Posts Made By: Tom Masterson

I'm looking at purchasing the Meade 8.8mm, and 6.7mm UltraWide eyepieces. I was wondering if anyone has had a chance to do a side by side with the Series 5000 and 4000 versions of these eyepieces. I recently purchased the 30mm Series 5000 UWA and really like it. In the mid focal length range - 20mm, 16mm, 12mm, I'm using TeleVue Nagler type 2s. I've read many positive comments about both versions of the 8.8s, so I'm interested in hearing about subtle differences between the two - if any. The 6.7s I haven't researched much.

I'm not interested in any alternatives brands or focal lengths because I'm good for other focal lengths and I've decided to get the Meade 8.8 and 6.7 UWA, just not which versions.

FYI - All my scopes are eyepiece friendly. One is a Meade 12" SCT, and the other two are f/8, f/7 Apos.

Thanks,

Well, for the time being it looks like the Sun is waking up from its long slumber. I bet its been a year since I've done any imaging. Here's a few I took today after dusting off my H-Alpha equipment and camera.

This one is a large active region. It looks like an area that would involve a couple of spots, but there were no spots seen, so maybe some may develop in this area.

Imaged @ .5a
50mm aperture at about 1200mm focal length.
500 frames captured as an avi, stacked in Registax4 and tweeked in PhotoShop V6
Seeing was quite poor.

Tom,

Not an exact match to your question but it's close. For a while I had a PST and a Lunt LS50/B1200. As to performance, the Lunt filter showed something I've only seen in the 90mm Coronados and in my Coronado rear mounted filter. That's the thin ring of the Chromosphere around the edge of the solar disk. I was shocked that it was visible in the 50mm filter. This told me right away the clarity and contrast was excellent in the Lunt filter. My PST - a fine example by the way - NEVER showed the Chromosphere(ic?) ring.

That said, I still feel the PST is an awesome value. A perfect scope for the beginner, or for quick portable "look-sees."

I've never looked through a LS60HA/B1200 but if it performs anything like my LS50HA/B1200 filter it will greatly outperform the stock PST.

7/7/10

Image composed of aprox 150 stacked frames out of 500 using Registax 5, and processed with PhotoPlus X3.

Haven't imaged the Sun in a while. I had some extra time todays and it was a beautiful clear day. I was treated to a view of a couple awesome Filaments. Thought I'd share an image.

Enjoy!

Here's another of some activity surrounding a large spot.

And a quick shot of some Prominences.

Thomas:

I sometimes use a light blue filter to darken the image especially at lower power. Even a light green filter works. If you have any planetary filters, try them.

This does nothing to the bandpass of the filter, it just dims the image enough that the eye and camera see a little less "noise" or glare. I have the belief that visually the eye has trouble with monochromaic light. The red sensitive cones fatigue and contrast fades. If you move the image slightly in the eyepiece finer details appear. By darkening this image with the filters the cones seem to retain their sensitivity better and contrast APPEARS to improve. CCD cameras are pretty sensitive and they too can be overwhelmed by brightness.

I've also discovered these filters help for digital photography. The two cameras I've tried - a Olympus 2020 and a Minolta Dimage 7hi both produce an image that is too bright even at the fastest shutter speed to show much surface detail. Using the light contrasting filters helps. Although for prominences they are not needed because you need longer exposures to capture them well.

The only way to truely increase contrast is to tighten the bandpass with a second etalon. The way this works is it narrows the bandpass a little, but more so straightens the bandpass curve which controls the off band noise entering the image. The bandpass curve looks like a pointed bell-shaped curve. The bandpass is measured at the half way mark up the curve. Below that point as the curve widens it represents light entering the image that is increasingly off band but dropping in intensity. By adding a second etalon you steepen the curve so less light falls outside the bandpass as noise.

Hope this helps. And I hope I didn't put anyone to sleep with my yammering.

Tom

Hi Tom.

Boy I wish it were that easy. I'd get a pair too, but to have any effect I suspect a corrector has to intercept the light cone before the focal plane or close by. If it doesn't the diverging cone could expand quite a bit in the 5 inches or so inside the binoviewer before hitting the eyepiece. Maybe a long enough, high f/ratio cone might work, but for most scopes I think we'd run out of internal optic diameter first. Hummm....

An alternative "might" be to use the binoviewer itself as the spacer for the corrector. The first element would go in the nose and the second element would consist of a pair in the eyepiece. I'm not sure how this would work because the design would be constrained once again by the clear lightpath of the binoviewer. The other drawback would be each corrector would have to be designed for each binos optical path length. More hummmm....

Ya know, if that would work, one could design the second corrector(s) to somehow remain in the eyepiece holder so the eyepieces could be switched without unthreading two lenses. Geeze, maybe even a self-correcting binoviewer is possible!!!

Uh-oh! Gota go... oh, ummmm does anyone know if the Patent office is open Sundays!!!????

Great question though. I bet if it CAN be done, it WILL be done, but when?

Tom

Steve:

You stinkah. You could take me outside, put a gun to my head, tell me to point to Saturn, and I couldn't!!!! Boo-hoo-hoo. Not sure if my eyes are wet because its still raining outside or its just me crying again because ANOTHER Saturday night is cloudy!

Anyway. Thanks for the mental image. Sounds AWESOME. Seeing Encke is not small feat! I did get my first two-eyed view of the ringed planet through short suckerholes a few nights ago. Sure is P U R D Y.

Be careful now. Don't want the ol' peepers freezing to the eyepieces.

Tom M