Widefield Scope - Advice Please

[PhotoGav]

Its always dangerous when it's cloudy - too much time to browse the internet and drool over new equipment...

So, I do love my Skywatcher ED80, we have had many a good night together, but..... That scope over there looks absolutely gorgeous and it's corners are so sharp and it's so fast and look at that build quality... Ooooh.

I have narrowed it down to two options: Takahashi FSQ 85 ED with reducer (328mm @ f3.86) vs. Williams Optics Star 71 (348mm @ f4.9). Money wise that's £3169 vs £789.

What do you get with the Tak for the extra £2380 that the WO won't deliver to an acceptable level (Ed: please define acceptable?).

The question is: Should I just save up and go for the Tak?

Both would be used with my QSI 683WSG on an HEQ5.

Thanks in advance.

[Liquid360]

I just purchased a new FSQ-106 and my advice would be, should you have the means, get the FSQ. Just remember that with it you'll need at least a grand or two for the various extra bits, reducer, adapters, etc...

[Tinker1947]

Why not go for a second hand William's OS 71, if your happy with the results save for the TAK, sell the OS 71 breaking even on that outlay...

[ollypenrice]

The Tak is incomparably better, as it should be for the price. But in what ways?

- Better made all round with a very good focuser and everything strong and flex free. 

- Larger corrected circle but not large enough for full frame. (I tried it.)

- Faster F ratio, significantly faster.

And now for what really matters most...

- Smaller stellar images, AKA pinpoint stars.

- Far better colour correction.

- Freedom from blue bloat.

These are really three ways of saying the same thing but the big difference is in the stellar images. The FSQ85 produces images which don't look as if they've come from a small telescope. The tiny stars give that 'big scope' look. My 85 is now in Sara's capable hands. I only sold it because I wanted to move to full frame and set up our tandem rig using Tom O'Donoghue's existing 106/full frame setup.

If I'm not mistaken, at least seven FSQ85s have been bought by guests who came and used ours here. They must have liked ours!

Olly

[PhotoGav]

Interesting idea Tinker, though I'm not sure there will be many new 71 Astrographs on the second hand market quite yet... Unless the owner is upgrading to the Tak!!

Thank you for your responses Liquid and Olly. It's good to hear that the Tak is well worth the extra money. I think I will have to save up for that.

[Barry-Wilson]

And now for what really matters most...

- The FSQ85 produces images which don't look as if they've come from a small telescope. The tiny stars give that 'big scope' look. My 85 is now in Sara's capable hands.

Olly

Gav

Having very recently moved from an Esprit 80ed to a Tak FSQ85 I was struck by the quality of the raw Fits image on my screen when the first sub downloaded - Olly succinctly states the distinction above.  The stellar images are tight and controlled.  The optical quality is exceptional.

I know budget is always a consideration however the FSQ85 has made 3 or 4 appearances on AB&S this last year.  You never know, keep a watchful eye and one may appear.

Best wishes,

Barry

[ollypenrice]

Gav

Having very recently moved from an Esprit 80ed to a Tak FSQ85 I was struck by the quality of the raw Fits image on my screen when the first sub downloaded - Olly succinctly states the distinction above.  The stellar images are tight and controlled.  The optical quality is exceptional.

I know budget is always a consideration however the FSQ85 has made 3 or 4 appearances on AB&S this last year.  You never know, keep a watchful eye and one may appear.

Best wishes,

Barry

Yes. I distinctly remember my first night out with the FSQ85 and the next day's processing. It was just a mile wide smile all the way. The data was incredible.

Olly

[Gina]

Interesting   I was about to ask a similar question - is spending many thousands on a scope really worth it?  Apart from the much renowned Takahashi I was also thinking of things like the new Rowe-Ackermann Astrograph.  Is one expensive scope with filter wheel much better than a triple imaging rig of three similar scopes, fixed filters and three matching cameras?  Grabbing three times as many photons at a time.

Similarly, with the Sony imaging sensors being lower noise than the Kodak KAF sensors, is it really worth going for a large frame size with the poorer type of sensor.

[PhotoGav]

Thanks Barry & Olly. Ian King has everything in stock... Argh, the temptation!

Gina - 'poorer type of sensor'? That's a bit harsh on Sony isn't it?!

[Gina]

I meant that the Kodak sensor was worse.

[PhotoGav]

I know, but being a KAF user...

[Gina]

Let me just say that I don't speak from personal experience as I havent used a KAF - just what I've been told by a couple of people who have used both.  I should have made that clear when I first said it.  I didn't mean any offence and didn't mean to denigrate anyone else's equipment.

[swag72]

Here's the thing Gav, Do you think that changing your scope is the way forward? Do you think that you will bet thousands of pounds worth of better images?

