Midnight_lightning

17 minutes ago, Skipper Billy said:

I have heard that the Esprits are not too shy of Takahashi performance but if my Tak 106 was ever stolen or damaged I would buy the same again without a doubt - flat right into the corners even with a full frame sensor, zero spacing issues, tight round stars.

But will a HEQ5 do it justice??  Probably not - I would spend the money on the mount then look at a better scope.

Uncropped image attached - Tak 106 and Atik 16200

 

Super image Skipper, seen a few of yours on UKAI

The 106Q is out of my budget  so I didn't look at it but just looking at a handful of 106q images on Astrobin and all of them had superb stars - much better than anything else I have looked at.

2 minutes ago, Timebandit said:

 

 

I have not read any negatives regarding the Esprit 120 . Actually they seem to get so many positive comments regarding being a top notch refractor at very sensible money.

But from your write up it sound that you have already answered the question yourself. As you seem to prefer the images of those taken with the Esprit when compared to other refractor images in your short list. Go for what images you already like , the Esprit

 

 

 

Absolutely makes sense but this will almost certainly be the last scope I buy (Pension lump sum) so whilst I really like the Esprit I'm still hoping there is something even better if I spend a bit more. My very subjective evidence suggests maybe not but I'm still hoping someone proves me wrong. Also, I focused on Star Shape, some of these other scopes may be more or less sharper and have better/worse contrast.

30 minutes ago, Big Bang! said:

This was the first test image (30 minutes) just to test the back focus on the Esprit/flattener combination - it might need a slight tweak; no cooling so hot pixels everywhere.  PixInsight Eccentricity puts it at .40

Gus

That looks good, very like my smaller 80, and the star shapes are much better than most of the images I found on Astrobin 

34 minutes ago, Big Bang! said:

I have an Esprit 120ED Pro.  Utterly delighted, can't fault it.  I remember reading the reviews at the time I bought it that suggested it was essentially as good as anything else that most people can afford.  I bought the flattener with it at the time.

I have just upgraded my camera from an Atik One to an Atik 16200 to take advantage of the 44mm imaging circle this Esprit offers.  First light was two nights ago - round stars all the way to the corners.  

On the basis of my knowledge I would say the Esprit is very good value for money.

Gus

Part of my plan is to get to a FF sensor, good to know your stars are sharp with an APC-S. Be good to see your image

I bought my Esprit via Teleskop Express and it was tuned by a chap called Tommy (he's not there anymore). He stripped it down from new, collimated it, retaped the lens cell and provided reports - most of which went over my head but it recorded 94.4 strehl which I suspect isn't bad for a mass produced scope.

2 hours ago, johninderby said:

FLOs new StellaMira 104 would be worth considering. Bit better optics than the Esprit and better build quality.

 

I looked at that one early on and it is interesting but I would like a larger aperture and FL - also it's an unknown at this point which makes it more of a gamble.

3 hours ago, rl said:

I think Andrew S's comment says it all. And spending the change on a chunkier mount with proven pedigree has to be a step up providing you're not planning to carry it around. .

On the other hand, playing devil's advocate, you have looked at the final results. Doubtless as objectively as possible. But has the ease with which those images have been obtained been considered? A lot of the scopes on that list are multi-use by design..both visual and AP.  You seem to be concentrating on the AP side of things. Would a dedicated astrograph be better, like a FSQ85/106? No flattener spacing to worry about, and a bit faster shortening exposure times? No back focus issues getting filter wheels in the chain et cetera...You can have a lot of frustration getting the scope/ flattener combo working properly if  you're pixel peeping for perfection in the corners.  The astrograph is a one-trick-pony but they do that trick exceedingly well. 

Some of this is a numbers game (apart from cost). Every premium scope will be checked over very thoroughly before leaving the factory and 99.9% will be perfect. The other 0.1% got dropped on the way. As for the ED120, I've never heard a bad word about them.....but I doubt if the QA is quite as good. But if you buy from a good dealer you can always change it if it's not up to snuff on arrival. 

I've never owned a premium refractor, and just having tried to argue the case for one...in truth I'm not convincing myself!

An EQ6 is certainly an option but I would rather stay with the HEQ5 if possible - its so good (c 0.21" RMS with my 80/400) and I currently leave everything set up indoors and just lift the whole thing out for imaging.

My analysis is massively subjective and I have no background to any of the images - the only thing I can say is that I looked at a lot of images before coming to a conclusion. That's why I am open to being corrected and would love to see high quality images from any of these scopes - preferably before people use software to make the stars round!

Back focus is a pain and I have gone to great lengths with my 80 - having to get complex custom adapters made. One of the massive advantages of the GT102 is the flattener/reducer has adjustment built in - just screw in/out to adjust BF. 

A key objective is to have a longer focal length say  600-800mm to pick off smaller targets and be able to use a reducer for larger targets.

