Posts Made By: Tom Hole

Pls help me find M57... I'm thinking if I add a Telrad, I might have a better shot at it. Whadya think?

http://home.earthlink.net/~tomhole/finderfront.jpg

http://home.earthlink.net/~tomhole/findertop.jpg



Clear skies,

Tom

What filters are you guys using to bring out the dust storm? I wasn't seeing it unfiltered at 500x, I just wasn't seeing what should have been there. Seems like a low contrast detail similar to what Jupiter exhibits at high power. So, tomorrow morning, I want to try to get a peak at the dust storm at lower power and wanted to try a filter as well.

Clear skies,

Tom

Hello everyone,

Tonight, as the sky was darkening, I decided I wanted to do some star testing with and without the binos. My setup was the 10" 1200mm dob, TV binovues, 2x corrector, 16mm Nagler type 5's. I had the binovue and corrector inserted into a 2.5x powermate for 5x (375x). The cyclops mode was the 16 NT5 in a 5x powermate. Seeing was a 7 , transparency 4 in haze.

The curiousity: the star test with the binos looked better than the star test cyclops. I've always thought there was some correction error on this mirror, but haven't bought Suiter's book to confirm this. But the star test with the binos looked better than cyclops. The diffraction rings and airy disc in focus were much easier to see (not sure why that is) and the diffraction rings inside and outside focus matched up a little better. I didn't get a chance to try a star test with just the 2x barlow as the corrector as a high overcast rolled in. I'm also going to try this with the Denk 2" OCS when it gets back.

My guess is that my XT10, TV binos and 2x corrector just get along very well together. I did a star test with the Denk standards before I shipped them to some friends for evaluation, but I can't remember exactly what I saw. When I get them back, I'll try this with them.

Again, more useless data, but data none the less.

Clear skies,

Tom

A friend of mine let me borrow his 16mm Nagler type 5's to try in my binoviewer. I was using them in the TV binos, 2x corrector, XT10. Seeing was a 4, transparency good. I was working 150x (2x tv corrector) and 375x (2x corrector into the 2x barlow and 2x powermate).

I was a little worried that I could not take in the entire 82 deg AFOV because of my daytime testing, but once I was dark adapted, it was awesome. Eye placement to take in the whole FOV was comfortable (er is listed as 10mm) and the sharpness and contrast were typical Nagler.

First target was the moon. It was still pretty light out and there was a thin overcast, but I was impressed with the fact that I could see the entire moon at 150x.

Next targets were some old friends from this past winter, Andromeda and its buddy M110. Wow. At 150x, Andromeda filled about 3/4 of the .55 deg TFOV. Went over to M110 and it was wonderful as well. I decided to do a quick light loss check. Nothing noticeable on M31, but M110 was noticeably dimmer. Comparison was pretty easy as the TV corrector is 2x so I just put the Nagler in the 2x barlow for comparison. This was alos a more fair comparison than the later ones with an extra set of glass in front of the corrector. I measured the 2x barlow at 2.2x, so I was probably getting a little higher mag on the cyclops mode(165x). But even at a slightly higher mag, the cyclops view was definitely brighter.

Now I needed to find a globular cluster. I usually only look at Mars early in the morning so I had to search around for one. M15 was nearby and visible through the trees. The widefield of the Nagler was more than ample to hold the entire cluster at 375x. I compared to cyclops at the same power and there was a noticeable light loss. Also, the cyclops image was sharper than the bino image. Not by a lot, but it was noticeable. I felt the comfort of binoviewing outweighed the loss of light and sharpness, but if you are trying to eek out every bit of performance on DSO's, the cyclops is better.

Mars was moving up so I could see it from the driveway, so I thought I'd end the morning there. As expected, the views were very good. The dust storm was showing up and it's bigger than it was yesterday. It looked almost as big as the south polar cap. I used the #21 filter on one eyepiece with very good results. I compared it to cyclops at the same power (375x) and found that the image was just a bit sharper in the cyclops view, but I could see more with the binos.

