Adam J

1 hour ago, Veloman said:

I'm thinking of purchasing the above and dipping my toe into AP, but concerned that I'll regret not spending more and getting the 80ED. Any thoughts?

Rob

You will have many other things you need that extra cash for more than you need the difference between an ED80 and the 72ED, the 72ED is also a much more user friendly scope. 

https://www.rothervalleyoptics.co.uk/rvo-horizon-60-ed-doublet-refractor-ota.html

or 

https://www.rothervalleyoptics.co.uk/rvo-horizon-72-ed-doublet-refractor-ota.html

with FPL53 glass are your real upgrade path in my view and not the SW80ED. Both will be slightly sharper due to better CA correction. 

Two other features on the RVO 72 are great in my opinion and the imaging packages good value. 

1) It has a collimatable lens cell something not seen on. other clones of this scope design and actually very important. 

2) They test their refractors in house and are guaranteeing 0.95 strehl. 

...shame about the colour but you won't notice in the dark and I don't like the SW green either anyway. 

Adam

3 hours ago, DSOBug said:

New to this hobby, been watching ton's of YouTube vids getting some ideas and learning.  I may have a lot of questions later down the road.  Ive added some pictures to show the rig I'm building, this is the main components I'm building around.  I have already got these Items shown. I picked up the Redcat 51 at a real good price, it came with a Skyguider pro that I sold to get the AM5.  It also came with a Canon EOS T6i. I'm looking into selling this camera and getting a Canon 60D for now I'm looking also doing some milky way shots and moving stars videos. Also I'm looking at a ZWO Camera's not sure which one to get to fit this rig. I'm looking at the Asiair ZWO ASI183MC Pro or the ASI533MC Pro to do some DSO shots not sure which one to get. And still learning about filters and color wheels.  Kinda overwhelmed with all this learning curve but I'm a trooper and wont quit because I'm eager to learn.  Look forward to Chatting with everyone and learning.... Cheers 🙂

Honestly the spot size on the redcat is so good that its one of few scopes that can actually take advantage of the small pixels on the 183mc pro, but I have got to say that my preference accross the board at any focal length is to go with mono. In which case my choise would be a mono 533. If 183 then why buy new so many to be had on the second hand market, but if you want faster imaging the 533mc is the choice as it will image faster with the bigger pixels.

Adam

On 20/09/2023 at 17:22, FLO said:

There is a lot to like about the new Starfield Gear60 f/5 Petzval APO telescope. 

• Fully multicoated Petzval optics (includes ED glass). 

 

 

Steve,

You quote ED optics both here and on the FLO site descriptions, this to me normally means FPL-51 equiverlent, yet on starfeilds own site its calling them FPL53.

https://starfieldoptics.com/gear60-quad

If it is FPL-53 this is something that deserves a mention and should be on the description as its an expensive freature not to mention.

Adam

On the used market: Got a AZEQ6 GTI for £650 and sold my HEQ5 for £650 to buy it. Free upgrade. 

I got my ASI1600mmpro for only £1025 new in the Christmas sale back in 2018. 

I paid 'only' 250 for my Astrodons months before they doubled in price too. 

Adam

On 22/09/2023 at 17:33, iantaylor2uk said:

It's good to have competition in this space. Looks like a direct competitor to Askar''s FRA 300 f/5 scope, which I've been very pleased with.

I would guess it's a clone. Identical optics with some different focuser and dew shield mechanics so optics probably made by sharp star. 

On 26/09/2023 at 17:34, Elp said:

There's a small amount on the one side of that brighter star on the RHS but usually its a uniform sized glow around the star, if you try imaging Vega/Alnitak etc you'll likely see it more pronounced. I think that image looks fine. I've got baaders and can't really justify needing any others, they're expensive enough as it is.

yeah that's not a filter halo that's from a curved surface or it would not be offset from the star like that. Filter halos are almost universally centred on the star as you say. 

Was never really happy with this one when I posted it back in 2020 could not get thechannel balance right. Opinions welcome.

Esprit 100

ASI1600mmpro

Astrodon 5nm Filters

4min subs,

18hours total intergration.

New:

Cheers,

Adam

3 hours ago, Louis D said:

If you're just popping out for 10 or 15 minutes to grab a quick peek at a planet, the 127 Mak is a terrible choice.  It shows all sorts of chromatic aberrations at high power on bright objects while trying to cool down.  By comparison, I see no such issues with a similarly sized Newtonian.  My 90mm triplet shows spikes around bright objects while trying to cool down, so also not a good quick peek choice.  My 72ED doublet is pretty much ready to go immediately, though.