Personally I'd go secondhand with particular attention paid to the fits file. I say that as people with new scopes (premium ones as well) do have some issues and they do perhaps need a little tinkering with as well. I knew that when I got my second hand FSQ85 it was already working - No screws / focuser / reducer / optics needed any tinkering with. If I bought new I know I'd have an expectation that it would work out of the box.

How about upgrading that HEQ5? Now there's a thought!

[PhotoGav]

Let me just say that I don't speak from personal experience as I havent used a KAF - just what I've been told by a couple of people who have used both.  I should have made that clear when I first said it.  I didn't mean any offence and didn't mean to denigrate anyone else's equipment.

Don't worry Gina, I had my tongue in my cheek when replying. It just made me chuckle, the idea of a 'poor' sensor. You are totally right, the Sony is much less noisy than the Kodak. I've compared single subs and the KAF is pretty snowy. Your question is a valid one - is the chip real estate increase worth it given the increase in noise? In my experience, the KAF sensor is outstanding! Yes, there is noise, but with dark subtraction and stacking that disappears to a more than satisfactory level. The images that I have managed to make so far are more detailed, richer and generally better than I had anticipated. I have no doubt that the Sony chip would have made great images too, but for one, M31 wouldn't have fitted so well into my frame. In fact real estate is exactly the reason why I am even considering a different scope. So, if you are after a wider FOV, the Kodak sensor wins. If you are after 'cleaner' subs, the Sony wins. Which would be more important to you?!

[PhotoGav]

Interesting thoughts Sara. Seeing Barry's experiences of his new Tak, you are right about the tinkering required vs the expectations of perfection out of the box. However, when up and running, yes I would expect and enjoy significant improvement!

The reason why I have even started down this route is field of view... I am 3/4 of the way through a two pane Ha/OIII mosaic of The Heart Nebula. The weather has turned and I am left with one pane of OIII to collect. For one, the mosaic adds a level of complexity and two, with the Tak the whole object would have fitted in, I would now have all the required data, could be processing the final image and be ready for my next target once the weather sorts itself out. Is that worth £3k? Probably not, but you soon forget how much you've spent on things, especially when the first subs start rolling in!

Mount upgrade??! Don't, please! There's also a Filter Upgrade on the list....! Actually, I find that my mount is working well and 1800s subs are no problem. The upgrade will come when I need to be able to carry a larger payload.

What I really need above all else are clear dark nights. Do you know any stockists?!

[ollypenrice]

Interesting   I was about to ask a similar question - is spending many thousands on a scope really worth it?  Apart from the much renowned Takahashi I was also thinking of things like the new Rowe-Ackermann Astrograph.  Is one expensive scope with filter wheel much better than a triple imaging rig of three similar scopes, fixed filters and three matching cameras?  Grabbing three times as many photons at a time.

Similarly, with the Sony imaging sensors being lower noise than the Kodak KAF sensors, is it really worth going for a large frame size with the poorer type of sensor.

Good questions.

Spend a bomb on a premium apo or spend a similar sum on a dual rig? (You do need 2 cameras and a bigger mount, but given Tak prices you can do that!) My answer would be this; If using a small sensor and narrowband filters maybe go for the budget scope in a dual rig. The Tak struts its stuff in terms of covering a big sensor and correcting the full visual spectrum. For doing LRGB on a small chip the choice is harder. The Tak is stunningly good in LRGB. If using a big chip it has to be the Tak.

Sony versus Kodak? I streamline my calibration of the Kodak data I collect in the three fullframes I use (Mine, Tom's and Yves') partly because I'm inundated with it after a long clear night. (Over 20 hours is possible. A nice problem to have, you might say!) I use one master flat per camera, not one per filter. I use a bad pixel map and a master bias so that any sub length can get the same calibration. I run a hot pixel filter and column defect remover and I get perfectly clean stacks which rarely need cosmetic attention. What's the problem? I don't see one. Sure, if Sony made a full frame I'd be in there, who wouldn't, but the calibration work-around is fine.

I love the big chip. If I put a small Sony chip in the FSQ106 and a big Kodak chip in the TEC140 and take roughly the same framing the TEC will easily win. More resolution, smaller stars. But slower, of course.

Olly 

[swag72]

I think that a dual rig has definite merits and perhaps that's the route I'd consider instead of getting a premium scope. 2 ED80's would make a good rig and would be no slouch. Life is full of compromises, we'd all love a triple rig with premium optics, mono CCD's and 3nm Astrodon narrownband filters, all atop a monster of a mount - But in reality it's about making the best of what you have.

Do you spend the ££'s on one optic and spend many nights trying to get data in the UK or do you get a second ED80 for example and a camera and dual rig the lot? Double the data in the same amount of time. Hell, in one night you could get enough data to finish an image. That has got to be attractive with the weather you face.

[PhotoGav]

It is an interesting idea - the dual rig option... Expensive though. Another thought is that good conditions are pretty rare here in the UK, so there is something to be said from gathering subs across different nights - chances are there will be one good period in amongst the sessions. It is however very frustrating coping with the weather... Apparently it's only going to get worse over time too.... :-(

I think I'd like to live in the middle of the desert in the middle of Africa somewhere... Very clear and dark!

