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Which 100mm Tak?


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I'm sure experts will be along shortly but I believe the DC uses a standard focuser; the DF a 2.7" focuser. They are f7.4 and have identical optics..
The DZ uses a lower dispersion second element (Lanthanum?) to reduce blue bloat for imaging. It is f8.

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12 minutes ago, Mr Spock said:

I'm sure experts will be along shortly but I believe the DC uses a standard focuser; the DF a 2.7" focuser. They are f7.4 and have identical optics..
The DZ uses a lower dispersion second element (Lanthanum?) to reduce blue bloat for imaging. It is f8.

Thank you, I'm looking for a scope that will keep up quicker in my sometimes rapidly dropping temps, eventhough my scopes are kept "outside". The triplets can lag and I want to maximize the views during these conditions.  Also being considered is the SVX102D but at f7 I'm not so sure... the 127mm looks good at f8" but I have the Tak triplet.

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I just looked and the description just said fluorite "in the back" for them all. I wonder if the f8 provides the same visual obs as the f7.4? Splitting hairs or is there a difference? Anyone try them both?

The acclimation issue is the main one in reality I guess.

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Any!

The DC and DF are basically the same but for the focuser. Optically they are vibrant, giving lovely views of the belts of Jupiter and bringing out some glorious star colours. Stu bought a DC and replaced the focuser with a feathertouch, which although expensive, is a great way to go as the optics are awesome. The DC focuser is the same used on the 60mm Tak and youd need a 2" to 1.25" adapter if you want to use 2" eyepieces. The DF has a heftier focuser same as the DZ, and takes 2" straight out of the box. You may decide on the Tak, or More Blue microfocuser, but i manage ok with the standard one even at high power, but im tight! 

The DZ is beautiful too. It has a retractable dew shield which is a bit of a gimmick really as it only slides about 3", so what's the point? Optically the DZ gives a more icey view which I've been told is similar to the TSA. Tak claim the DZ is a high power telescope, so when mine arrived I managed to push it upto 1000X using a 1.6mm Vixen HR and 2X Ultima SV Barlow. Star images remained unbelievably sharp and perfectly formed, so perfect in fact that I kept checking and rechecking I'd got my calculation right.

 Both the DC/DF and DZ handle magnification really well. I can't remember pushing my DC, which I bought in March 2015, with the same determination as I did with my DZ, but the DC showed Venus beautifully at 474X, so it was no slouch on the power front. As for CA, I think you've more chance of getting false colour from the eyepieces used, especially if they're wide angle, than from the telescope. So all are fast cooling (15mins from a warm room to sub zero), high power and colour free, with the DC/DF giving a warmer tone, while the DZ is cooler more akin to the DL. Other than that, to my eye they are more similar than different. I have to admit to having a major soft spot for the DC/DF, and wouldn't bother chasing a DZ unless one was within arms reach. 

 Of course there's always the chance a DL or older FS, or earlier FC may come along on the second hand market. The FS is a Fraunhofer design with a thinner fluorite element at the front, where as the FC's use a Steinheil design with a thicker fluorite element behind. Vixen's older FL102 was a Steinheil and is excellent if you can find one.

 

 

 

 

 

 

 

Edited by mikeDnight
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15 minutes ago, mikeDnight said:

So all are fast cooling (15mins), high power and colour free, with the DC/DF giving a warmer tone, while the DZ is cooler more akin to the DL.

Awesome reply Mike!

I can get over 30C temp swings here and April usually brings a few along with great crystal clear seeing. It'll go from +15c in the day to -25c over the evening. This can affect the TSA during an obs under these conditions.

Hmm I'm thinking f8...

"Chasing DZ" -what do you mean?

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10 minutes ago, jetstream said:

 

"Chasing DZ" -what do you mean?

It seems the DZ isn't currently unavailable due to supply issues, but the DC and DF can still be found off the shelf. Obviously if your heart is set on a DZ, then that's the one to go for, but i read somewhere recently (possibly on CN), that it could be a year before any become available.

Edited by mikeDnight
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1 minute ago, mikeDnight said:

It seems the DZ isn't currently unavailable due to supply issues, but the DC and DF can still be found off the shelf. Obviously if your heart is set on a DZ, then that's the one to go for, but i read somewhere recently (possibly on CN), that it could be a year before any become available.

Well I think I'll be happy with any of the models but probably the bigger focuser model. These are high transmission scopes? I like looking at very large diffuse nebs like Barnards Loop, Meissa etc I use a 42mm LVW for these objects. So no difference in noticeable transmission between the f7.4 and f8?

