Is your OTA the only keeper on the long term? - Forums

Topic starter

Dec 23, 2023

Hello fellow astrophotographers.
I wanted to share a thought I recently posted in a thread on CloudyNights. I'm curious to know if you also share the idea that your optical tube assembly (OTA) is perhaps the one piece of equipment that can truly stand the test of time. I'd love to hear your thoughts on this!One thing I have learned over the years is that the single piece of equipment that will truly last a lifetime is the OTA. I have had my Televue NP101is since 2006, and I see no reason to trade it for any other OTA in the same segment. The same cannot be said for the mount, camera, and other electronically assisted components in your rig.That being said, if you are buying low to mid-range equipment, you can easily sell it in the aftermarket later on, so I wouldn't worry too much. If you don't like your OTA, you can go ahead and sell it quite quickly.If you are more inclined towards the high end of the spectrum, OTAs are not as easy to sell or trade unless you are considering giving it away at a ridiculously low price point.I would recommend choosing the OTA very carefully according to your needs since it is likely to be with you for a very long time, perhaps decades.As for the rest of your rig, obsolescence is inevitable at some point. For instance, the advent of harmonic mounts with strain wave motors in the hobby will eventually prompt us to trade our old mounts for some iteration of this new breed of mounts. Needless to say, a new camera with far better quantum efficiency, optimal pixel size for your focal length, and low noise is probably already on the design board in the engineering departments of the best brands out there.Cheers Guy

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Ped

Dec 24, 2023

Hi Guy. As you've mentioned, astro equipment have evolved substantially over the years. The evolution in CMOS cameras, with smaller pixels and more affordable and larger sensors, are placing greater strain on some optics. This has led to different optical designs or changes in some reducers/correctors in order to achieve better performance at the edge of frames - so never say never!

Having said all of this, I consider my AP130GTX to be a keeper

- Pedro

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Guillermo (Guy) Yanez

Topic starter

Dec 27, 2023

Hi Guy. As you've mentioned, astro equipment have evolved substantially over the years. The evolution in CMOS cameras, with smaller pixels and more affordable and larger sensors, are placing greater strain on some optics. This has led to different optical designs or changes in some reducers/correctors in order to achieve better performance at the edge of frames - so never say never!

Having said all of this, I consider my AP130GTX to be a keeper

- Pedro

Wow, if I had purchased the AP130GTX several years ago, I might still be paying it off, LOL. Congratulations on owning that scope—it must be a keeper, and, of course, it demands a sturdy mount to fully leverage its specs: Also in the AP family?In my case, I was fortunate enough to acquire the Televue NP system with a 2.4" drawtube exit, theoretically allowing for a full-frame camera (though I'm not entirely confident that stars would remain pinpoint all the way to the edge of the field). Moreover, the Petzval design is currently fitting for today's imaging needs, especially if you prefer avoiding the use of a field flattener or dealing with backfocus distance.I'd argue that refractors currently lead the way in terms of longevity for imaging. Old SCTs or Newtonians may not meet the requirements of today's new cameras, autofocusers, and rotators, among other things.That being said, there has to be someone out there currently achieving great results with a Meade LX200 OTA.

Guy

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Monty Chandler

Dec 27, 2023

Yes. The glass and mirrors in my scopes are indeed as good as they will ever be and if I take care of them they will never be any worse than they are right now.

Moore's Law will continue in the electronics field in sensors, computers, storage, etc so they'll all have better versions in the future. However, not obsolete as fast as one might think. Image acquisition doesn't take very much compute power at all. I remind myself that my DSLR (1Ds Mark III) was purchased in 2007 and it still takes awesome photo's that people purchase. The mounts, being mechanical, will indeed need maintenance or replacement. Future heavy telescopes may require these new mounts, but for now my eq6r pro does the job fairly well.

Also, I think there's a fair number of old folks, like me, who've only got a limited time left on the planet so thinking 10 or 15 years out isn't a priority. This reality keeps my gear in check.

I do envy the younger ones getting into this hobby. You'll be creating magnificent images.

Cheers!

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Bill McLaughlin

Perfect post

Dec 27, 2023

Mounts, especially the cheaper ones, have evolved a lot in the past few years. Having said that, with enough use belts and gears will wear out, bearings too although much more slowly. One reason I went to a direct drive L-350. No gears, no belts, just two big bearings and encoders with enough resolution that it greatly exceeds even good seeing. Should last essentially forever, which is why the Space Domain Awareness outfits use them - they just don't wear out.