It really depends on your intended use case which telescope will provide the best images.

exactly I wanted a quick grab and go option for use with a 5yesr old that has no patience for cooling. The 102 is ready to go by the time I have aligned it for the most part. Cooling on a Mak scales poorly with size. 

8 hours ago, bosun21 said:

The 102 is another viable option but don’t complain if you give it a heavy bump knocking the collimation as there’s no way to rectify it. Just something else to bear in mind.

That's not totally correct, my 102 can be collimated. There are two versions of the scope, one that can't be collimated and is packaged with mounts and one that is sold as OTA only and has a full set of collimation screws.  Both versions are sold by FLO. 

7 hours ago, GTom said:

Deal, 118 vs 100 then. 18% more resolution and 40% more light grasp.

62% more expensive for 18% more resolution. But probably not even that, because of the primary shading the central obstruction is larger in comparison to the mirror. It's also bigger, heavier and takes longer to cool down. Neither are for DSO. It's all good, but the 102 is a valid option over the 127 dependent on budget and other requirements. 

9 hours ago, bosun21 said:

Do you think the 102 is operating at its full aperture? I highly doubt it. I know that the 150mm is operating around 142mm. I also heard that it’s the 180 being the only model operating at full aperture.

a tally the 102 is very close the F-ratio is the giveaway. The design needs about a F13 ratio to work at full aperture that's 100mm for the 102mm so hardly any difference. The 127 is the worst it's not even F12.

On 03/09/2023 at 21:06, Olli said:

Hi everyone ,

I am considering saving for a second scope to go with my refractor and have wanted a Mak for such a long time due to it being known as a planet killer which will be its primary use. How much of a difference is the Mak127 compared to the 102 and also the physical size? As I’m trying to keep it small and lightweight as possible.  The 127 is  unfortunately a bit more than I’d like to spend though if it is a noticeable difference then I will consider.  Is the 200mm difference in focal length also noticeable? 
 

any advice would be appreciated!

There is not as much difference as you might think as the 127mm does not have a 127mm clear aperture only 118mm. No idea how SW get away with that. Honestly the 102 cools faster and is more portable as it will go in hold luggage easier. The 118mm will outperform it just don't expect the margin you would get if it was a true 5 inch scope. 

On 22/08/2023 at 21:12, Snoani said:

Here is another widefield of the region around Sadr.  The nebula is 7 hours and 20 minutes taken with an L-Extreme filter and 3 hours of RGB for the stars, using an Askar FMA180 scope and ZWO ASI294MC Pro.  All data was captured this month and processed in Pixinsight.  

original FMA180 or the pro model? 

On 17/08/2023 at 12:57, SiD the Turtle said:

I've had this camera a few years now and it's always had the same problem, if it is a problem. Here's a stretched 180s dark frame, no stacking, processing etc. apart from auto stretch:

This is with the camera disconnected from the image train, lens cap on and in a cardboard box with the gaps taped up (for testing, obviously this isn't great for cooling long term), in a room with the lights off in the middle of the night!

I haven't seen it impacting my imaging, but I'm curious as to what it is. Doesn't look like amp glow.

Any ideas?

 

it's amp glow and totally normal. 

5 hours ago, vlaiv said:

I still would not image with such scope and yellow filter without aperture mask.

Residual chromatic aberration is still present with fast scopes, even with yellow filter - but there is also issue of spherochromatism.

Only one wavelength will be free of spherical aberration - others will have more or less of it and with fast achromats - it is usually more

Take a look at spherical assessment of ST102 F/5 achromat:

Green is almost free of spherical - but other two colors suffer from under / over correction

In the end - it is a tradeoff - one can image even with fast achromatic scope - if one accepts to:

1. use filter to remove part of spectrum thus loosing some of the light

2. use aperture mask to reduce aberrations further - and again loosing some of the light

3. reduce sampling rate so that residual blur does not impact image sharpness as much

Got to be honest that is not its only issue, collimation is off and it has a touch of astigmatism too. Still might be hard to see hidden under the CA. 

Adam

9 hours ago, AndrewRrrrrr said:

I was wondering about this......

You buy a fab APO so you don't get colour disortion (blue fringes etc) when doing visual. And this is because the different colours have slightly different focus points. i.e. when the red is in focus, the blue is slightly out of focus.

