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Sharpstar 94mm f/5.5 ED Triplet Apo - First Impressions

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#1 rkille

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Posted 28 October 2020 - 09:11 PM

Just purchased the new Sharpstar 94mm f/5.5 ED Triplet Apo and thought I would share my first impressions.  As far as build quality everything seems good. I would probably give it a 4.5 out of 5 stars overall.   I can't yet comment on the visual or photographic quality since I am waiting for the clouds to clear.  I will post my observation impressions as soon as I have them.  I was not able to find any other reviews or reviews of the scope out there yet, so I thought I would start a thread and see if anyone else who has this scope would like to share their impressions as well.  Or if you are considering purchasing this scope, feel free to ask questions.  I've created a quick unboxing video here: https://youtu.be/44rVp85VXBA

 

I will be using this visually as well as with the following cameras.  ASI 294MC Pro, ASI 2600 MC Pro, Sony a7iii DSLR.  

 

 sharpstar_94.jpg

OTA Specifications:

Aperture: 94mm
Limiting star magnitude: 11.62
Focus ratio: f/5.5
Resolution: 1.28 angular seconds
Objective type: Triplet air-spaced APO (two extra-low dispersion ED glass)
Total length of the tube: 450mm (collapsed), 575mm (extended)
Focuser travel: 58mm
Dewshield outside diameter: 118mm
Tube outside diamter: 104mm
Accessories: Tube Rings, Dovetail Plate, Handle
Weight: 4.2kg (9.4lbs)

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA


Edited by rkille, 28 October 2020 - 09:24 PM.

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#2 Jim Waters

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Posted 28 October 2020 - 09:14 PM

Please post an update with astro images when the clouds clear.

#3 M11Mike

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Posted 28 October 2020 - 09:28 PM

Congrats and best of luck with your new scope. 

 

Quickie question - have you ever owned and used a 3.5"- 4.0" APO, like a TAK or AP???  (or even taken a good look at one)  



#4 rkille

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Posted 28 October 2020 - 09:46 PM

Thanks, M11Mike!  

Truthfully, no. I have not owned an APO in this size and would not call myself a "visual observer"  Mostly into astro-photography. But do visual on occasion. All my gear is listed on my genesisobservator.org website.  As part of the Toledo Astronomy Association and having friends who own similar scopes, as well as having attended several star parties I have had a chance to get my hands on and observe several similar scopes.  I especially have been wanting to get the TAK FSQ-106EDX4 since I got a good look at it at NEAF 2019.  This is no TAK for sure, but for the price, seems better then some scopes I have seen in the range.  Once I put it through the paces, I will be able to give a better assessment.    

 

As far as my visual review, I will be relying heavily on my friend who is a visual observer superstar and has been visually observing for 30+ years.  He owns many APOs and can spot the slightest of chromatic adoration from a mile away.  I will share his impressions as well. And hope to get impressions from other club members as well.  Hopefully this coming Saturday when he skies are set to clear.

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA     


Edited by rkille, 28 October 2020 - 09:59 PM.


#5 Rick Runcie

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Posted 29 October 2020 - 02:11 PM

Good luck with your new scope. I'm sure you'll get some fantastic images with it. I still marvel at the calendar you produced and gave me at WSP.  Clear and steady skies

Rick from NJ.



#6 rkille

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Posted 16 November 2020 - 06:04 PM

Visual Review

I've had the scope out at least 4 times now to do some visual.  Had several other club members also give their impressions.  In short, visually this seems to be a great scope. All visual observations were using the native 517mm focal length. Used several quality eyepieces from 23 to 8mm. My favorite was with the the Celestron 19 mm Luminos.  We looked at a variety of targets, such as M31, M13, M27, M45 and several others.  Stars were pinpoint with no chromatic aberration when in focus.   Perhaps more importantly, when using the smaller mm eyepieces we didn't see any false color in the airy disk of bright starts outside of focus.  Maybe there was a slight rim of magenta inside focus, but not everyone agreed.  Some saw it, others did not.  Also, if your very experienced you can see the slight difference in pinpoint sharpness toward the edge of the field of view.  But it is not at all noticeable unless you are looking for it and nothing that is not to be expected for a 4" scope with f/5.5 ratio.  I guess if I was to give a visual rating, it would be 4.5 out of 5 stars.   I am certainly not disappointed. 

 

I am not quite yet ready to give my photographic review, but my first impression has been good.  Before I give the review, I want to get the right adapter for the proper backspacing.  I did use the .8x focal reducer to snap a picture of M31. The backspacing with this adapter is 55mm.  My spacing was no where close, so of course the stars at the edge were egg shaped.  However, colors and starts at the center looked great. I didn't see anything to give me concern.  I was using a ASI 2600MC Pro APSC sensor for this.  Once I get the backspacing dialed into where it needs to be, I will share actual pictures.  I plan to use the following cameras, ASI 294MC Pro,  ASI 2600MC Pro and Sony a7iii Full frame mirrorless.  Stay tuned for more.

