Merlin66

Alex,

A perfect addition to this discussion!!

All we need now is for Rodd to submit an image of his set-up for comparison.

Not my images, (from a previous SGL thread) but you can see how the OAG can be tested during the day......

https://astronomy-imaging-camera.com/products/accessories/zwo-oag/

If the EFW is 20mm and the backfocus on the camera is 17.5 (assuming a T to T adaptor) this would infer a 37.5mm distance 

It could be that you need a spacer between the OAG and the filter wheel (or one between the filter wheel and the OAG) to bring this up to around 50-55mm to produce a focus at the guide camera.

Sounds like the guide focus could be too close to the top of the OAG body to allow the Lodestar to go inward. The lodestar needs 12.5mm plus adaptor

If you can get an acceptable image from the Lodestar  using the main telescope focusser then other than verifying the distance - see my previous message - I don't know what to suggest.

Hmmmm

If the focus travel is longer than the backfocus of your OAG>Fliterwheel>ASI 1600 then you should have found a Lodestar focus - somewhere.

Have you tried the Lodestar on another telescope to verify the settings - exposure etc.

I use the Lodestar (under PHD2 - Latest Ascom driver) to guide my spectroscope using a "similar" oag set-up on a C11 at f10.........

I understand...

That's why I suggested focusing the Lodestar (using the telescope focusser) first - just to confirm 100% it's seeing the light beam and can indeed focus on your system.

Then review the imaging camera to see how far you have to move the telescope focusser to bring it into focus - the difference is what you need to address with the Lodestar positioning.

I assume your set-up is OAG>filter wheel>ASI 1600..... Roughly what's the distance from the centre of the OAG to the imaging plane?  55,60mm??

Does the Lodestar "usually" work OK? ie when imaging on it's own?

If everything else checks out I'd work backwards - ignore the imaging camera for the moment and get the lodestar to focus.... then move the Lodestar in/out the OAG until it's close to your measure 55-60(?) and retest the Lodestar focus when it works OK, then look at the imaging focus .... one small adjustment to the imaging camera, one small adjustment to the Lodestar - repeat until success.

I currently use the ZWO ASI 174MM for solar imaging, and I'm awaiting delivery (on back order) of an ASI 183MM to use on the shorter focal length scopes (to give easier full disk images)

I use FireCapture V2.6 for acquisition, AutoStakker V3 for quality stacking the AVI files and Registax 5 (I find it better than Registax6 at times) for the application of wavelets.

SharpCap or FireCapture work well with the ASI cameras.

Yes, you can run effective "live view" - just change the exposure to show sufficient detail.

(I use an ASI 174MM with a SM60/ED80 for solar imaging, but about to buy a ASI 183MM)

Over the years I’ve used many SCT - from all the variations and sizes of the Meade LX200 series and now the Celestron 9.25 and C11.

although not perfect, they were all fit for purpose. 

The C11 I currently use displays good Ronchi lines and adequately meets my needs for precision spectrography.

Hmmm, that still shows a significant LED pollution in the filter transmission bandwidths.....

Unfortunately the broad spectrum LED can't effectively be filtered out.

Where you have transmission bands (Hb, OIII, Ha etc) you will also have background LED light pollution.......

A couple of comments:

The link mentioned refers to IR not UV.....

Shining a high intensity IR LED "searchlight" at the camera filter bears little resemblance to actual user conditions.......

(In the diagram filter#2 is the one removed and Filter#1 -the anti alias/ dust shake filter is usually retained.)

The attached PDF file shows real spectroscopic transmission tests done on the front filter.....

The final IR transmission is not much worse than that found in the  original Canon camera ....................

Canon front filter test.pdf

The eyepiece box I still use was made back in the early 1970's. The foam insert has changed a little over the years and the original TV eyepieces from the 80's are still as good as ever.

OK.

The UV-IR has no affect on the amount or intensity of the Ha transmitted through the Quark. 

It just reduces the energy loading on the Quark itself.

The “UV/IR and diagonal” reference is under the larger aperture (above 80mm) section of the document......

Pig,

Sorry to correct you.....

http://www.daystarfilters.com/inout_article_base/index.php?page=view/article/26/Energy-Rejection-for-QUARK---UVIR-or-Front-mount

It appears NO addition energy rejection is necessary with apertures less than 80mm

Yes, but it really depends on the size of your refractor...above 110mm aperture an ERF or at least a good UV/IR filter is needed.

Thanks!

Unfortunately the Spectra-L200 is no longer in production.

I designed the original OVIO multi-slit plate for the Spectra-L200.

Yes, with a suitable transfer lens and the slit inclined at 15 deg you see the 6mm long slit gap and the reference number.

Check out our website for more info. http://www.astronomicalspectroscopy.com/instrument.html

I use the DMK 21 618 for a while.

Higher QE at Ha than the standard version, but very small webcam sized chip.

There are better options availed today.

(I still use my DMK 41 and DMK51)

OK, you're on the right track.

I use the ASI 174MM for solar - pixel size suits my set-up and the frame rates are FAST!!!

The newer ASI 178MM would be a good bet.

You'll need a USB3 connection and a fast SSD drive to collect the data (2-3Gb per session)

Acquisition and processing.....FireCapture or SharpCap will give you good AVI (or SER) file to allow stacking for quality. Registax 6 or Autostakker V2/V3 will do the necessary stacking and "tweaking"

Any photo imaging program (PainShopPro, PS etc. etc.) can be used to apply the colourisation....

http://www.firecapture.de/

http://www.sharpcap.co.uk/sharpcap

https://www.astronomie.be/registax/

http://www.astrokraai.nl/software/latest.php

You are correct.

My 100mm was an approximation.

No, they are for WL enhancement......

If you eventually use a larger refractor (>100mm) , then with the Quark you may need an ERF (energy rejection filter) - a good UV-IR filter as a basic option.

I enjoy both visual and solar imaging.

Yes, over a period of minutes you can see the development of the proms and movements around sun spots and active areas.

Imaging a sequence with an image say every five minutes over a period of a couple of hours dramatically shows the dynamic nature of the proms and the solar surface in general.