(this maybe completely wrong in which case the rest of this is misled)

So if I'm using a mono camera with automated focussing, can I get a not-so-amazing scope (maybe trade some more aperture for less colour correction) and as long as I set the image aquistion software to focus on change of filter, I should be all good?

(thinking I could sell my AA Wave80 Super ED triplet and get a AA 125 EDF as these seem to go for the same (ish)  and be none-the-worse off?

Any thoughts?

Andrew

It doesn't quite work as simply as that, it's not just about the focal point being different it's about spherical error changing with wavelength. Hence although you can focus for RGB at best focus B and sometimes R will not be as sharp as G and that leads to blue bloat or purple halo irrespective of you refocusing. Longitudinal chromatic error and spherochromatism are traded against each other in all lens designs so if you want to bring all colours to focus at the same point you normal end up having to trade against a reduction in focus quality for some wavelengths normally blue. Also as others point out you can't do this for Lum anyway. To avoid this design compromise you need a triplet design slower than F6, a quad design will do better and doublet worse. 

In most cases.modern processing will fix things for you but for galaxy imaging. your going to inevitably loose some resolution. 

Adam

2 hours ago, alcol620 said:

Hi Folks       first test completed. set target temperature at 1 deg and took 10 minutes to cool down, left to run for 10 minutes. Took 30 flats usual settings and stacked them. Result: no indication of the usual noisy area.
Then cooled the camera down to -13deg left for 10 minutes and took another 30 flats. Result: the usual noisy area appeared.
Job for tomorrow: dry the tablets and see what the result is.
One thing that puzzles me it that if it is dampness inside the camera, why does the noisy area always appear in the same area of the image? I would have thought that the moisture would move around and the crystals, whatever they are, would form on different parts of the sensor?

The cooler is not in direct contact with the sensor. The pins for the sensor are on the rear so heat is conducted away via these, causes some none uniformity in cooling. 

Once the tablets have been refreshed you need to leave them to dry the chamber for 48 hours ish before re-testing. 

Adam

On 02/08/2023 at 16:51, alcol620 said:

Hoping someone can give me feedback on the cause of spotty pattern on flats. This seems to have appeared a few weeks ago. Using Pixinsight, I have stacked around 30 flats callibrated with dark flats. The Pixinsight rejection-high image resulting from calibrating and stacking the flats is attached illustrates the area of distortion on the image. This also appears on the master flat image, to a lesser degree. Using the flat to calibrate the lights leaves slightly darkened area on the stacked light frame over the samea area as appears in the flats.
I also shot the flats with the same settings but with the camera rotated. The distortion appeared in the same place on the image. Suggesting that the problem is inside the camera. I opened the camera and cleaned it. It made little difference, apart from adding a few dust motes. Is there some sort of problem with the sensor? the flats are 9s duration and ADu around 35000. I have attached an image showing the area rejection-high  and a stacked flat frame. Feedback very welcome.

As others said Ivan on the sensor caused by moisture in the chamber, it's just going to keep getting worse. Best bet is to open it up and refresh the desiccant. 

Adam

10 hours ago, Elp said:

Just been uploaded to FLO:

https://www.firstlightoptics.com/askar-telescopes/askar-103-apo-triplet-refractor.html

Looking for opinions, mainly for AP use on all around targets.

It will likely have some bloat in the blue and not be what I would consider a true apo but it should be manageable with blue filters cutting at 420-430nm or higher and or UV/IR like a Astronomic L3 or Baader UV/IR. But once you do that I am sure it's going to be great for the money. The reason I conclude that is hidden in the spot diagram. Askar normal generate the blue line at 430nm but for some 'inexplicable' reason the choose to specify it at 440nm for this scope, that says it all to me it's not a true APO but it's good for it's price. 

Adam

11 hours ago, iwols said:

do you think that flats would correct the 2600 on the 1.25" just for now as i am thinking ,get the asi2600 try them on the 1.25" then move to the 36mm filter/wheel in time?

probably not workable, just crop it down. 

13 hours ago, DaveS said:

Looking at the ad, he's including an LRGB filter set, so even more of a no-brainer.

OMG you are right, OP why have you no bought it yet lol. 

Also mono is much faster in terms of data collection than and OSC due to lum. Just more effort, there is a difference. The effort is worth it. 