[ollypenrice]

For us the dual rig is a dream because, even if the weather is disappointing, you can indeed do an image in a night. There are several SGL imagers who've taken this route. A friend in Lyon is really going for it with a veritable battery of ED80s on a big AP and Greg Parker runs the Mini Wasp, too.

Olly

[Gina]

Good questions.

Spend a bomb on a premium apo or spend a similar sum on a dual rig? (You do need 2 cameras and a bigger mount, but given Tak prices you can do that!) My answer would be this; If using a small sensor and narrowband filters maybe go for the budget scope in a dual rig. The Tak struts its stuff in terms of covering a big sensor and correcting the full visual spectrum. For doing LRGB on a small chip the choice is harder. The Tak is stunningly good in LRGB. If using a big chip it has to be the Tak.

Sony versus Kodak? I streamline my calibration of the Kodak data I collect in the three fullframes I use (Mine, Tom's and Yves') partly because I'm inundated with it after a long clear night. (Over 20 hours is possible. A nice problem to have, you might say!) I use one master flat per camera, not one per filter. I use a bad pixel map and a master bias so that any sub length can get the same calibration. I run a hot pixel filter and column defect remover and I get perfectly clean stacks which rarely need cosmetic attention. What's the problem? I don't see one. Sure, if Sony made a full frame I'd be in there, who wouldn't, but the calibration work-around is fine.

I love the big chip. If I put a small Sony chip in the FSQ106 and a big Kodak chip in the TEC140 and take roughly the same framing the TEC will easily win. More resolution, smaller stars. But slower, of course.

Olly 

Thank you Olly - very interesting and helpful   That confirms what I had already gleaned for all I've read and heard.  For NB in a UK environment with limited opportunity for imaging I think a triple imaging rig with its better photon gathering ability may be the better option, though three scopes and three cameras are probably going to cost more than a Baby Q.  Though the cost can be spread out more.

The Baby Q with its focal reducer would give a slightly wider view than I get with the SW Esprit 80ED would get a slightly wider FOV which may get the likes of the Heart and the Soul Nebula in the frame.  OTOH my previous experiments with good quality film SLR lenses encourage me to get my widefield triple imaging rig finished.  eg. the 200mm f4 lenses give twice the angular FOV and results are good when stopped down to f5.  The 105mm f2.8 stopped down to f4, twice as much again.  NB filters virtually remove any chromatic aberration and separate imaging systems eliminate the need to refocus between filters when using a FW in addition to capturing many more photons.

Regarding sensor size, I have been very pleased with the Atik 460EX with its Sony sensor and the much simpler data processing I find a delight.  Going to a larged frame size also involves buying very expensive larger filters.  So my personal preference is still with the Sony sensor and small filters having explored the alternatives.

[Gina]

My ultimate aim for smaller sized DSO imaging is a triple rig handling narrow band with Astrodon 5nm Ha, 3mn OIII and 5nm SII 1.25" filters with SW Esprit 80ED Pro scopes and Atik 460EX mono cameras.  For galaxies I may stick with the MN190 and EFW2 with LRGB filters and Ha could be added from the Ha ED80 system.

I currently have one Esprit and two Evostar ED80s plus two 460EXs and one 314L+ ready to assemble into a triple rig on the EQ8 and MN190.  Not quite ideal but I'm going to give it a go until I gather the funds for another 460EX and two more Esprits.  Putting the 314L+ on the Esprit and 460s on the Evostars tends to even out the different FOVs.

[Twisted Lip]

Another issue with double/triple rigs is the mount. I had a double rig on an NEQ6 (ED80 and WO GTF81) and with cameras etc was pretty much on my weight limit. I suspect to handle it you'd need an EQ8 upwards.

Basically we all need to win the lottery lol

Will

[Gina]

That's the main reason I bought an EQ8   My rig will be well within the weight limit   The EQ8 is quite a beast

[Liquid360]

It was similar advice which drove me to adding an SV90 to my setup so that I could increase photon capture while still seeing what the FSQ was all about. The SV I purchased used and the FSQ new. Ultimately I'd love to add an a baby Q. I'm still so very new to all of this, I've no business advising anyone of anything, but on paper at least a multi frac setup makes good sense.

[ollypenrice]

It was similar advice which drove me to adding an SV90 to my setup so that I could increase photon capture while still seeing what the FSQ was all about. The SV I purchased used and the FSQ new. Ultimately I'd love to add an a baby Q. I'm still so very new to all of this, I've no business advising anyone of anything, but on paper at least a multi frac setup makes good sense.

ImageUploadedByTapatalk1413483736.141477.jpg

Not just on paper...

On a bad night with just a four hour window...

Not complaining.

Olly