP and as they are sensitive to over Voltage I decided this would be ideal and I would use the 9 Volt output. I also decided to reverse the negative centre pin polarity on the paddle as most power supplies these days are positive centre pin. I connected the cell and the mount powered up beautifully.😀 This completed I next turned my attention to the stability of the tripod. I was quite surprised how long the vibrations took to damp out and though I suspected the tripod might be a bit light I didn't think it was going to be this bad. On investigating more closely I noticed that there was play between the Vixen mount base and the EQ5 top of the tripod. It seemed as if it wasn't fully seating even when the screw was tight it was bottoming out on the inner guide of the Vixen mount base. I had some heavy duty non slip flooring in the garage and made a gasket out of this to "pack" the base in order to clear the inner guide. Well it worked a treat, rock solid, no movement. Only a Tak on high power would tell me if this had improved matters. On to observing. TBH FLO had put a sticker on the box saying "May contain snow". Well happily I think it must have melted in the post. 😉 Unfortunately the Tak didn't come from FLO but RVO who must have filled it with clouds, it's been a terrible nuisance but finally they cleared today so tonight would be the night. I unfortunately found out today that I've got to work tomorrow so it couldn't be a late affair. I was out before dark and set up. As soon as I'd done I turned and noticed Jupiter was just visible in the daylight. I quickly located the gas giant on low power 30X and quickly went to 92X. Jupiter looked very bright,still and razor sharp showing the two equatorial belts with some detail in them. I slipped in the Barlow and teased the power up to 150x and the planet looked awesome with hints of more belts as the seeing came and went. I went to full mag of 208X and the detail was easier to see, It still appeared and disappeared but in the brief moments of good seeing I could make out lots of detail, 3 belts North and South of the darker equatorial belts and shape and some structure glimpsed to the eq belts too. The planet also looked razor sharp and simply beautiful. Jupiter had a purple halo but it wasn't really noticeable when observing the details. 3 moons only on show as Ganymede was occulted by the planet. The moons in focus were clearly discs and each had one perfect diffraction ring. I spent a good hour on Jupiter and I cannot describe how utterly beautiful the view was but I was completely blown away. The seeing worsened as time went by so a new target was needed. The Moon was up next and i started at 30X turned the focus wheel and WOW!!! The moon looked amazing, more so than I've ever seen before. Don't get me wrong it wasn't more detailed, I have a 12" Dob that shows a lot more detail but the Tak view was simply more beautiful. Up the power to 92X and the focus just snapped in, I gasped out loud. The Moon was almost filling the view to the field stop with just a black ring of space to frame it and it was super sharp. Up to max 208X and again the Moon was super sharp and stunning in colour and contrast. I felt the scope was just idling at this power and could easily take more. I went back to the 92X just to appreciate the view of the entire Moon and swung the scope to observe the limb. There was a faint greenish yellow outline to the limb but as I moved my eye around the view it came and went, almost certainly the eyepiece, The sky was absolutely jet black. I'm still stunned by what this little Tak was serving up. Mars showed a lovely view with awesome colour and occasionally dark surface markings which came and went as the seeing worsened. I could not make out any polar caps. Finally I decided to try another star test on a brighter star than Polaris and Capella was high and not far from Mars so I swung the DF over to it. In focus at 208X the airy disc was bright with glare spikes and the diffraction ring was broken and unstable. Obviously the seeing wasn't good enough but I racked the focuser 4 waves either side of focus and the patterns were again identical, the outer ring was flaring in the unstable air but the rings were perfectly round, evenly spaced and identical in brightness. I decided to call it a night but in conclusion the mount was a lot more stable, not perfect but useable. It's clear the little Tak is an utter star and much better than any scope I've ever owned. It's obviously capable of showing so much more detail and if I ever get it on the solar system in some excellent seeing I believe I will be even more blown away. I also need to get out to a dark sky and get some widefield views in the near future. Well time to wind up this lengthy post as I've gone on long enough. 😆