 

One more thing. - There is an option to screw in a 2" filter inside the scope.  

2in.jpg    .8x Reducer optional =>ss94reducer.jpg

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA


Edited by rkille, 16 November 2020 - 06:35 PM.

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#7 sergiodiaz

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Posted 21 November 2020 - 06:24 AM

Thanks for the reviews, Russell!

 

I'm interested in this scope as it seems like a good compromise in portability, aperture and f-ratio, at least on paper. 

One question, as the backspacing of the reducer is 55mm, I would expect that the coupling with DSLRs and mirrorless cameras wouldn't need fine tuning, or at least be "about right" with standard bayonet-to-M48 adapters. Did you try with your Sony A7III?

 

Sergio

Seville, Spain

http://sergiodiaz.eu

https://www.astrobin...rs/sergio.diaz/



#8 Stevan Klaas

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Posted 02 December 2020 - 07:17 AM

Just received mine yesterday, the TS one from Teleskop Service.

Looks great, really. And heavier than I imagined.

Came with a heavy carry case too, this the no reducer/flattener option.

I will need a low latitute kit to make it work with my M-Zero, to continue imaging without meridian flip, since the cables of the camera hit the tripod.

But the small counterweight is enough to balance it.

Regards,
Stevan

53290C64-596F-46D2-856A-09FDBCD236C3.jpeg
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#9 StarAlert

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Posted 06 December 2020 - 09:56 AM

Visual Review

I've had the scope out at least 4 times now to do some visual.  Had several other club members also give their impressions.  In short, visually this seems to be a great scope. All visual observations were using the native 517mm focal length. Used several quality eyepieces from 23 to 8mm. My favorite was with the the Celestron 19 mm Luminos.  We looked at a variety of targets, such as M31, M13, M27, M45 and several others.  Stars were pinpoint with no chromatic aberration when in focus.   Perhaps more importantly, when using the smaller mm eyepieces we didn't see any false color in the airy disk of bright starts outside of focus.  Maybe there was a slight rim of magenta inside focus, but not everyone agreed.  Some saw it, others did not.  Also, if your very experienced you can see the slight difference in pinpoint sharpness toward the edge of the field of view.  But it is not at all noticeable unless you are looking for it and nothing that is not to be expected for a 4" scope with f/5.5 ratio.  I guess if I was to give a visual rating, it would be 4.5 out of 5 stars.   I am certainly not disappointed. 

 

I am not quite yet ready to give my photographic review, but my first impression has been good.  Before I give the review, I want to get the right adapter for the proper backspacing.  I did use the .8x focal reducer to snap a picture of M31. The backspacing with this adapter is 55mm.  My spacing was no where close, so of course the stars at the edge were egg shaped.  However, colors and starts at the center looked great. I didn't see anything to give me concern.  I was using a ASI 2600MC Pro APSC sensor for this.  Once I get the backspacing dialed into where it needs to be, I will share actual pictures.  I plan to use the following cameras, ASI 294MC Pro,  ASI 2600MC Pro and Sony a7iii Full frame mirrorless.  Stay tuned for more.

 

One more thing. - There is an option to screw in a 2" filter inside the scope.  

2in.jpg    .8x Reducer optional =>ss94reducer.jpg

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA

I received my Sharpstar 94 EDPH from Camera Concepts yesterday. Out of the box it looked great. The only problem I had was with the focuser. Turning the course focuser knob was absolutely horrible. I couldn’t believe the QC sheet that came with the scope had the box checked for  “smooth focuser”. The fine focus was good, though.

 

So I disassembled the entire focuser and pinion to try and figure out what the issue was. It turned out to be the two set screws that hold the pinion in the focuser were too tight causing a very “clunky” rotation for just the course adjustment. After loosening them up just a bit, the focuser now works great.
 

After I fixed the focuser, I had a chance to take a look through the scope later last night. I concur with Russell. Stars are pin point and I couldn’t see any color at all... even on Sirius! This is my first “fast” APO (I own an f8 and f9 Tak and an f8 TEC), and the Sharpstar’s field curvature outside about the middle 20% is very obvious to me. Now, I know why these scopes aren’t recommended for visual. In the center, though the views were superb! I split Almach and Castor with perfect, beautiful airy discs. 
 

I can’t wait to see how it performs with the Apex 0.65x flattener/reducer. 


Edited by StarAlert, 06 December 2020 - 11:49 AM.

