Upgrade from my PST or stay with it?

[jackd]

I currently own a Coronado PST... I love the views, but I have had a terrible time trying to get a decent image with it. I've had it for around two years and I just feel like I should have bought something more imaging friendly, but I didn't know any better when I made the purchase.

I guess my question is, if I spend the money and upgrade scopes, will it be easier for me to image? Or is imaging just a magical talent some people have and some people don't?

I am looking at the LS60THa and the LS60THaDS. Both are a lot of money - and I am far from rich - but I really want to get into this hobby.

By the way, I have attached what I consider my very best photo yet, using my PST. Very frustrating!

[keithatrochdale]

You could always graft it onto a TAL100;

Do you know about these two sites?

http://halpha.nso.edu/index.html#top

and

http://solarchat.natca.net/

[Luke]

I think it will partly come down to the camera you use. Which camera did you use with the PST, and would you be using the same camera with the 60mm? I have only used a 60mm myself (a SolarMax).

The 60mm I think ticks a lot of boxes. You can get quite high resolution with it, and unless you go the PST mod route, you're looking at spending a *lot* more bucks for the next big step up in resolution. I'd love a 90mm etalon, that's probably my long-term hope to go together with my more grab-and-go 60mm, but a 60mm does enough to keep me happy imaging-wise without sweating too much with aperture fever. That is also partly because if conditions are not good enough, you can't get the full benefit with the high resolution stuff. Sometimes my 60mm can't be pushed to its limits. Just got to make sure I don't get too near anyone's 100mm in case the fever breaks out again

[allcart]

unless you are a DIY enthusiast and have a real desire to mod the pst, I would go straight for the LS60T with B1200 blocking filter. You could easily spend half the price of the pressure tuned LS60T on the parts  needed for modding the pst.

I spent a considerable amount modding scopes and had a lot of fun doing it, but still bought a LS60T and then a 60mm double stack filter. I use these far more than the modded scopes now. If I added the money I spent on modding to the money I spent on the LS60t DS, I could have easily bought a Lunt 80mm DS.

[ollypenrice]

The LS60 is a big step up on the PST in my view. 

Agood mono fast frame camera is also a bonus, of course.

Olly

[jackd]

keithatrochdale - I am not mechanical enough to pull something like that off. I lack when it comes to 'modifying' anything.

Luke - I am currently using a Nikon D90, but I am willing to spend a little on a decent camera. But if I do, I would want it to work for night astronomy as well as for solar. Have any suggestions on what I should get?

ollypenrice - A mono fast frame camera? What is a decent one for the LS60THa?

Thanks for the input everyone!

[jackd]

These are the scopes I am considering...

http://www.buytelescopes.com/lunt-solar-systems-ls60tha-60mm-h-alpha-solar-telescope-w-2-crayford-focuser-pressure-tuner-and-b1200-blocking-filter

http://www.buytelescopes.com/lunt-solar-systems-ls60thads-60mm-h-alpha-solar-telescope-w-double-stacked-50-etalon-system-2-crayford-pressure-tuner-and-b1200

[allcart]

The Lunt 60T with pressure tuner is a very good scope. You will not be dissappointed. Opinions on the 50mm double stack vary. I chose to spend a bit more and got the 60mm Ds filter. I was not dissappointed.

My favourite Cam for solar imaging is the DMK31. It has a decent framerate up to 30fps. You can get the whole disc with a 4 pane mosaic, but when combined with a X1.6 barlow lens it gives fantastic views of proms and features. i also use a X2.5 powermate for closer views but the seeing has to be better. I think the LS60T, DMK31 and x1.6 barlow is a great combination.

[Luke]

Ideally you'd use a mono video camera, as the hydrogen-alpha image will only be recorded by the red pixels with a colour camera/DSLR, and recording several hundred frames and using software to stack the best ones helps get better results. With a mono camera all the pixels will record the h-a. So you won't get as detailed an image with a colour camera.

