ollypenrice

On 28/06/2019 at 14:36, Astrosurf said:

Sounds great. This? https://en.wikipedia.org/wiki/Simeis_147

EDIT: hmmm, too low on the horizon at the mo.

It is also enormous. It's at least a 2 panel at 500mm FL with a full frame chip. Wonderful, though.

Olly

Such a useful accessory and, for me, the simple ones like this are far less hassle than the over-engineered capstan wheel rotators.

Olly

My own view is that we should concentrate on looking through optics and not at them.  They rarely, if ever, look perfect when we scrutinize them but it's surprising how dirty they have to be for a perceptible degradation to occur when we use them. Since this thread will be read by people in the future I think it's worth saying that the consensus in the community is to resist the temptation to clean mirrors which are not pretty dirty. In the case of refractors, however, there is a case for removing pollen which can attack anti-reflective coatings if left in place. 

My point here is a general one and not directed specifically at the OP.

Olly

If you've never felt the need for it forget it!

lly

45 minutes ago, Datalord said:

 

Thing is, I can literally do the same action multiple times and get a different result every time. The absolute definition of madness.

The absolute definition of IT in the real world, in my view!

Olly

On 28/09/2018 at 16:14, Andyb90 said:

I couldn't see on the TS website whether it's a flattener as well. I've emailed them to check.

So the faster the setup generally the more difficult it is to achieve and maintain accurate focus manually. Is that correct? I haven't got auto focusing setup at the moment. I use the star HFR readings in SGPro for focusing manually.

Andy.

Yes, the light cone has a steeper angle as in a capital X where the left hand half of the letter is the incoming beam and focus is at the point of crossover in the middle.  Because pixels have a finite size you have a little tolerance each side of the point of crossover but the steeper the light cone the less is that tolerance (or depth of field). Smaller pixels also give you less tolerance.

Your motivation seems to be to reach F4. If this is to make imaging faster a reducer may not do this. For the F ratio rule to work you would have to fix the focal length and add more aperture.* Reducing the focal length at the same aperture is not equivalent. The sound reason for using a reducer is to increase the field of view and if you actually want all that is in the new field you will get to an acceptable S/N ratio faster but at lower resolution.

Olly

* This is what happens in camera lenses and explains why the F ratio rule does work in this context.

1 hour ago, Datalord said:

Can you give me a bit more information on this? Are you using PinPoint and/or using an ASA mount and software?

Yeah, no lies there.

The good news is that I have it set up well enough that it literally would make no difference whether my mount was in my living room, backyard or in Spain. This software is incredibly demanding on the exactly right parameters everywhere and the documentation and forums are virtually dead. I just now read a thread from 2016 where an ASA representative was quoted to say that he didn't understand why users who have used the mounts for years needs better documentation. I now understand why they are leaving the amateur segment...

Meanwhile I could just flip the table on the software and just guide it better than I have ever had any mount guide before. 🙄

Well, as a remote imaging host I've come to suspect that not guiding is a lot more trouble than guiding...

Olly

15 hours ago, Datalord said:

 

I promised them beer, wine and whisky next time I visit.

That's not going to do much for the next customer's PA... 

Not being into IT, I'm following this thread with a mixture of awe and dread!

Hope you get it sorted. Remote imaging is the hardest kind, I think, in the early stages at least.

Olly

I owe Ian King an enormous debt in terms of the sound advice he offered me when I decided to embark on DS imaging, advice I often pass on to this day with its source acknowledged. It can only be a good thing that two completely reliable and expert astronomy retailers are merging like this because your overlapping specialities and areas of expertise seem to mesh so well.

I can only wish you well for the future and do so with both my head and my heart.

Olly

Could be slightly pinched optics.

Olly

On 17/06/2019 at 10:00, JamesF said:

Yeah, I could probably give some of the eleven year olds a run for their money

James

At my best in cycling I would've been fourth best junior girl in Britain over ten miles!  

I just wish your observatory would take on even the tiniest hint of scruffiness. As it is I daren't go up to mine for shame until it's dark and I can't see the inside!

Olly

1 hour ago, Jkulin said:

I used to fish, but gave up because of my beliefs many years ago, but when I did, I made my own rods and bait, I wrote many articles for books and magazines and appeared on the front cover of the Angling Times and Anglers Mail a large number of times, but I would never have claimed a capture if I had not cast, hooked and landed the fish and tied my own rigs, this is me 27 years ago when I had hair!: -

That's not hair, it's scales!

lly

1 hour ago, michael.h.f.wilkinson said:

Feel free to differ in opinion, but please keep the tone friendly.

