4.5 to 5inch Apos….

[Neutrinosoup]

Are there any decent quality lightweight apo refractors in the 5 inch range or are they all beginning to get too heavy for Grab and Go??

At 4 inches there’s the Tak FC-100DC that’s as light as most 3 inch apos….

Are there equivalents to this moving up an inch?

thanks,

Niall

[Nik271]

https://www.firstlightoptics.com/telescopes-in-stock/stellamira-125mm-ed-doublet-f78-refractor-telescope.html

OTA is only 4.7 kgs. I don't know of anything lighter among the 5 inch refractors. 

But it's obviously long (almost a meter at F7.8)

 

[John]

4 minutes ago, Nik271 said:

https://www.firstlightoptics.com/telescopes-in-stock/stellamira-125mm-ed-doublet-f78-refractor-telescope.html

OTA is only 4.7 kgs. I don't know of anything lighter among the 5 inch refractors. 

But it's obviously long (almost a meter at F7.8)

 

Just what I was going to post !

My ED120 is around 1kg heavier than that.

Borg make very lightweight refractors and the 125sd might be a touch lighter than the Stellamira 125 but I've no idea if they are still available.

 

 

Edited February 23 by John

[dweller25]

The Askar 120 triplet OTA is 5.7Kg

Including tube rings and dovetail it’s 6.5Kg

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

[dweller25]

And here is a 120mm doublet Fluorite from Agema

https://www.agemaoptics.com/telescopes/agema-sd-120/

Edited February 23 by dweller25

[dweller25]

And the Vixen 115mm at 4.4Kg

https://www.harrisontelescopes.co.uk/acatalog/vixen-sd115-.html

[Elp]

Define light.

Borg are generally the lightest around but only go up to 107mm with the current range.

[Mumia]

If you can get it somewhere, I recommend the TMB 115. A beautiful, handy refractor. Super Feathertouch focuser, which is extendable and works with any type of bino. Dew is retractable. It may not be the lightest, but it's short. The images are delicious! Below is a comparison with Takahashi 100.

The following refractor with a certified lens, with strhel 96.8. So qualitatively, he is in the same league as his Japanese colleague.

[Mumia]

I only recommend the Kruppax tube because it is 2x lighter than CNC

[DirkSteele]

Its quite tricky.  One you move to 5" inches as an optical designer you start to have to make choices.  Keep chromatic aberration controlled means with a doublet a longer focal length and hence longer scope which is heavier because there is more of it (plus a greater moment arm meaning more robust mounting solution) or move to triplet which adds more heavy glass and bigger lens cell which increases weight but allows the focal length to remain shorter so less tube weight and perhaps a lower moment of inertia.

I guess there is also the question of what you consider grab and go.? I also have the LZOS 115 and have taken that all over the place but including mount (plus perhaps counterweights), tripod, finder and eyepieces etc, I am still getting up into the mid-teens or more in kg which many might not consider truly grab and go.  Conversely, my Tak FC-100DC on a Gitzo Carbon Fibre tripod and Sightron Alt Az mount is staying under 6kg and I can carry around with one hand.

As it is, I cannot think of much else available that has not already been mentioned.

Edited February 23 by DirkSteele
extra info

[Icesheet]

6 minutes ago, DirkSteele said:

As it is, I cannot think of much else available that has not already been mentioned.

I’ll add the Tak TSA120!

[Deadlake]

1 hour ago, Mumia said:

If you can get it somewhere, I recommend the TMB 115. A beautiful, handy refractor. Super Feathertouch focuser, which is extendable and works with any type of bino. Dew is retractable. It may not be the lightest, but it's short. The images are delicious! Below is a comparison with Takahashi 100.

The following refractor with a certified lens, with strhel 96.8. So qualitatively, he is in the same league as his Japanese colleague.

You much does the TMB 115 weigh?

The 105 mm with a FT3545  is  around 7 kg, however compacts to 495 mm long...

I took it out to Albury cricket ground last night and although the moon was out managed to see some nebulosity around Orion, with no filter and a APM 100 mm UFF in.

Last night was also colder then expected, the Kruppax tube kept the dew away! 

To be honest it's all about how much mount can be transported, the scope choice then flows from that.

Edited February 23 by Deadlake

[DirkSteele]

5 minutes ago, Deadlake said:

You much does the TMB 115 weigh?

The 105 mm with a FT3545  is  around 7 kg, however compacts to 495 mm long...

I took it out to Albury cricket ground last night and although the moon was out managed to see some nebulosity around Orion, with no filter and a APM 100 mm UFF in.

To be honest it's all about how much mount can be transported, the scope choice then flows from that.

In my old form with the sliding drawtube and 2" Feathertouch is was about 6.4kg I think which was about the same as my 2" FT 105.  I now have a 3" on the back and the weight is a little higher.  But call it 7kg, Ercole is 3kg (needs a counterweight at this weight to be super smooth so add 5kg plus bar), Gitzo Series 5 is 2.8kg and then finder and diagonal etc and mid teens kg.  Hence good to know what one considers grab and go (I think this).

[F15Rules]

+1 for the Vixen SD115S F7.7, barebones tube weight 4.4kg. A good deal lighter, shorter, slimmer than my wonderful ex Tak FS128.

Cheaper than some 4" Taks with almost 1/3 additional aperture..very noticeable.

Dave

[Deadlake]

29 minutes ago, DirkSteele said:

In my old form with the sliding drawtube and 2" Feathertouch is was about 6.4kg I think which was about the same as my 2" FT 105.  I now have a 3" on the back and the weight is a little higher.  But call it 7kg, Ercole is 3kg (needs a counterweight at this weight to be super smooth so add 5kg plus bar), Gitzo Series 5 is 2.8kg and then finder and diagonal etc and mid teens kg.  Hence good to know what one considers grab and go (I think this).

Well the AZ75 is 4.5 kg and using a carbon tripod around 8 kg in total. 
The main difference is a 130 mm will work quite well on it. 
The only reason I did not take the 130 mm was the child seat in the back and I was already late. The boot was full of a dog crate.

[John]

1 hour ago, Mumia said:

I only recommend the Kruppax tube because it is 2x lighter than CNC

Plus, it's immune from dew 🙂

[Mumia]

1 hour ago, Deadlake said:

You much does the TMB 115 weigh?

The 105 mm with a FT3545  is  around 7 kg, however compacts to 495 mm long...

I took it out to Albury cricket ground last night and although the moon was out managed to see some nebulosity around Orion, with no filter and a APM 100 mm UFF in.

Last night was also colder then expected, the Kruppax tube kept the dew away! 

To be honest it's all about how much mount can be transported, the scope choice then flows from that.

OTA 5,5 kg Kruppax

Edited February 23 by Mumia