Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Takahashi Starbase 80 - My User Notes

  • Please log in to reply
57 replies to this topic

#51 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1884
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 09 November 2019 - 04:13 PM

I appreciate Takahashi's dedication to the amateur community and long standing traditions of making a product that gets out of the way. I also appreciate these reviews and respect those for posting as they see it. Of course everyone(?) here knows these are not claimed to be Takahashi telescopes, but one they are willing to be associated with in what I'd like to believe is a good faith effort to get folks off on the right foot in this hobby.
I think the answer why people think so highly of Takahashi is merit based. Specifically, their designs and optical characteristics provide those answers. However, the nagging of peoples' expression of joy and appreciation for their Taks is too getting old and annoying. There are other brands of telescopes, in particular, where one will get flamed for offering anything but praise. I'm fine with that. It would be interesting to know what incenses people so much with this particular company's following; it seems to be a passion to itself.

Yep, there are a few other companies too that have this cult like, groupie mentality and it doesn’t make sense.  It’s like...are these folks on the payroll? Do they get a nice check at Christmas time every year for their support? Is there something else that we’re missing as to why the extreme fervor that occurs over specific brands? I like various brands too and have tried many but these companies aren’t charities.  They are businesses and their goal is to make money.  How they do that is by making products that satisfy enough users needs for a fair price.  That’s it.  That’s where it ends.  I currently am enjoying my Explore Sci triplet but the minute I decide to upgrade and possibly get something else I won’t feel like I’m cheating on anyone.  Ya know?

 

that being said, I’ll probably buy a TAK at some point here but I won’t treat it like it’s the lost ark or the shroud of Turin.  It’s just a telescope.  A nice one, yes....but just a telescope. ;)


  • starmason, Bomber Bob and BFaucett like this

#52 starmason

starmason

    Explorer 1

  • *****
  • Posts: 92
  • Joined: 08 Jan 2006
  • Loc: Long Island, NY

Posted 09 November 2019 - 09:42 PM

Yep, there are a few other companies too that have this cult like, groupie mentality and it doesn’t make sense.  It’s like...are these folks on the payroll? Do they get a nice check at Christmas time every year for their support? Is there something else that we’re missing as to why the extreme fervor that occurs over specific brands? I like various brands too and have tried many but these companies aren’t charities.  They are businesses and their goal is to make money.  How they do that is by making products that satisfy enough users needs for a fair price.  That’s it.  That’s where it ends.  I currently am enjoying my Explore Sci triplet but the minute I decide to upgrade and possibly get something else I won’t feel like I’m cheating on anyone.  Ya know?

 

that being said, I’ll probably buy a TAK at some point here but I won’t treat it like it’s the lost ark or the shroud of Turin.  It’s just a telescope.  A nice one, yes....but just a telescope. wink.gif

Owner loyalty has been going on for centuries.  If a product delivers superior performance - like a car, telescope, eyepiece or other product and there are very few or no negative comments owner loyalty takes place on many occasions.  Takahashi has been consistently providing top quality products since their humble beginnings.  The same can be said for AP. TV, Stellarvue, Zeiss and Vixen - among a few others.  When a product provides consistent quality there will be repeat sales. 


  • payner likes this

#53 SandyHouTex

SandyHouTex

    Skylab

  • *****
  • Posts: 4137
  • Joined: 02 Jun 2009
  • Loc: Houston, Texas, USA

Posted 09 November 2019 - 10:57 PM

Thanks.  I had assumed it was not the Tak prism and this confirms that.  If it had been the Tak prism it would have offset the cost of the package somewhat.

 

That diagonal looks a little odd to me in two regards:

  • It reminds me of some undersized 1.25" mirror diagonals that look like they were adaptations of 0.965", but with a better housing in this instance.  The tip off is the 1.25" nosepiece and eyepiece holder appear to be wider than the diagonal body. 
  • I can't tell for sure from the image, but it looks like it has an aggressively narrow aperture stop, which would be necessary with an undersized mirror as well. 

