ollypenrice

Any chance at all of processing it in Photoshop?

Ducks behind the sandbags...

lly

At the EP can you be sure you're seeing meteors rather than satellites? To the unaided eye they are very different but the small field of view at the scope gives an impression of speed.

Olly

Very crisp. I like widefield planetary images because they raise the thought of what a time lapse would look like over billions of years as star after star flowered in this way and then faded.

Olly

I see no stippling, Rodd. It's a finely resolved Bubble and I think the bubble itself would take more sharpening.

Super.

Olly

Very, very high quality images. I particularly love the lighting of the Tulip.

Olly

Your left hand arrow is bang on. Your downward pointing one needs to go down a little and a tad left to hit the top of Bubble. (I confirmed by dropping a deep image of the object onto yours in Registar.) As you say, it's a faint devil but you have it!

Olly

These are great images. I've never tried the Propeller, though I really ought to do so, especially since I'm reading a biography of Amelia Earhart at the moment. We can almost see her coming towards us from the great beyond...

Olly

Beautifully framed image with the faint stuff, like the 'second broom handle,' showing nicely.

Olly

Bit late to this party! Early on the question of drop-down flaps for roll offs came up. No need to be fearful of these, they are ridiculously easy to make and automate. I've done three, all on this principle:

*

We did no sketches or calculations for these mechanisms but just 'grew' them as we went. The last piece you fit is the roof's horizontal arm ending in the little wheel. Put the flap vertical with the roof rolled shut and then screw on the wheeled arm so it's pressing against the angled arm on the flap. It will then always close the flap just nicely. The little counterweight on the angled flap arm (see first image) simply ensures that the flap starts to open when the roof rolls back. (Otherwise it may stay upright and bang down later.) Because we have image-possible horizons all our roll offs have rolling upper sides as well as roof.

Olly

I don't think it would be worth it. The high contrast of the Tak will probably make up for a great deal of its sub 6 inch aperture.

Olly

...but do bear in mind that, especially during initial cool-down, focus will change rapidly.

Olly

A classic account. Saturn has seduced more people than any other object in the sky. While teaching an astronomy evening class at an Adult Ed college I set up an 8 inch scope in the car park, massively light polluted, and pointed it at the ringed planet. A retired miner took a good long look and when he stepped back from the eyepiece he fixed me with a gaze I remember more than twenty years later, shook his head, tried to speak but couldn't, and simply shook my hand in silence.

Olly

9 hours ago, vlaiv said:

I would add following:

Get as many of dark as possible. Don't settle for 20. I sometime used more than x10 that number.

 

I often use 30 minute subs...  

I did once try 20 versus 60 darks and could find no difference in the output image but, if you are using shorter subs, more certainly won't do any harm.

Olly

51 minutes ago, Michael Kieth Adams said:

If I’m understanding this  it appears as if you are saying that the speed of light is not actually a speed but a constant with some of the qualities of a velocity.  Interesting .  Difficult to wrap your head around but makes sense  sort of.  Matter does become energy sometimes either the exceeding of the speed of light is part of it, or there is another avenue that we don’t know.  I’m still not clear on how the expansion of the universe does not produce velocities between point A and point B.  If it does produce velocities then my question about point of view might have some validity.   Particles leaving the sun have velocities when they leave the sun.  Those velocities change depending on where you are.  Speed is relative which means if I’ve got it right means that the mass of those particles changes based on where they are measured from.

Perhaps wrongly, I think of it like this. I'd welcome Andrew's view on the matter!

Edwin Hubble observed that distant galaxies are receding from us at a speed which increases linearly with their distance. One explanation would be that we were at the centre of this expansion but this is rejected out of respect for the Copernican priniciple and because their is no evidence to support the idea. So cosmologists prefer the idea that every galaxy would observe what we do: distant galaxies are receding from them as they are from us. Now they cannot all be at the centre of the universe's expansion because, for one thing, this would attribute to other galaxies conflicting directions of recession.  And none of these galaxies feels as if it's been accelerated into movement at all.

So recession caused by the expansion of the universe is quite unlike recession caused by acceleration, which must have a direction. There is no acceleration of the separating galaxies because they are moving apart not because they have been accelerated but because the space between them is expanding. This means that their mass does not increase and their recession velocity can greatly exceed the speed of light.

One version of the 'surface of a balloon' analogy represents galaxies as coins glued onto the surface of the balloon so that, being stuck, they cannot 'move' in the normal sense. But when you blow into the balloon they none the less move away from each other, each considering itself to be at rest. (The dimension containing the distance between the centre of the balloon and its surface does not exist in the analogy.)

