Gina's Esprit 80ED Pro Unboxing and First Impressions

[ollypenrice]

The stars are a million miles away from being acceptable. Dammit, something is creating those spikes. Hey, well done for the overall image but, no, the stars are not right. I'll stick my neck out and say that something is intruding into the the lightpath. If I'm wrong (I'm used to this  ) then I'll take it on the chin.

But how can 'random bad optics' create a neat set of  unwanted diffraction spikes? I don't believe it.

Olly

Edited November 13, 2013 by ollypenrice

[kirkster501]

Nice picture Gina but why do the stars have that "pink" hue? They don't look natural to my eyes.

[Earl]

This is without the flattener

Things could get better then

[ollypenrice]

This is one of those things for which a clear explanation will be found. The effects are clear and that's the main thing.

Olly

Edited November 13, 2013 by ollypenrice

[Adrian]

Let's just look at these stars. They have six evenly distributed spikes. This doesn't smack of pinching (triangular stars) or any other randomly generated effect because the effect is too regular. It smacks to me of six regularly spaced intrusions into the light path. So, first question, does the Esprit 80 have six lens clips? Are there any other possibilities for incursions into the lighpath? Dewsheild, OAG, F/W, filters, adapters? I'd advise Gina to pull the whole rig apart (again! I know, I know, I've been doing it all day myself sorting a new F/W) and peer through the%

Edited November 13, 2013 by Adrian

[r3i]

Nice picture Gina but why do the stars have that "pink" hue? They don't look natural to my eyes.

That's a common occurrence when combining individual NB images into a colour image.  See this thread for a similar example and methods to address it: http://stargazerslounge.com/topic/199303-flying-horse-nebula-ngc-7380/

[Gina]

Nice picture Gina but why do the stars have that "pink" hue? They don't look natural to my eyes.

When the Hubble Palette processing is applied the stars become pink/magenta.  Here is the same image with the pink removed.

Edited November 14, 2013 by Gina

[Gina]

Here is a copy of a post I inadvertently posted in my EQ8 thread by mistake - I had a rough day yesterday!

"I've brought all the kit indoors and had a good look through it.  There are no projections into the optical path that I can see.  In fact everything looks perfect.   It looks a really high quality scope."

Back to today...  I'll strip the kit down and see if I can take photos and then you can all take a look and see if you can see anything that could cause this problem.

[Gina]

The stars are a million miles away from being acceptable. Dammit, something is creating those spikes. Hey, well done for the overall image but, no, the stars are not right. I'll stick my neck out and say that something is intruding into the the lightpath. If I'm wrong (I'm used to this  ) then I'll take it on the chin.

But how can 'random bad optics' create a neat set of  unwanted diffraction spikes? I don't believe it.

Olly

I agree.  This is very puzzling.  The investigation continues...

[ollypenrice]

The aperture mask test would be indicative if it cured the effect. I've had a good hunt around on the web without finding anything like this aberration. The nearest to it, which wasn't all that near but was a generally spikey look, came from a turned down mirror. I don't know if a refractor lens can mimick such an effect.

Olly

[Gina]

The aperture mask test would be indicative if it cured the effect. I've had a good hunt around on the web without finding anything like this aberration. The nearest to it, which wasn't all that near but was a generally spikey look, came from a turned down mirror. I don't know if a refractor lens can mimick such an effect.

Olly

I'll try the aperture mask next time we get some clear night skies.  I hope I can get a round enough hole - I've got a hole cutter for card somewhere, have to see if I can find it Thank you for doing the web search

[Gina]

I'll take and post photos this afternoon.  This telescope does come apart - the focuser comes off the lens assembly and the dewshield unscrews too exposing the lens cell which is attached to the body with three collimation adjusting screws.  Within the body is a baffle which has 7 irregularly spaced slots at the edge where the thin metal is bent over and glued to the body tube.  When I saw them I thought "ah" - then I counted them and looked carefully at their spacing - these wouldn't cause the 6 pointed stars.  The lens elements are held in place by screw rings and what appear to be rubber rings.  There are no clips and as far as I can tell, no likelyhood of any untoward lens pressure/pinching.  The whole thing looks well made.

