Alien 13

12 minutes ago, andrew s said:

No scientific theory is a fact and no facts/observations are theory independent. Theory is judged on how well it works.

Any particular theory you feel is being neglected?

Regards Andrew 

Nothing specific Andrew, just a worry that we stop exploring new ideas.

Alan

I think we need to remember that the big bang theory is just that and not a fact, I worry that some less fashionable ones get dismissed too quickly.

Alan

It was common for all Canon cameras to operate best at 800-1600 ISO but that has changed now, some designs have a much more linear response and so are fine at a lower ISO and there are no benefits with going higher.

Alan

I agree that mirror slap can be quite noisy and using mirror lock up doesn't help because the mirror still has to move with each exposure unless you are running in full live view mode. I would check out the thin strip of foam at the top of the camera sensor box to see if its damaged (it probably will be as it gets hammered) and replace if necessary. My camera has several silent shooting modes but even then the noise is still noticeable.

Alan

Agreed, in fact a scope on a mount could be seen as multiple weights attached to lots of springs all resonating at differing frequencies, additional mass in the mount lowers the frequency and may damp the vibration but doesn't stop it. An ideal system is one where one resonance doesn't excite resonance in another component.

Alan

Nice

Alan

I am sure that one of the most asked questions is "how do I attach my camera to my scope" the talk could look at things like backfocus/extension tubes/coma correctors/field flatteners and the importance of the mount in relation to the scopes focal length...

Alan

Not sure why bad weather should stop a flight, this is the 21st century and as far as I know Faraday cages still work..

Alan

Curved sensors so no more faffing about with Field Flatteners or Coma Correctors....

Alan

7 minutes ago, DirkSteele said:

Astronomy is all about contrast and we have black paint, knife edge baffles, some flock their scopes. But none of that match the light absorbing qualities of VantaBlack. It’s about time it was used in telescopes.

 

The use of VantaBlack in eyepiece internals/ Mak baffle tubes and scope/camera internals could be game changing, I wonder if a Newt that had all its internals and spider vanes covered would show diffraction spikes?

Alan

There are quite a few Canon cameras that can be fully controlled including use of live view by the "canon camera connect" app which works on Apple and Android, the app list the cameras that are compatible.

Alan

6 minutes ago, Robindonne said:

That or some russian tsar was what i thought.   But when i use a reducer im good to go?   That makes it easy to search for the solution.  Of course a big thx for the info and sorry for the copyright thing.  

No problem, any images I post are free to use by anyone..

Alan

5 hours ago, Robindonne said:

I stole a picture from another thread with the same scope.  The person has indeed a small extension for it.
So if the reducer just shorten the needed length by a couple of mm’s an extender is the option to go.  
 But based on planning to use an oag, is it an idea to look for a thick oag and solve both problems with one device?   

Lol thats me in my Star Wars gown. The scope needs a two inch extension if using it without a FR/FF but none is required when using one.. There is no extension in use in that picture, its just that the FF/FR has been pulled out a bit to hit the end stop of the undercut.

Alan

1 hour ago, Callum1985 said:

I have bit the bullet and gone for the 600d.. Thank you for your advice and roll on Friday when it arrives... (you know them clouds are gonna roll in!!) 

Great choice..

Alan

Looks like a bargain to me, have bought lenses in the past and they are not cheap..

Alan

I have to admit that even my EQ3-2 with ally tripod is far to heavy for me these days even though I only have to move it 12 feet to get outside, do most of my stuff with a static set up that weighs a few Kg all in.

Alan

4 minutes ago, Thalestris24 said:

My ideal tripod has a 50kg payload, weighs 500g, and costs £20...

You could have 1 out of 3... 

Alan

I have never had a problem with the eq3 aluminium tripod provided it is used at its lowest level, easy in my case with a flippy DSLR and RA polarscope viewer but I never go above 400mm f/l.

Alan

This would have been my perfect job but retire soon, all the best to those that apply.

Alan

1 minute ago, saac said:

Step away from the dull  strangely warm metal Alan. 

 

Jim 

I say a block but its only about 20g have a few grams or uranium too, found in a skip.

Alan

Looked but couldn't find the circuit diagram, have loads of sources like Talumar lenses old military compasses and a block of plutonium somewhere..

Alan

2 hours ago, ollypenrice said:

No sub F4 optical single optical system currently available tempts me in the slightest but I can perfectly well see why it tempts others. They are not wrong to be tempted! I just need 'easy.'

Olly

Not even the mighty Samyang 135 mm f/2 lens?

Alan

The results from your machine beat my Alienware laptop into the ground so expect to pay big money if you want an improvement i.e. north of 4K.

Alan

I hate optics, for instance when observing you will get more photons in your naked eye than any telescope no matter how big it is, what changes is the field of view you see. Imaging is just as bad, a large scope collects more photons but they are useless if the arc/sec per pixel is all wrong as is a 10 meter diameter scope with an APS-C sized sensor. Remember the old Mt Palomar images with a 200 inch scope with huge photographic plates and the similarity to images taken with a small frac and small sensor...

Alan

Nice idea but it would require a larger than normal secondary mirror that would be similar in size to one that directs the beam through a hole in the primary.  Have not figured out though if your design would give a correct oriented image yet which could be useful.

Alan