michael.h.f.wilkinson

I checked out the Comet Chasing site and it says you need a 10" scope or larger. It might be well placed, but at magnitude 10.4 at the start of the month, and fading by 1.1 magnitudes at the end, it seems to be hard. I might give it a shot with my 8" scope from a dark site, but I am not sure how that will go.

I found a neat little Omegon-branded 12 V 12 Ah Lithium polymer battery pack, which can power my iOptron HEM15 mount in the field. It fits in my coat pocket. has cigarette lighter and USB connectors, so no tinkering or soldering needed. Will report on it's performance once I get to use it properly.

Currently my H-400 count has stalled at 320 (H-2500 at 588). Most spotted with my Celestron C8, some with big binoculars (Omegon 15x70, Helios Apollo 15x70 and LightQuest 16x80). Haven't had much luck observing the last year or so. Should really try to get more of these objects.

As others have said, the scope isn't worth investing in, and the original eyepieces are not very good at all. SR-4 stands for symmetric Ramsden 4mm, which has a tiny field of view, poor colour correction, and terribly short eye relief. The Huygens eyepieces (H12 and H20) are also generally poor quality, with very limited field of view. Finding object is very hard with such a small field of view, even with a finder scope. Getting one of the 150mm scopes listed above is a much better investment.

1 hour ago, ollypenrice said:

Wouldn't your Sigma telephoto beat this easily? Not as portable, though.

Olly

Not sure about that, and anyway, I cannot take that to the USA in my hand luggage and carry the APM 80mm F/6. I find what I am getting so far is close to or better than my DSLR shots with the Canon 100-400mm L lens. I will test this on white-light solar when weather allows. My 100-400mm gave me pretty decent results on the eclipse in 2017 in white light, as the crop below shows, so I am not too worried about the quality of this little lens.

Really nice shot of one of my favourite galaxies

On 29/01/2024 at 18:04, astrolulu said:

Hello Michael. If I can give you any advice - first try to reduce the size of the image to the smallest one that does not result in the loss of the smallest details, and only then sharpen the image.

Better still, get better data and better focus (using a proper planetary camera)

I only use a zoom EP (WO 7.5-22.5 mm) which I use for solar observing at work. I like it a lot, but the FOV is somewhat limited, but it fits the sun in the FOV neatly, and it has sufficient eye relief (18-19.5 mm). That is very important for me, as I need to wear glasses when observing. Most zooms are lacking in this respect. The APM 77-15.4 sounds very interesting, I must say

As a mount I cannot fault the iOptron HEM15 (so far). Really nice and compact, only 5 kg including carbon tripod. Not cheap, however.

I am travelling to Texas for the eclipse, and my current rig is:

iOptron HEM15 mount plus tripod (5kg check-in luggage)

APM 80mm F/6 triplet imaging scope (2.5kg hand luggage)

Lunt Ca-K module (haven't weighed it yet, hand luggage)

Carl Zeiss 500 mm F/8 mirror lens (1 kg, hand luggage)

ASI183MC for white light ASI178MM for Ca-K imaging (120g each, check in luggage)

Lightweight laptop for imaging/data acquisition (1.2kg, hand luggage)

If you replace the Zeiss telephoto with a guide scope, and my non-cooled ASI183MC with a cooled camera, this would work for DSOs. The Samyang 135mm is brilliant for this kind of work, and it combines neatly with the HEM15. It works even without guiding, as this shot shows (120s subs, just tracking on the HEM15)

That is absolutely gorgeous!

I wonder if the star adventurers are solid enough for an 82 mm refractor. I have an APM 80 mm F/6 triplet, usually used with 0.8x focal reducer, and use a more substantial mount (Vixen Great Polaris, although I plan to try out the iOptron HEM15 shortly). I have no experience with the star adventurers, I should add. Just my tuppence

Magnificent images!

Lovely collection! Great animation too

Very nice indeed!

I don't have the ASI533, but with my ASI183MC I need very short exposures in daylight at reasonable gain settings. For example, using the camera on the moon (which is after all in full sunlight) at about F/10 requires just a few milliseconds of exposure time so as not to saturate the camera. The ASI533 can go down to 32 microseconds so you should be able to find a usable setting. You might want to try planetary imaging software and use lunar settings for daylight photography.

Superb image. That's an area I would love to tackle with my pair of Samyang 135 mm lenses

It is a spectacular image, and although i also tend to prefer more natural looks, I would not call this overcooked. The amount of contrast and saturation preferred is ultimately a matter of taste, so what counts is what you like.

Lovely image. Great detail in the main target, and some lovely background galaxies captured as well. I really should give this target a go with my Schmidt-Newton.

I think Martin (Budgie1) says makes sense. Going for a slightly shorter focal length makes life a lot easier, I find. My stalwart deep-sky imaging scope I use mainly on my Vixen Great Polaris mount (the EQ5 is a clone of that most cloned mount) is an APM 80 mm F/6 triplet, usually with focal reducer (second-hand Tele-Vue TRF-2008 0.8x reducer/flattener). I only started using longer focal lengths when I got a heavier mount (Great Polaris DX), on which I use  with a scope with similar focal length (but lighter weight) as the SVbony without, and Evostar 100ED with reducer (I use a 6"F/5 Schmidt-Newton).  I also note that while the SVbony scope is faster than the Evostar, it has FPL51 glass, whereas the Evostar FPL53. This would suggest that the colour correction of the Evostar is better (but that isn't guaranteed). Going for a smaller scope like the Evostar 80ED or a triplet like mine can certainly get great results. The forum is littered with examples. Here is one with the APM 80mm at F/4.8 and modded Canon 550D.

That is lovely. Lots of detail, but nothing overblown. Very natural looking

There are two mechanisms at play: stereo and focus. The stereo mechanism uses disparity of positions of features between left and right images to estimate distance. The muscles surrounding the eyes will rotate the eyes accordingly to put the object of interest in the foveae of both eyes. The difference in orientation gives the estimated distance. At large distances this does not really work. Focus simply changes the curvature of the eye lens to get the sharpest possible image on the fovea. When looking through a telescope, it is best to relax the eyes, so the lenses revert to their infinity setting (or its nearest equivalent for) and changing the focus of the telescope to get the sharpest possible image. Note that the image plane might be close, but the eyepieces transforms this into a virtual image at infinity at proper focus.

Absolutely lovely images of an object I had never heard of. Might well try that at some time

I find open clusters are best viewed in a really wide field. You then see them in context, whereas if they fill most of the FOV you just feel you are looking at a bright star field.

7 minutes ago, Louis D said:

For high power viewing while wearing eyeglasses, the original Vixen LV line is really good.  They come up used for $60 to $70 apiece here in the States quite often.  Some are even cheaper if the rubber eye cup is tearing through from years of folding and unfolding.

I had a couple of LV EPs (7 and 9 mm) and they were superb on planets. I then moved to Pentax XWs (5, 7, and 10 mm) and they have a definite edge, and far wider FOV, but the LVs are great. If you can pick them up for that kind of money, go for them! I now have some SLVs (5, 9 and 15 mm) in a lightweight travel setup, and can't fault them. The only noticeable difference with the XWs  is field of view. Build quality is fine too