I tend to agree with some of the early posts in this thread that all is fine as long as you are honest about the sources of the data. Astronomy is a science, so you can use other peoples' work provided you give credit where credit is due. If getting data from a rented remote telescope is "cheating", does this mean we can take credit for the kit we have, having just bought it off the shelf? Should we all build our own scopes, mounts, and cameras? So provided you mention the source of the data, and only take credit for the processing, all is well in my book. Moreover, if I plan the imaging (targets, instrumentation used, exposure times), I can take credit for that part as well. I recently got into a discussion with an astronomer from the Instituto Astrofisica de Canarias, and we got into a discussion on the potential of lucky imaging on really big scopes. He actually suggested donating 5 minutes of time on a seriously fast camera on a seriously large telescope. Unfortunately, powers higher up didn't want to "waste" even such a short time on the instrument for an experiment they thought would fail, but had I got the data and turned it into a neat image, would that be cheating?

In the analogy of fishing posted earlier: I personally don't have the patience to go fishing, but I can cook some seriously good fish and seafood dishes. I can take full credit for the cookery, not the capture or culture of the fish, scallops, clams, etc involved. I would never pose with the fish, but I would happily pose with the resulting dish!

I wouldn't pose with a fish either. It gets pretty hot down here...

lly

23 minutes ago, mihaighita said:

 

The mount moves when tightening both the central bolt and the altitude locking bolt. On the central bolt I tried everything to make it stop, from thrust washer to grease between 2 washers to compression bearing and while the last 2 methods did alleviate the problem, the rotation of the mount did not entirely go away. On the altitude locking bolt I've yet to find a cure that will stop the mount moving, I think it slightly flexes the structure and I tend to leave the altitude bolt a bit loosen or anticipate the move and move the star a bit off... On a fixed location where you have time to fiddle with the PA and anticipate the mount movements it's not a deal breaker but the considerations from above were about the mount being used as a portable mount (even in the splittable version).

I love the mount, after the setup on my pier and the PA "nightmare" it just disappeared in the background for most of the time and I imaged with it between 395mm (reduced FSQ 106) and 2000mm (250mm RC) without any problem. And as a testimonial on how sturdy the mount is, I had an incident with the wind taking it down from a berlebach tripod last autumn. It was loaded with the 250mm RC and the FSQ at about 40 kgs of scope and cameras and another 40 kgs of counterweights and the damage the mount sustained was minor (Dec housing bent and, ofcourse, the DEC motor severed from the housing). It's true that the fall was somehow slowed by my body 😁... Lucas fixed the mount quick and perfect after this incident, it took more for me to recover than the mount to be fixed. 

With all of the above said, I will surely buy the second version as the secondary mount for my upcoming observatory in Tuscany...

I remember Sara saying this as well but it has never affected my PA efforts. There must be a reason. How about this: in the threaded system which pulls or pushes the mount east or west there must be some backlash because there always is. Now the top nut turns clockwise so if the adjusting system has its backlash still present for a clockwise movement of the mount you'll get the effect you describe. But if that backlash has already been taken up you won't. What I'm thinking is that whether or not a final turn on the centre nut will move the mount will depend on the direction of the last thing you did with the adjusters. It might be worth checking that the adjuster's backlash is on the 'anticlockwise side' and is already taken up. Does this make sense?

Olly

24 minutes ago, Jonk said:

I think that may refer to the final tightening of the main central bolt holding the mount to the pier / adaptor plate?

Possibly so, yes. The trick, I think, with any kind of mechanical adjuster that has to be locked finally in place is not to have it too free to begin with. I keep a fair bit of tension in the moving (adjustable) parts before final tightening. This applies to anything - engine tappets, motorbike rear wheels for chain adjustment, etc etc.

Olly

7 minutes ago, Star101 said:

The things I did learn about using the  T30 Telescope at Itelescope was the sensitivity of the camera. 

I did have to test the scope/camera first to get a feel for how M16 would look. Here are the test shots. Had I done 300 second subs then the image would be poor. So there is a little bit of work required  

Personally, I cannot afford to purchase such a great scope as T30. I don't have a spare £60K, I have also been to Ollys place and what a lovely part of the world he lives in and yes, I am envious of all the wonderful scopes he has there. I would love to have clear skies every night where I live but its not going to happen....So should I be ashamed of using other scopes? Does this mean only the rich, who can afford expensive scope setups, should be allowed to image and submit those images?......Of course not!! 

