Yesterday was my first opportunity in over 2 weeks to get my Lunt LS60tHa out for some Imaging the clouds were rolling in fast so I had to quickly take these images.I tried some white light Imaging for the first time with my Skywatcher Evostar ED72 .5 focal reducer and ASI 120mm-s camera. I stacked 100 frames as the seeing was good at the time. I would like to do better Imaging in White light. I do have a Celestron 6SE SCT . I could use , would this scope with filters achieve better results. Thanks for looking, any suggestions would be most welcome
Martin
rs4.jpg (49.55 KiB) Viewed 2290 times
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
Hi Martin,
Yes, you would get better results: bigger aperture.
You would need the Baader ND3.8 Astrosolar. This is just for imaging, not visual.
You can buy a complete filter or a sheet of Astrosolar. Then you would have to make your own holder.
BTW: nice images, that 2741 is a real beauty.
CS! Bart.
Hi Bart, thank you for your reply, how much definition do you loose using a visual filter as opposed to an imaging filte?r, there is a Celetron filter at a good price on E-bay right now
Martin
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
Can't tell you that. I suppose it is a ND5.0 filter made out of glass? Then your exposure time would be substantially longer. So more effect of the seeing.
Normally only quite expensive glass filters can compete with the advantages of Astrosolar.
As regards white light, Baader solar film is optically much better quality than any glass filter, unless the glass is very expensive indeed. I tried Baader ND5 filter on my Celestron C11 and there was not enough light to image with. The exposure times were so long it was not worth trying. I now use ND3.8 and the exposure times are fast enough to take images. Also what is a must is to use a UV/IR block filter on your camera as the out of focus light makes your WL images blurred. This makes a huge difference to focus. Also a Continuum filter helps a lot too to improve contrast.
can confirm the ND3.8 gives much better results than the ND5. I have been using the ND5 in my C8 at prime focus and this still ok, but adding extra filters (baader continuum ...) will make exposure to slow. Also if adding any barlow to increase f/ratio will need the 3.8. (ND 3.8 is difficult to find nowadays for larger apertures, think the largest size sold now is A4 format)
Looking at the white light images think you also can get a better resolution. Did I read correctly you are using a .5 reducer on the Skywatcher? That will
give you an F/3 ratio which is WAY undersampled with the ASI120MM-S having 3.75µ pixels. Maybe a 2x or 2.5x barlow would give a better match between telescope and camera.
Thank you Paul and Alexandra , I now have some good points to work on.
Martin
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
http://brierleyhillsolar.blogspot.co.uk/ Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
Thought I'd give this thread a recap, I had poor results on my first attempt at white light Imaging. This is my second attempt taken today . I used my ED72 and my ASI120mm camera at prime focus,5.0 solar film El-cheapo IR cut filter and an El-cheapo Wratten #58 green filter. Post processing AS!2 and registax.
I can actually see some surface detail. Next time I'll use some slight focal reduction to fit the full disc to the sensor.
Martin
Attachments
Proms_135424_Exposure=3.jpg (131.25 KiB) Viewed 1960 times
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/