New Takahashi FC100DZ

[883]

I’m thinking what’s really new in this scope... Make sense a f8 when you have a f.7.5? A new lens? I just bought a f7.5...😢

http://www.takahashijapan.com/ct-news/news_topics/news_19VII09_fc-100dz.html

883

Edited July 9, 2019 by 883

[John]

F/8.2 fluorite doublet which fits between the F/7.4 and F/9 of the DL and the DF / DC models. Sliding dew shield, which is a nice touch.

The performance charts look pretty good - they claim that it's as good as the F/9 but with the advantage of the faster focal ratio and faster again for imaging with the .66x reducer in use - just F/5.3.

It's a sort of homage to the original FC series back in the 1980's according to the translated  web page.

Maybe an 125mm version on it's way as well ? (thats just a guess !).

Another desireable Tak !

Maybe the F/9 won't be produced again and the F/7.4 models will be replaced in due course by this single multi-use focal ratio model ?

 

[883]

Perhaps it would have been simpler to equip the DC/DF with a sliding dewshield...😐 

[John]

19 minutes ago, 883 said:

Perhaps it would have been simpler to equip the DC/DF with a sliding dewshield...😐 

That would require a re-design of the objective lens cell which is perhaps not a small matter ?

Looking at the performance charts and spot diagrams and comparing them with those of the FC-100DL I think the important point is not so much that the peformance at F/8.2 looks to be very, very close to that of the F/9 but that when the .66x focal reducer is used, the spot sizes remain very tight even at F/5.3. This seems to me the key feature optically of this doublet - it remains a very high peformer even when focally reduced. Imagers will be attracted by that.

 

[John]

Ooops !!!! - I don't know where I got F/8.2 from - the DZ is F/8 "native" focal ratio. Must have misread something !

[Highburymark]

Interesting addition to the range. One of the nice features of the F/7.4 FC-100DC is its shortish tube, which allows it to fit into cabin luggage for trips abroad. However that does require the non sliding dew shield to be unscrewed. Haven't looked at the specs of the DZ yet but if it's airline portable at F/8 that will be a big selling point in my view. 

[John]

14 minutes ago, Highburymark said:

Interesting addition to the range. One of the nice features of the F/7.4 FC-100DC is its shortish tube, which allows it to fit into cabin luggage for trips abroad. However that does require the non sliding dew shield to be unscrewed. Haven't looked at the specs of the DZ yet but if it's airline portable at F/8 that will be a big selling point in my view. 

Apparently, with the dew shield retracted and the diagonal plus extensions removed from the focuser the DZ measures 595mm in total length. It weighs 3.8kg.

 

[Stu]

4 minutes ago, John said:

Apparently, with the dew shield retracted and the diagonal plus extensions removed from the focuser the DZ measures 595mm in total length. It weighs 3.8kg.

 

Too long for carry on unfortunately. Sure it will be another very nice scope but would rather they launched a 125mm, or even a 130mm doublet.

[Highburymark]

Ok thanks John. Significantly heavier than the 2.8kg DC and 4cm too long for airline bags. 

[John]

Just now, Stu said:

Too long for carry on unfortunately. Sure it will be another very nice scope but would rather they launched a 125mm, or even a 130mm doublet.

I have the feeling that a 125 doublet might be along sometime. I may be wrong but it would not surprise me in a couple of years if the FC line was a single 100mm (the DZ) and also included a 125mm and maybe even an 80mm ?

 

[Stu]

Just now, John said:

I have the feeling that a 125 doublet might be along sometime. I may be wrong but it would not surprise me in a couple of years if the FC line was a single 100mm (the DZ) and also included a 125mm and maybe even an 80mm ?

 

Would be very tempted by the 125 if they did John, fingers crossed!

[Stardust1]

19 hours ago, John said:

I have the feeling that a 125 doublet might be along sometime. I may be wrong but it would not surprise me in a couple of years if the FC line was a single 100mm (the DZ) and also included a 125mm and maybe even an 80mm ?

 

Takahashi might produce more doublets as they have stopped production of the FSQ-130ED. Now they may have more time for other scopes. Hopefully it will be an FC-140 or better FC-150 with sliding dew shield. Only time will tell 😉

There is already an excellent TSA-120, when cooled it will produce stunning views. It's not that heavy for an 120mm scope. If you can cope with a little longer cool down compared to a doublet, then the TSA-120 is the way to go in the 120-125mm range.

