Quick nebula sessions before clouds

[GavStar]

A frustrating evening observing today. I was chasing holes in the clouds. Back to the tec after a few weeks experimenting with the c11. Was a pleasant change until the clouds completely covered everything.

Through a hole I got some nice views of the California and heart nebulas. The photo visual reducer worked well on the tec to give a wider fov.

 

[Olli]

Nice images I’m quite impressed by what you can take with your s9. If that is what you used  

[GavStar]

29 minutes ago, Dinoco said:

Nice images I’m quite impressed by what you can take with your s9. If that is what you used  

Yes it was the S9 - I really like that phone for astro phone photos. Much better than iPhone imo ( just the camera bit)

[scarp15]

They do make engaging references, as an enhanced impression for dark sky visual observation. 

[GavStar]

10 hours ago, scarp15 said:

They do make engaging references, as an enhanced impression for dark sky visual observation. 

The normal Astro photos found in this forum and elsewhere on the web are amazing.

However, clearly they aren’t very helpful in terms of an indication of what an observer would actually see at the eyepiece. That’s where I found books like turn left at Orion and Qualia’s posts in this forum really helpful for a) setting expectations suitably low and b ) assisting in spotting the objects.

For a while I’ve been considering how best to record my visual observations and my approach has been to put written reports on here in part for my future reference. However, there’s nothing like a good picture to really describe an observation - that’s why I’m so impressed with the sketching that some members here do.

However, I can’t draw for toffee so with these phone pics I get a good visual reference for me (and others hopefully!) of my observations to refer back to in the future. The photos I’m posting are very close to what I see at the eyepiece, although I’m gradually improving my photos so that on some objects they marginally exceed eyepiece views.

Lastly and unexpectedly I’m having a lot of fun with the phone pics. They’re very quick and easy to do so supplement my visual observing rather than take it over.

[jetstream]

The images are great Gavin and these two mirror what I see from home under the best conditions and with an appropriate scope. ie I see a grey version of the California the same as your image shows, and with the same structure and wisps. Your images are really helpful, keep them coming! Thanks, Gerry

[GavStar]

15 minutes ago, jetstream said:

The images are great Gavin and these two mirror what I see from home under the best conditions and with an appropriate scope. ie I see a grey version of the California the same as your image shows, and with the same structure and wisps. Your images are really helpful, keep them coming! Thanks, Gerry

Now that’s good to hear Gerry jetstream - mirroring what you see from your amazing skies with a big dob ? 

Only on emission nebulae I think. 

On galaxies (particularly spiral) you would be way ahead. Although I was pretty pleased with my views of the needle and Sombrero galaxies recently.

I’d be very interested in how your views of globular clusters compare with my images? They are meant to be a good object for NV.

I do really want to get the NV under a moonless dark site - so far I’ve just been doing London or the moon has hampered the views.

[PeterW]

Transparency is key.... which of course reduces the odds further if you are looking for one with clear moonless nights away from London. The Heart shows you could do with a wider field of view.... have you used the 3x multiplier?

PEterW

[jetstream]

4 hours ago, PeterW said:

have you used the 3x multiplier?

What is this Peter?

[PeterW]

A Galilean multiplier lens that goes on the front of the NV for wide field use. For seeing the large nebulae in their prosper scale and setting.

Peter

[GavStar]

5 hours ago, PeterW said:

Transparency is key.... which of course reduces the odds further if you are looking for one with clear moonless nights away from London. The Heart shows you could do with a wider field of view.... have you used the 3x multiplier?

PEterW

Peter,

Yes I’ve used the 3x multiplier but didn’t find it very enjoyable. With a 1.25 filter put in the end of the NV monocular, there was quite a bit of vignetting and I found the views so so. 

In fact I find the super wide field views given by the NV at 1x or 3x (I prefer the 1x of these two) not really to my taste at the moment. Maybe in the summer when the Sagittarius cloud is around, I will like them more.

So far I much prefer using the NV monoculars in conjunction with a scope to give a higher mag more detailed view. And I like having them on a mount for stable viewing rather than handheld.

The max fovs (including reducer in the larger scopes) I get with my various scopes are:

72mm refractor 5.1 degrees 8x

100mm refractor 3.0 degrees 13x

130mm refractor with reducer 3.6 degrees 11x

160mm refractor with reducer (the setup I used for the above photos) 2.6 degrees 15x

11inch sct with reducer 1.1 degrees 38x

Currently I’m happy with the 5 degree fov provided by the 72mm scope for widefield viewing (but this may change ?)

[PeterW]

Should cover most stuff. I pop the 2” filter on the front of the 3x, I agree the field is somewhat squeeze£.

peter

[Highburymark]

You are pushing me dangerously close to having a conversation with my bank manager Gavin. Thank God Photonis 4G tubes appear to be in short supply at the moment. On a slightly more serious note, you seemed to be getting reasonably tight stars with the C11, but presume you see an improvement in sharpness with the fracs? Do the differences between SCT and frac optics show just as clearly through night vision devices?

[PeterW]

Goodie, more converts.... 

PEter

[GavStar]

Mark, 

Interesting comment about photonis 4g being in short supply. I’ve just checked the actinblack website and I see that the photonis 4g is no longer a tube option to buy. Do you know any more? 

I’ve also heard that 3G tubes are difficult to obtain in the US currently as well due to army demand!

Regarding star shapes and sharpness of view, NV is a great leveller for scopes. This is because the star shaped are determined by the NV monocular (resolution, quality of tube etc). I think the photonis 4g tube produces some of the best NV star shapes available. Less bloat than US 3G ones apparently due to the different technology. But the us 3g tubes have an advantage in being more light sensitive.

In addition use of heavy filtering in NV such as 6nm Ha and 685 filters does I think reduce the impact of CA or other aberrations.

So in summary, no significant difference I see in quality of view between the sct and my tec160. I guess the only benefit I have with the tec now is planetary and double stars. For me at the moment, it just seems that on virtually every type of DSO, NV wins comfortably over normal vision.

I’ve spent a few years looking for small incremental improvements for my viewing such as bbhs diagonals, televue eyepieces, tec refractors. All nice but only small improvements each time. The NV has been a giant leap forward...

PS incidentally on the photos above with the tec, you can see quite a bit of coma on the stars at the edge. I was pushing things by using a reducer but its something I will look out for more. Also I was in a bit of a rush and didn’t put my glasses on to focus for the camera properly. The stars in the centre are out of focus a bit - if I get these in focus maybe the coma will be better.

[GavStar]

Regarding my point about coma on the outer stars - I investigated this last night with the same tec160 plus AP reducer setup and it does seem that the coma resulted from not being properly in focus.

Here’s a photo I took last night of the rosette where I was careful to get the focus correct and the stars look good across the fov.