I compared using the 2x barlow and 2.5x powermate in front of the 2x corrector. Both give me 5x magnification (375x with the 16mm Naglers). I preferred the barlow over the powermate. I felt the powermate, in this role, gave a bit softer image on M15 and Mars.



Clear skies,

Tom

With respect to the Naglers, I'm getting a pair. I know that binos make less expensive ep's better. I have been using plossls for the last 3 weeks. They do look good in the binos. But, the Naglers are in another league. I felt the difference between the Nagler view and the plossl view was as dramatic as it is in cyclops mode. That tack sharp, 82 deg AFOV is simply remarkable in the binoviewers. I could not get the entire FOV at once with the Naglers in cyclops. I could with the binoviewers. One big round field of stars. So, I'm gonna stray from the pack a bit and say that the Naglers are worth the $$$ for the added performance. THe same benefits that binoviewers afford plossls are afforded the Naglers, and the Naglers win.

With respect to the brightness and sharpness, I don't think I've discovered anything new. This has been my experience all along with the binoviewers. The image is slightly softer and noticeably dimmer. I thought it might be the extra glass that I was using to get to high powers, but I saw the same thing at 150x with just the 2x corrector on the binos.

I might still find myself in cyclops mode when I am at a dark sight and want everything I can get wrt to light throughput and sharpness on DSOs. But for right now, I can't stand to look at anything with one eye, so I may just end up with a bigger telescope.

The end.

Tom

Got about 45 minutes in this morning before a high overcast layer rolled in (0435-0510 ET).

It looked to me like the dust cloud has epanded west and north. It is almost all the way down to the south polar region. I couldn't tell how far east it was as it's full extent had not rotated into view. Maybe someone on the let coast can catch it.

Tom

I need a mount for a 13 lbs, 127mm, f/8 refractor (Burgess 1278). With accessories (rings, finder, binoviewers) probably looking at 16 lbs and 39 inches.

Some obserivng habits:

1. Visual only
2. I move around a lot in my driveway, street and neighbor's driveways to see the different parts of the sky
3. Tracking is highly desired, but I'd like the ability to go manual for cruising
4. goto/dsc not required, but would like the option to add it
5. I have never owned nor operated anything but a dob

I am leaning towards the CG5 Advanced with single axis drive. Atlas is too heavy. Vixen/Losmandy too expensive. Gibraltar is very nice, but won't track. Apogee HD is in the running, but quality is unknown. I have no idea what to expect, just don't want wobbly.

I was also looking at some surveyor tripods to replace the Apogee HD tripod. Is that a good route?

Pls help a dob guy make it in the world of eq mounts.

Clear skies,

Tom

At Walt's suggestion, I am looking at getting a TAL GEM mount. I have the option of getting it with a nice pier or sturdy tripod. I have no idea which to select. Scope is the Burges 127 f/8 achromat. I will be moving it around quite a bit in the driveway/street when viewing and will occasionally bring it to star parties that are on grass. The pier seems like it would be limited in it's ability to be leveld and the tripod seems like it would get in the way at zenith. Any input is welcome for this dob driver.

Clear skies,

Tom

I need a good tutorial on GEM's. Anybody got a quick link to a good read?

Thanks and clear skies,

Tom (dob driver)

I have my first GEM being made by John Davis and I need a tripod for it. The mount weighs 30 lbs and has a 40 lbs capacity, counterweights 20 lbs and the current scope for it will be a Burgess 127mm f/8 achromat weighing in at 17 lbs. So, we have 67 lbs of stuff.

I found this:

http://www.mytoolstore.com/berger/tripods2.html

The wooden surveyors tripod.

Also checked out Al's astro and Astronomics offerings.

Also looked at Burlebach's from Germany.

I'd like to keep it under $200. The mount is a tank so I'd like a threesome to go under it that can keep up with the mount. I may end up putting my dob on it some day as well (10" XT10, 35 lbs).

So, here's what I'm thinking. Get a shorter tripod (please recommend one) and put a mini pier on it (recommendations welcome). That will give me a short tripod for the dob and a taller one (with the mini pier) for the refractor. Any recommendations for min and max height?

Thanks,

Tom