Some video cameras are better suited for solar imaging than others. Riklaunim has a lot of info here and knows far more about cameras than I will ever know (see the Planetary Cameras section in particular):

http://www.rkblog.rk.edu.pl/w/p/astrophotography-and-observations/

The video camera might also be handy for imaging the Moon and planets, how well suited it is for all those things depends on the camera. However, a video camera is not usually very good for imaging deep sky objects, as it's mainly for taking video of relatively bright things rather than long exposure images of faint things. I can't remember but I think my video camera is limited to something like 30 seconds maximum exposure, which is very short for deep sky images in general. With my DSLR I sometimes wanted to take 20 minute exposures of deep sky objects (and some of the people with cooled CCD cameras take one hour long exposures, I believe!)

Luke - I am currently using a Nikon D90, but I am willing to spend a little on a decent camera. But if I do, I would want it to work for night astronomy as well as for solar. Have any suggestions on what I should get?

[jackd]

allcart - Is there a big price difference between the 50mm and 60mm DS Filters?

Luke - Thanks for the links and info!

 I am seriously considering the DMK31, but is there a decent cam out there that will allow me to get the entire solar disc in the frame, without having to do the mosaic?

[Merlin66]

the DMK51 would come close to full frame....

I question the need for an upgrade...

Over on the solar chat site, Asimov had presented some excellent solar images with his PST - some of them being much better than achieved with larger apertures.

http://solarchat.natca.net/

It comes down to seeing conditions, a good fast camera and experience in stacking and processing the raw video file.

It's difficult to find the "Holy Grail" of cameras - one which does everything....

Solar imaging, is solar imaging.

DSO long exposure imaging, is DSO long exposure imaging.

IMHO I'd go for a camera upgrade FIRST. Get the experience  (and success) before committing more $$$ to solar imaging.

Just my 2c

[Luke]

I've heard of a few people with the Lunt 60 using a DMK41 with a 0.8 reducer to get full disc within the frame, but I don't know which reducer they use or how they arrange it. It's a bit easier for me to find a large enough sensor for my SolarMax 60 as it has a shorter focal length, 400mm, versus the 500mm of the Lunt. For me the camera choice was between a Point Grey Chameleon (mosaics required for a full disc) or the very expensive Point Grey Grasshopper 3, which does full disc on my SolarMax. I went for the Grasshopper, which cost a lot of £££'s, but I have more or less had to give up on deep sky imaging, solar is my main thing now for imaging and I would have spent more on a cooled CCD, filter wheel and goodness knows what kind of a monster mount upgrade for DSO's!! I hope one day I can get back to deep sky properly, but I'm certain the solar bug has bitten me for life

[michael.h.f.wilkinson]

I did some mosaics with the small chip of the DMK21 with my LS35, and they came out nicely. The ASI130 I have produces nice full disk images if I can avoid getting fringes. Ultimately, the result with a DMK21 was better (and beyond what most DSLRs can do). The DMK also works nicely on planets and the moon, so it is useful at night. I am also gunning for an LS60PTHa. BTW, there is a Solarmax 60mm etalon + 15mm blocking filter on ABS-UK going for a good price, might be worth a look.

[allcart]

Thats about it Luke. I just use a small 1.25 reducer straight onto a short nosepiece on the cam for a full disk with the DMK41. I do find mosaics are fairly easy to accomplish so I tend to do them rather than use a reducer. I favour the DMK31 as it is a good compromise between chip size and framerate. If I were going to invest more money on a solar cam, I would be looking at point Grey or Skyris cams.

Some folks get decent resuts with other ccd's but I have only ever used DMK's.

