Time to buy a decient screen then , the edges are white in my Compaq Q2009 .
Here come the doomsayers , but please keep it coming ,,,,,
You kinda forgot that this shot is raw , it would be easy to cheat and process any defects out but that's sort of cheating .
Brian.
I have a professional colour calibrated monitor for editing and the shots show green fringing on my screen as well
It's entirely normal to see a little fringing at low power and more fringing as the magnification increases, in addition to a subtle (or not so subtle, depending on the observer) mauve haze across the image, but even fast achromats can give very sharp and detailed images with the addition of filters.
In any case they're very nice pics Brian
So , in your expert opinion ( that you are more than welcome to share) what's so ( in your words) , ' Absolutely Objectionable' , about this shot ?
Taken with my terrible for luna photography 127mm Istar Achromat ?
This was taken eyepiece projection , 5mm TV Radian giving 200x , not quite dark , using my HTC one smart phone . Here it is .
Take your best shot old mate .
Zero processing , just a raw shot cropped a little for the page . .
On the Copernicus shot , just stunning ! awesome shot . Reminds me why I am a Luna , Planetary observer , so very well done .
But I need to ask how much computer enhancements have been done to acheave this beautiful shot ? .
Thanks and keep em coming .
Brian.
Quote:
Originally Posted by Satchmo
At about 20X - X40 prime focus magnification with an Achro - which these shots represent, CA will not be noticeable . At X400, using eyepiece projection for a descent close up shot the CA in these Achro refractors will be absolutely objectionable in the pictures - even for visual observing pretty useless....
I am not sure exactly what you are proving in these photos - the subtext being that somehow CA in achros is an overrated criticism ?
Have attached a picture of Copernicus using frame stacking , by Anthony Wesley using a basic 10" F6 reflector in 2005 - just to put some perspective on this !
Last edited by sheeny; 30-07-2013 at 04:40 PM.
Reason: inappropriate comment
Absolutely objectionable ??? in who's opinion ?
That's the kind off Achromat bashing that puts newbies off the larger achromat Satchmo , un-founded bigotry that needs addressing for the masses out here that cant afford an APO and don't want the cumbersomness of a Dob but want a nice real scope , the refractor .
So , in your expert opinion ( that you are more than welcome to share) what's so ( in your words) , ' Absolutely Objectionable' , about this shot ?
Taken with my terrible for luna photography 127mm Istar Achromat ?
This was taken eyepiece projection , 5mm TV Radian giving 200x , not quite dark , using my HTC one smart phone . Here it is .
Take your best shot old mate .
Zero processing , just a raw shot cropped a little for the page . .
On the Copernicus shot , just stunning ! awesome shot . Reminds me why I am a Luna , Planetary observer , so very well done .
But I need to ask how much computer enhancements have been done to acheave this beautiful shot ? .
Thanks and keep em coming .
Brian.
Firstly, I think in my own opinion acromat’s are pretty ordinary for Astro photowork except mono work, and yes I can see fringing and colour on the edges – I have colour with my cheap 127ED as well. BUT, you asked a question or postulated a statement? – You got an opinion and because you don’t like and now you are prepared to belittle and bait the person that posted?
With ref to the pic posted in #24, I am getting a purple tinge on my screen on the left and some greenish hues in the highlights.
My screen has been calibrated for my son's graphics/photography work.
I think the effect is going to be there with any achromat. Personally I did find that the Istar 6"F10 I had was better than other achros I have used but that may have been due to the F10 ratio. My 135year old 3" F15 is the least colourful achro I have used. I did not really understand how much extraneous colour the achro showed until I put it side by side with the TSA120, the difference could not be missed on the moon, Jupiter, Saturn or brighter stars. But if I had not come by the Tak at such a great price at the right time I would have gladly kept the Istar.
But seriously these discussions of Achro v Apo v Mirror happen all too often and cause so much disharmony. Such a shame !
Hi , here is a couple of shots from this last week taken of the moon in its waning phases .The last was 3am this morning after work ISO 400 1/4 second .
....
I think they are great shots Brian.
The miniscule amount of false colour there (which I had to strain to see after it was pointed out) is certainly not objectionable to me....
I should do one through my Skywatcher 100mm f/5 - so much colour, it would look like there was a mardi gras up there!
At the risk of inflaming the situation... a few people have mentioned that imaging in mono will fix the CA, but that, in itself is not quite right.
Imaging in mono will hide the CA as another shade of grey. To get a truly sharp image requires the use of a filter before capture to narrow the bandwidth of the light being captured.
Personally I thought the original two shots were nice shots especially having no post processing done so I dont see anything Absolutely Objectionable to the shots.