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38 minutes ago, jetstream said:

Well I think I'll be happy with any of the models but probably the bigger focuser model. These are high transmission scopes? I like looking at very large diffuse nebs like Barnards Loop, Meissa etc I use a 42mm LVW for these objects. So no difference in noticeable transmission between the f7.4 and f8?

I’m sure the DZ ultimately gives a slightly better image at higher powers, and under your seeing conditions that may well be something that you can see/benefit from. In the UK I suspect it would rarely be detectable but I’ve never tried a DZ side by side so don’t actually know.

I preferred the DC because of its light weight and knew that I was always going to put an FT on it so wasn’t bothered about the standard focuser. That said, FTs are pretty much unobtainium now which is a shame.

I love widefield views, so the slightly shorter focal length is a little more to me appealing than the f8 and given your suggested targets that may be a factor.

All great scopes though, I doubt you would be disappointed by any of them. I bought mine after reading Mike’s reports using his, and have never once regretted the decision. It’s been my most used scope for years 👍

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2 minutes ago, Stu said:

It’s been my most used scope for years 👍

I like hearing this Stu!

Well, maybe I'll pursue a DZ but if the wait is too long the the bigger focuser f7.4. I'm trying to assemble some lightish weight but top notch eyepieces at the moment and need something at 4mm I think . So far the 2.4HR, 2.5 XO, 3.4 HR and I do have the much values VIP barlow to throw in the mix.  I should have bought all the HR's - what was I thinking??!! I have to find some field stop location to figure some stuff out.

I'll set the TSA and DZ/DC /DF up side by side so I dont miss any good views under variable conditions. I just cant wait for the planets to be high up there in the sky. Planetary is another favourite of favourites here.

These 100mm Taks, after years of hearing about them have suddenly grabbed my attention.

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The Takahashi FC-100 DZ seems to be  immediately available from this European retailer; have a look:

https://www.intercon-spacetec.de/teleskope/teleskope-bauart/apochromat/5838-takahashi-fc-100dz-komplettpaket-.html

Over the last twenty-five years, I made several purchases from intercon-spactec (e.g. the "Füssener Astrostuhl"), and found them very reliable; they have been Takahashi retailers for more than two decades.

Stephan

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1 hour ago, jetstream said:

Well I think I'll be happy with any of the models but probably the bigger focuser model. These are high transmission scopes? I like looking at very large diffuse nebs like Barnards Loop, Meissa etc I use a 42mm LVW for these objects. So no difference in noticeable transmission between the f7.4 and f8?

I haven't detected any difference between the two as far as transmission goes. Infact Tak's own user manual mentions the bright images produced by Fluorite as being beyond any ED glass, but i suspect they're really talking about the extremes of the spectrum detectable by CCD's. My own site isn't as transparent as it used to be, yet I still had some memorable views when I've managed to attain a high level of dark adaption. The 42mm LVW should be awesome, and the F7.4 will give you a slightly wider field of view, but F8 would have been considered an RFT only a few years ago. Today many think its long! :icon_scratch: I remember Walter Scott Houston writing about Barnard's loope in the book Deep Sky Wonders. He said the best way to view it was through an Olll filter alone - no telescope! I've never seen it myself and so can't really comment. I could have just saved you a fortune! :laugh2:

 

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h

1 hour ago, jetstream said:

I'm trying to assemble some lightish weight but top notch eyepieces at the moment and need something at 4mm I think . L

That’ll be the 4mm TOE then. My favourite and best eyepiece. Works effortlessly in both my 8” dob and 3” apo. Used it extensively for Jupiter, Mars, WL solar, lunar and doubles observations. Very recently used it to detect Sirius’ companion. Extremely high quality, lightweight and comfortable. 

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Out of interest the Actual astronomy podcast (not affiliated) has a resent episode on the history of the 100mm Taks...there are quite a few. Interesting listening as they also go into the history of the company.

Edited by Kobayashi Maru
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Here are a few old sketches made using the FC100DC. I normally use a binoviewer for planetary, and mono for deep sky sketching with a blackout blanket so as to attain a reasonable level of dark adaption. The sketches represent the detail seen throughout the time of yhe observation, which is usually 10mins for Jupiter, 15mins for Mars, and up to an hour for the deep sky observations.