That ubiquitous Celestron RDF package has all those finder feet options, makes it easy to find a fit to most tubes.

The mirror in the diagonal is the size of the body, 1 1/4 inches wide X about 1 15/16 inch long.  So it’s definitely not an undersized .965 inch mirror.  There are round baffles in the front and top to control light scatter, as with other high quality diagonals.  I can also say that I’ve used a 25mm Kellner with no vignetting,


Edited by SandyHouTex, 09 November 2019 - 11:03 PM.


#54 rgsalinger

rgsalinger

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5179
  • Joined: 19 Feb 2007
  • Loc: Carlsbad Ca

Posted 09 November 2019 - 11:03 PM

If you have nothing to say about the actual topic, then please use private messages or start your own thread. This thread is about a specific telescope and a specific report. Please stick to the topic at hand and please stop hijacking the thread which is about the Starbase refractor and NOT about who does or doesn't like Takahashi telescopes.

Rgrds-Ross


  • paul m schofield, Bomber Bob, clearwaterdave and 3 others like this

#55 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1884
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 10 November 2019 - 07:46 AM

Owner loyalty has been going on for centuries.  If a product delivers superior performance - like a car, telescope, eyepiece or other product and there are very few or no negative comments owner loyalty takes place on many occasions.  Takahashi has been consistently providing top quality products since their humble beginnings.  The same can be said for AP. TV, Stellarvue, Zeiss and Vixen - among a few others.  When a product provides consistent quality there will be repeat sales. 

I get it.  I probably didn’t say what I wanted to the right way.  Came out wrong.  Of course if you find a brand that keeps delivering you’re staying with it.  All good. :)



#56 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 8123
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 12 November 2019 - 07:34 PM

The mirror in the diagonal is the size of the body, 1 1/4 inches wide X about 1 15/16 inch long.  So it’s definitely not an undersized .965 inch mirror.  There are round baffles in the front and top to control light scatter, as with other high quality diagonals.  I can also say that I’ve used a 25mm Kellner with no vignetting,

I take it that you haven't actually measured the true mirror dimensions, as 31.75mm wide would be hard to fit considering that the nosepiece OD will be something like 31.5mm, and the nosepiece in the image seems to be a bit wider than the inner curve of the housing edges (which presumably defines the max mirror diameter.)  Looking at images more closely and taking a look at two cheapo 0.965" diagonals this one looks like it might be something in between, wider than the very narrow 0.965" but narrower than a standard 1.25", and with fairly large ledges/baffles that would compensate for potential wall reflections. 

 

I removed and measured my cheap "TPO" 1.25" dielectric mirror at 32.7mm wide and 45.7mm long (octagonal cut.)  GSO hybrid 1.25x0.965" diagonal seems to be the same as the TPO based on appearance and outer housing dimensions.  These have baffle threading (as does the Tak Prism) and the TPO has nearly 28mm ID for the nose piece while the Tak Prism is slightly wider.  There is a small lip for the eyepiece barrel in both the Tak prism and that mirror.   The outer housing dimension is over 43mm wide on the minor axis for the several actual 1.25" mirrors I have. 

 

Doing some rough estimates from the posted Starbase images I put the ledges at about 23mm ID.  I doubt that vignetting from that would be particularly noticeable with a 25mm field stop, but it would be there.  I see this even with the narrower field stops of 1.25" RACI's when using ~25mm field stops.  Visually, vignetting is not that noticeable until one is approaching an actual aperture limit--witness the many refractors with quite small fully illuminated fields (e.g. 12mm or less).  One can get some fairly good contrast in the center of the field with excessive baffling...but at the cost of illumination for wide field.  

 

Anyway, it would be useful to get some actual measurements of the diagonal particulars.  And of course the other paramount considerations are checking collimation of the diagonal and star testing for any astigmatism. 