Edited November 14, 2013 by Gina

[Gina]

One plus point for this telescope I forgot to mention from my overnight unattended imaging run...  It has a nice long and effective dew shield   I haven't as yet made a dew heater for it and in spite of a quite horrendous dew with everything dripping with water, the objective lens showed no sign of dewing up   It was exposed to the dew all night from just after dark up until dawn and beyond.  Before I left it and went to bed I noticed the scope had just passed the meridian so I used CdC to re-slew back to the Heart from the other direction, and then used AT to get exactly back on target.  DSS coped fine with the mix of subs with 180 degree rotation in the middle of the run   So the scope was pointing near vertical for most of the time - the worst position for dew I would think.

SO it seems this scope can do without a dew heater most of the time   Now that I think is quite something

[Gina]

Here are the photos of the scope and the FW.  I can't see anythine that would cause the pointy stars - anyone else see anything?   I've included a photo of the lens mounting method which seems pretty foolproof to me.  Also to be seen are the collimation screws.  The whole thing seems well designed and well produced to me and I can't see why there should be any problems with it.

[Gina]

I think for testing the aperture reduction I can wedge the adapter that is used to attach the flattener to the focuser with some polyether foam in the dew shield and against the lens cell.  This is just over 80mm OD and around 60mm ID thus reducing the aperture from 80mm to 60mm.

[Adrian]

Sorry - don't know what happened when I edited my post - it was just a reminder that 3 objects in the light path could cause a 6-point pattern, as with a 3 vane spider on a newtonian.

Gina, the first photo shows some reflective areas around the edge - it couldn't be this I suppose 

Or did you leave the focus mask on (I'll get my coat  )

Edited November 14, 2013 by Adrian

[Gina]

Sorry - don't know what happened when I edited my post - it was just a reminder that 3 objects in the light path could cause a 6-point pattern, as with a 3 vane spider on a newtonian.

Gina, the first photo shows some reflective areas around the edge - it couldn't be this I suppose 

Or did you leave the focus mask on (I'll get my coat  )

Thank you   But yes, I know 3 objects will produce 6 point stars.  Those are actually slots letting the light through.  As I said above, there are 7 of these but enequally spaced.  I don't think these would/could cause the problem but I could cover them up.

I don't used focus masks

[Davey-T]

Blimey Gina it's taking me all my time keeping up with this thread, it's turning into a riveting soap opera, can't wait for the next installment

Dave

Edited November 14, 2013 by Davey-T

[Alien 13]

I know im quite new to this but have seen tiny spikes with my setup i have to zoom in a lot but they are visible on the bright stars so im very interested in your findings. I do have a noob question though do you get this effect with any other refractor since you installed the EQ8 and was also wondering if there was any high frequency mechanical resonance upsetting things.

[kirkster501]

When the Hubble Palette processing is applied the stars become pink/magenta.  Here is the same image with the pink removed.

Heart 2013-11-13 Hubble Palette white stars.jpg

I prefer this version.

Also, apologies if my commetn was a bit terse - it could be construed as such and I never meant it like that.  You do a lot better than I could ever do!  I just wondered why the stars were pinkish.

[Gina]

I know im quite new to this but have seen tiny spikes with my setup i have to zoom in a lot but they are visible on the bright stars so im very interested in your findings. I do have a noob question though do you get this effect with any other refractor since you installed the EQ8 and was also wondering if there was any high frequency mechanical resonance upsetting things.

So far this is the only refractor I have used with the EQ8 and the only other scope was the MN190 but that wasn't for long and I didn't do any imaging as I recall.  I don't think it could be the mount.

Edited November 14, 2013 by Gina

[scoobee]

Hi

i am reading this with interest as i cannot decided on what to get next, WO GT81 verses Espirt running with a mod DSLR

[Chris]

I think we will know more once the aperture is stopped down, clouds be kind and clear off!

[Gina]

I think we will know more once the aperture is stopped down, clouds be kind and clear off!

Yes.  I'm hoping to try this tonight - WF good for a couple of hours of clear sky but things can change

[Tinker1947]

I know nothing about how the internals work ect, but would some flocking not help on any surface that doesn't need to reflect photons...the first picture with the little white bits would be a prime suspect for me...