Jack, the price difference between 60mm and 50mm filters seems to be about $600

[Luke]

Allan, Sarah and I probably want to add a second solar camera later in the year. The thing that is putting me off the Skyris is that as far as I know, you can't adjust the gamma. Maybe some people don't adjust gamma anyway and I've seen some nice solar results with the Skyris (Ant's early shots with the Skyris and PST look very promising, a lot of detail was coming though), but I adjust the gamma quite a lot. Given the big variation in brightness with solar, I'm puzzled why the Skyris, aimed at solar imaging as well, doesn't have gamma adjustment, whereas the DMK equivalents do as far as I know

At the more affordable end of cameras, ASI looks interesting to me, I think Jim Lafferty was impressed given the price, but I'm not up to speed on the latest cameras out there, it seems to be moving so quickly!

[michael.h.f.wilkinson]

The ASI 130 shows pattern noise, and I had to use darks and flats to get good results. Interference fringes can be a problem, but you can get good results:

My ASI120 is a colour camera, so I have not used it on the sun

[AstroManDan]

I think you can get more out of the PST. I use a DMK21 AU618 and a Televue Powermate 2.5x to obtain focus.

But I have also used a short C mount adaptor with my DMK21 to get this:

[michael.h.f.wilkinson]

Just dug up one of the better DMK21 images using my LS35

The PST should be able to get similar results

[allcart]

Ah, thanks for reminding me about the gamma on the Skyris luke. I do use gamma adjustment a lot when solar imaging so maybe the Skyris would not be for me either. They are also usb3 so you have to consider whether your computer is up to it as well.

But getting back to Jack's original question. To upgrade or not................

Take the best full disc pst image you can find, and compare it with an average LS60T full disc image,. See any difference?

Then look at whats achievable with tthe right camera and a little practice.( Look at Dr Robins pics). Anyone can do that with a Lunt and a bit of practice, but not anyone could do it with a PST.

[Luke]

Jack, my two cents on the "to upgrade or not..."

Ask yourself how keen you are to get solar images. If you are very, very keen and willing to spend a bit of time learning the camera settings and checking out a few tutorials, and can budget it, I'd encourage you to go for the 60mm and a mono video camera. Without the mono camera I think there is more of a risk you won't be happy with the results, especially given the cost of the scope...

Allan, I haven't used a PST, but the impression I get is I think along the same lines, that a bit of expertise is more required with the PST than with a 60mm. Just my impression not having actually used one, from what people say and the images they take.

Re: the USB3 and whether your computer can cope, good point. That said I was staggered by how relatively well a £300 laptop with USB 2 did with my Grasshopper 3 2.8MP USB3! It captured at the full 26FPS frame rate in 8 bit mode (which I often use because of the smaller file size and to my eyes not much of a loss compared to 16-bit) and at a still usable 16FPS (dropped from 26FPS) in 16-bit mode! I didn't expect that! I had to use Point Grey's own USB Pro driver rather than the default USB driver, otherwise the system was incredibly unstable. With the PG driver, it's been rock solid

[allcart]

Good info re the grasshopper and USB3 driver Luke. I'll remember that if I plan a camera upgrade.

[riklaunim]

Mono camera changes a lot vs color on Sun. Bigger Lunt will have better resolution but it needs good cam too.

Aside of big DMK there are e2v sensors in cheap cameras.

[jackd]

Thanks everyone for all the advice! I have decided to get the Lunt60 with pressure tuner... And a DMK41.

I found a Teleview .8 reducer, should I give that a try to get the full disc?

And lastly, but probably most importantly..... What mount do I get? I obviously need something that tracks the sun, but I'm running out of money for anything expensive! Any ideas?

[allcart]

The Teleview is over expensive and overkill for what you need jack. I use a simple variable power focal reducer that screws into the front of the DMK just like a 1.25 filter would. Here is a link to the one I use. http://www.modernastronomy.com/accessories.html#accFocalReducers

Its called a Variable Power Focal Reducer, and is pretty cheap.. £24.....and does what you need.

I'll leave others to advise on mounts as I use a Celestron AVX, and although it is brilliant, there are cheaper alternatives of which I have no experience.

[jackd]

Would this work for a mount?

http://www.optcorp.com/coronado-ds-mount-dsm-for-solar-telescopes-dsm.html