fwm891

Incredable Goran. Superb imaging.

Stacked all the subs as one stack in APP, colour has gone but stars are now more even elliptical shape...

Pixel scale on this is: 0.47571 sec/pixel and the scopes current focal length works out at 1630.3 mm, about 6mm longer than the 1624 mm in it's specs.

Playtime continues

59 minutes ago, ollypenrice said:

In which program do you stack? In AstroArt, which I use, you have to specify a maximum rotation angle so you opt for 180 degrees. There may be an equivalent in whatever you're using, perhaps a setting you hadn't noticed had changed?

The stars are a bit odd and seem to have 'bites' out of each side. Do they look any different if you stack only pre-  or post-flip subs? Most things would be the same either way but not something induced by tilt under gravity.

Olly

Hi Olly, The image above is a combination of the two stacks (pre and post flip). I tried for a long time last night to find the best focus: manually and via electronic means. Defocused stars were showing off centred dough nuts so collimation is a definite issue here at the moment. I'm just about to have another play with the two stacks using different software and see where that takes things...

As a base to start from here is my 1st light image of M51 (no adjustments fromm delivery).

Total of 14x 300s subs, processed in PI and scaled in PS.

PI had great problems stacking these subs as it was shot in two sessions each side of a meridian flip and the initial stacks failed to rotate the images post flip anf gave me two non rotated images in the same frame - very artistic but not what the doctor ordered. So I ended up stackingg the two sets separately, rotating one set and combining the two.

Lots of errors but the potential is there...

Well after trawling through many varying RC collimation techniques on the web I found this one: https://www.dropbox.com/sh/1349fp34gqpbalm/AADPeMNonKZNk-1AkKUZ1dL4a?dl=0&preview=RC8+Collimating+Frustration+revision+1.4.pdf

Inital reading was a little daunting but definitely the most thorough how-to I've found.

Well true to tradition - new scope and clouds. In fact it was clear until 5 mins before dpd delivered the TS 8 inch RC then it rained with hail...

Anyway I digress.

I set the scope up on a ridgid tripod and pointed it at a light blank wall to check out the collimation with just the focuser fitted, racked right in with a peep sight in the focuser. Quite pleased just a minor tweak on the secondary adjust bought the reflections into alignment. But then the problem. All the collimation reviews I've read, and what I've done with other RC's I've owned is to then adjust the primary to leave a thin ring of daylight around the secondary housing - concentric with the tube baffles. BUT no ring of light. I had to take out the peep sight and place my eye further in the focuser before I could see anything around the secondary housing. I found this odd but then I didn't know if TS had changed the design/layout of the scope making it impossible to see a ring. Perhaps they intend their customers to buy a laser collimator?

So I turn the scope around on the tripod to view a distant tree to establish I could at least get an image. I needed all 3 of the supplied extension tubes, plus a further 35mm extension tube and the focuser with another 30mm extension to get an image of the tree (well top branches) with my asi533 attached. I've never had that much extension behind the back plate before so I thought I'd check the secondary to see if I could ease it up the tube a little to bring the focus in further, getting rid of some of the extension from what is a back heavy scope anyway. The secondary mirror was right up against it's support so no outward movement was possible.

There was one thing I noticed (probably wrong) but the spider vanes are a shallow non symmetric triangle and I'm thinking that perhaps the vanes have been reversed taking the secondary mounting 2-3mm further into the tube. That would certainly push the focus further back requiring the extra extension. Forecast says clear tomorrow so I'll try it as-is first with the long extension. i will get a small inward shift when viewing stars as the tree whilst a good distance isn't at infinity. But to me I think I'm about 50-60mm further back that I should be. A plate solve should tell me what the native focal length is, it should be 1624mm...

I'll add some photos tomorrow to show what I'm thinking may be an issue.

TBC

I have a 533 and have never taken dark or bias frames. A flat for dust bunnies sometimes if a test frame shows a problem. Otherwise it's DBE in PI to even out a background.

Will the filter not screw into the front of the 0.8x flattener?

Inspiring stuff. The number of times I've tried (slowly) to straighten up after viewing something at an eyepiece (doesn't happen too often!) and been put off looking at something lower down knowing that I need to straighten up again afterwards. I have the skills just never thought to much about solving the problem....

Thanks @Tiny Clanger

If you're using an OAG have you set the scopes focal length in PHD2?        Red Brain / Guiding...

I'm not a lunar fan but that is a great image Steve.

