Posts Made By: Chuck Burton

I called Losmandy today to get that information, but even THEY are out of stock and could not provide that info.! If you have one of of those, I'd appreciate the information.  Thanks! 

Hello Robert:

That's an excellent question. I had both myopia and astigmatism issues and wore bifocal lenses in my glasses. As a "cataract surgery survivor," (2012) who is also an astronomy enthusiast, cataract surgery was a big deal for me. Fortunately, I had a surgeon who was very familiar with this issue. Some of these may not be applicable to your condition. You have a range of options with IOLs. Straight plastic replacement with no myopic or astigmatism correction, or IOLs with correction for one or both of those conditions, or, a sort of bifocal option, or a "soft" lens option they had just come out with at the time, that would eliminate the need for bifocals, since the eye itself would be able to focus this lens near and far. The surgeon told me that the "bi-focal" and "soft lens" options would affect my ability to focus star images across a wide field. He recommended that I stick with the hard plastic lenses, with or without the correction built in.  That's what I ended up doing.  Post surgery, I was able to ditch my glasses entirely. The clarity and pinpoint star images were breathtaking in their magnificent contrast. It was like being reborn! This cataract stuff sneaks up on you over the years and you just don't realize how bad things have gotten.

That was 10 years ago. The third year in, my astigmatism began to return. I had to go back to wearing glasses to correct it. But I still don't need correction for myopia - just the astigmatism, so the lenses in my glasses are very thin.

Today, you probably have options that weren't available 10 years ago.  But here are a few ideas to discuss with you doc.  Good luck!

- Chuck     

Started observing Saturn with a 17.5" f/4.5 reflector at ~2:30 AM MDT. The sky was mostly clear, with some drifting thin clouds occasionally obscuring the view. The atmosphere was fairly turbulent, and as a result, it was difficult to discern Saturn's cloud bands except for fleeting moments of clarity. At about 3:20 MDT, observing at 360X through a Meade 5.5 UWA during one of those moments, the cloud belts snapped into focus and the perfect tiny black dot of Titan's shadow was clearly visible, east of Saturn's meridian.

Later, around 4:15 MDT, I was observing with a 4.5mm Delos at 445X. The air turbulence had subsided a bit, and Titan's shadow had moved very close to the meridian at this point, dancing in and out of view.

As an aside, I had also set up my 152mm f/5.9 refractor, a relatively cheap, fast achromatic scope that I use exclusively for wide field, deep sky observing. The chromatic aberration in this scope makes it entirely unsuitable for doing any lunar or planetary observing.  In between "squinting sessions," trying to see Titan's shadow in the 17.5", I would take a few breaks to look through the refractor at deep sky objects. I thought I would compare some 2" O-III filters that I have acquired over the years, made by various manufacturers. It was an interesting exercise. Maybe I'll do a review on that later.

Anyway, just for grins, I turned the refractor towards Saturn and dropped in the 4.5 Delos (200X in this scope). I was stunned by the sharpness, contrast, and clarity of Saturn in this scope. There was barely any perceptible CA, perhaps because Saturn is dimmer and slightly yellow? In any case, I think if this had been a better night, I might have been able to see Titan's shadow in this scope. I also think it might still produce a good image at 250X or even 300X. So, before the next Shadow Transit, I'll have to scramble to find a TeleVue PowerMate to test my theory.

I've been observing with telescopes for over 50 years, since the days of my childhood. I've observed many shadow transits of the Jovian moons. This was the first time I ever attempted to view a shadow transit of Titan. I was surprised by how much smaller Titan's shadow disc was, passing across the face of the planet. It was a thrill to actually see it!

Originally Posted by Rod Kaufman

Nice review of your observing experience, Chuck. It seems you were able to make the most out of somewhat difficult seeing conditions with reasonably high power views. You had what I would call a memorable moment of which I've been fortunate to have in my many years of observing. too. 

For example, during a past and very close Mars opposition, and with excellent albeit brief seeing conditions, I was able to glean the sense of depth of the clouds above the surface of the planet as If I were in a spaceship above the planet looking down upon it. I was observing with my 16" f4.5 astrosystems dob with a baader contrast filter (essential for Mars, IMO) and an 8mm eyepiece.

BTW, I used to own a 6" f6.5 achromatic refractor and I hardly noticed any CA on Saturn, either...

Hi Rod - Thanks for sharing your observing experience!  I've never seen Mars in the level of detail that you described. Maybe I'll try that Baader Contrast filter at the next opposition. 

Clear Skies!

- Chuck

I hope this is the right forum to post my question in. Metal art prints that I've had made, seem to have limited dynamic range, that is, loss of detail in the shadows, blown highlights, etc. Does anyone know of a metal art print shop that does a good job with deep sky astrophotographic subjects? Thanks for any recommendations and observations!