
televue powermate 5x
- albertw
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televue powermate 5x was created by albertw
Anyone have one of these? Basically its a 5x barlow, it seems to have a fairly good reputation.
I'm thinking of getting one as my scope isnt very good a magnifying things, in particular with a webcam (focal lenth is just over 1 meter). I have a Meade 2x barlow, and have used the meade 3x short barlow. Trying to get a decent sized Mars on the webcam ccd is the motivation behind this!
It works out at about 200EUR from the states/canada.
Any thoughts?
Cheers,
~Al (who really should start saving money and stop buying gizmos!)
Chairperson, International Dark Sky Association - Irish Section
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- michaeloconnell
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Replied by michaeloconnell on topic Re: televue powermate 5x
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- albertw
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Replied by albertw on topic Re: televue powermate 5x
I can see roughly www.cademuir.net/astro/images/moon.jpg that much of the moon in the webcam, I'll have to work out exactly how many arcsecs that would be with a 5x tonight.
I've tried stacking the 2x barlow with a 3x meade `shorty` barlow, I wasnt that impressed with the resultant image. Not sure of the corect optical term, but there was noticable red fringes on the top of the pbjects and blue on the bottom. This was possibly due to things being slightly out of alignment as the weight of the barlows and the wecam could have pulled them out of line, or possibly there was just too much glass.
Once I can keep the image reasonably steady (i.e. stay in the frame!) then I'll be happy enough, the software can sort it out! The scope is a lot more steady now that I've removed the teflon washers from the mount.
I've never tied to attach the webcam to an eyepiece, all just prime focus stuff so far. I'll give i a go some night when the boss gets back and I can borrow his laptop!
Definatly more for me to think about anyway.
Thanks,
~Al
Chairperson, International Dark Sky Association - Irish Section
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- michaeloconnell
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Replied by michaeloconnell on topic Re: televue powermate 5x
Michael
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- dave_lillis
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- Super Giant
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Replied by dave_lillis on topic Re: televue powermate 5x
I managed to get my hands on a Toucam pro (Michaels recommendation) and I discovered one very nifty thing about it.
If you leave the lens on the camera and use an eyepiece (say 26 mm), you effectively have a varialbe zoom lens camera. By unscrewing the webcam lens as far as possible (without it coming off), you get a fairly wide field of view, nearly half the field of view of the eyepiece, if you screw the lens in as far as possible, you get a very narrow field of view (around three times zoom as far as I remember). I used elastic bands to attach the camera to the eyepiece, not the best but its fairly stable.
BTW, You focus the camera by twisting the Lens, so the lens can pop out, great I though so now I can do high mag imaging through the scope also.
Hope this is helpfull.
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.

+ 12"LX200, MK67, Meade2045, 4"refractor
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- dave_lillis
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- Super Giant
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Replied by dave_lillis on topic Re: televue powermate 5x
Is the colour full red on one side of the focus and blue on the other ??
If soo this is probabily the cause, otherwise you might have some type of chromatic abberation or lens defect.
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.

+ 12"LX200, MK67, Meade2045, 4"refractor
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- albertw
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Replied by albertw on topic Re: televue powermate 5x
If you seeing red on the one half of an image and blue on the other half, the camera is probabily not square to the mirror/lens of your scope.
Is the colour full red on one side of the focus and blue on the other ??
If soo this is probabily the cause, otherwise you might have some type of chromatic abberation or lens defect.
Have a look at www.cademuir.net/astro/images/saturn.jpg see the way the top is blue and the bottom is orange? Its a stacked webcam image, though a single frame shows the prooblem also www.cademuir.net/astro/images/saturn-single.jpg
It keeps the same orientation when I rotate the webcam which would suggest something with the scopes optics, though I cant detect this visually.
Cheers,
~Al
Chairperson, International Dark Sky Association - Irish Section
www.darksky.ie/
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- michaeloconnell
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Replied by michaeloconnell on topic Saturn - chromatic abberation
Was it taken using an eyepiece or just the barlow?
Michael
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- albertw
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Replied by albertw on topic Re: Saturn - chromatic abberation
Was it taken with the camera lens in or out?
This was with the lens out. The lens of the toucam unscrews exposing the ccd. I have an adaptor that screws into the camera and lets me slot it into the focuser.
Just the barlow, I'm not using any eyepieces in this method.Was it taken using an eyepiece or just the barlow?
Cheers,
~Al
Chairperson, International Dark Sky Association - Irish Section
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- michaeloconnell
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Replied by michaeloconnell on topic Re: televue powermate 5x
If you had told me you tookthe image any other way, I'd have said it was due to all the glass. However, you have minimised it as much as possible. I can't see how the problem would be with the barlow. We all know the reputation TeleVue have. And it's an LXD55 you have, if memory serves me correctly, which is reputed to have good quality optics. The Mogg adaptor also ensures that the CCD chip is perpendicular to the light path.
Did you try stacking the image with Registax 2. I don't know much about it but I think the new version can help correct for chromatic aberration. Might be worth looking into.
I also think I remember reading somewhere that some people remove the little piece of glass that is on the CCD chip itself. Don't know how accurate this is or if I have my story mixed up. Look it up though - may be useful.
If worst comes to worst, at least you'll have very good quality B/W images. Don't know how much consolation this is to you though.
Anyway, food for thought - hope this is useful. Keep us informed. I'd be interested if you can progress any of these issues.
Michael
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- albertw
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Replied by albertw on topic Re: televue powermate 5x
One point, Im using a Meade APO 2x barlow not a televue (yet! cause they are out of stock, and changing the powermate 5x to have a tring adaptor on the end, hence the shipping delays)
There are a couple of experiments I can try next time its clear:
1. Rotate the webcan in the focuser to be sure its not part of the webcam.
2. Rotate the optical tube of the scope and see if it keeps the same orientation.
This should rule out or pinpoint any scope problems. One suggestion I got on the lxd55 list was that it could be atmospheric diffraction (refraction?).
I've got registax 2 though I cant see where it is doing colour alignment, does it split the avi file into 3 (red green blue) align, stack, then merege them? There are some LRGB controls but not the functionality im looking for I dont think. is there another tool that I can use to split the avi into colour streams first?
Cheers,
~Al
Chairperson, International Dark Sky Association - Irish Section
www.darksky.ie/
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- michaeloconnell
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Replied by michaeloconnell on topic Re: televue powermate 5x
aberrator.astronomy.net/registax/html/rgb_shift.html
Hope this is of help.
Michael
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- albertw
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Replied by albertw on topic Re: televue powermate 5x
Have a look at this link
aberrator.astronomy.net/registax/html/rgb_shift.html /quote]
So thats what that box doesThanks for the link I'll try that tonight.
Ive checked up on the CCD, and some folks do remove it but only as it blocks some wavelengths. It seems more for the perfectionists! I think I'll leave it there to protect the CCD chip for the moment.
Thanks,
~Al
Chairperson, International Dark Sky Association - Irish Section
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- michaeloconnell
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Replied by michaeloconnell on topic IR Filter
Michael
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- dave_lillis
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Replied by dave_lillis on topic Re: televue powermate 5x
I tried it out on my scope (12"SCT) and the chromatic abberation (colours) was severe, bad colours around stars, like coloured wearing 3D glasses. The reason for this is the the shorty barlow is designed for F14+ systems and when I put it in on my F10, its been pushed beyond its design spec.
I see that the LXD55 is a pretty fast scope so maybe the 2X apochromatic cant handle the fast scope given that most of Meades gear is F10+ (except for the LXD55s of course) and this barlow predates the LXD55 by years
ANOTHER POSSIBILITY, is atmospheric defraction. If the object is near the horizon (within 30degrees) you do get red/blue edges on objects. This is very noticable on bright objects like Venus and gave me a heart attack when I first saw it. See if the orientration changes through out the night.
Sorry for the long mail, hope its useful.
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.

+ 12"LX200, MK67, Meade2045, 4"refractor
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- dave_lillis
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Replied by dave_lillis on topic Re: televue powermate 5x
A spec of dust on the CCD will block image area, the damage you could cause cleaning it is irreversible, you're basically touching the surface of an integrated circuit !!! static electricity .. etc....
and atmospheric moisture will corrode it in a matter of months (depends on how good the surface coating on the chip is)!!!
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.

+ 12"LX200, MK67, Meade2045, 4"refractor
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