56 minutes ago, jacko61 said:

I had this issue with my Canon 70d until recently. A 3 minute exposure would take 3 minutes to save.  Some kind soul told me to turn off noise reduction in the camera and long exposures now take about a second to save. No idea if Nikon have the same setting but it would be worth a look. 

Graeme

Thanks Graeme, No not that sort of issue for me just file size with 1:1 binning. SGP setting will allow me to crop the AF field size so I'll try that next time the 800E goes on the ZS73.

I have an autofocus unit (sestoSenso 2) which I use on a WO ZS 73. Whether I use it depends on which camera I attach.

If I attach my ASI 533 then I will use the AF unit. However, if I attach my Nikon 800E the files take so long to download and assess focus if becomes a slog - then a visual on the magnified camera screen is much faster.

The other issue is subject brightness, if your FoV has few faint stars tthen an AF unit will be the better option otherwise your moving to a nearby brighter star each time you change a filter. Using a mask or a magnified screen view with faint stars is almost impossible.

@RugbyReneI've owned an Avalon Linear Fast Reverse mount and can say that it's a superb mount. I had warnings from (mainly CN) that the belt drive wasn't up to it - load of b--ls. I now have an iOptron CEM60 (non EC) and that too guides really well especially now PHD2 can guide on multiple field stars.

Good luck with the search.

Altair do a 115 Wave series APO

Interested in comments on an 8 inch f8 RC, looking to get one.

I had a few years back an Altair Astro (GSO clone) which I sold (why!!!) and I'm now looking at it's replacement. I see FLO do their StellaLyra, RVO do an iOptron Photon and there are others. Just wondering on other good/not so good views on them...

Cheers

2 hours ago, peter shah said:

lovely work Francis....

Thanks Peter,

I was hoping skies would be a little more transparent - maybe next time...

After waiting for these to get out from behind trees the weather turned quit murky so I'll put this down as a Mk1 attempt and try again on another night...

Shot 25x 300s subs but could only use 16.

Just about make out the tails but definitely needs clear dark skies.

Well it is galaxy season so I just had to have a go at this...

20x 300s subs,  ASI533 MC Pro cooled to -12°C, Baader UV/IR cut filter

RASA 8 on an iOptron CEM 60 standard

Link to annotated image: https://www.astrobin.com/fhmsiu/0/

Hope you like

1 hour ago, Laurieast said:

Where does the lolly stick fit into all this?

Nice deep field!

It turns out that the WO version of a Vixen dovetail bar is narrower than a standard Vixen dovetail bar so when mounted the whole optical train is shifted over to one side and unless you add extra weight to the opposite side it won't balance. A loolly stick shifted the OTA assemble back to it's central point...

2 hours ago, AbsolutelyN said:

Loads of galaxies here looks great. I've never heard of a mono DSLR before though. How does that work? Has the sensor been swapped out? 

The mono DSLR. The sensor has been striped of all filters (bayer matrix) and all glassware. The chip is essentially bare. Ultimate full spectrum mono mod.

I've had a couple of issues with PHD and balance with my CEM25P / WO ZS73 combination lately and spent quite some time getting the balance right yesterday and put it to a test last night. (A lolly stick proved the best solution!).

12x 300s subs were shot at 1600 iso on a mono modified Nikon D5100. Images were processed in PI then resized in PS before posting here.

Plate solved image: https://www.astrobin.com/xodxry/?nc=user

3 hours ago, steppenwolf said:

Can't be sure that mine was a Charles Frank but it would have been 60 years ago that my parents bought me a black cardboard tubed refractor via the 'Look and Learn' magazine. I remember well that I had to be VERY careful when focussing inwards as it was all too easy to blow the single lens off the front as the white plastic retaining ring was not a great fit!!

Yes I remember blowing the lens off the front too. Lots of tape I remember using now...

About 60 years ago (in a galaxy far far away!) my Dad bought me a Charles Frank refractor which consisted of two cardboard tubes. At the front of the bigger tube was a single bi-convex objective lens (uncoated) at the other end of the smaller tube a lump of rubber with a tiny little eye lens molded into it.

It was advertised in one of the daily papers in a little ad in the classified section.

Everything viewed showed red and blue fringes but It got me hooked on this hobby.

Anyone else have the same beinnings?

Take a look at this series - modified 2 450D's using the method. No soldering required.

http://dslrmodifications.com/rebelmod450d12.html