refractor Refractor size question…..

[Neutrinosoup]

Pretty much set on a the Tak FC-100DC (from a previous thread). Its low weight is a huge bonus for me.

Before I go ahead….are there any apos in the 110 to 120 zone that are similarly light or does size and weight  start to spiral significantly upwards at that stage? (Pretty sure the answer is yes…)

Thanks 

Niall

[Elp]

The Borg 107 is around the same weight as that Tak.

[Stu]

3 minutes ago, Neutrinosoup said:

Pretty much set on a the Tak FC-100DC (from a previous thread). Its low weight is a huge bonus for me.

Before I go ahead….are there any apos in the 110 to 120 zone that are similarly light or does size and weight  start to spiral significantly upwards at that stage? (Pretty sure the answer is yes…)

Thanks 

Niall

My view would be stick at the 100DC. Yes, things get heavier and longer fairly quickly as the aperture goes up. You could go for a shorter focal ratio in a larger aperture but the optics tend to get heavier due to the steeper curves required, and they have other compromises too.

Apologies if I’ve posted this too much before, but it shows the difference between the FC-100DC and the FS-128, 128mm f8.1. Obviously that’s bigger than you were suggesting but you can draw some conclusions by scaling from one to the other. Bear in mind that the FC-100DC is about the most compact 4” scope there is.

[Stu]

5 minutes ago, Elp said:

The Borg 107 is around the same weight as that Tak.

4.3kg vs 2.8kg

[Elp]

7 minutes ago, Stu said:

4.3kg vs 2.8kg

Looking at FLO both OTAs seem to be 2.8Kg. The Borg in astrograph config is 4.3, but the FT and Kansai focuser ones are the lighter ones. But I doubt those weights are even correct, as standard they should always list them as OTA weight and fully loaded with the supplied accessories separately.

Obviously the OP needs to consider the hardware too as it adds significant weight.

Edited November 23, 2023 by Elp

[Neutrinosoup]

8 minutes ago, Stu said:

My view would be stick at the 100DC. Yes, things get heavier and longer fairly quickly as the aperture goes up. You could go for a shorter focal ratio in a larger aperture but the optics tend to get heavier due to the steeper curves required, and they have other compromises too.

Apologies if I’ve posted this too much before, but it shows the difference between the FC-100DC and the FS-128, 128mm f8.1. Obviously that’s bigger than you were suggesting but you can draw some conclusions by scaling from one to the other. Bear in mind that the FC-100DC is about the most compact 4” scope there is.

Thanks!, that picture speaks a 1000 words!!!

[Elp]

Another thing you have to factor in is the balance due to the length. My SF102 is supposed to be 4.2Kg with the hardware but it feels significantly heavier in hand and when clamping it down you have to be mindful of the heavier glass up front and the torque it adds.

[MartianHill]

@Neutrinosoup

The new Askar 120 weighs 6.5kgs

https://www.firstlightoptics.com/askar-telescopes/askar-120-apo-triplet-refractor.html

 But those Fluorite 4” Takahashi’s are superb

Edited November 23, 2023 by MartianHill

[John]

There are many 80mm refractors that weigh more than the Tak FC100-DC does !

 

Edited November 23, 2023 by John

[Paz]

You are on the right track with the fc100 dc if you want a low weight high quality 4" refractor, I would be very happy with one of those.

[Mr Spock]

You won't get much better than an FC-100 

[Franklin]

Takahashi FC-100 is the best and the lightest top-notch 4" refractor available off the shelves. Some say they are expensive but you have to pay for quality just like everything else in life and they are a good deal cheaper than getting on the AP waiting list.

[mikeDnight]

I really like the SW 120ED which can be mounted on an EQ5 or Vixen GP, or an AZ4 for easier grab and go. I never found the 120ED to be particularly heavy, although it is significantly heavier than a FC100DC, but still an easy scope to carry and set up. But if you're looking for what is probably the best light weight 4" apo currently available the DC is outstanding. I had no regrets selling my SW120ED after observing with a FC100DC.

[Sunshine]

6 hours ago, mikeDnight said:

I had no regrets selling my SW120ED after observing with a FC100DC.

This pretty much says it all, I would not hesitate a bit on the DC.

[MartianHill]

12 hours ago, Neutrinosoup said:

Pretty much set on a the Tak FC-100DC (from a previous thread). Its low weight is a huge bonus for me.

Before I go ahead….are there any apos in the 110 to 120 zone that are similarly light or does size and weight  start to spiral significantly upwards at that stage? (Pretty sure the answer is yes…)

Thanks 

Niall

There’s an FC100-DZ in the for sale section

[Stu]

12 hours ago, Elp said:

Looking at FLO both OTAs seem to be 2.8Kg. The Borg in astrograph config is 4.3, but the FT and Kansai focuser ones are the lighter ones. But I doubt those weights are even correct, as standard they should always list them as OTA weight and fully loaded with the supplied accessories separately.

Obviously the OP needs to consider the hardware too as it adds significant weight.

Ah yes, I see that now. Looks like one is 2.7kg. Never tried a Borg.

The weight looks right for the Tak, and it doesn’t come with rings or a clamp, that’s extra so they can’t quote a loaded weight. I use 95mm MoreBlue rings, somewhat sacrilegiously, but find them lighter and suit the compact nature of the scope well.

[Neutrinosoup]

9 hours ago, MartianHill said:

There’s an FC100-DZ in the for sale section

Probably not what I want but where’s the “for sale” section? I don’t see it

[Cornelius Varley]

12 minutes ago, Neutrinosoup said:

Probably not what I want but where’s the “for sale” section? I don’t see it

The For Sale/Swap section with become available to you once you have reached the following requirements: at least 30 days membership and more than 25 posts (posts in the welcome section and non-astro lounge don't count towards this).