billhinge

Check out the definitive page for weird telescopes http://spider.seds.org/scopes/dstevick/weird.html 

This is the original page your pic was taken from http://spider.seds.org/scopes/dstevick/trischi.html

Buchroeder design Tri-Schiefspiegler on this provisional structure. The optics for the 300mm Tri-Schief  ....

I always wanted a Stevick Paul

On 15/08/2021 at 13:14, ollypenrice said:

@Grant  Pixinsight's Photometric Colour Calibration requires focal length and pixel size. Any chance of this being supplied? It would also be interesting to know the kit being used but you might have reason to withhold that information and it isn't necessary for the processing. Boy, I love the luminance!

lly

Any reason not to pull it from the image metadata, thats what I normally do?

I  think after a while it just clicks and becomes second nature without have to follow a prescriptive workflow - best book I  found was Mastering Pixinsight by  Rogelio Bernal Andreo. It explains why PI tool settings are not what you may assume when tweaking .  Well explained with a second reference volume

Also  try the monthly competitions from last year, they have virtually perfect data to experiment  on

The starnet app is good but my gripe is it seems to get fooled by really bright stars etc

Something I wanted to try from when I  made a 8.5" mirror  in the  70's.  My concern  is about getting the chemicals (through customs). A few years ago I  bought some distilled water and acetone from local chemists. Boots  refused to  sell acetone and gave me a  hard time over distilled water! Next local chemist  made me sign the poison register for  small bottle  of acetone.   (I  know you  can get them by the gallon on ebay now). They used to have instructions  in  the old ATM vol 1 to 3

I believe you  also  need nitric acid, I'd  be worried about it getting stopped at customs but in principle it sounds cool.  I guess not many folk have tried it given its easy enough to aluminise 

Don't you have to burnish it as well? Potential downside risk sounds high in relation to  any upside benefit unless you are after the 'experience' of having done it in which case the cost shouldn't matter

I bought the parts  for a CG5 DIY belt mod from here several years ago  https://www.beltingonline.com/to-suit-9mm-wide-belt-c-272_284_479/36-tooth-htd3-pulley-363m09f-p-7728.html

------------------------------------------------------
2 x 15 Tooth HTD3 Pulley (15-3M-09F) (HP15-3M-09F)  = £14.23
Modify Bore? 5mm
Grubscrew Holes? 2off M3
2 x 3mm HTD® Timing Belts (4573)  = £3.91
Width in mm 9
Belt Length in mm 111
Tension Cords Glass Fibre
Material Neoprene Black Rubber
2 x 24 Tooth HTD3 Pulley (24-3M-09F) (HP24-3M-09F)  = £11.43
Modify Bore? Not Required
Grubscrew Holes? 2off M3
Keyway? Not Required

I believe the parts can be customised is some way if you find the right one, they also do different belt  qualities - I  went with high torque drive = HTD   (google timing belt pulleys)

That's pretty cool, something I had always wondered. For a long time I  kept an eye open for a used one with the intention to add goto  etc (I think I have the know how and I had a mk III which I completely stripped,  cleaned and put back together so I appreciate the workmanship 🙂 ). 

I  notice there are 2 Fullerscopes mark iv's in the for sale section, a bit like buses  you never see one and then 2 turn  up at once!

Seriously though I always wondered  what the weight capacity of those things were?  Any ideas, what would be the modern  equivalent

I think it looks good, like an  old iMac 🙂

I had a CG5, got a skywatcher now - prefer the skywatcher, better and cheaper wifi dongle as well

Noise on CG5 is due to the plastic case amplifying motor noise, taking it off greatly reduces sound

Get a berlebach and sell the tripod 

All PI LRGB, wavelets, curves and masks

Kind of  funny, I did a  project  on iodine 138 decay many years ago as part of my university third year astrophysics project. One of the products is a positron and a neutrino.

It's quite easy to measure neutrino mass squared, it always comes out negative but there is an error bar which could could just make  it positive.

Convention is always to take extreme positive value as it can't possibly be negative 🤣 many unwanted things seem to get explained away in physics

Not specifically this model but I have done many Panasonics  inc de-bayering plus one Canon - I had loads of £50 burners from ebay

Those ribbons and connectors are real easy to break, bent pins, plus static frying things - buy a mat and cable!

good video on PBS explaining it all

Photoshop is less than £10pm and includes lightroom, seems reasonable to me, why object on principle? Its easier than PI and very useful, especially if you buy plugins

I have  PI  from  when it first came out, I haven't found it requires any heavy  duty hardware (2018 macbook pro)

as Martin said, get the trial to see if  you can get your head around it, requires you to think about what you want to  do and change default settings rather than follow a strict workflow . Its one of those things that seems mysterious then after a while it just clicks

I'm getting rid of my kruppax 😇

36 minutes ago, Deadlake said:

I ordered mine with the 3.5 FT, if you take the base model add the 3.5 " FT its about £500 off the mark II models. 

