152mm TechnoSky Quark shots

[Ewan]

Evening all,

Had a 2nd attempt today at grabbing some data, went a little better but still in need of practice hope you like them.

152mm TechnoSky Frac , 135mm D-ERF, 0.5 2" Reducer & Quark

10% from 1000 frames

 

Thanks for looking.

 

PS :-  Might wanna move back 6' for the first image sorry my boob :-)

[MilwaukeeLion]

Amazing images, terrific. 

[Pete Presland]

Superb close ups!

[Stu]

Those are incredible Ewan! The visual view through Derek's 152mm with Quark was pretty amazing, but the detail in your shots is stunning.

[Davey-T]

Excellent images Ewan, super close ups, had a stab yesterday but seeing was pants.

Keep eyeing up that Altair 152 now only £830.00 from Ian King, I'm never going to get a 10 Micron mount at this rate

Dave

[laudropb]

Very nice set of images. Lovely detail captured.

[michael.h.f.wilkinson]

Superb detail shots!

[Ewan]

[pietervdv]

Very nice looking pics! You mention that an 135mm ERF was used. Does that mean the main 152mm objective was stopped down to 135mm?

Or are you imaging with the ERF placed inside the tube, so using the scope's full aperture?

 

Regards,

Pieter

[Davey-T]

It means the 135 is lot's cheaper than the 160 and doesn't affect imaging.

Neither are cheap though

Dave

[pietervdv]

I know ERF filters get very expensive in larger sizes, that was not my question. I was asking where the ERF is installed in this telescope. In front of the objective or a distance behind the objective inside the tube.

For solar imaging aperture rules, so it certainly does have an impact if you stop down the aperture.

 

Pieter

[DrRobin]

Like them Ewan?  They are fantastic, what is not too like.

Robin

[Ewan]

On ‎24‎/‎03‎/‎2016 at 22:08, pietervdv said:

I know ERF filters get very expensive in larger sizes, that was not my question. I was asking where the ERF is installed in this telescope. In front of the objective or a distance behind the objective inside the tube.

For solar imaging aperture rules, so it certainly does have an impact if you stop down the aperture.

 

Pieter

Yes aperture does rule..........most of the time but not all.

Yes it is a front mounted 135mm D-ERF from Baader, specially made to suit the dew shield size so it fits like a glove.

As the frac is F5.9 Rupert at Astrograph worked out the 135mm was optimal size for the Quarks ideal F ratio to work best.

Also seeing plays a big part & here in the UK the gain I would have got going from 135mm to 160mm would have been negligible.  The current inside the tube is meant to stay very cool so less interference from air current as well.

The cost wasn't an issue but wasting money was tbh.

[Ewan]

Just found the reply by Rupert as to why the 135mm was optimal for me.

'Hi Guys

Just to respond about the reason for recommending a 135mm ERF for the 152 instead of the full size (in this case it would have been a 160mm).

1) This 152 is a native F5.9. When used with a Quark that results in an effective F25.3. This will result in the Quark working at probably its least efficient as light is not passing through the etalon parallel. With the aperture reduced to 135mm the F ratio becomes 28.7 which is low enough to get the Quark working as well as it is going to resulting in a narrower bandpass and hence more contrast of surface features. Tests have shown that a 0.5A rear mounted filter running at F25 acts more like a 0.7A filter.

2) Seeing affects observing and imaging by a large amount. If we were all able image from perfect locations we could benefit from large apertures. In the real world we are surrounded by all sorts of things which interfere. It is generally accepted that the upper limit for reliable seeing is about 130mm. That does not mean to say a larger aperture won't deliver better results but it does mean it will be the exception rather than the rule. Therefore a 135mm solar scope should deliver results that are as good as you can possibly get most of the time.

3) Its a heck of a lot cheaper to buy the 135mm and cell!'

 

And I also found this a very good read in case anyone is looking at buying a similar set up.

http://www.daystarfilters.com/inout_article_base/index.php?page=view/article/7/About-Seeing-Limitations-and-Resolution

Hope this is of help to some.

 

Thanks Robin as well mate glad you liked them.