131 replies to this topic

[Sarkikos]

I can warm up my core well enough.  It's the hands that get cold easily and stay cold.  I have Raynaud's Syndrome.  https://www.google.c...nNTAWPaBjFzAAAA  Even indoors sometimes the ends of my fingers have a slight purplish hue.  I've actually learned to consciously increase blood flow to my hands to make my hands warmer.  But when it's really cold outside, it's just overpowering and my hands get icy cold anyway.  I guess I need to concentrate harder. 

 

Yes, I always wear a cord on my glasses when observing.  When viewing planets and other objects that require detailed viewing, I usually take the glasses off.

 

Mike

Edited by Sarkikos, 19 November 2020 - 12:36 PM.

[Jon Isaacs]

Last night I took out my ST80.  The weather was clear but cold, in the low 30's F.  I usually mount it on a Bogen 055XB tripod with either a MicroStar Deluxe or a 501HDV head.  But this time I used a Stellervue M2 on Manfrotto 058B.  This setup gave me much better stability and balance control with heavy eyepieces.  My selection of eyepieces was 41 Pan, 31 Nagler and 21 Ethos.  I had the TSFLAT2 screwed onto the barrel of a Baader 2" BBHS diagonal.  

 

M45, the Pleiades, was the main object for testing the TSFLAT2 with these eyepieces.  The 41 Pan and 31 Nagler both showed flat fields.  There was some astigmatism, but I think this was from my eyes, not the optical system.  I could see astigmatism with my progressive eyeglasses on or off, but much worse with them off.  My prescription is two years old, so it has probably changed.  The 21 Ethos, with the widest apparent field of view, showed the most astigmatism.

 

I took the three eyepieces back into my house and screwed a Dioptrx onto each one.  I looked at the Pleiades again through each eyepiece with Dioptrx - without my eyeglasses, of course.  For each, I dialed in the best correction with the Dioptrx.  Now the stars were pretty sharp from center to edge in the 41 Pan and the 31 Nagler.  However, the 21 Ethos still showed some aberration at edge of field when the telescope was focused at center, and vice versa.  It looked to me like a combination of FC and astigmatism.

 

One take away from this, for my own purposes, is that I will probably leave a Dioptrx on the 41 Pan, 31 Nager and 21 Ethos.  In the past I haven't liked using Dioptrx because with Dioptrxy I need to flip my eyeglasses on to see the sky naked eye and read charts, and then flip them off again to view through the eyepiece.  This makes star hopping a PITA.  But at these wide fields and low powers, finding the object shouldn't really be a big problem.

 

Mike 

 

I spent maybe 3 hours over two nights under magnitude 21 skies with the ST-80 and the TS-FLAT2 screwed to the body of the William Optics 2 inch diagonal.  I also experimented with spacing, placing on the barrel as well using spacers and pulling the eyepiece out to adjust the focuser.  

 

I used the 41mm Panoptic, the 31mm Nagler, the 21mm, 13mm and 8mm Ethos.  

 

The TSFlat2 screwed directly to the diagonal seemed to provide the best correction even the 41mm Panoptic seemed fine without additional spacing.  The specs says that shouldn't work. 

 

Like Mike, I found the 21mm Ethos to be the only one that presented significant aberrations.  I did do some comparisons with the TSFLAT2 and without, it definitely improved the view but it saw something similar to Mike, astigmatism of curvature.  

 

The view with the other eyepieces were very good, nearly perfect near the edge, even with a brighter star.  

 

Last night, after some time with the ST-80, I switched back to the AT-80LE, the F6, ED Doublet.  It's definitely better but not the same super wide fields of view.  With the AT-80LE, I pulled the 21mm Ethos out just a tad and it seemed near perfect.  

 

One test is to focus on star at the edge of the field and see if it is focus at the center. This is standard operating procedure with the NP-101, focus on any star anywhere and the field will be is focus.  The TSFLAT isn't quite that good in terms of consistency but it's very good.

 

And you'd have to be very picky not to think this $200 piece of gear doesn't make a big improvement in the field of an ST-80.

 

JOn

[tony_spina]

Well my TSFLAT2  came in today.  The plan is to test with the ST120 and ST80.  Will use with a APM 30mm UFF and 22 Nagler 

 

I will use the Astro-Tech dielectric diagonal with the nose piece removed and the TSFLAT2 attached directly to the diagonal body

Edited by tony_spina, 19 November 2020 - 08:13 PM.

[CubeDweller]

Ordered the ST80 (Orion) yesterday. Still need to pick out a diagonal and probably a new focuser, depending on what I find upon arrival of the scope.