I use an SX814 atm which is quite a smal chip but my next upgrade will be a larger chip, possibly one of the new full frame CMOS camera's which is why I am so keen to have round stars across the FOV - NO point in going full frame if non of these scopes can cope with it. They are all good in the centre but many soon trail off towards the edges.

Having spent weeks of research I am still trying to find my next telescope, something to give me a longer reach and better definition than my excellent Esprit 80/400. 

Good Star shape is especially important all the way into the corners.

I started looking at £2-3K scopes and am now also considering increasing the budget - here are my current candidates:

• Esprit 120
• APM 107/700
• Altair 115 ED
• APM LZOZ 115/805
• WO GT102
• Vixen SD 115 S
• TSA-120

Based on reviews and reading forum posts I expected the TSA-120 and APM LZOS 115 to come out strongly on top.

However having spent a day looking at images on the web taken with each of these scopes I have ranked them in order of teh ones I found had best star shape across the FOV - the results surprised me.

Many of these have good star shape near the centre but, even with a flattener or reducer, show marked stretch into the corners - particularly with full frame cameras. Astigmatism and mis-aligned colours were also noticeable even in the higher end scopes. 

It is highly subjective due to differences in flatteners, guiding, cropping, cameras, processing etc etc but I made notes as I went through the analysis and the Esprit 120 came out top and surprisingly the Tak didn't seem better than the cheaper scopes. In a blind test I would find it difficult to distinguish between most of these scopes although I suspect the Esprit 120 would do better than most.

I was hoping to find a light weight 115 or 120 to go on my HEQ5 but I'm now wondering whether to get the Esprit and use the c. £2500 I save to buy a stellar tuned EQ6 mount.

I would really like to hear your views if you use one of these scopes, and also please post see your images showing sharp round stars across the frame.

I'm happy to be proved wrong, I would rather stay with my HEQ5, and welcome any help in making a decision.

15 hours ago, Alien 13 said:

I would like to add a small note regarding Monitor calibration using devices like the Spyder, I have the Spyder 5 pro and what it does is create a custom colour profile for your graphics card but does not in fact calibrate the Monitor itself.

Alan

I'm completely new to this topic, as you may have guessed. My monitor comes with Eizo's ColourNavigator software - am I right in thinking that using this with the Spyder will do the calibration? 

Thanks Vlaiv for that excellent answer and analogy. I purchased a sensor today and have an Adobe RGB capable monitor but I think given what you say I will calibrate the screen but stay with sRGB. I doubt most people would see the difference in my images and it quite honestly this hobby is hard enough without adding anything that isn't essential   

Thanks again for replying, very helpful.

7 minutes ago, Star Struck said:

I have an Eizo monitor and they support 100% sRgb.

You will need a screen profiler, there are other makes than Spyder, as it is essential to keep your monitor calibrated. Very easy to do and should be done regularly.

I would avoid Adobe Rgb as it is essentially for high end printing and is very specialised. Stick with sRgb and you cannot go wrong.

what do you intend to do with your final images and let this guide your choice. SRgb can be used on all devices, #creens, web etc. 

Tony

I currently display images online and have had numerous images printed at A3 size which I have around the home. I have some interest from friends about buying prints so may offer prints for sale at some point. 

My objective is to do everything I can to produce the best images possible but not to make life unnecessarily difficult. If using Adoobe is going to cause problems I will stay away from it. 

Any more views on the choice between sRGB and Adobe RGB?

13 hours ago, richard ashbee said:

Sorry forgot to say you can see the before and after once you have calibrated the screen, best to redo every month

Thanks Richard, looks like I need to but a spyder

I recently upgraded my graphics card and ever since all images on screen are brighter and more saturated than they used to be. 

For some things I like the new look but my astro images are too rich - bottom line is I intend to calibrate my screen, don't know what to do but am reading up on it.

One question I am struggling with is should I use sRGB or Adobe RGB? 

I've read sRGB is better for on screen display and Adobe for printing - but is that it?

I also read somewhere years ago not to use Adobe RGB because it would " lead to problems" - cant remember what they were worried about.

My screen is an Eizo CS240 and supports 99% AdobeRGB and is 10 bit from 16bit - whatever that means.

So, if anyone could enlighten me I would be grateful - I do most processing using APP/PI and Affinity Photo.

Thanks

Jon 

Thanks Mark, the SW pier is interesting, its hard to know whether it would be more or less stable than the tripod but would certainly fix the issue and the wheels would be a plus. Chopping an extension is a good idea too - thanks for the offer. Think I will get the new dovetail fitted and then see what I still need resolve. 

Thanks Ken, really useful.

3 minutes ago, MarkAR said:

Sorry, it's just the extension for my AZ EQ6.

Extends the height 8".

Thanks Mark, I'm on an HEQ5 and the only extension I can find is 16" high and made for observing - I think its too tall for solid AP. If I could find a 4" version it would be perfect.

