Marvin Jenkins

Just now, saac said:

When you are in the quantum realm all possibilities are in play until they are not!

Jim

Sounds like a free pass to say that what ever I type in the quantum world could be true. Turns out that 87.23950% of my calculations are made up on the spot.

But in the quantum world they may well be correct.

22 hours ago, robin_astro said:

They can be any colour you like -  until you look at them  🙂

But you said 'NO' so how can anything that can't be, be any colour you like?

Marv

Just watched the docking and couldn't help a few screen grabs.

To quote #robin_astro..... No 

2 hours ago, robin_astro said:

No. 

https://www.forbes.com/sites/startswithabang/2020/01/02/no-we-still-cant-use-quantum-entanglement-to-communicate-faster-than-light/

 

I am impressed with the forthright reply,.

Absolute certainty is a rare unicorn. 

Marv

2 minutes ago, Marvin Jenkins said:

Twofers always seem great at the time.

How is your outreach doing? I remember you were doing more than most to promote our shared interest?

1 minute ago, Gfamily said:

I may have mentioned at one point that our opticians were doing their "two for one" deal, so - as well as the everyday varifocal pair, I got a single vision pair for astronomical use, and they live with the scope box. 

Used them occasionally, but the next year, after something of a 9 month gap (and after a revision of my prescription) I tried them again.  No problems with them at the eyepiece, but when I then looked at theit was a different matter                       

Twofers always seem great at the time.

2 minutes ago, Marvin Jenkins said:

A statement of utter genius. I have no way of thanking you.

MNOEG is now my non existant friend.

Marv

Just now, saac said:

Hang a tag from your focuser with the message "virtual outreach guests please refrain from adjusting my focus".

Of  course you could overcome all of this by putting a camera on the scope and displaying the image to guests on either a laptop or phone screen.  Not the same experience I know but no need to adjust for multiple non existent outreach guests' focus requirements .  

Jim 

A statement of utter genius. I have no way of thanking you.

34 minutes ago, saac said:

Spectacles are not just for reading (nearby) and distant correction. They can be if that is the prescription but they can also be for everything in between, it all very much depends on the prescription (corrective requirement).  It is also quite possible that a person with a particular corrective requirement will be unable to focus an image from an eyepiece. 

Remember too that the focuser is not focusing the image on the retina, rather it is presenting a focused image at the eyepiece focal plane. The eye of the observer still has to focus that image on their retina in order for it to be sharp. 

Jim 

 

That second paragraph seems to answer my initial question perfectly.

In effect the EP and Focuser gets the image sharp, the second optical path 'eyeball' does its bit.

However most EBs are flawed through short or long sight. Other stuff I don't understand including stronger eye, mis aligned eyes.

So to boil it down. I need to put up with my non existent outreach guests, not messing with  my focal position?

Marv

3 minutes ago, ollypenrice said:

A local Brit, also called Jim, is a retired eye surgeon (and pilot, and aeroplane builder, and motorcyclist, and model engineer...) but talking to him can leave you exhausted in less than five minutes!  Great guy, though.

Olly

I guess it's all in the perspective?

1 minute ago, Xilman said:

Yup.  The outside edge of each lens is markedly thicker than the inside edge.

So the whole spectacle lense is like a wedge shape? In effect acting like a prism?

20 minutes ago, Xilman said:

My eyes point in different directions and my spectacles include prisms to bring them into alignment. With binoculars I see two images if both optical paths are clear, so I keep one eyepiece cap in place when using them.  This has the advantage as I can swap eyepieces when one becomes dewed up from proximity to a warm wet eyeball.

That is incredible. Do your glasses look much different to normal spectacles?

Just now, saac said:

I like the idea of a course on the eyeball - sign me up too.  I must admit whenever I go for my annual check up at the optometrist I'm like a kid in a candy store asking questions about all the tests and all the equipment. It really is fascinating, as is anything to do with the human body, a remarkable machine. 

Jim 

Well you know eyeball courses are very informative. I am signing up right now when I see one.

Just now, saac said:

Spectacles are not just for reading (nearby) and distant correction. They can be if that is the prescription but they can also be for everything in between, it all very much depends on the prescription (corrective requirement).  It is also quite possible that a person with a particular corrective requirement will be unable to focus an image from an eyepiece. 

Jim 

Good info. I didn't know that. Thank you. Seems I need to take a course in ... The eyeball. So much I do not know obviously.

2 minutes ago, saac said:

When I wear glasses then my daughter, non spectacle wearer, will not need to refocus or only minimal adjustment. If I remove my glasses and focus to suit my eyesight then on handing over my daughter will need to make a pretty noticeable focus adjustment. This makes sense as the point of glasses, corrective lenses, is in effective to provide the wearer close to 20:20 vision. 

