30 replies to this topic

[Joe G]

Here are the results of my Orion EON 120mm F7.5 FPL 53 doublet.  Seems about right?  Experts chime in.

 

Green:

 

 

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[Joe G]

Red:

 

 

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[Joe G]

Blue:

 

 

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[Joe G]

White:

 

 

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[Elusivephotons]

Hey Joe, I have the Skywatcher version of this scope so I'm definitely interested in these results.  Would it not make sense to run these images through the DPAC evaluation software out there?  (I think it's available?)  This would give you some numbers to work with anyway... 

[CHASLX200]

Looks like it is pretty good.

[Joe G]

Hey Joe, I have the Skywatcher version of this scope so I'm definitely interested in these results.  Would it not make sense to run these images through the DPAC evaluation software out there?  (I think it's available?)  This would give you some numbers to work with anyway... 

Yes it would.  I just started this DPAC thing.  Now much more comfortable.  I'll tackle that next.

 

I am sure Maciek's program isn't too difficult.  Just another thing to learn.

[Scott in NC]

Spherical correction looks pretty good in green (almost no significant SA to speak of), with mild undercorrection in red and mild overcorrection in blue.  I can’t tell if there are any zones or not.  Try to work on getting better focus on the “at focus” images.  Unfortunately, I can’t explain exactly how to do it.  That’s just something you’ll have to fiddle around with, and you’ll know good focus when you see it.  
 

Nice job, though—look how much progress you’ve made since the weekend!

[Joe G]

Spherical correction looks pretty good in green (almost no significant SA to speak of), with mild undercorrection in red and mild overcorrection in blue.  I can’t tell if there are any zones or not.  Try to work on getting better focus on the “at focus” images.  Unfortunately, I can’t explain exactly how to do it.  That’s just something you’ll have to fiddle around with, and you’ll know good focus when you see it.  
 

Nice job, though—look how much progress you’ve made since the weekend!

Yep.  I think this is typical of this lens.  Largely highly regarded.

 

I do wrestle with the in focus images.  I think I will take a few more shots in various increments and see what you think.

 

I am waiting for an adapter from Agena to test my two FSQs.  That should be interesting.  Not a huge sample but better than just one.

 

I need to get my technique down just a bit more and then run it through Maciek's program.  Maybe redo them all.

 

The Ronchi eyepiece that I have been using is the one I cobbled together.  It is a 2" extension tube with a 2" square glass plate Ronchi screen with a 2" eyepiece cap cut into two.  What is nice is that I don't need to switch out the eyepiece.  I can just pull out a LED and insert another.  I can take all four colors in about 15 minutes.  Don't need to reposition the camera.

[peleuba]

Nice job, though—look how much progress you’ve made since the weekend!

 

Agree.  Big improvement.  You are on your way, Joe.   

 

Maybe a little less brightness on the LED.  On my tester, I included a potentiometer which allows you to throttle the LED back so its not so bright.  You only want it as bright as needed to show the detail.  Too much light and the subtle features of the lens surface are washed out.

[Elusivephotons]

Hey Joe. Just curious if you had a chance to run these through the analysis program? Or if you have any intention of doing so?

[Joe G]

So here is what I just did.  Seems consistent that most think these are really nice lenses. 

 

Green.

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[Joe G]

Red

 

 

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[Joe G]

Blue

 

 

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[Joe G]

Seems really nice for a FPL 53 doublet.  These lenses have a great reputation.

[John Huntley]

Those results seem consistent with the ones that Herr Rohr was getting with ED120's when he tested them a few years back. 

[RAKing]

I have been very pleased with my 120 EON the past few years.  Looks like yours is very good, too.

 

Nice work!  

 

Ron

[Jeff B]

A very nice sample and keep up the good work Joe.

 

As Paul suggests, reduce the brightness of the red and blue LEDs to eliminate overexposure/blooming of those images, which will increase contrast.  Also use Maciek's program on images from both sides of focus as a nice check on your process.   You should get good "agreement" (though you seem to be doing a very nice job with it).

 

Your objective is "behaving" very similar to my early SW sample of the same objective: smooth, with nice edges and best correction in the green to  green/blue portion of the spectrum.  Visually there is no coma or astigmatism at high magnification.  A very sharp, low scatter objective really.

 

Joe, what are your visual comments?

   

Jeff

[SandyHouTex]

Here are the results of my Orion EON 120mm F7.5 FPL 53 doublet.  Seems about right?  Experts chime in.

 

Green:

I have one of these and it is a excellent both optically and mechanically.

[Spikey131]

I have been very pleased with my 120 EON the past few years.  Looks like yours is very good, too.

 

Ron

They look good on the outside as well….

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[RAKing]

They look good on the outside as well….

 

I agree!  Even though it doesn't matter quite as much as the optics and mechanics, this is the most beautiful telescope I ever owned.

 

Ron

 

[Joe G]

A very nice sample and keep up the good work Joe.

 

As Paul suggests, reduce the brightness of the red and blue LEDs to eliminate overexposure/blooming of those images, which will increase contrast.  Also use Maciek's program on images from both sides of focus as a nice check on your process.   You should get good "agreement" (though you seem to be doing a very nice job with it).

 

Your objective is "behaving" very similar to my early SW sample of the same objective: smooth, with nice edges and best correction in the green to  green/blue portion of the spectrum.  Visually there is no coma or astigmatism at high magnification.  A very sharp, low scatter objective really.

 

Joe, what are your visual comments?

   

Jeff

I just got a potentiometer to add to the mix.

 

I just got this scope a few months ago.  Have used it once and it seems nice.  The sun doesn't shine in California anymore.

[Jeff B]

And it's bino-frendly cousin from Sky Watcher.

 

A very satisfying combination of aperture, quality optics, weight/envelope and mechanics, especially with the ML 2.5"  focuser.

 

Jeff

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[Joe G]

I agree!  Even though it doesn't matter quite as much as the optics and mechanics, this is the most beautiful telescope I ever owned.

 

Ron

 

120 EON 102522.JPG

The first refractor I purchased was an Orion Express 80mm achromat.  William Optics made an "APOgrade" FPL53 replacement. I still have the scope but it isn't at my house so I can't test it.  But that black anodized tube.  Wow.  It is the same anodized finish of the EON 120.

 

So I always wanted the EON 120 and that tube.  I have to agree.  It is the most beautiful telescope tube I have ever owned.

[dawnpatrol]

I agree!  Even though it doesn't matter quite as much as the optics and mechanics, this is the most beautiful telescope I ever owned.

 

Ron

Same here. I've been impressed with the optics and mechanics of mine and it's really a beautiful scope. 

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