Thanks discardedastro, that is really useful info - I'll need to do a new PC build before long so maybe will go back to AMD - always used to like their processors.

I agree the vignetting is worrying and will investigate,  seems very odd they haven't gt this right on such an expensive camera.

4 hours ago, Merlin66 said:

Jon,

I used this adaptor on the spectroscope, worked well. I didn't experience any tilt issues.

 

Thanks Merlin, good to know.

2 hours ago, Ken82 said:

Hi Jon,

I've been using an asi 6200mm for a couple of months now and im very pleased. Please excuse the poor processing attempt as im completely new to LRGB imaging and clearly still trying to learn the ropes. 

I primarily bought the camera and scope for widefield narrowband imaging which i plan to bin 2x2 in software. Since its galaxy season i decided to give it ago and see what resolution i could gain with 3.75u pixels. Im very pleased what this camera achieves at 1.5"arc sec per pixel on galaxies ive imaged so far and shows its very versatile in that respect. 

One thing you will need to be mindful off is your scope will need to be very well corrected to illuminate such a large sensor, I can see definite star elongation on my takahashi fsq 106 near the corners (possibly also due to tilt). The 2x7" filter wheel bolts perfectly onto the camera and works very well. Cooling is a breeze compared to my asi071 and takes very little time to achieve -10 and maintain the temperature (usually around 30% power with an outside temp of 0-5c). I dont think the M54 opening was a clever idea from zwo as the OAG  will cause vignetting being so far from sensor. I dont use the OAG but even adding a M54 male to male adapter (ouo 32 or ouo 31) causes vignetting as these are too narrow internally and ouo32 is far too long. Off course im being fussy and this could be overcome by flats assuming your scope is corrected for 42+mm. Unfortunately the tilt adapter which is removed and re connected to the OAG or filter wheel is of little use as you would have to remove the whole optical train to make an adjustment at M54 (Maybe someone has a better idea on this?)

Vlaiv has been a great help giving me the technical analysis of darks, flats and lights which have all been consistent in adu and show read noise to be comparable to the zwo graphs. I Cant speak highly enough of him!  

Images i have included are a simple stack and stretch of 102x1.5min luminance and 25x1.5min RGB. I had to crop oddly due to leaving the laptop shining onto the scope causing a reflection to the right hand side. 

If you need any darks etc to look at please dont hesitate to pm me !

I hope that is helpful any questions please let me know. 

Ken 

Edit- In terms of processing i was also concerned with 61mp! Im using an i7 9750 with 1tb NVME M2 SSD AND 32GB ram which appears to work very well at the moment. I see no reason to upgrade the processor at this time. Images do take up a considerable amount of space but i plan to put it all on an external HDD. 

Hi Ken, 

Thanks for the detailed response, that has clarified a few things and also provided other things for me to think about :). 

I built my PC maybe 6 years ago and will need to check the spec but something like good i5,  m2 250GB, 12GB RAM so maybe looking a bit weak now. 

I would be interested to see a full frame version if you have one?

Thanks again for the info

Jon

3 hours ago, MarkAR said:

Yup, that'll be a problem.

Just checked my setup and it looks like the extension pier will be fine.

Which pier do you use?

4 hours ago, MarkAR said:

I've got my FW pretty much straight up, pier extension came last night so that will give me even more clearance. So far the balance is pretty good with the FW upwards.

Got a picture you can show?

 

Ill see if I can get a photo tomorrow, I have tried it with the FW straight up but it just means my Lodestar OAG camera is straight down and just as big as the FW. If I rotate it I then cant balance the mount.

4 hours ago, barkis said:

 

As to balance,  are you unable to move your OTA further forward in the dovetail, and or the tube rings.  A picture of your setup might help with further suggestions.

Ron.

 

Yes, unfortunately I have moved everything as far as I can, a larger dovetail will certainly help. I cant get a photo at the moment as everything is locked up.

5 hours ago, Laurin Dave said:

A pier extension, plus maybe a much longer dovetail (are you using one or just the foot on the ED80) to allow you to  move the scope as far forward as possible and add some extra weight on the camera end for balance

Dave

Its a new scope, GT102, and I am using the foot at the moment which I can just get balance when its mounted right at the end. I have ordered a longer dovetail which will certainly help but I don't think will solve the issue. A pier extension would certainly do it although I haven't been able to find a short one.

Just now, barkis said:

Could fitting a diagonal help?  If you could still achieve focus that is. 

Ron.

Thanks Ron, I think a diagonal would exacerbate the balancing issue but its an interesting suggestion and great lateral thinking

I have always used CCD cameras to date but am now looking at the new CMOS high mp cameras and possibly full frame.

Just wondered if anyone is using one and how they are getting on with it?

One of the things I am wondering about is processing the data - the ASI6200MM is 62mp and I'm wondering if you need a Cray and an SSD NAS to do the processing?

Thanks

Jon