For me, I agree with Olly above, It all comes down to how its presented. Which category etc. Show where it is captured and just be honest.  

60s

120s

300s

Off topic but was that with a camera without anti blooming gate? An ST10 or such-like?

Olly

What's emerging as the key phrase here is  '...and claim the image is your own.'  But this claim isn't just one claim because it comes in several versions. I claim it's mine with my own gear, I claim it's mine with someone else's gear operated by myself, I claim it's mine with some else's gear operated by them, I claim it's mine from downloaded data...'  I would think it remiss to choose the wrong version when posting the image but does anybody do that? A few people steal images but how many actually lie about acquisition? It can't be many. We'd know - and sometimes when we see the odd image we do know.

Olly

2 hours ago, Demonperformer said:

A response which nicely ignores the point of my question.

I note from your signature that there are a lot of scopes, mounts, cameras and accessories that you presumably consider to be "yours" because you have given money to the person who did the work of making them. You also presumably consider the results gained by using this equipment to be "yours" (despite having not manufactured the chip in the camera you are using?). Indeed, the question arises, did you write all the software that you are using to process "your" picture? If not, it isn't really "yours" ...

So where does one draw the line?

If I give money to someone who has done the work of setting up a scope to buy an amount of time on that scope, the time and the results gained (using my skill - such as it is - of selecting & framing my object, and selecting settings, including filter choice) are similarly "mine" as long as I do not claim to have done something I haven't.

One draws the line wherever ones wants to because the line's jurisdiction applies only to the person who draws it.

Olly

8 hours ago, Datalord said:

Olly, I actually understand your argument and I can see why it is true in one way. But I also disagree in that comparing scopes based on FOV is artificial. 

I went from a 11" f2.2 to a 12" f8. Biggest difference you can imagine. And I would not shoot the same targets, that would be nonsense. But the rc gives me access to more objects, which space is gloriously full of. If I could have Hubble's 54.000mm FL I would use that for fun new targets. I would not go for Orion with it. 

I propose these recurring discussions take their beginning with: "what targets do you prefer?". Then comes finding the scope/camera combination that suits this best.

If I were looking at 12" f4 vs 16" f4, they are in my world virtually the same. The targets you can acquire are virtually the same. What you do get is simply more photons hitting the camera, which does translate to improvement in signal to noise, for the given camera surface. Faster and better pictures. 

I would not bother. A 16" RC on the other hand would be a completely new world of wonder opening up, alas also incredible pain. 

We seem to come to the same conclusion here. I very much doubt that real results would change by much.

If you have a site with exceptionally stable seeing the 16 inch RC would indeed deliver a new world of wonders. In most parts of the world, however, it would deliver a shedload of 'empty resolution' onto a minute FOV!

I didn't want to sidetrack the mount thread but merely raise the issue of the value of this increased payload because that might impact on mount choice.

Olly

8 hours ago, mihaighita said:

 

The performance of the Mesu 200 is amazing considering the price.  It has some flaws in the design and some in manufacturing but nothing is perfect 😁 . 

If you do the things above everything is portable. I bet there are people that can lift on a pier/tripod an even heavier mount. My concern with the transportability of the Mesu 200 is about the fragility of the exposed motors/encoders. Even a small mistake can lead to a catastrophe (I had to replace my DEC encoder because the mount arrived to me in with the encoder ruined most probably from shipping). Also the edges of the mount are so sharp, I had a lot of cuts trying to lift it to it's pier. Then there is the tedious problem with the mount rotating when at the end of doing the PA one wants to tight the mount axes, that makes the PA extremely time consuming. And, as a last thing against portability, it's weird to take a mount that is capable of at least 50 kg of scope for astrophotography and put a 8-9 kg FSQ on it, there are some other mounts in the price range that are marvelous travelers and can carry a relatively small telescope. 

 

I'm trying to think of what you mean by the mount rotating during PA. I'm observatory based so it's a long time since I did a PA but I honestly can't remember any issue like this. I do remember installing the first one here with its original owner and we both thought it was incredibly easy. We aligned using drift. I did use the polarscope when I installed our second one and, again, I remember it as painless. One guest brings his Mesu most years and sets up very quickly, too. I'm not saying you're wrong, just that I can't imagine the issue.

The housings round the drive wheels are fabricated on all but the first Mesus and are more angular, I agree. On ours they are rounded and one piece. (How they are constructed is a bit of a mystery, rather like a ship in a bottle!)

Olly

1 hour ago, Anne S said:

Does the night assistant job come with accommodation?

 Not at the moment! (Well, I guess we could run to a plastic bag...) However, as we head deeper into our dotage, who knows?

Olly

45 minutes ago, tomato said:

I’m sorry Olly, but I’m  not with you on this one. I might agree if I routinely collected quality subs every session, but until I do, processing for me is very much a ‘trying to make a silk purse out of a sow’s ear’ type of activity, from which I rarely derive much enjoyment. That much repeated phrase from the early programming days ‘Garbage in, Garbage out’ keeps ringing in my ears.

There are a number of posts on SGL where very accomplished imagers have said something like “the data made processing a breeze”, or words to that effect, that’s where I want to be.

Unfortunately, I still want to do it from the UK, that’s the challenge for me.

I don't see why you think you're disagreeing with me! Think about it with brutal honesty: all data is garbage, even Hubble's. With the exception of some nearby stars Hubble data should record most stars as single pixel point sources, but it doesn't. As amateurs we are in the same boat but at a different point on the 'continuum of garbage.' (😁 I wouldn't want to be remembered for this phrase!) 

I hope that I have never said anything like, 'The data made processing a breeze,' though with 32,000 posts I fear I might have forgotten myself on occasion! Processing for the Hubble team, as for us, is about getting the best out of the available data. It is never a breeze. I honestly don't think I've ever found an image easy to process. If the data is really good you raise the bar. But I've certainly found some data abominably difficult to process precisely because it was good. That's to say that it contained tantalizing hints of the very faint.

However, the best data comes from the best skies as your last point rightly implies. Without new technology (not inconceivable) that won't change.

Olly

18 minutes ago, vlaiv said:

No, it's not about resolution / resolving power (yes, 16 inch will have small theoretical advantage even in poor seeing, but that is besides the point).

Your post that I first answered to, stated that you can't see any advantage in going with larger scope. I offered distinct advantage of larger scope - it will be faster for given target sampling rate. If one is willing to sacrifice FOV (has reasonably large sensor for intended targets), will bin data anyway, then why not go for biggest aperture one can handle?

It won't be faster if the imager has to do a mosaic to replace the reduced FOV.

If we allow ourselves complete freedom to invent any camera we like then the 16 inch will beat the 12 inch because we can invent a camera with a larger chip to replace the lost FOV of the 16 inch (though we might need to invent a new coma corrector as well). We can also invent a camera for the 16 inch which has not only a larger chip to restore the FOV of the 12 inch but also has larger pixels to hit the sweet spot of 0.9"PP (or whatever). The problem is, once we have invented these cameras do we know anyone twitching with enthusiasm to make them for us? And since the future seems to be moving away from CCD and towards CMOS the simple binning solution (which I have never believed was that simple anyway since not all cameras bin well) becomes not so simple.

Olly

20 minutes ago, Gina said:

Don't mention the B word!!!!!!

There are two B words...

lly

This debate will run and run. It is my good fortune to know Paul so that his comment below is even funnier than it would be to someone who didn't know him:

I think that if you don't collect your own sand and trace minerals, build a kiln, produce your own blanks, grind and polish your own mirror...

Carole is right to point out that that de-aligning my mounts and rotating my cameras to random angles might go down badly. She's entitled to feel that what she did here isn't entirely hers but I'm entitled to feel that it is. If you rent a hire car, do you expect to reset the tappet clearances, align the tracking, regulate the fuel injection and balance the brakes before setting off? 

I find imaging an interesting business, which is just as well since I do it, one way or another, for a living. But how interested can I be in polar aligning, setting up guiding and filing subs in a coherent manner? In the last ten years none of these activities has changed at all. Capture is a mechanical business. It's rendered more interesting when you start to analyse your results and experiment with changing your exposure times, RGB balance, proportion of Lum, proportion of Ha, etc etc. But this is based on feedback from the real business of imaging - which is processing. I have two jobs, Night Assistant in which I help make sure the stuff works and, if guests want it, Processing Assistant. If anyone would like to apply for the first of those jobs I'd be glad to hear from them, but the pay would be lousy.  The second of those jobs is mine all mine and it isn't up for grabs!

After a while we all capture the data our sky and our patience and kit will allow. But what do we do with it? For me, that's where the fun begins.

Olly