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#10 Stevan Klaas

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Posted 06 December 2020 - 11:20 AM

Hi,

Have not purchased yet the reducer, but my sensor is tiny, ASI183, 16mm diagonal.

Bad weather in Switzerland, so not tested yet.

Looking forward to seeing it in operation under my city center skies to begin. Not before January I guess.

And also keen to see what you get out of it !

Stevan

Edited by Stevan Klaas, 06 December 2020 - 11:22 AM.


#11 StarAlert

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Posted 06 December 2020 - 01:56 PM

Does anyone know what the threading is on the back of the 94EDPH focuser? I measure about 73 or 74mm. 



#12 sergiodiaz

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Posted 06 December 2020 - 02:48 PM

I don't own the scope, but according to TS Optics, it should be M74x1:

 

"[...] the reducer fits directly to the M74x1 internal thread of the focuser [...]"

https://www.teleskop...r-Teleskop.html

 

Does anyone know what the threading is on the back of the 94EDPH focuser? I measure about 73 or 74mm. 


Edited by sergiodiaz, 06 December 2020 - 02:49 PM.


#13 StarAlert

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Posted 06 December 2020 - 04:06 PM

I don't own the scope, but according to TS Optics, it should be M74x1:

 

"[...] the reducer fits directly to the M74x1 internal thread of the focuser [...]"

https://www.teleskop...r-Teleskop.html

Great... thanks!



#14 StarAlert

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Posted 07 December 2020 - 12:34 PM

Here are a couple images I took last night between lots of high clouds. I was using my ASI533MC. 

 

I gotta say WOW! I love operating at f3.6.

 

M31: 10s x 10frames with Astronomik UHC filter

M31
 
M45: 5s x 18frames with UHC filter
M45
 
 
Edit.... and this is from Bortle 7/8 skies. 

Edited by StarAlert, 07 December 2020 - 12:36 PM.

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#15 rkille

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Posted 07 December 2020 - 03:26 PM

Viking 1,

If you don't own the scope, not sure why you are posting pictures.  How is this relevant to the Sharpstar 94mm?

 

I just want to clarify that the Sharpstar scope is f/5.5 and f/4.4 with the .8x reducer.  

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Russell K.

genesisobservatory.org

Toledo, OH, USA



#16 StarAlert

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Posted 07 December 2020 - 05:12 PM

Viking 1,

If you don't own the scope, not sure why you are posting pictures.  How is this relevant to the Sharpstar 94mm?

 

I just want to clarify that the Sharpstar scope is f/5.5 and f/4.4 with the .8x reducer.  

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA

I don't know if this was meant as a reply to me (StarAlert), Viking 1 is based on the number of posts you make. 

 

I do own the Sharpstar 94EDPH (see post #9). Those images were taken with it, an Apex 0.65x reducer/flattener and my ASI533MC camera. 

 

So I'm running the Sharpstar at f3.6.  


Edited by StarAlert, 07 December 2020 - 05:13 PM.

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#17 rkille

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Posted 07 December 2020 - 07:41 PM

Gotha. I apologize.  That's cool that you are using with an Apex 0.65x reducer/flattener to bring it down to f/3.6.   

 

Here are a couple of pictures I took of the Sadr star region in Cygnus using the Sharpstar 94 with the .8x reducer at f/4.4  No filter.

Camera: APS-C sensor size using ZWO ASI 2600 MC Pro. 

 

Backspacing was correct at 55mm. At least I think it was. I measured with a caliper. 

 

I was very impressed.  Stars look decently round in the corners!  Hurray!  There is some very slight elongation of brighter stars in the bottom left and maybe also some in the bottom right.  But pretty acceptable.  Perhaps my image train is slightly tilted or something.  Although, everything is screwed in directly. There are no compression ring connections in my train.  Perhaps there was something else going on as well.  I don't think it would be a tracking issue, as I think would affect all stars.  I still need to try with my Full Frame Sony a7iii for the true test.  I will keep trying to dial this in.  

 

Single 60sec.  Downscaled to 2400x1600 

60s_2400x1600.jpg

 

Full scale 6244x4160 link here.

 

 

Single 15sec image Downscaled to 2400x1600 

15s_2400x1600.jpg

 

Full scale 15sec 6244x4160 link here.

 

 

I also took a picture of the Rosette this same night. Here is the final processed image. 

ShapStar 94mm with .8x Reducer/Flattener

Optolong-LExtreme filter

Full Moon

180s x 15 subs = total 45min.

No darks, flats, bias or any of that stuff.  Just a processed Sharpcap stack.

NGC2237_2400sFinal.jpg

 

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA


Edited by rkille, 08 December 2020 - 02:10 AM.