However the shots do show CA which also would have been visible visually so I dont think you could use them to support any claim that an Achro has no CA either visually or for AP.
Personally I just dont like to see CA visually but as I say that is just my personal preference and thankfully my scope shows no CA but that comes at a cost.
Thanks Phil, at last some one with some common sense on this subject .
Spot on mate . .
This is what was trying to get across .
The CA is that slight its irrevelovent in my eyes .
On that the photo of 3rd quarter is almost identical to the absolutely beautiful image my TV Radian 14mm throws up , same image scale and lack of CA or any other aberrations as this shot shows , just beautiful .
On that , this is a $630 OTA not !! a 5k +APO .
One more thing I hear you on the cost thing , my Takahashi Mewlon 210 is perfect in every way .
Brian.
Quote:
Originally Posted by issdaol
Personally I thought the original two shots were nice shots especially having no post processing done so I dont see anything Absolutely Objectionable to the shots.
However the shots do show CA which also would have been visible visually so I dont think you could use them to support any claim that an Achro has no CA either visually or for AP.
Personally I just dont like to see CA visually but as I say that is just my personal preference and thankfully my scope shows no CA but that comes at a cost.
Thanks Phil, at last some one with some common sense on this subject .
Spot on mate . .
This is what was trying to get across .
The CA is that slight its irrevelovent in my eyes .
On that the photo of 3rd quarter is almost identical to the absolutely beautiful image my TV Radian 14mm throws up , same image scale and lack of CA or any other aberrations as this shot shows , just beautiful .
On that , this is a $630 OTA not !! a 5k +APO .
One more thing I hear you on the cost thing , my Takahashi Mewlon 210 is perfect in every way .
Brian.
You can pick up a nice APO for under $1k these days, don't have to spend a fortune. I got a 90mm - F/7 last year to use with my OSC as the ED80 had bad color correction. You get green around the limbs because the blue doesn't focus where the red and green are. If you shoot mono it's still not as sharp as an APO but you can manage colors betters with a filter wheel.
Maybe but I would hate to see the short cuts made to sell a 5 inch APO for 'under a grand' , thanks but I will stick with my 127mm f/8 Istar / saxon thank you very much , nice optics for sure .
Your shots are a great eye opener , but in the 'Blue' looks a bit sad tho ? and its a shame your ED80 was a dud , the one I had ( now sold ) had awesome optics .
Brian.
Quote:
Originally Posted by multiweb
You can pick up a nice APO for under $1k these days, don't have to spend a fortune. I got a 90mm - F/7 last year to use with my OSC as the ED80 had bad color correction. You get green around the limbs because the blue doesn't focus where the red and green are. If you shoot mono it's still not as sharp as an APO but you can manage colors betters with a filter wheel.
Maybe but I would hate to see the short cuts made to sell a 5 inch APO for 'under a grand' , thanks but I will stick with my 127mm f/8 Istar / saxon thank you very much , nice optics for sure .
Your shots are a great eye opener , but in the 'Blue' looks a bit sad tho ? and its a shame your ED80 was a dud , the one I had ( now sold ) had awesome optics .
Brian.
Man... this is like talking to a wall.... you need to read all the previous post in this thread. Who knows? You might learn something.
This is a crop of your shot btw. Just wanted to illustrate that the blue was out of focus and explained why as did many people in previous posts so you know where to go from there.
Did anyone here happen to notice the camera used to get these photo's?
HTC one smart phone.
So, of course it isn't to the standards that can be gotten with a more dedicated set up.
It was a bit of fun posted for a bit of fun, so get a grip.
What it says is that amateurs can have some fun AND have photo proof of the excitingly innocent way they spend their nights.
btw - if Brian says the CA is unobtrusive then... it's unobtusive.
Cool , but I don't use/need filters with my Istar , it good enough for me , that's the whole point of this thread was to show how good our 'Lowely' old achromats can perform for lunar photography , not spending hours at a computer screen with X- amount or processing power to extract the last bit of info from the shot , Stacking , Mono , Colour ,, bla , bla , bla that's invisible to the naked eye anyway ,,, whew .
And NO filters , thank you very much , I like my moon a,la natural .... , that's the way it is in real life if I ain't mistaken , warts and all .
Brian.
Quote:
Originally Posted by multiweb
This is a crop of your shot btw. Just wanted to illustrate that the blue was out of focus and explained why as did many people in previous posts so you know where to go from there.
Time to buy a decient screen then , the edges are white in my Compaq Q2009 .
.
– an achromat is an achromat?
Man... this is like talking to a wall.... you need to read all the previous post in this thread. Who knows? You might learn something. 
.. , that's the way it is in real life if I ain't mistaken , warts and all 
