632 replies to this topic

[RichA]

The difference is more dramatic when the full spectrum is used, which is not the case with Ha solar or Ha NV observing, and when powers are above lowish to high.

 

Having said that, I have owned a 102mm F5 achromat for 20-years and use it for low power, deep sky, wide field observing visually or with a Ha filter and image intensifier for NV observing. For those uses, fast achromats are great.

 

Fast achromats can be had used at relatively low prices. They are a good bargain if you have the need for what they offer.

 

Bob 

You still get spherical aberration, even without the CA.  Can't filter  that out.

[jragsdale]

You still get spherical aberration, even without the CA.  Can't filter  that out.

Spherical aberration isn't inherent with a fast achromat, although it does become more difficult to correct the whole spectrum for spherical aberration the faster a lens becomes. What you're thinking of is field curvature or angular distortion that gets more prominent with a faster optical system.

[mdowns]

Back to the ads folks.

[Kasmos]

They sandcast the outer part of it, not the steel tube that focuses.

Who would have thought the drawtube was sand cast?

 

I don't own a TAK, and if they are like most others, there's a good chance the drawtube is not steel.

[SandyHouTex]

Who would have thought the drawtube was sand cast?

 

I don't own a TAK, and if they are like most others, there's a good chance the drawtube is not steel.

I own 8 Tak refractors and if they're not steel, they're chromed steel.  Too heavy for aluminum.  Maybe chromed brass but I doubt it.

 

And I have a minor in materials.

Edited by SandyHouTex, 04 September 2024 - 05:16 PM.

[Russell Smith]

https://www.cloudyni...ll-the-goodies/

 

If this has been posted, it deserves two. Terra is selling the FC-76 she purchased from Dave Trott. Sadly, not in the cards for me.

[CHASLX200]

https://www.cloudyni...ll-the-goodies/

 

If this has been posted, it deserves two. Terra is selling the FC-76 she purchased from Dave Trott. Sadly, not in the cards for me.

Guess she likes the AT80EDT or whatever it is better. I kinda hanker for another 3" Tak jack but on a speeding freeze until i move 7 scopes.

[Russell Smith]

Guess she likes the AT80EDT or whatever it is better. I kinda hanker for another 3" Tak jack but on a speeding freeze until i move 7 scopes.

Road trip, and it fits in whatever you are driving.

[CHASLX200]

Road trip, and it fits in whatever you are driving.

Ship that small thing. She is like a million miles from me and i am going offshore fishing for a while Thurs.

[cambutton]

https://www.facebook...2Y8UmQ3ZEZ6mdx/

 

 Astroscan in Pasco  Washington. Five RKE eyepieces and barlow. GEM adapter, bag, and sling. $475

[Russell Smith]

https://www.facebook...2Y8UmQ3ZEZ6mdx/

 

 Astroscan in Pasco  Washington. Five RKE eyepieces and barlow. GEM adapter, bag, and sling. $475

Wow. Thats alot of cash but with the full set of eyepieces, paperwork, accessories. also the whole package looks new.

[Kasmos]

I own 8 Tak refractors and if they're not steel, they're chromed steel.  Too heavy for aluminum.  Maybe chromed brass but I doubt it.

 

And I have a minor in materials.

I wouldn't think they'd use alumium or steel. I'd guess brass and chrome plated on older models or whatever that frosty satin finish is on newer ones. Put a magnet on it.

[Terra Nova]

Guess she likes the AT80EDT or whatever it is better. I kinda hanker for another 3" Tak jack but on a speeding freeze until i move 7 scopes.

You guessed wrong! It's my Questar that's taken it's place. The AT80EDT is a wonderful scope but a very different beast. It took the place of my TV Pronto.

[Retentive]

Astroscan in Fl.

https://www.facebook...909/?ref=search

[Russell Smith]

FL-90S.

https://www.cloudyni...ite-apochromat/

[Terra Nova]

Ship that small thing. She is like a million miles from me and i am going offshore fishing for a while Thurs.

More like 900 miles! You're off by a little bit more than three orders of magnitude.

 

I stated local pickup or delivery within a hundred miles or so because that is my preference, I never stated that I wouldn’t ship. I’ll ship contingent on agreed upon terms.

[Steve C.]

Lately I lists two prices for anything I have for sale - Pick up or Shipped. I include a fee for my time and trouble.

[cavedweller]

Parks Mount with Byers RA Gear and DSC; $450; Pickup only in Chico, CA:

 

https://astromart.co...hafts-tall-pier

[jgraham]

There's an original, early production 2080 LX OTA for sale in the CN Classifieds...

https://www.cloudyni...eade 8" SCT OTA

The secondary with only 2 adjustment screws dates the production. Optically my example is excellent. Mechanically there are a few quirks that only appear in these early models.

[Senex Bibax]

Not sure what this one is, but it is older, it's Japanese and it's 60mm x 800. Looks complete in the original wooden box. $50.00 CAD in Powassan, ON (150 or so km north of Toronto): https://www.kijiji.c...cope/1701665277

[SandyHouTex]

I wouldn't think they'd use alumium or steel. I'd guess brass and chrome plated on older models or whatever that frosty satin finish is on newer ones. Put a magnet on it.

A magnet doesn't stick, but stainless steel, at least the austenitic types aren't magnetic anyway.  The austenitic stainless steels like 304 and 316, the commonly used ones, aren't. 

[flywing1]

Tasco 60mm 152x , auction in North Syracuse, NY, focuser label says " TASCO coated, No. 21301", is this a really early one?

 

https://hibid.com/lo...ox?ref=lot-list

 

Meade LX200GPS telescope with EPs, auction in Winchester, VA

 

https://hibid.com/lo...es?ref=lot-list

[Kasmos]

Not sure what this one is, but it is older, it's Japanese and it's 60mm x 800. Looks complete in the original wooden box. $50.00 CAD in Powassan, ON (150 or so km north of Toronto): https://www.kijiji.c...cope/1701665277

Dai-Ichi Kogaku (DK)

[cavedweller]

There's an original, early production 2080 LX OTA for sale in the CN Classifieds...

https://www.cloudyni...eade 8" SCT OTA

The secondary with only 2 adjustment screws dates the production. Optically my example is excellent. Mechanically there are a few quirks that only appear in these early models.

 

Probably an insignificant observation, but the 2080 predates any LX naming schemes, no?

[CHASLX200]

Parks Mount with Byers RA Gear and DSC; $450; Pickup only in Chico, CA:

 

https://astromart.co...hafts-tall-pier

I could use it for my C11.