 

[Stu]

1 hour ago, Stardust1 said:

Takahashi might produce more doublets as they have stopped production of the FSQ-130ED. Now they may have more time for other scopes. Hopefully it will be an FC-140 or better FC-150 with sliding dew shield. Only time will tell 😉

There is already an excellent TSA-120, when cooled it will produce stunning views. It's not that heavy for an 120mm scope. If you can cope with a little longer cool down compared to a doublet, then the TSA-120 is the way to go in the 120-125mm range.

 

I think the TSA-120 is a far bigger and  heavier scope than an FC125 would be so I would rather they produced something in this range, 125 to 130 to keep it manageable.

It's a nice game to play anyway, we will see what, if anything, they come up with 👍👍

[Stardust1]

43 minutes ago, Stu said:

I think the TSA-120 is a far bigger and  heavier scope than an FC125 would be so I would rather they produced something in this range, 125 to 130 to keep it manageable.

It's a nice game to play anyway, we will see what, if anything, they come up with 👍👍

If Tak stretches the design philosophy of the FC-100D to a FC125, then yes it will be lighter then the TSA-120. 

To me the 120mm apo is a no mans land refractor. It doesn't excel in weight, it's heavier then a 4". It's just a little brighter then a 4". It doesn't give me the wow factor over an FC-100D or an FS-102. The TSA-120 is brighter then a FC-100D on deepsky, but on the planets (Jupiter) these scope are very close. I have compared these scopes many nights side by side in excellent seeing on Jupiter.  In the end I sold the TSA-120 and kept the FC-100D. A 140mm, like my TEC-140 is a wow on Jupiter compared to my FS-102.

Though I do love the portability of a FC-100D. I think these small scopes are one of the best 4" around for visual use. The jump from FC-100D to a FC-140 or FC-150 will be huge 😉

I'm looking forward to the first reviews of the FC-100DZ.

Edited July 10, 2019 by Stardust1

[Axunator]

On 10/07/2019 at 01:48, Highburymark said:

Ok thanks John. Significantly heavier than the 2.8kg DC and 4cm too long for airline bags. 

Focuser in FC-100D’s is easy to screw off and on without tools for ultra-compact transport if needed - that will shave appr. 10 cm off the length (don’t have my DF now at hand to measure exactly but that’s the ballpark figure), and I presume this will apply also to the DZ.

However, with the dew shield screwed off the DF is even shorter than DZ due to its 6 cm shorter f.l. But then you have to protect the lens somehow and pack the dew shield safely to protect it from getting bent out of shape. So I’d feel safer to travel with the new DZ...

Edited July 11, 2019 by Axunator

[Highburymark]

On 11/07/2019 at 08:29, Axunator said:

Focuser in FC-100D’s is easy to screw off and on without tools for ultra-compact transport if needed - that will shave appr. 10 cm off the length (don’t have my DF now at hand to measure exactly but that’s the ballpark figure), and I presume this will apply also to the DZ.

However, with the dew shield screwed off the DF is even shorter than DZ due to its 6 cm shorter f.l. But then you have to protect the lens somehow and pack the dew shield safely to protect it from getting bent out of shape. So I’d feel safer to travel with the new DZ...

Indeed - I've taken my DC abroad three times now by unscrewing the focuser and dew shield - works well but still not ideal for such an expensive telescope. 

[mikeDnight]

On 09/07/2019 at 12:08, 883 said:

I’m thinking what’s really new in this scope... Make sense a f8 when you have a f.7.5? A new lens? I just bought a f7.5...😢

http://www.takahashijapan.com/ct-news/news_topics/news_19VII09_fc-100dz.html

883

The DZ uses a different mating element and offers better colour correction than even the DL, though I doubt anyone would notice the difference visually. I think the DZ is primarily aimed at the imager, although it's a remarkable visual scope too. It also appears to be the replacement for the TSA102 which has now been discontinued. The sliding dew shield seems pretty pointless to me, as it only has 80mm of travel and I don't care much for it.  Optically, scope itself is pretty awesome, but so is the DC, DF, & DL. I wouldn't lose too much sleep over which performs better visually! I had a DC before buying a DZ, and the DC has proved to be my most used scope, showing me more than any other,  simply because I used it on virtually every clear night throughout the five years I had it. The biggest real difference between the DC and the DZ, and one that you would definitely notice, is that the DZ is around a £1000 more expensive.

Edited February 8 by mikeDnight