neil phillips

Lovely work Steve. 

 Just for fun Roof hugging 15 degree elevation. Sky watcher 90mm F10 achro. 

17 minutes ago, Space Cowboy said:

How high was Jupiter Neil? That's quite remarkable for a diddy scope!

Exactly what i thought Stuart. Hard to be exact my clocks gone bananas on the lappy. But i can tell it was before the sun came up, But daylight so as a guess i reckon maybe 25 degrees give or take, slightly lower or higher. 

Its interesting on a few fronts. And really just confirms to me something I've debated in the past. Regarding sampling under certain situations. Ideal was around F11.5. I was considerably over that F20 and that doesn't take into account the long ADC extension. The native image correct sampling would have been more difficult to get focus. The size would be tiny. But seriously oversampled and zoomed in to 175% i could start to see small differences of focus about 2 mm in movement really tiny amounts were making big differences in perceived detail. Its highly likely the reason i have done so well. Is breaking all the rules. However uncomfortable that is for our theorist friends. Couple that with the 150" resize. has made a mockery of the little scopes ability. I knew it was a goodun But at that elevation. I was floored. The amount of detail on show. Normally with these kind of things you just see a couple of bands. maybe 3.with little else going on. I can see a collection of white ovals on this lol. Crazy little scope

Just now, Gonariu said:

Could you remind me where is this thread which I would wont read? Thanks.

Hi the thread was here

4 hours ago, glafnazur said:

I've got one of the old blue tubes and for the price I paid I can't fault it. I use it mainly as a grab and go scope for double stars.

Exactly grab and go, quick cooldown. Something I've missed. They can be real bargains agreed

4 hours ago, John said:

That looks like a nice one 🙂

We discussed in another thread the potential for variability in these lower cost achromats and I'm afraid that I have one of the 90mm F/10's that is not so good 🙄

Glad you got a good one 👍

Hi John that was quite a relevant thread. Really is a lottery draw isn't it. I knew fairly quickly the figure was quite good after a initial Star test. Both sides of focus seemed quite close. Took me a minute or so to garner there was a small amount of under or over correction (cant remember which side of focus ) But it was minimal. Less than i generally see. Stars also were reasonably clean. I may check the focuser alignment at some point. Unlikely to be bang on. But small gains on that. Now to make another solar filter. It wont compete with my other scopes obviously, But that's missing the point. I didn't buy it for that.  also doesn't give me a hernia setting it up like the big guns. And cools within twenty minuets. More tolerant of seeing ect. And really just a lot of fun. Lunar will be nice when high

 Just for fun and testing purposes. Imaged the gas giants. With small scope. Purchased this 90mm SW Achromatic refractor F10, mainly because i wanted a small solar scope, And a quick grab and go for those visual moments i enjoy with small scopes. I sold all my refractors. When i needed funds. Glad to have another back. I have to say i am very impressed. Its definitely a keeper Thanks goes to Pat who sold it to me. Both captures considerably oversampled F20. then resized to 150% could be forgiven for thinking a much larger scope took them. A sign of a good lens figure.

1 hour ago, John said:

Yes I did and it was an excellent refractor. My first taste of a "big" refractor 🙂

There is a pre-owned one on a certain vendors website at the moment for just £200 which seems an absolute bargain to me.

Interestingly, I also had the Meade branded version (the AR5) of the same scope a couple of years later. The optics on the Meade one were just not as good not matter how much I fiddled with the collimation. 

 

Their lies the rub. Figure variance. Lottory anyone ? With a little luck a first taste of a big refractor can be a really enjoyable experience. A poor mans highlife. Theirs something inspiring about a large frac on a mount 

I've enjoyed some cheap refractors over the years, warts and all. In fact I've just purchased another after needing some funds and selling my entire collection. But thankfully when i want performance without spending many thousands of pounds a large mirror being either a SCT Mak CC Newtonian will always come to the rescue. But flawed optics can be enjoyed wholeheartedly. Both visually and imaging Though for me some flaws are more tolerable. CA not a biggy. spherical aberration and astigmatism more troubling. For lunar greyscale imaging what CA ? Bresser 5 inch achromat. cost me £180 secondhand. Lovely refractor. Would prefer a 5 inch Tak yes. Maybe one day i live in hope. For imaging cheap refractors in greyscale are less flawed 

Example both 5 inch achro 

The evidence is mostly anecdotal. But based on good science, often repeatable, and fairly consistent. I've seen it enough over the years to be convinced of it. Though the conditions for it, can vary quite a bit over the same area. From hardly noticeable to horrendous. The further the target is away from the problem the less its impact will have 

Agree with the other comments 100%

1 hour ago, VNA said:

Hello, why the turkey crossed the road???

 

 

(because the chicken would not do it!!!!!

 

 

Sir William  Herschel did more than build scopes, he composed beautiful music, although he did not built "big" orchestra but formed big mirrors!

 

 

And that's often another connection a lot of amateur astronomers also are also musical.

2 hours ago, Roy Foreman said:

Hi Neil and thanks for your comments. Yes, the CC does seem to have a special clarity. I think it may be due to it being an all mirror system with no lenses in the train. I was working at F/12 which is 3045mm FL.

I thought I had eliminated the alignment box problems but some obviously slipped through. It comes from shooting in daylight with hazy skies. AS3 is probably trying to align the sky glow. Tried all different box sizes and brightness thresholds and even tried manual placement, but nothing seemed to work reliably.

The selective enlargements showed too much pixellation so I resized them in PS. I guess I may have overdone it a bit.

