Homunculus, again..

[bojan]

4 years ago, I bagged Homunculus with C11+Canon 60D, link is here.
Over last weekend I tried again, this time with IMX291 webcam and C11+FR.65, processed in SharpCap and Registax.
The circular artifact is the consequence of eta being saturated and aggressive use of wavelets to bring out the Homunculus itself.
The image is stack of 124 frames, exposure time was 63.5 ms.

[AlexN]

That's an amazingly tight field of view mate! well done!

[Dave882 (David)]

Nice work!! I can make out the internal structure in the lobes quite well. After many attempts on this target myself I also came to the conclusion that fast frame rate lucky imaging was the best method. I’m just wondering why you used the reducer? I think for such a bright object and for the imaging techniques you’re using the longer focal length would be beneficial

[bojan]

Hi Dave,

I used reducer because it was there .. so because I was just experimenting, not expecting a lot.

Next time I will go with 2x teleconverter

[rogerg (Roger)]

That's fantastic. I'd love to try for this again myself but need a camera or scope upgrade I tried years ago with my NABG and that was never going to work

[Startrek (Martin)]

Great effort to be able to pull that sort of detail from the little man
Well done indeed !!

Martin

[JA]

Well done - on getting so up close and personal on the H and showing its inner detail.
I have seen another image on a 180mm aperture, which suggests an even shorter exposure of 1/60th* of a second would help. And of course the atmosphere has to be in your favour so close up. I'm looking forward to the next one with 2X TC

Best
JA

* Actually thinking on it further, you had a 0.65 reducer in there in your image, so removing it in future you'd loose ~1EV and also if using the 2X TC you'd loose another 2EV, so your original exposure time of ~1/15 th of a second (63.5ms) may be OK as it would certainly be dimmer (1/8th the light per unit area compared with your original setup) and may help overcome the oversaturation issue you raised. Perhaps even 1/8 th or 1/4 sec or bracket the exposures. Have fun.

[bojan]

Originally Posted by JA

...
* Actually thinking on it further, you had a 0.65 reducer in there in your image, so removing it in future you'd loose ~1EV and also if using the 2X TC you'd loose another 2EV, so your original exposure time of ~1/15 th of a second (63.5ms) may be OK as it would certainly be dimmer (1/8th the light per unit area compared with your original setup) and may help overcome the oversaturation issue you raised. Perhaps even 1/8 th or 1/4 sec or bracket the exposures. Have fun.

Exactly right !
Over weekend I tried the C11 prime focus with IMX291, and results are discouraging.. nebula was considerably dimmer (because its image was larger), but eta was blazing with the same intensity, so FR was a good (unintentional) choice for this combination.

However - 4 years ago I did eta with C11+2X teleconverter+Canon60D.

60D (now it is modified) is obviously better camera

I think the better approach for object like this (bright central star, dim nebula nearby) would be some sort of shade for central star (coronograph).. something Rolf Olsen used for his Beta Pictoris dust ring observation back in '11.