Adam

On 30/07/2023 at 22:52, GTom said:

I am not sure if we see vignetting or light reflection on your copy. There are no sharp edges like in the original post. Still, reflected light is a problem that needs to be mitigated to our best capacities. I wonder if using Baader's 3.5nm filter that I got would make any difference.

just to be clear, are the flats not working? You don't explicitly say or show a stacked image. 

On 31/07/2023 at 15:19, Swoop1 said:

Bearing in mind that I have certain budgetary restraints at the moment (Head Of Finance looked sternly down her nose at me when asking about kit the other day), I am thinking about the next step for me in deep sky imaging.

I currently have a ZWO ASI290MC and a Sony a6300.

The ASI id brilliant for planetary and lunar but I'm not convinced on deep sky.

The Sony is reasonable on wide field but, exposures in the region of 30 seconds show a lot of noise and glow. 30s is the longest exposure I can use without an intervalometer and I'm not sure an intervalometer would improve things.

I have seen product from modded Canon cameras and I already have a Canon T ring so, is there any major advantage on skipping a modded Canon and going straight to a more expensive but better long term prospect of a cooled dedicated astro camera?

If your budget is about £300 then this is impossible to beat at the price. But you would need to pick up as a minimum a LRGB set or a Ha filter to get started. 

https://www.astrobuysell.com/uk/propview.php?view=201930

4 year back you would have been looking at £900 for this camera used and £1250 new. 

Don't like that then there is also a Orion 533mc camera on Astro buy sell at them moment too for £550. 

These days you have more options so unless you can only muster £250 max then can't recommend a DSLR any more to start out. 

Adam

3 hours ago, Stellaris said:

Hi, I currently own a Sky Watcher 150/750P, a NEQ3-2 Pro Goto, and a Fujifilm x-t2. I’m more interested in your opinion vis-a-vis my scope. I’ve only recently gotten into Astrophotography, and I’m wondering whether i made the right choice of equipment or not. My most recent images are rather zoomed in when it comes to nebulae, I can’t seem to find targets that are more suitable for the FOV of my scope. Any feedback, thoughts, suggestions, and or possible targets to shoot would be greatly appreciated.
I also wonder if there’s a way to simulate a telescope’s view on a target based on aperture and focal length. (Like a composition simulator if that makes sense)
Thank you all for your answers in advance.

My honest opinion is that you need to switch out that telescope the NEQ3-2 pro is not going to Handel it for astrophotography. It will struggle with anything bigger than a 60mm refractor and the shorter the focal length the better. If you change the scope you can make the mount and the camera work for wide field targets. I assume the X-t2 is not modified. If not you will need to choose your targets with care. 

Adam

5 hours ago, Scott Badger said:

No offense taken and enjoying the discussion. I don't disagree with anything you say above, other than your suspicion that more than just deconvolution is involved. I can't prove it, but Russ Croman has been very forward with information about the tools he's created, and AI in general, and for me at least, he's established enough credibility that I'm willing to to take him at his word unless or until there's clear evidence that something else is going on. That said, there's certainly no question that BX, like any other decon tool, can create artefacts if the settings aren't optimal and sometimes, depending on the quality of the data, it won't have much effect at all. Like other tools still in development, bugs can also come up, and as I mentioned before, I think the OP's image may be an example of that. I've not seen anything like it with my use of BX, and there was a similar report in another thread (CL or the PI forum) from someone who had just gotten the new version (I haven't updated mine yet).

To your examples, I've not seen it turn structures into stars, but I have seen the reverse; stars strung into a filament like structure. This can happen (as it happened to me with Andromeda) when the stars are small and part of a larger scale structure, like a galaxy. Using the manual psf setting and enabling "Nonstellar then Stellar" solved that particular issue, but in the end you sometimes just have to back off on the amount setting (or use a smaller psf), even if you aren't getting as much improvement as you were hoping for. Anyhow, it's no different than any other tool in that artefacts are possible and like you said, it's up to the operator to assess the results and try again if necessary. Something to note as well is that BX uses a tiled approach (part of what it can do that we can't with traditional tools), so depending on the number of stars in a particular tile, or the quality of stars in that part of the image, the sharpening effect and/or artefacts created can vary across the image. That's why the manual psf mode should always be used, and maybe why it can appear that an artefact is something 'added' to the image (i.e no direct/mathematical relationship with the image data) when it occurs in just one area as opposed to throughout the image like we'd see with a traditional decon tool.

Cheers,
Scott

Interesting thought occurs to me in that turning the settings up to the max, while not visually preasing, might produce extreams of results that give a clue as to the underlying process or direction being used by the AI.

Adam