Olly

1 hour ago, Anthonyexmouth said:

Now I've got a cooled camera I set it off making a dark library. What's the best process for creating a master dark? Do you just stack them as you would lights? 

Is it worth making a master dark?

I follow the advice of the makers of AstroArt, my stacking program. I take about 20 and stack them without alignment using the simplest algorithm, 'Average.' I've found that the most important thing is to exclude light so I don't do them on the telescope, I take the camera off and put its screw-fit metal chip cover on. It's certainly easier to use one master dark than a whole set of individual ones each time.

Olly

Very fine result, Peter. The refractors strike again!

Olly

I'll be at home but that's fine!

lly

I think it's an out of focus star with a dust mote at the edge. I don't think the smaller stars are in focus, personally. Thee are hot pixels showing, though.

Olly

Is this for DS imaging?

Because the C8 has a fairly long focal length, even with reducer, it will need a mount which can handle the weight and deliver the tracking accuracy you need. The accuracy may be a lot harder to meet than the weight requirement. It will ultimately depend on the pixel scale at which you are imaging. This will depend on the camera's pixel size. You can find your pixel scale here: http://www.12dstring.me.uk/fovcalc.php  If the imaging is casual and you're not hell bent on exploiting the full resolution of the C8 (which is always going to be difficult with most cameras) then accepting imperfect guiding would be OK provided it were roughly equally imperfect in both axes, giving you round stars.

HEQ5 'possible,' EQ6 'better.'

Olly

29 minutes ago, msacco said:

 

 

Yeah I suspected that's the reason, so now that we know we don't want a zoom bino's, what would be the best specs for a pair of bino's?

Looks like the default is pretty much 10x50, wonder what would fit me the best, any suggestions?

Once again, I can only buy on aliexpress/ebay.

Whether you will prefer 7 or 8x or 10x is a very personal thing. When I was younger I felt OK with 10x but now I greatly prefer the image stability of 8x. Any chance of trying some to see how you feel about them?

Olly

4 minutes ago, msacco said:

Just to make sure I understand correctly though, the 10-24x could simply behave as a 10x50, but also has the option to go 24x50.

I'm really not familiar enough, but I do think about me wanting to sometimes use higher magnification than that, would the 10-24x50 and the 10x50 perform the same when both of them are on 10x?

The extra glass and complexity come at a very high cost in terms of optical quality, especially in instruments which are budget to begin with. There is no free lunch in the optics industry. Besides, you cannot possibly hand hold at 24x. On the bird forums you won't find anybody hand holding at over 10x without image stabilization.

Olly

On 25/05/2019 at 19:07, steppenwolf said:

Olly’s method should work well but you will have to take a little bit of an ‘average guess’ to allow for the variations in FWHM due to the seeing.

Yes, a tweak based on eyeballing the perimiter stars will be needed. My method also allows you to find out whether or not you can still operate pen and paper...

lly

On 13/07/2019 at 11:15, pietervdv said:

Hi all,

Some feedback on the Baader 4,5 nm O3 filter; I like it a lot! It is a very nice match to my Astrodon 5nm h-alpha filter. The stars are very similar in shape and size, which will allow me to make some nice bi-colour images. If I may give one small point of criticism; there are again some halos noticeable (remember the old 8,5nm O3 filter) around very bright stars. It could be something else in my imaging train, not 100% sure yet... But overall I am happy with this purchase. It will be a return for me to colour imaging after shooting b&w for a long time.

Here is the first light; a quick and dirty bicolour on NGC7000. Scope was my 10" newton, exposure was 2 hours in HA and 2 hours in O3. Colours mixed as HA:O3:O3.

 

Thanks,

Regards,

Pieter

 

Nice to see you in Technicolor again, Pieter! That's a great image with tiny stars.

Olly

I'd keep the magnification down to 10x at most and enjoy the wide field and portability of hand held binos. My own are 8x42. That, a comfy chair, some charts and you're off!

Olly

10 hours ago, Datalord said:

Got around to stacking the "Good" images. 37 of them, clipping off the worst eccentricity and FWHM. Then I normalized, stacked and nuked it with the exact same ScreenTransferFunction as I did with the full junk stack.

Left is "junk", right is "good".

I can't see much difference. If anything, there is a bit better control over the noise in the "junk" stack.

I agree. Precious little in it but the darkest parts are a tad smoother in the full set. Good experiment and well worth the effort.

Olly