bingevader

Fully clothed I hope Gina!

With all the whistles and bells? I quite like the sound of the DSC.

I have an 8mm plossl and that's plenty low enough for me! If you want a replacement for the 6mm that is a reasonable price, then I can highly recommend the WO SPL 6mm.

Definitely. The BSTs would be the goto recommendation atm. It'll be difficult to give any suggestions otherwise. I like all the EPs in my sig with the 8" dobs.

If you want to see the bottom of a coke bottle, maybe! 🤔

Nice one John! What are you using to mount the phone? I've just received a Celestron NexYZ, but have not yet had the chance to give it a go.

The "Lectures" bit was slightly misleading! I gave up after realising it was an interview.

I flew straight by! Nice view of the ISS!

Then why not use them?

Yes indeed. I have a 1.25" to 2" adaptor from Revelation Astro. Not as cheap as ebay, but threaded. I bought mine to use my (1.25") 14mm ep whilst using my 2" eps. Means I don't have to swap everything out when swapping between.

I've always understood this. But why doesn't this then result in "wasted light" if the exit pupil is too big? That's where I need clarification.

Sums it up for me very nicely, thanks John. At these magnifications the loss of light makes little difference.

And this is still true if the magnification remains the same but the diameter of the EP increases (so no reduction in magnification to brighten the image)? I will quite happily stand corrected, I've been living with a misconception for some years! There was a vogue for larger and large EPs at one point and I remember the same conversation then. Maybe I didn't remember it and that's the problem!

The AFOV is determined by the field stop (gives the edges of the FOV) and the focal length of the EP.

Yes, absolutely, but the exit pupil (amongst other things) determines how much of the light from Jupiter hits the retina. If the exit pupil is too big, Jupiter will be dimmer. It's an overall effect, not just a centre and edges, or bright things and empty space effect. You'll have to wait for someone who can explain the physics for a better answer, I just know that it's the way it is!

I didn't. I made no correlation between exit pupil and brightness. I said, that if you lost 10% (only as an example) of the light, then it is lost, regardless of where you are looking.

Nearly, but not quite. The pictures are too complicated for me! You aren't receiving all of the light from the planet, there is still an overall loss and so a dimmer planet. Imagine a 5p coin as the ep and a 20p coin (okay, not round) as your pupil. The 5p fits nicely in the 20p, all the light is received. If you now swap the 5p for a 2p, it's now bigger than the 20p. Not all of the light can enter the pupil, there is an overall reduction in the percentage of the light reaching the retina. It's not that some bits are bright and others aren't, there's an overall reduction.

Hi, I don't think you are quite right with your middle paragraph. Using an EP with too large an exit pupil does result in 'wasted light' because you can't get all that light into your eye. You moving your eye around doesn't mean you are picking up any extra light, you are still only receiving the same amount of light on your retina. If the loss was, for example, 10%, it would still be a 10% loss regardless of where you looked. You can't physically get all that light into you eye so there is always 'wasted light'. With the 100° EPs (as long as they fall within the limits of your pupil size) you are not losing any light. Your retina is receiving 100% of the light leaving the EP regardless of the angle at which you observe through the EP. I'm sure there must be some diagrams to explain, I'll have a look. The 'wasted light' bit has never bothered me though, because if it is a pleasurable view, what difference does it make?

Not going there! Would definitely be in breach of SGL rules! Great sketches. I can remember looking at the Castell filters when I bought my ES filter. I can't remember why I opted for the ES over the Castell though, sorry.

I have the 2" ES UHC and have seen the veil nebula through it in an 8" dob.

Hadn't noticed this thread before! Mine is simple, over the past 20 years I have had 2! etx90 and SW 8" dob.

Hola, welcome to SGL.

In the garden I use separate. In school we now have a zoom and barlow, very convenient. On hols, or grab and go, I take 2 or 3 EPs and a 2x barlow. I don't know if that helps, but it gives you an idea of the options.

look no further than our own sketching thread.

I don't know what telescope cuto is using, but I don't find going much beyond my 14mm with the 8" dob very useful for DSOs. Price wise, I'm not sure there's anything else in the same bracket as the OVL at 82º. Just ordered the 7mm.