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dkamen

Dec 27, 2023

Guillermo (Guy) Yanez:
Hello fellow astrophotographers.
I wanted to share a thought I recently posted in a thread on CloudyNights. I'm curious to know if you also share the idea that your optical tube assembly (OTA) is perhaps the one piece of equipment that can truly stand the test of time. I'd love to hear your thoughts on this!One thing I have learned over the years is that the single piece of equipment that will truly last a lifetime is the OTA. I have had my Televue NP101is since 2006, and I see no reason to trade it for any other OTA in the same segment. The same cannot be said for the mount, camera, and other electronically assisted components in your rig.That being said, if you are buying low to mid-range equipment, you can easily sell it in the aftermarket later on, so I wouldn't worry too much. If you don't like your OTA, you can go ahead and sell it quite quickly.If you are more inclined towards the high end of the spectrum, OTAs are not as easy to sell or trade unless you are considering giving it away at a ridiculously low price point.I would recommend choosing the OTA very carefully according to your needs since it is likely to be with you for a very long time, perhaps decades.As for the rest of your rig, obsolescence is inevitable at some point. For instance, the advent of harmonic mounts with strain wave motors in the hobby will eventually prompt us to trade our old mounts for some iteration of this new breed of mounts. Needless to say, a new camera with far better quantum efficiency, optimal pixel size for your focal length, and low noise is probably already on the design board in the engineering departments of the best brands out there.Cheers Guy

Well, yes, it's like lenses. My Nikkor DX 35mm f/1.8 AF wore four camera bodies in 9 years and I only stopped using it with the Z50 once the 40mm f/2 came out. Which is not that good, I must say, just similar enough and no-adaptor-enough for the move to make sense ergonomically

Rafał Szwejkowski

IOTD Staff

Dec 28, 2023 · Edited: Dec 28, 2023

The mounts are now going though a transition but after we reach a point when a generic harmonic mount drops to $999 for ~20-30 lbs. capacity things will slow down for mounts too (this should happen relatively fast due to the relative simplicity of the concept of "jerky but responsive" mount).

On the other hand cameras are stagnant after a period of rapid progress leading to IMX455/571 class chips.

For OTAs there's desire to make shorter FL scopes at a given aperture (marketing them as "fast") and also pushing cheaper designs to the limit, hoping that ubiquitous narrowband imaging won't reveal the mediocre optics. But as stated above, good scopes are a lasting investment, they don't become obsolete too quickly.

Guillermo (Guy) Yanez

Topic starter

Dec 28, 2023

Rafał Szwejkowski:
The mounts are now going though a transition but after we reach a point when a generic harmonic mount drops to $999 for ~20-30 lbs. capacity things will slow down for mounts too (this should happen relatively fast due to the relative simplicity of the concept of "jerky but responsive" mount).

On the other hand cameras are stagnant after a period of rapid progress leading to IMX455/571 class chips.

For OTAs there's desire to make shorter FL scopes at a given aperture (marketing them as "fast") and also pushing cheaper designs to the limit, hoping that ubiquitous narrowband imaging won't reveal the mediocre optics. But as stated above, good scopes are a lasting investment, they don't become obsolete too quickly.

I can't wait to see what is coming up next on harmonic mounts. It would be great if things move in the direction you are pointing at. I sometimes wonder if it is going to be Skywatcher that triggers the price drop in this segment. On the camera side, stagnant, yes perhaps, but it might be a short to mid term condition. I am not sure if that implies it is going to be the standard for years to come. Back a decade or two, we all thought CMOS would never kick CCD out of the market, that SBIG would be the undisputed long-term leader, and that the Kodak KAF 8300 was on the sweet spot of cost-efficient performance and would be in everyone's rig for a very long time. I still have my SBIG ST8300M lying around, but the 5.4-pixel size, unstable Windows driver performance with NINA, and slow imaging capacity (8 seconds to load a new frame) make me see why the new kids in town are superior in these respects. I think that since the surveillance camera market is growing at a high pace, new improved sensors suitable for low-light conditions are just around the corner.

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John Hayes

Frequent contributor

Exemplary contributor

Dec 28, 2023

It all depends on what you are after. I have a GTX130 and it is definitely a superb telescope so it might be hard to part with. It produces absolutely pinpoint stars corner to corner over a big chip. I started in the hobby with an 8” Newtonian that I built in 8th grade and refurbished in grad school—and yes, I still have most of the parts for that scope lying around. I then got a C14 (non-Edge) that I had for a few years before I sold it. After that, I got an Edge 14, that I really liked but it also got sold. For many years, I had a fantastic C14 Edge that was a totally custom scope with very high quality optics in New Mexico that I never thought that I’d get rid of, but the idea of putting a scope in Chile brought an end to that idea and now friend of mine owns and runs it. I thought that my 20” scope in Chile would be my last but after two years, I decided to sell it and move to a 24” scope. I suppose that the manufacturer made me an offer that I just couldn’t refuse. I’m not getting any younger so the 24” will probably be my last “big” scope. Those things aren’t cheap and I can’t see spending even more to get anything any bigger.

So, to directly answer the OPs question: No, I’ve owed way too many OTAs over the years to think that any of them are “keepers”. I don’t view telescopes as collector items. If it gets to the point where I’m not using a scope or want to try something different, I sell it and move on.

John

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