Jim 

Thank you for this but I my confusion is that spectacles in my mind, are for wearing for reading, driving, and even more distant vision correction.

I am still wondering why specs are needed at the EP when the Focuser is doing the work?

Marv

1 minute ago, ollypenrice said:

It is baffling, sometimes. Someone apparently happy with what they have seen will hand you back the scope so far out of focus that it can only have given them pure visual mush.

What we underestimate is that some people don't take naturally to looking through optical aid, just as some people don't take naturally to driving a car or changing gear on a bicycle.  I stopped waiting for night with beginner guests and got them used to looking at a distant electricity board sign half way up a nearby hillside. The text was readable if you were in focus. If not, it wasn't. This was a simple self-test for the guests and a simple third person test for me.

At astro outreach events it is simply not viable to hand an instrument over to to a new observer in the expectation that they will see what is there. Some will and some won't. This seems unreasonable to us but that's how it is.

Olly

At least you had a chance, so well done. My experience has been small and different.

A work friend of mine has a six year old daughter who is fascinated by books of the solar system and space stuff in general. I offered a late evening into summer night use of my 150pds EQ5 as a personal outreach as the planets were very good back then.

Instead a local astro group had a night of the stars and the poor young girl was asleep waiting in a line.

My next door neighbour is a summer holiday visitor. He has two teenage sons very interested in science of all kinds. After seeing me observing he asked if his sons could come round and observe which I was more than accommodating.

The next evening they went out to dinner, then to bed. A few nights later they went out and returned at 3am.

The following day they explained that they had paid to have a private tour of an historic observatory at Fumel and looked at Saturn through a large SCT.

They then said they highly recommend it, I should try it some time!!!!

At that point I thought better off on your own son.

23 minutes ago, John said:

The challenge is, at a busy outreach event, each person only gets a very short time at the eyepiece. I had queues up to 20 folks long at times this weekend so fine tuning the views for each observer, most of whom had never looked through a scope before, just wasn't practical.

I did start to do what @Stu suggests above and anticipate the next persons needs by racking in a few mm if they were wearing glasses then encouraging them to try without the glasses, initially at least. Quite often that seemed to work but of course I couldn't see what their eye was seeing !

 

More power to you with the out reach. I have tried it at a limited level and found the response baffling.

24 minutes ago, Stu said:

What I find frustrating is when you KNOW someone will need to refocus but they look through and say ‘no, that’s fine’ 🤬. An example would be if they do not wear glasses, and I have focused the scope using my short sighted eyes. To counter this, I sometimes try to focus wearing my glasses in the hope that this results in a focused view for someone with good vision.

How does this work with a bino viewer! That's two eyes potentially not the same in the same skull 💀 

I just thought of something from my original post observing with my friend.

He is 15 years younger than me lucky #*×. However he is a smoker which I am not. I noticed during the night the odd aromatic pungent smell.

I am wondering if my observing guests eyes were a little 'more relaxed' than mine. Probably more dilated giving a bigger aperture possibly, but effecting focus point.

Marvin

23 minutes ago, John said:

That could be a statement that applies outside of astronomy as well for me 😁

I think you may be onto something there.

Next clear night with some moon I am going force my wife to partake in a visual experiment on account of of her terrible eyesight. Corrected with glasses she has no issue but without I have referred to her vision as molevision.

I propose an experiment. I am going to achieve pin sharp focus for my eyeball and mark the focus tube, then ask the subject to observe with and without specs.

For both of these observations I will ask the subject to adjust focus to attain what they think is perfect focus, then mark the draw tube.

My wife is short sighted. I am going to use a 130 newt collimated correctly. With a Plossle EP around 24mm for decent eye relief giving around 27x magnification.

Has anyone else tried anything like this?

Marv

Interesting  to have your experience on hand. I live the life of a hermit so I have very little on hand to base observations/comparisons. 

I also would have thought that spectacle wearers were at a dis advantage having to look through an extra layer of glass.

Marv

I was thinking get rid of the birch. There is a hole there for a pier! And the title pure click bait, shame on you 🤣

I was observing with a friend who doesn't have a scope of his own.

Taking turns at the EP I couldn't help but notice that each time observed he gave a slight tweek of the 10:1 fine focuser.

My turn to look and I had to re tweek to regain focus. All the tweeking started to annoy me as I thought once an EP was in focus, it is simply at the sweet spot.

I don't know how to explain my question, but do we see EP focus point differently for each individual.

This has also made me wonder about spectacle wearers. I always assumed that specs corrected long site or short site which I would have thought would be made redundant at the EP by simply focusing.

What is going on here?

Marvin