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#18 StarAlert

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Posted 09 December 2020 - 09:44 AM

I gotta say I really like the Sharpstar 94 with the Apex 0.65x F/R for EAA. Five to ten 10-sec subs seems to be sweet spot for near real-time viewing of faint DSOs. All images below were taken with the Optolong L-Pro and UV/IR filter. 

Eastern Veil: 10sec subs x 9

Eastern Veil L-Pro 9 x 10s

Double Cluster: 10sec subs x 9
Double Cluster 9 x 10s

 

 

10sec subs x 17. This one is really interesting to me. It’s the Bubble Nebula along with M52. But what is the muppet-like nebula photo bombing my image at the top? I can’t find any reference to it in SkySafari. 

Bubble & M52 17 x 10s

 

 

M45: I can’t believe how much nebulosity I can see after just nine frames. 10sec subs x 9.

M45 9 x 10s

 

 

And finally an image of M31 without the clouds. 10sec subs x 18.

M31 18 x 10s

 

 

Overall, I’m VERY happy with the SharpStar paired with the Apex reducer/flattener. I’m now able to see far more from my Bortle 7/8 skies than I ever was able to with just my TEC160. 


Edited by StarAlert, 09 December 2020 - 09:23 PM.

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#19 rkille

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Posted 09 December 2020 - 11:43 AM

StarAlert,

Thanks for the pictures. The muppet-like nebula you refer to is most likely SH2-159

This picture should help.

 

bubble-region.jpg

________________________________________________________________

Russell K.

genesisobservatory.org

Toledo, OH, USA


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#20 Stevan Klaas

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Posted 09 December 2020 - 06:04 PM

Hi,

Here is my first light on Iris Nebula. It is one sub exposure of 180 sec in luminance with the ASI183 Mono. Focus was manual with SGPro history feature.

Just a stretch.

Good surprise is that it is quite fast, even compared with my previous Newton f4.5.

Bad one : I didn’t imagine that a refractor could yield such a deformation of the stars, it is comparable to a Newton without coma corrector !

I thought I could use it without flattener, obviously not...

I’ll have to get one, or a reducer/flattener 😒

Stevan

Attached Thumbnails

  • EB61D65D-8674-4D3B-91AA-DC63A862CA90.jpeg

Edited by Stevan Klaas, 09 December 2020 - 06:05 PM.

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#21 Cbaxter

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Posted 09 December 2020 - 06:13 PM

For the owners of this scope; It is quite fast which is very appealing to me for a casual AP/EAA scope, but I am wondering how much CA shows up in images (I wouldn't be using it visually at all). I don't mind some CA, just curious on the extent of it strictly from the experience of owners who have imaged with it. If possible a single unedited sub to look at would be much appreciated.

I may just order one since I found some in stock and astro gear seems to be out of stock often these days.

Thanks and clear skies!

#22 StarAlert

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Posted 09 December 2020 - 07:23 PM

Hi,

Here is my first light on Iris Nebula. It is one sub exposure of 180 sec in luminance with the ASI183 Mono. Focus was manual with SGPro history feature.

Just a stretch.

Good surprise is that it is quite fast, even compared with my previous Newton f4.5.

Bad one : I didn’t imagine that a refractor could yield such a deformation of the stars, it is comparable to a Newton without coma corrector !

I thought I could use it without flattener, obviously not...

I’ll have to get one, or a reducer/flattener

Stevan

Yes, you're going to need a flattener with this scope. I don't see anyway around it. My first light with this scope was with an eyepiece a couple nights ago. I could see field curvature outside of the middle 30%. But this is to be expected when you get into fast scopes, whether it's coma with fast Newts or field curvature with fast APOs. 


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#23 StarAlert

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Posted 09 December 2020 - 07:26 PM

For the owners of this scope; It is quite fast which is very appealing to me for a casual AP/EAA scope, but I am wondering how much CA shows up in images (I wouldn't be using it visually at all). I don't mind some CA, just curious on the extent of it strictly from the experience of owners who have imaged with it. If possible a single unedited sub to look at would be much appreciated.

I may just order one since I found some in stock and astro gear seems to be out of stock often these days.

Thanks and clear skies!

I might be able to do this tonight if the skies stay clear long enough. How long of an exposure do you want? 



#24 Cbaxter

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Posted 09 December 2020 - 07:41 PM

Hi!

That'd be great if you get the opportunity. 60-120 seconds should be just fine, with only a luminance or uv-ir cut filter in place. If you don't get the opportunity, I would also appreciate your written opinion on the CA you encounter during post processing. Thanks!

Clear skies!

#25 StarAlert

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Posted 09 December 2020 - 07:48 PM

Ok. I’ll see what I can do. I don’t do any post processing. All the images I’ve posted are stacked using ASILive and I just save the image.


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