Would be nice but mine is second hand dating back  to about 2005 or earlier, it seems to have a custom made 2.5" ST, trouble is I want to fit the 82mm  Riccardi. 

15 hours ago, Space Hopper said:

Well......it may sound slightly crazy, but i've decided to retube it and fit the large 3.5" FT focuser.

I want to image with it in the near future and have a full frame camera, so plan to use a large type reducer.

 

 

I have the 115mm TMB LZOS and was looking to change to a 3.5" ST focuser to fit the Riccardi reducer/flattener, I have been in  touch with Markus at APM and Wayne at Starlight and it seems those old tubes are slightly the wrong size to fit the new ST focusers without an adapter, unfortunately they wanted me to ship the scope out to Germany or US to fit a bespoke adapter 😬

If I do replace the tube I may go the moonraker route, I can get a shiny silver 3.5" ST to match the tube 😄

now reported as 4.1 sigma

https://www.bbc.co.uk/news/56643677 or  https://phys.org/news/2021-04-tantalizing-results-defy-physics-rulebook.html

There is currently a one in a 40,000 chance that the result could be a statistical fluke - equating to a statistical level of confidence described as 4.1 sigma.

You have to use your imagination , eg  something like this https://www.skf.com/group/products/rolling-bearings/roller-bearings/needle-roller-thrust-bearings

Where could they go?

APM seem  to supply some objectives  for DIY

https://www.apm-telescopes.de/en/apm-products/lenses-cell.html

D&G do them  in usa

or you could get moonraker to build it for you (looking to get my LZOS done)

http://moonrakertelescopes.co.uk/telescope-range.html (not cheap option)

Probably cheaper to buy new/2nd hand, seems a faff getting a new cell and objective of exactly same spec, hard enough getting a focuser to fit specific tube diameter (looking to replace 2.5" custom featherlite with a custom 3.5" silver featherlite)

ebay?

For what its worth,  I think  replacing the worm bearings and 6007RZ RA bearing will make more difference, the teflon bearings seem to be just gap fillers 

If you are going to re-engineer it, I  would suggest  looking at the problem Celestron are trying to solve on a tight budget  and  see if you can do better with better/different components which may be slightly different  size eg needle bearings (you may need to do some exact measuring) rather than copying their components, try different  grease

But  remember it wont turn  into a Paramount ...

I replaced every bearing and added custom belt drive, yes it was interesting and a learning experience and I then bought an EQ6! (but  at least I know how everything works)

On 26/03/2021 at 12:23, billhinge said:

I  blame TV or lack of now. Back  in the 70's they did good  educational tv, one of  the  unsung goodies was Weekend World on Sunday 12.00 lunchtime with Peter Jay and Brian Walden

https://en.wikipedia.org/wiki/Weekend_World

Even as kid I  was interested in  velocity of money, M0 to M4 money supply, Keynesian economics models vs gold standard, and rising costs of materials at the factory gates, domino theory etc 🙂 

guess   it influenced me to expect price rises - never  let a good crisis go  to  waste (they even put prices up when they changed from  old money to decimal ;-( 

Given the Suez ship is blocking traffic to the tune of  $10bn per day it wouldn't surprise me if there were further price rises, someone is  going to have to be out of pocket, I  guess it won't  be shipping companies  and suppliers ...

I  blame TV or lack of now. Back  in the 70's they did good  educational tv, one of  the  unsung goodies was Weekend World on Sunday 12.00 lunchtime with Peter Jay and Brian Walden

https://en.wikipedia.org/wiki/Weekend_World

Even as kid I  was interested in  velocity of money, M0 to M4 money supply, Keynesian economics models vs gold standard, and rising costs of materials at the factory gates, domino theory etc 🙂 

guess   it influenced me to expect price rises - never  let a good crisis go  to  waste (they even put prices up when they changed from  old money to decimal ;-( 

Hardly without warning, I think it was pretty obvious that with Brexit tarrifs  and covid supply chain issues that prices would go up. I'm surprised they didn't go up sooner, I assume they will go up more  next year as the post covid financial hangover rumbles on.

I'm not  averse to spreading out large purchases on credit cards  over 3  or 4 months but I generally pay them off, bought everything I thought I may need  before December

I bought a lot  of new stuff last year as I hope to retire in  a year or two 

Maybe it's an age thing? back in the 70's and 80's  you expected rising prices  and high interest rates, from the 90's onward  people had it "lucky",   cheap quality imports and  relatively low  inflation/interest rates ?

I bought a second hand artograph off ebay, paid  half normal price  (well made, variable lux and colour temp, good quality leds -  not  cheap but assuming you get what you pay  for)

https://www.artograph.com/lightpad-series/lightpad-lx-950/