-
Posts
38,260 -
Joined
-
Last visited
-
Days Won
307
Content Type
Profiles
Forums
Gallery
Events
Blogs
Everything posted by ollypenrice
-
Stars or Galaxies
ollypenrice replied to Goldfinger's topic in Getting Started General Help and Advice
You can generate one on most computer planetarium packages simply by limiting the magnitudes it presents to whatever is your naked eye limit, so 5.5 to 6.0 for most people, I guess. Olly -
Refractor or Reflector?
ollypenrice replied to Ravi Hegde's topic in Getting Started Equipment Help and Advice
When set up perfectly (collimated and squared up) the refector will win. If the reflector is not set up properly, the refractor will win. The refractor will require little or no maintenance while the reflector will require more. If you become keen you might buy a larger reflector and keep the refractor for what it does well. If buying a larger reflector you might well not want to keep the small reflector. Olly -
Hi Ron, what a pleasure to see you back. I'm useless on the IT side and love mounts with handsets! They really are easy to use. Olly
-
That was worth doing! Olly
-
Very exciting and a lovely image. Olly
-
Lovely filamentory detail and I agree entirely with your own analysis. Olly
-
There are many approaches to this target and yours emphasizes the dust as a source of reflection. In other words we see the dust 'lit up' by starlight. Normally, in images without a manic Ha input, the dust is only a source of obscuration. Certainly, what your images gives, to me at least, is something I've never seen before. I think it's genuinely outstanding. Olly
-
A permanent setup divides the hassle by somewhere between 10 and 100... Olly
-
Before deviating from your standard sub length I would simply use your regular length and see if the core is over exposed at the linear stage. If it isn't, you don't need short subs, you just need a masked or layered stretch. (I'd use PS layer masks rather the very Pixinsighty-looking HDR wavelets.) I haven't done this target with a CMOS but I resolved the core star completely in 15 minute luminance subs with a CCD. It really is only that star which is likely to be a problem. Just away from it you need deep data to catch the faint but tantalizing pinks which live there. If you do need shorts for the star you only need a few subs because, so close to saturation, there will be no noise to worry about. In my view 120 sec and 300 sec will give you essentially the same result except that one will be slightly better than the other. I would just go with whichever is best because the better one will be better across the board. I also think, based on Trapezium experience, that 30 seconds will be too long to be a big help on the central star. I'd just shoot half a dozen 10 second subs to rescue the star if needed. Olly Edit: I found an old Iris core done with full length CCD exposures. There are things I could do much better now but it makes the case for the longer subs. Note the faint pinks right next to the star. Those need signal. Frankly, I didn't like the PI result above very much.
-
Takahashi refractor advice.
ollypenrice replied to Grump Martian's topic in Discussions - Scopes / Whole setups
I think the chances of a misplaced winning ticket blowing from the pavement into my bag of groceries is statistically little different from the buying of a ticket.... lly -
£500 for the Samyang 135? Olly
-
Takahashi refractor advice.
ollypenrice replied to Grump Martian's topic in Discussions - Scopes / Whole setups
So should I. I don't actually have a ticket but buying one has no statistically significant effect on whether or not you win... lly -
Takahashi refractor advice.
ollypenrice replied to Grump Martian's topic in Discussions - Scopes / Whole setups
Wish they made pensions which would pay for one... lly -
Project with Paul Kummer and Peter Woods. 2 panel mosaic, Samyang 135/TS 2600 OSC/Avalon M Uno. Our recent RASA data for the horse's head itself was gently blended in at low opacity but didn't make a radical difference. Olly
-
You need an F2 system! (I'm just about to post a widefield version from the Samyang, also F2.( lly
-
Coincidence! Keith was here last year... I agree that the blues do look a little green and I've already reduced that slightly. However, it's very much present in the data and this system isn't prone to any such bias so I thought I'd leave it. Maybe that's how it is or maybe we've got an unusual colour bias but it has been consistent across well separated imaging runs. Olly
-
Project with Paul Kummer, who drove the scope and did the stacking, calibrating and joining. 2 panel mosaic using RASA8, ASI2600MC Pro, Avalon Linear. Processed in PI and Photoshop. An interesting large-scale object and ridiculously horse-like to my eye! Olly
- 11 replies
-
- 19
-
The satellite situation is like the plastic situation. We are drowning in plastic, yet still we churn it out. Olly
-
I give you fair warning: the term 'pretty pictures' with regard to astrophotography lights my blue touch paper. I haven't spent the last fifteen years of my life trying to take pretty pictures. So, deep breath and move on... I think you're right to be concerned about the 'debris cascade' effect, Peter but I think the genius types behind software and the short-sub CMOS revolution will preserve astrophotography. (I was semi-railroaded into CMOS by circumstance but, woo-hoo, it is glorious! Olly
-
I've had Mesus heavily loaded and never seen this. How about the floor itself? Could the wind be moving the shed which then moves the floor? (Maybe try your metre on the floor itself?) What about trying to check the vibration while the mount is not tracking? That might eliminate irregularity in the drive train. Are you confident that the balance is correct? (I must say that my Mesus did not seem terribly sensitive to balance.) How windy is windy at your location? Have you contacted Lucas? Olly
-
I think that's a very good rendition indeed. The little spiral has crisp detail, too. Regarding when to use Star Xterminator, I use it on a partial stretch, say around 70% of final. I got a better result this way than with an application on the linear data. Olly
-
Really nice to put a bit of effort into something often marginalized by its big neighour. Bravo. Olly
-
I rather agree with Steve, above. M33 is a rogue case for the X-suite because, as Oskari pointed out on another thread, it is speckled with stars. For me, the first image is very colour-cold and the second a little colour warm. I'd be no more inclined to believe PI's photometric CC than I'd believe the late Mystic Meg. The problem is not the integrity of the program but its sensitivity to input error. Cool down the second image a little and I'd have that one any day. (I had similar misgivings in my own reprocess of M33, but it was the only one in which the new methods didn't knock the old ones out of the park.) Olly
-
Which Telescope?
ollypenrice replied to Stephen Frost's topic in Getting Started General Help and Advice
Stop! Astrophotography is terribly complicated, frequently counter intuitive and always expensive. WiFi is completely irrelevant to the problem. I know this is hard to accept but it would be better to accept it now than accept it after wasting a lot of money on a setup that will never work. Let's begin at the beginning: - You have a camera which can record light. - You need optics to focus that light onto the camera chip. - Astronomical targets are faint and need long exposures. But... - The Earth rotates relative to the sky so you need a mount which can unwind that rotation by rotating the other way. But... - That unwinding must be done equatorially as opposed to just right-left/up-down. - And that unwinding must be done with a mechanical precision which is beyond conventional engineering... - And the longer the focal length, the more insanely precise that unwinding needs to be. Don't spend a single penny before getting to the bottom of all this. Olly