58630094d09a1_2016-12-2800_00_04.jpg.5340c14342fef8ec276c18509c910c4f.thumb.jpg.feb74a3505cfac2a39e7c6db997eed7c.jpg

M42 again.274570300_2019-03-2620_26_50.jpg.157a9e32bcfc1751a3615ba51a0ce649.jpg.9d6b01a302dc8aa35c5955b4a7ff95923.jpg.f6bc981c721f33f98bb825b916d6002c.jpg

M27 

596c8af360b73_2017-07-1711_01_00.jpg.aa568bb84a19b6cebbe49d1efdf9e60c.jpg.3b0e6fa2d9893854dbc889557aa7b070.jpg.dceb2b69670843de302800411c9cef74.jpg.cba4843887587facc7ddf952bdd055f7.jpg

M57 

5a6263f1917d9_2017-07-1819_16_53.jpg.c5fd42254b40e71644e3f7bb0fa009c4.jpg.b19ef21b758104ab093b41aa0eddc64c.jpg

 

2022-02-1109_04_07.thumb.jpg.f31192014953bce1838a3b422b4ef0cb.jpg

 

IMG_20160310_114919.JPG.173f96ef930d01e73fa883ee78f71aef.thumb.jpeg.07cf36b259aff0411284efe616c8f2cf.jpeg

 

IMG_20160310_114724.JPG.a968347674bca050a4e1521de9b613e7.thumb.jpeg.f5010cd9327a8ec3bd90a533e6f12e44.jpeg

 

2023-02-2122_09_51.thumb.jpg.92ec300ed69b79b802661aac2dad8e3f.jpg570d46c2bf1e4_2016-04-1219_37_26.jpg.e6bd3fac55292911f3387a26e6c79d4f.thumb.jpg.d386558ae7189d08e57f10c80adc3ec2.jpg570d46f5d6de7_2016-04-1219_30_07.jpg.8b3b360e887297f5b322da81a9f62fc0.thumb.jpg.7ed4dcf964f392ccaf0066e03c2e02f8.jpg570d472461414_2016-04-1219_28_36.jpg.af9c4cd4cbb921d8ba48ccaf08846cc7.thumb.jpg.f0c217ba4b7576b00d22878483605132.jpg570d468aa9b88_2016-04-1219_38_47.jpg.b103ade636ad5c8d1aa68ab85493313a.thumb.jpg.3cc1aeb4d1bf1cdd005e0c202863afec.jpg5721c582569c9_2016-04-2809_00_46.jpg.20450e610fa359a968e199a78e4fd370.thumb.jpg.4b8106a1d0ef63d62bd0721f7d8ac1c0.jpg572b25e65c356_2016-05-0509_10_54.jpg.1cfff59f645a4a2bf45962f6228a5608.thumb.jpg.895e31b0a459c571be646c20a6bb1dfc.jpg58825f90a65e1_2017-01-2018_42_29.jpg.061b4885d9e04d7141a7a9bcca24a736.thumb.jpg.4124f6dcc857be4bfd92b2876049776a.jpg58792c01ca4a7_2017-01-1319_19_55.jpg.d21c85dcbe06c3f9c99efdce07302558.thumb.jpg.e6000029f5e983420b7eeece3a60f45f.jpg

 

 

Edited by mikeDnight
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@mikeDnight Ok your not allowed to observe under great seeing! The detail at the mags your using is exceptional.

In the first M42 sketch you got the "Hook" in the wing and also some of the lower loop. M78 is extensive and excellent. You are also in the strike zone on M82 mag wise for the detail, I do the same. That is unless I use the 24" and get it at 200x with a 2.6mm exit pupil lol. The view of it at 120X in that scope is staggering bright.

Ok back on topic.

The Flame is also on the money.

Thanks Mike there is no question about the light throughput of the Tak 100 thats for sure.

The planets are also excellent. Like I say I'd marvel at the sights you would see under top seeing. Here can be vg at times, but down south they say its superb.

Crystal clear again and I'm pondering strategy to get the TSA equalized and stable. Warm now but the temps will drop quickly, I have it in an insulated scope coat- hopefully keeping it near last nights temps to match tonights.

I just know the Tak doublet would be my friend in these conditions. Splash on the DZ or get the DF...., its too bad my exchange is poor right now. So off I ponder lol!

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Nice podcast, although with a number of small errors from the presenter's. The FC series all have the same diameter tube; the DF has identical optics as the DC, and it's focuser is green or blue not black. The DL had the black focuser; and all of the new FC's are Steinheil and not Fraunhofer. Other than that it was nice to listen to.

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2 hours ago, mikeDnight said:

Nice podcast, although with a number of small errors from the presenter's. The FC series all have the same diameter tube; the DF has identical optics as the DC, and it's focuser is green or blue not black. The DL had the black focuser; and all of the new FC's are Steinheil and not Fraunhofer. Other than that it was nice to listen to.

Having listened to it a few nights ago, I felt the same Mike. Nice enthusiasm with a few bloopers in the details.

The first run (100) of DL's had the black focuser as I recall . The 2nd run (which I also thought was limited to 100 but maybe not ?) had the blue focuser. 

I think I would be very happy to own any of the FC 100's 🙂

 

Edited by John
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