Should be a fun project. Just bought a house with dark skies (live in Atlanta currently.)

[tony_spina]

Well my TSFLAT2  came in today.  The plan is to test with the ST120 and ST80.  Will use with a APM 30mm UFF and 22 Nagler 

 

I will use the Astro-Tech dielectric diagonal with the nose piece removed and the TSFLAT2 attached directly to the diagonal body

Ok so I had a brief time to test before the clouds rolled in.  I can say that this sample of the TSFLAT2 works.   The previous sample I got several months ago was defective, strong astigmatism across the entire field. Although a hassle to ship back to Germany, the folks at TS made it easy.

 

The best performance was with the APM 30mm UFF in both scopes.  The 22T4 Nagler had about 2mm of focus differences between the center and edge sharpness.  I didn't get a chance to try different spacing by lifting the eyepiece up.

 

Hope to try the 35mm Pan next

 

I must say it was nice panning with the 30mm in the ST120.  Can't wait to take it to a dark sky site

[CHASLX200]

A true flat field would be a sweepers dream.

[kklei940]

Ok so I had a brief time to test before the clouds rolled in.  I can say that this sample of the TSFLAT2 works.   The previous sample I got several months ago was defective, strong astigmatism across the entire field. Although a hassle to ship back to Germany, the folks at TS made it easy.

 

The best performance was with the APM 30mm UFF in both scopes.  The 22T4 Nagler had about 2mm of focus differences between the center and edge sharpness.  I didn't get a chance to try different spacing by lifting the eyepiece up.

 

Hope to try the 35mm Pan next

 

I must say it was nice panning with the 30mm in the ST120.  Can't wait to take it to a dark sky site

Tony, just wondering how the TSFLAT 2 worked with the 35 Pan. Also wondering if you could post a pic of how you had it set up. I have the AT Dielectric Diagonal and have an Orion ST-80 coming on Monday. Will also be picking up a 2" focuser soon. So it would basically be the same set up you have.

[BlueTrane2028]

I'm as open to spending money on this hobby as anyone out there... but objectively, is there anything that an ST80 or clone does that a OneSky 130mm reflector can't?

I find myself somewhat underwhelmed by the 90mm f/10 Orion that I found yesterday, I'm spoiled by reflector aperture.  Mars, the Moon, M42, it's clearly the weakest performer on all of them when compared to my reflectors.  Am I likely to feel the same way about an ST80? Variety is the spice of life, so I'm trying hard to resist selling the 90mm immediately (actually it is up for sale on Facebook, just for more than it's likely to bring... lowering the price would likely trigger a sale, but if someone feels like jumping in where it's at, I'm not going to say no).

[Ihtegla Sar]

The ST80 is capable of a much wider field of view than a One Sky. The One Sky is going to be limited to about a 2.5 degree field. The ST80 can do about a 4 degree field of view with the stock focuser and a 6 degree field if you install a 2" focuser.

The One Sky has a focal length of 650mm. Your 90mm f/10 has a focal length of of 900mm. The ST80 has a focal length of only 400mm. This allows it to have a wider field.

[hcf]

I'm as open to spending money on this hobby as anyone out there... but objectively, is there anything that an ST80 or clone does that a OneSky 130mm reflector can't?
 

The AWB does have strengths for visual. 

 

Some wins for the ST80/clones

 

1. It is more portable. Airplane/backpacking friendly: at less than 3lb, you can take it with a lightweight tripod and a fluid head in cabin luggage and have weight to spare. The AWB is compact, and could fit in cabin luggage but you would still need a table.
2. More versatile: Can be used as a guide scope for AP. Orion does sell a guider package with it.
3. Another example of versatility and a favorite of mine, is the opportunity to do beginners AP/EAA/Observational AP with it.  My $90 ST80 clone + $100 EXOS Nano EQ mount, cost me about the same as an AWB, but with  DIY added RA guiding, and a DSLR that I had, I could see by imaging way more than my 8" Dob with visual. Examples: Horsehead and Flame, Mag 13 Supernovae, Pluto  from Bortle 7 skies. If I had to this with an AWB it would cost me a lot more for the mount, just because the OTA is much  heavier.

Edited by hcf, 21 November 2020 - 11:14 PM.

[BlueTrane2028]

The ST80 is capable of a much wider field of view than a One Sky. The One Sky is going to be limited to about a 2.5 degree field. The ST80 can do about a 4 degree field of view with the stock focuser and a 6 degree field if you install a 2" focuser.

The One Sky has a focal length of 650mm. Your 90mm f/10 has a focal length of of 900mm. The ST80 has a focal length of only 400mm. This allows it to have a wider field.

Is a 2" focuser actually worth it in these? I know with a Newtonian, if your secondary isn't big enough, it won't light up the entirety of a wide 2" eyepiece.

A 6 degree actual field, now my interest is up.

[Tom Stock]

Is a 2" focuser actually worth it in these? I know with a Newtonian, if your secondary isn't big enough, it won't light up the entirety of a wide 2" eyepiece.

A 6 degree actual field, now my interest is up.

It's not going to be better on planets and globulars, or even the moon than your reflectors.  But it will do something they cant.  You can walk it outside, pan the sky with super low power wide field views in a matter of minutes.  For me that's huge. It takes 20 minutes to get my SCT set up, many many trips back and forth up and down the stairs for counterweights, dew shield, eyepieces, tripod, eq head, battery, ota, cables, etc. I can't even see polaris or enough area for alignment stars from my yard so a goto alignment isn't really possible.  When it clouds over, I have to do all that again in reverse.

 

BUT, I can walk outside and be using the ST80 in 15 seconds. I can move it around the yard to dodge trees.  When I get bored or clouded over, I can carry it right back inside on the equatorial mount with one arm, eyepieces in the other, and go do something else.  It gives me wide low power views that are impossible with my other scopes.

 

Better? No, just different.

Edited by Tom Stock, 22 November 2020 - 12:58 AM.

[Ihtegla Sar]

Is a 2" focuser actually worth it in these? I know with a Newtonian, if your secondary isn't big enough, it won't light up the entirety of a wide 2" eyepiece.

A 6 degree actual field, now my interest is up.

The ST80 is a refractor so there is no issue with the secondary not being big enough nor will the secondary cast a shadow if you use too low of a power.

There may be issues with field curvature but those have been reportedly corrected with the TSFLAT2 corrector. I haven't had a chance to test mine yet.

[Jon Isaacs]

The ST80 is a refractor so there is no issue with the secondary not being big enough nor will the secondary cast a shadow if you use too low of a power.

There may be issues with field curvature but those have been reportedly corrected with the TSFLAT2 corrector. I haven't had a chance to test mine yet.

 There can also be issues with the baffle placement.  This can cause vignetting.  When I put the 2 inch focuser on my ST-80, I removed the baffle and flocked the OTA TeleVue style.

 

Jon

[tony_spina]

I'm as open to spending money on this hobby as anyone out there... but objectively, is there anything that an ST80 or clone does that a OneSky 130mm reflector can't?

I find myself somewhat underwhelmed by the 90mm f/10 Orion that I found yesterday, I'm spoiled by reflector aperture.  Mars, the Moon, M42, it's clearly the weakest performer on all of them when compared to my reflectors.  Am I likely to feel the same way about an ST80? Variety is the spice of life, so I'm trying hard to resist selling the 90mm immediately (actually it is up for sale on Facebook, just for more than it's likely to bring... lowering the price would likely trigger a sale, but if someone feels like jumping in where it's at, I'm not going to say no).

The ST80 @400mm focal length with a 2" focuser will give you the widest views. Besides the wide views. I like the pinpoint star views that only a refractor provides.  

[tony_spina]

Tony, just wondering how the TSFLAT 2 worked with the 35 Pan. Also wondering if you could post a pic of how you had it set up. I have the AT Dielectric Diagonal and have an Orion ST-80 coming on Monday. Will also be picking up a 2" focuser soon. So it would basically be the same set up you have.

Didn't  get a chance to try the 35 Pan yet.. will get you a pic of the diagonal and TSFLAT2  later today 

[Ihtegla Sar]

There can also be issues with the baffle placement. This can cause vignetting. When I put the 2 inch focuser on my ST-80, I removed the baffle and flocked the OTA TeleVue style.

Jon

I've heard on some models the baffle can also reduce the aperture to 76 or 72. How did you get the baffle out?

[dmgriff]

 

Not that good a picture, sorry.

 

Generic ST80/rings (from ScopeStuff, a few years ago). Original 1.25in focuser. Large ScopeStuff focuser knob. Carry/Storage case from a little 80mm plastic spotter with tripod. Originally, I had a Lumicon 96% reflective diagonal on it. Now, that is on another scope. AT 1/10 lambda star diagonal and TV 45 degree erect image.

 

Doubt that I will ever part with this little scope. Glad I have it around.

 

Good viewing,

 

Dave

Edited by dmgriff, 22 November 2020 - 06:46 PM.

[Jon Isaacs]

The ST80 @400mm focal length with a 2" focuser will give you the widest views. Besides the wide views. I like the pinpoint star views that only a refractor provides.  

 

My Newtonians/Dobs provide pinpoint stars, assuming they're cooled and collimated and the seeing is sufficient.. 

 

For the ST-80 to provide reasonably sharp stars across a wide field of view, it takes very good eyepieces and the TSFLAT2. This is similar to a Newtonian with a coma corrector. 

 

Jon

[Jon Isaacs]

I've heard on some models the baffle can also reduce the aperture to 76 or 72. How did you get the baffle out?

 

It just slides out, it's held by friction.

 

Jon

[Jon Isaacs]

 

Not that good a picture, sorry.

 

Generic ST80/rings (from ScopeStuff, a few years ago). Original 1.25in focuser. Large ScopeStuff focuser knob. Carry/Storage case from a little 80mm plastic spotter with tripod. Originally, I had a Lumicon 96% reflective diagonal on it. Now, that is on another scope. AT 1/10 lambda star diagonal and TV 45 degree erect image.

 

Doubt that I will ever part with this little scope. Glad I have it around.

 

Good viewing,

 

Dave

 

 

 

 

Dave:

 

I like your scope.

 

A 2 inch focuser on a ST-80 changes it's personality. It becomes heavier, bulkier and more than twice as expensive. It becomes a one trick pony. Your scope retains the essential nature of the ST-80 with some nice upgrades. The focuser wheel is nice.

 

One comment:  I've found that with ST-80s, I can use a single ring as a clamshell, no need for two rings.  Standard Synta rings work.

 

My current Celestron ST-80 has a machined aluminum William Optics ring, it's wider, more robust but a single Synta ring does work.

 

 

Jon

[blastr42]

I'm as open to spending money on this hobby as anyone out there... but objectively, is there anything that an ST80 or clone does that a OneSky 130mm reflector can't?

Hi BlueTrane2028, the AWB is the scope I’m switching from to go to the ST80. I’ve owned the AWB for 6 years and I’ve fallen out of love with it for a number of reasons. Here’s why I am going from the OneSky 130 to the ST80.

1) Helical focuser, I hate it. The focuser is molded into the plastic and can’t be changed. Also, it has limited travel. Also ALSO, it’s off to the side, so large eyepieces/cameras put weird side loads on the secondary.
2) The telescoping arms for the secondary make it compact, but they can never be as rigid as a solid tube. Large eyepieces/cameras flex the arms, and the amount the arms flexes changes with altitude angle.
3) The tube is like a modern cellphone - well optimized for its intended purpose, but unable to me modified (I’m not talking about the baffles, or Teflon on the focused - I did those). The red dot finder has a semi-custom shoe and is on the secondary ring so you can’t change it to a right angle finder like I like (AND another finder would weigh to much).
4) The tube is mounted to a dovetail, not rings. You can’t add rings, because the tube is only the back half. With a dovetail and a fixed focuser, putting it on an EQ mount doesn’t work.
5) No EQ ability and a fixed-position side focuser means it doesn’t work for AP. You can’t balance the tube side to side (dovetail) or back to front (short dovetail on the back half).

As an all-in-one package, the AWB is fine for visual, but I want a scope that I can grow with. The ST80 has a cottage industry of mods and upgrades so you can learn about your scope and do more types of astronomy. If I like my ST80, I’ll be able to add additional features and acquire experience and hardware that’ll serve me well on $1,000 scopes - all for a MUCH lower entry point.

Is the AWB the most scope you can get for $200? Probably. But the compromises to fit it all into there means the scope gives up expandability and modification that would grow with the user.

Jeff

Edited by blastr42, 22 November 2020 - 08:31 PM.

[tony_spina]

My Newtonians/Dobs provide pinpoint stars, assuming they're cooled and collimated and the seeing is sufficient.. 

 

For the ST-80 to provide reasonably sharp stars across a wide field of view, it takes very good eyepieces and the TSFLAT2. This is similar to a Newtonian with a coma corrector. 

 

Jon

Not a fan of reflector diffraction spikes. 

Edited by tony_spina, 22 November 2020 - 09:11 PM.

[CHASLX200]

I would guess the TSFLAT2 cost a good bit vs what the ST80 cost.

[Jon Isaacs]

Not a fan of reflector diffraction spikes. 

It's only on bright stars that they are visible.  They don't bother me. 

 

Personally, I am OK with refractor views but realize that the reputation for pinpoint stars mostly comes from their being dim.  How often is Sirius a pin point?  

 

Jon