As for collimation, first I used a regular laser to adjust the focussed so that the beam hit the secondary centre mark, then adjusted the secondary to get the laser to return to origin. For the primary I had to resort to real star as it seemed to be the only way that worked accurately. It was a bit of a pain but hopefully wont need doing again for some time.

Yes i understand sky brightness causing the dreaded box problems. When you get better conditions, when the moon gains elevation again. And in darkness the box problem should resolve.  Its worth doing these runs in prep for the better sessions you can now look forward too. Experienced gained will help when conditions are right.

Each to there own of course Roy but at F12 personally i would be reducing size a little. Ideal sampling with your camera is around the F 9 to 10 mark i believe. Though a little more isn't always a bad thing I've found.

Taking the images from F12 and testing slight reductions 90% or 80% so forth should work wonders with great data. You may not agree, but its something I've found can tighten the images quite a bit. Even just down to 90%. From F12

Just the finer things of processing worth contemplating. I've watched your work for sometime and can tell your on the verge of world class performance. As with all things everything has to be perfected.  I reckon when the conditions come your going to knock it out of the ball park. Its easy to see the great quality your getting now. 

3 hours ago, Rusted said:

The best way to get lucky with seeing is to image as often as possible.
This is usually only possible with retirement.

That is so true on all fronts. If you want to score goals you have to be on the pitch

First images I've seen from any 10"CC. It has that CC vibe doesn't it. hard to quantify that statement i know. Hard to tell looking at images. But it does look collimated. No obvious blur factor going on.

Moon wasn't ideal on the 24th some 40 odd degrees in broad daylight max. quite a bit less at anything approaching dusk. As such i think its looking very promising. Has that CC sharpness vibe that i like. Are you at F12 ? Because the single images are coming up huge ? did you drizzle or something ?

images not really usable full size, look far better with big reductions ? trying to understand this ?

A couple of alignment box lines top right. might be worth running larger boxes on that edge ? 

But overall congrats Roy, scope seems to be performing nicely. I have a feeling flatness of field aside. You may find under the right conditions the 10"CC Could well outperform the Celestron 9.25 sct  just a guess based on my experiences with 7.3 of clear aperture CC Performance that i get. Namely sharpness.

These scopes can be supremely sharp. And it looks to me, conditions considered, your scope is showing those traits nicely already.  Excellent Roy.  Great early result. 

How hard did you find collimation ?  How did you eventually achieve it. I did mine using star testing. My avatar under my name is the de focused 7.3 CC

On 22/06/2023 at 15:05, CraigT82 said:

Inspired by @AbsolutelyN and his 250mm Quattro it it's white light role, I have this week made up a DIY white light filter for my 300p using Baader ND5.0 film and had it out in the sun yesterday and today.  Yesterday's results were terrible but today's are a little better, though I think this big scope is going to need some decent seeing to work.

This morning at just before 7.30am I captured 5k frames and stacked 10%.  Used my Altair 290m and Baader Solar continuum filter, with Baader 2.25x barlow. I tried again at around lunchtime but the image was absolute mush.

Processing was AS3!>IMPPG>Gimp

You like to do things the hard way. As you say large optics like this will be difficult to thermally settle. But when it does with good seeing the results will be good. Showing some good structure Craig. I got a reasonable result with 245mm Newtonian stopped down to 190mm. I know the filter protects, but i got paranoid. I didn't like baking my old cherished Newtonian. But results were starting to look reasonable when i stopped. 

Well done on going all out on this. Not easy

Picking up some cloud there. Nice Captures

Good to see you getting in some early captures. Good result 

7 hours ago, Franklin said:

 

Would never have thought of that, will look into that cheers Franklin

On 15/06/2023 at 05:56, Pete Presland said:

Some nice details visible there Neil, that is  a proper early start mate 🙂 

Many thanks Pete. Yes its early indeed.

Windows can cut power on a USB port if it detects a problem with the port. Mine just did exactly the same. camera wouldn't connect. I assume you've tried more than one port

I Think its in our blood. Many of us would have built huge scopes and did what John Herschel was doing. If born rich in the late 1700s. Just fascination and curiosity

Just now, Roy Challen said:

Superb image Neil. I think I've learned more about the appearance of Saturn from looking at your images than I have from reading books😄

Cheers Roy. Will enter darkness soon. So should improve hopefully.  Color gets affected more. Need good seeing and darkness for that. Hence IR 685. One thing i try to do is not over process. Tempting early on when image quality isn't at its best.

46 minutes ago, Space Cowboy said:

I've never used straps but if I got a bigger DOB I'd be looking into them. Maybe even a strap that went over the shoulder and clipped onto the OTA.  Sounds good in theory 🙂

I am normally ok. But it was just the water both hands lost grip. Will ponder how to prevent it happening again

Just now, Space Cowboy said:

Detail showing nicely even at this early stage Neil!

Would carrier straps be any use on the OTA? 

Its improving. And nice to do it, with the big optics. each improvement with that, is a acid test of its metal at the moment Stuart, I am still learning about it. its quite new. I re tweaked collimation, it was off slightly off. Checked after the near disaster. Collimation looked the same. It didn't bang that much luckily. Straps might be a good idea actually, anything in mind ? cheers

Cheers 

Just now, Kon said:

Excellent image. Much more details than earlier and the banding on the planet is resolved nicely.

My heart stopped when I read this!

Yeah it was lucky i caught it. Don't think it would have gone over, I was close to a wall, but crashing down with a loud bang for sure. I will take better steps to make sure its drier i think. I did wipe it down obviously not enough.

Cheers