#57 SandyHouTex

SandyHouTex

    Skylab

  • *****
  • Posts: 4137
  • Joined: 02 Jun 2009
  • Loc: Houston, Texas, USA

Posted 13 November 2019 - 11:39 AM

I take it that you haven't actually measured the true mirror dimensions, as 31.75mm wide would be hard to fit considering that the nosepiece OD will be something like 31.5mm, and the nosepiece in the image seems to be a bit wider than the inner curve of the housing edges (which presumably defines the max mirror diameter.)  Looking at images more closely and taking a look at two cheapo 0.965" diagonals this one looks like it might be something in between, wider than the very narrow 0.965" but narrower than a standard 1.25", and with fairly large ledges/baffles that would compensate for potential wall reflections. 

 

I removed and measured my cheap "TPO" 1.25" dielectric mirror at 32.7mm wide and 45.7mm long (octagonal cut.)  GSO hybrid 1.25x0.965" diagonal seems to be the same as the TPO based on appearance and outer housing dimensions.  These have baffle threading (as does the Tak Prism) and the TPO has nearly 28mm ID for the nose piece while the Tak Prism is slightly wider.  There is a small lip for the eyepiece barrel in both the Tak prism and that mirror.   The outer housing dimension is over 43mm wide on the minor axis for the several actual 1.25" mirrors I have. 

 

Doing some rough estimates from the posted Starbase images I put the ledges at about 23mm ID.  I doubt that vignetting from that would be particularly noticeable with a 25mm field stop, but it would be there.  I see this even with the narrower field stops of 1.25" RACI's when using ~25mm field stops.  Visually, vignetting is not that noticeable until one is approaching an actual aperture limit--witness the many refractors with quite small fully illuminated fields (e.g. 12mm or less).  One can get some fairly good contrast in the center of the field with excessive baffling...but at the cost of illumination for wide field.  

 

Anyway, it would be useful to get some actual measurements of the diagonal particulars.  And of course the other paramount considerations are checking collimation of the diagonal and star testing for any astigmatism. 

I'm not going to disassemble a brand new diagonal just to satisfy your suspicions.  I looked in the diagonal, past the baffles and the mirror goes all the way to the edge on both sides.  I then turned it over and measured the distance to the seams for the side plates and it was about 1 1/4 inches.  So I indeed did measure the mirror width.  The length was measured by putting a ruler on the 45 degree back and subtracting a little.  So I'm good within a 1/16th of an inch on that dimension.

 

The Starbase diagonal is well made and is not a cheap TPO diagonal.  Any comparisons to it are invalid.

 

So you have the actual measurements, and in use, there is no astigmatism.



#58 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 8123
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 13 November 2019 - 02:57 PM

No, I don't have the actual measurements.  You have given some estimates and left out the ledge/baffle diameter.  While estimating is fine as I don't expect people to disassemble everything, I also have to consider the demonstrated credibility/agenda of the source and what I can see in images.  It is like dealing with any salesman who is evasive about certain questions...perhaps they just don't understand the questions or perhaps they don't want to answer because the answers might not be flattering to the product.  We still don't even have measurements or estimates of those narrow appearing baffles on both ends. 

 

For example what I took from your comment about the 25mm Kellner not vignetting was:

  • Field stop not provided, and what I finally found in a thread was an image and measurement of 18.77mm  (I will call it 19mm accounting for some precision loss/bias measuring the inner diameter of a narrow curved surface with digital calipers.)  I will have to assume that is close enough to the actual.
  • 19mm field stop doesn't tell us anything useful about how a 1.25" diameter mirror diagonal performs for wide field low power.  Now if an eyepiece with a 25 or preferably 27mm field stop was utilized, then we would have some potentially valuable information.

I remain skeptical based as much on what hasn't been said or measured as by what has been said.  This is the difference between an attempt at a credible/objective evaluation that is useful, and somebody trying to sell something that might not be a good fit. 




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics