ollypenrice

10 hours ago, auspom said:

Not ideal if you're on the side of a hill, but Iget your point  

 It would have to be quite a steep hill, in reality. This is actually metioned in the manual. And if Tak users live too far north for the rather limited adjustment in altitude they routinely put something under a foot to tip the tripod.

By the way, I don't see how Alignmaster could have any knowledge at all of how the altitude angle was acheived (whether by tilting the pier/tripod or using the adjusters. The result is identical. Rather intelligently the levelling bubble on Avalons only runs east west, it isn't a circular bubble level.)

Olly

29 minutes ago, Daniel-K said:

if the stars are round why stress ?  

Because round stars don't indicate good guiding. Random errors will produce round stars - but large round stars.

10 minutes ago, carastro said:

I have the Skyshed pier and have no problems with it at all using an NEQ6, I like the design, it's is easy to install.

I did have a bit of problem when I previously had a CG5 GT on the pier as being smaller I could not see through the polarscope as the top pier plate was right where my chin needed to go, but once I swapped that for an NEQ6 that problem went away.  

Works better with a piggy backed guidescope than a side by side arrangement as less risk of scopes clashing with the pier plate.  

Contrary to what has been said about not needing the pier level, I did accidentally "slightly unlevel my top plate" once when removing the mount for Astro camp (this is because the top plate needed to be removed in order to get the central rod out).  I had not realised I had done this and it took me quite a long time to fathom out why I could not get a decent polar alignment or do an alignment procedure properly.  I also could not do a polar alignment using Alignmaster until I levelled that top plate.  

I don't remove the mount any more and no further problems.

 

I don't use Alignmaster and don't know how it works, but there is absolutely no doubt that mounts do not, in principle, need to be level. Try this thought experiment: take a perfectly aligned mount and get Harry Potter to hold it permanently in place by magic. In this situation you can remove the pier or tripod completely and Harry's magic will keep it perfect. Or you could shorten the tripod legs so they no longer touched the ground and then you could use the levelling adjusters to point the pier or tripod wherever you liked. The point is that this will have no effect at all on the polar alignment.

The best fast PA routine bar none is Takahashi's and their tripods have fixed legs.

Olly

If I have the right video in mind another member described it as 'snake oil,' which struck me as being about right.

People go to a lot of trouble to make their pier tops adjustable so as to be levelled. In fact a mount can be perfectly polar aligned when the mount is not fitted to a levelled pier top. As I've often pointed out, up- market Takahashi mounts have no facility for levelling - because it isn't necessary.

My own take on the 'snake oil' video was that the ground fastenings of the wonder pier being purveyed were too close to the pier itself. I always make piers with a reasonably large footprint.

Olly

28 minutes ago, jason32 said:

Thanks yes I figured that out and now point my camera towards the counter weight bar and it works fine. Thats one very intimidating setup you've got there...lol

Not mine. It belongs to a regular guest. But mine certainly intimidate me in their own way...

Olly

People using Newts for AP don't usually have the camera sticking out of the side. They rotate the tube so the camera is underneath, or pointing at the counterweight bar, if you like. If it's sticking out sideways you'll have trouble with dynamic balance - ie balance changing position during the mount's movement. Here's a very serious bit of imaging Newtonian in action at my place, Pieter Van de Velde's home made instrument. Note the position of the camera. https://pietervandevelde.smugmug.com/Pics/Equipm/i-gStw3gg/A

Olly

Some impressive results and a good idea for a thread. 

Erm, would it be considered unsporting of me to go and beg some time on this Alt-Az instrument up the road from me? 0.8M Ritchey Chrétien, direct drive, field de-rotator and a price tag of 6 million Euros...

Well it isn't an EQ!!! 

(There's always one...)

lly

There is simply no way of knowing for sure which reducer will work with which scope unless a) it's dedicated to that scope by the manufacturer or, b ) it's been tried and tested by someone else.

You could be confident that the dedicated SW one would work but it would be great to drop the F ratio still further with the AP. Provided someone can confirm from experience that the pairing works then that 0.67 would be a superb choice.

If you decide to ask around do be sure to note the chip sizes that have been tried with the pairing. Very small chips are not an exacting test. A very common enemy of the focal reducer is the internal reflection on or around bright stars.

Olly

That bottom flange has a suitably nautical look to it and is the right colour! Are you absolutely sure you haven't buried a Russian submarine in your garden with a bit sticking up for your scope?

Olly

They won't be on a DLSR, I'm upgrading to an 8300 CCD, so will be looking at LRGB and NB imaging.

From what I've read since, the general consensus is 'the narrower the better', especially for use during certain phases of the moon.

I can't find much on Baader vs AD RGBs though.....another topic.

I use Baaders but have processed a couple of images with the Astrodon LRGB. I'm a fan of the AD narrowband but was slightly relieved to find myself vaguely preferring the Baader RGB set. This might be through familiarity but at least I didn't feel my Baaders had to go straight in the bin!! I like the Baader LRGB set.

Olly

It isn't a case of 'better or worse' between the 3 and 5 Astrodons. The 5 passes the NII line while the 3nm doesn't. I use NB to enhance broadband images so I went for the very high contrast offered by the 3. It's discussed here. http://stargazerslounge.com/topic/206268-astrodon-3nm-versus-5nm-ha-filter/

To be honest I'd have thought that the Astrodons would be a big investment to use on only a quarter of the pixels with a DSLR.

Olly

Well, the big Orion with Tom, of course. 400 hours, 33 panels, two focal lengths, etc etc!!    Runner-up in the APOTY competition and more Tom's than mine. Still, I'll bung it in before he does!     

An HaRGB mosaic following structures in the North America region a bit forther south to see what was happening.

Another mosaic from the Crescent down to the Tulip done with guest Paul Kummer. HaLRGB.

Supernova remnant not so often seen near VdB152. (Lots of Ha!)

And finally another mosaic uniting M35, NGC2158, The Jellyfish, Sh2 247 and the Monkey Head. Multi focal length, HaOIIIRGB. About 60 hours.

An enjoyable year, as ever, and the Mesu has still never dropped a single sub. Cheers, Lucas. 

Olly

Thanks for the info Olly. I'm still considering it, but have to wait a while an see how the job situation works out. Think it was a 2" 3nm astrodon filter i found that cost almost as mutch as my scope :-))

Sent fra min D5803 via Tapatalk

Yes, I know, that's the one we have here. Terrifying!! 

Olly

That's still a good  image you have, with lots of detail in the nebula.

I haven't tried narrowband yet, but I guess:

as the moon reflects allmost all sunlight (wavelength-wise), my guess is that a narrowband filter won't work. The reflected Ha from the moon will interfere with the Ha from the object you're trying to capture. To capture the faint details of Ha-nebulae you'll still need a dark background; so, no moonlight.

Just my thoughts on this.

No, Ha is remarkably moon-proof, the narrower the bandpass the better. There is a huge difference in partial moonlight between our 3nm Astrodon and 7nm Baader. Other NB filters are hardly effective at all. (OIII is no good in the moon.) For all that, even with Ha the moon needs to be well away from full phase so I agree with Sara.

Olly

Hi Olly

Were you using the Atik 4000 with the 200m Canon when you felt that the pixels were too big? I have both - I was going to give them a try - but if you don't think they are a good combination I might give it a miss.

Out of interest - how does having too big a pixel size show up in the image? Or to put it another way - how can you tell?

Cheers

Ian

Hi Ian,

Yes, I used the 4000 with the 200mm Canon. At the time I had OSC 4000 and mono 4000 so I tried Ha from the mono and 0SC (RGB) from the OSC. I did a wide M45 with just the OSC, too.

The coarse sampling rate shows up in a loss of fine resolution and, more importantly, perhaps, in a blocky look so far as the stars go. If you keep the image presentation size small it is bearable but you can't offer the results at full size. In the end I regarded these results as interesting and as an inspiration to come back at a finer pixel scale and multi panel mosaic.

I'm trying to link to a couple of images I did with this setup but the net won't play. Sorry about that. I image (as do a lot of people) at 3.5 arcsecs per pixel with the FSQ106/Kodak 11 meg combination. That is about as coarse as I ever want to go, I reckon.

Olly

Hi Olly yes that looks just the job - the TS microfocuser I mean, not the Tak!

Whats your thoughts on the Canon lens with filter wheel for CCD ? Is there space for a wheel?

BTW I just tried to check the depth of the ZWO filter wheel and noitced they now have cooled ZWO ASI 174 on sale for $799. Bit off topicHas anyone ordered direct from ZWO - do we get hit for VAT etc?

I don't know. It might be tight to get a F/W in there but I think someone (Gerd Neumann, maybe?) made a slide drawer for CCD to camera lens. This is only going to work sweetly for CCDs with very small pixels. I used a Geoptik CCD-Lens adapter and it can take filters, but involves a full disassembly to change filters. I know someone who's done this but it would be a step too far for me. Cameras with integrated filterwheels (QSI and some Atiks) might have a short enough backfocus requirement. In fact I think they do but this would need checking.

Olly

The Canon lens can be used wide open if you use thirds focussing but it does give better results at F4 which is still faster than any APO I know of, the star 71 would probably out perform it though but is F4.9 ish.

Alan

Tak Baby Q, reduced, F3.9 and Tak 106, reduced, F3.6...   ... but a whiff more pricey than a 200L!!! I've used the Canon 2.8. It was very good but my CCD pixels were too big for it. TS do a micro-focuser. 

Olly

Tom's right, a sticky of cause and effect distortions would be a great resource. To be honest, I couldn't contribute to it because I've imaged with a WO ZS66, TeleVue Genesis (late eighties, F5), Meade 127, Altair Astro 102 and 115 apos, Tak Baby Q, two Tak FSQ106Ns and a TEC140 without ever having encountered any distortion problems out of the box - including some very old boxes... (This ignores visiting 'guest scopes' such as two other Baby Qs and two other 106 Taks, another TEC140 and - quite honestly, I forget the rest. But it does add up to a lot of refractors which just worked.) I could be wrong about the effects of tilt but I use refractors because- sorry to be boring - they just work.

Olly

The latest advice (received today) from my Takahashi dealer (apparently endorsed by the importer) is:

"To assemble the components and expect them to work at this level is not realistic."  

This is not just disgraceful, it is plain potty. Why on earth should a refractor of around F5 not 'just work?' It is hardly an insanely fast astrograph and that is the whole point of buying an FSQ. It's a 'sanely fast' astrograph and should be simple to use. We really have heard some strange ideas from Gnomus' vendor on this thread. I have literally thousands of hours of DS imaging time logged on three Tak FSQ instruments. The first was my Baby Q, bought new, and now used to well known good effect by Sara (with the very 8300 chip which the retailer considered, bizzarely, to have too-small pixels. It is probably the most-used chip with the Baby Q, world-wide.) The other two scopes are second hand FSQ106Ns belonging to myself and Tom O' Donoghue, the rig which just produced runner up image in the Astrophotographer of the Year competition. To put the second-handedness of my own scope into context, it arrived after Parcel Force had bashed a hole through it's flight case.

Not in the first flush of youth, then? No, not really. But does it 'just work?' Of course it does! So does Tom's. So did my Baby Q. So do the FSQs (two of them) working in my robotic shed on behalf of their owners. (No, one of them needed the focuser tightening, to be fair.) And so did the three visiting Baby Qs belonging to guests here and whose images I helped process (including ones taken with three micron pixels.)

The FSQ isn't a Hyperstar or some other bit of optical madness built without regard to the harsh realities of engineering. It's supposed to work and most of them, in my experience, do work - even after Parcel Force have molested them.

I smell snake oil.

Olly

Hmmm... I'm not sure it's Takahashi engineers who've been looking at this so much as the Tak importer who is essentially a retailer.

I've seen never seen tilt produce what looks like a spherical distortion and one limited almost entirely to the corners. The CCDI curvature test shows curvature on the extreme right hand side and at its worst in the two affected corners.

Of course I could be quite wrong but I cannot see tilt behaving like this.

Olly

Radial distortion cannot be tilt. Simple as that. Ian King's opinions need no endorsement from me but, FWIW, I do agree with him.

You might well find tilt in CCDI on Steve's images but that tilt cannot be the cause of the problem. (You might find a crack in your car's windscreen but that won't be why it doesn't start.)

Olly

Takahashi say that their scope will give 'pinpoints' out to 22 mm from optical centre. In the examples that I have posted do you see pinpoints at 12.5 mm from optical centre? Secondly, are you suggesting that if a company sells me a duff product, but then say that it is OK, I am just supposed to accept that?

Perhaps you are just teasing me, in which case I apologise for rising to the bait.

And there you have them.

Olly

I believe that Olly meant 'less' depth of field here? However, I do agree with Olly completely that you have a well optimised system with regard to the sampling -  you are comfortably in the right area in my opinion as well - hang it, I bought the same 'scope  BECAUSE it was a good match to the 8300 chip!

I am sorry to hear that the supplier has had a change of mind as I am not sure where that leaves you except perhaps checking out the tilt that I suggested earlier on in this thread but as for the pixel size being too small, although I was told something similar, I am far from convinced.

Thanks, Steve, he did!  I've been out of bed for the large part of four days and it's beginning to show... The Baby Q is a good match with far smaller pixels. Note Horwig's post here. http://stargazerslounge.com/topic/255014-deeper-into-m31-from-les-granges/ I worked on this data so I know it's genuine and the pixels are far smaller than those of the 8300.

Olly

Good grief, you are resolving at 2.47 arcseconds per pixel which is positively coarse, so the claim that your pixels are too small is risible. The UK 'sweet spot' is often estimated as being at 2.0 arcsecs per pixel and you are well above that. Imaging down to 0.6 is commonplace. I did it for two years on a full format camera. Many of my friends ask why I put up with 1.8"P/P on the TEC140/ full fformat outfit and I say, 'because it's nice and tolerant and relaxing to do.' So your  pixels are on the big side, not the small side, and you'd have plenty of imagers to confirm this.

On top of that your chip diagonal measures 22.5mm for a claimed imaging circle of 44mm so you are using a tad over half the full circle. So you have a forgiving pixel size and are using a chip which exploits about half the light cone. Reality check, you should not even be taxing the optics in the slightest. Sara can prove that a Baby Q can cover this chip easily.

However, the tilt remains a possibility. The fact that it wasn't there on the ED80 may not be proof of the chip's orthogonality because the Baby Q has a faster F ratio and so greater depth of field.

And I do suspect that, while it may not be perfect, you might have a very hard time beating the Baby Q once you get into long colour exposures...

As for that stuff about pixel scale, it's bunkum.

Olly

That good new Gnomus,had been reading post and Olly check out one of my sub on my 106 just to see if Qc is in all Tak.

I did so and thought it perfect. However the corrected circle on the 106 is so big that you can't find a camera to test its potential. A good thing for all our wallets, I dare say...

I'm glad you'g getting a new one to try, Gnomus.

Olly

Yup, that excludes PA conclusively.

I'm really sorry you're having this hassle.

Olly

PS I'd send that crop to the supplier.