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Review of Telrad Dew Shield +


Moonshane
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I already have a Telrad 'red dot' finder and really find it the most useful tool for putting my 12" Dobsonian telescope in the right general area of the sky. When used in conjunction with a right angle finder it means I often have the target in the eyepiece first time, even when using moderately high magnification; sometimes I don't even need the right angle finder.

As I already had a Rigel Quikfinder I used this on my 6" dobsonian as space for equipment is a little tighter on the OTA and I like the Rigel too. That said I really prefer the Telrad and when one came up for sale in good condition for £25 on Astrobuyandsell, I jumped at it, especially as it had two features not currently on the Telrad I have.

For those that don't have a Telrad (or Rigel) I can strongly recommend them (and often do) as the one way you can improve your targeting success rates in an evening's observing. They superimpose a target on the night sky and this helps in positioning the scope no end. They are attached to a finder base which attached to the OTA via double sided foam tapes and therefore there's no need to drill the OTA - they are quite light.

The first additional feature of the one I bought is that is a 'flashing target' option. In truth this might not be that useful as the target has a dimmer as standard although in my light polluted skies I sometimes struggle to see the stars I need to navigate to the target area so I'll reserve judgment at this point.

The second feature it had included is the subject of this review - the dew shield +. The + refers to the swinging mirror which is inside the dew shield and allows a right angled view of the target to prevent 'neck craning' in the same way that a right angle finder helps.

I was skeptical about the usefulness of this feature as it provides a mirror imaged view and seemed a little fiddly. Unfortunately these initial views were borne out when I used it.

In principal this does work and for some people it may be useful, eg someone with limited mobility, but for me it removes the intuitive quality of the Telrad and makes it more difficult to find things. Without the mirror it's a few seconds to line up, move to the optical finder and you are there. With the mirror in place it took me a little while to find even Jupiter!

The dew shield element seemed to work well enough and although it does restrict the screen slightly, it's not really a problem. I like the foldable nature of this and will retain it until I trial it on a more dew ridden night than the test night. I'll report back in due course on this.

For £19.99 for the dew shield and a whopping £34.99 for the dew shield+ I cannot really recommend these as accessories (the Telrad is really excellent in terms of the accessories you can get - you can replace almost all of the parts) - you can make your own dew shield out of £2 foam sheets - but for me and as it came with the Telrad at a normal used price, it's a good deal.

The mirror alas, has bee removed.

Cheers

Shane

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I was very interested to see what you thought to this version of the Telrad and it appears we were both correct in our reservations to how well the RA mirror would work. Going over it in my mind I think once you get accustomed (get in to habit of using) to the pulse reticule you may find this helpful depending on if the speed is adjustable between blinks ????

I think either way you had a good deal and it has opened up different options to you. A good review Shane but I look forward to hearing your impressions after using it for a while.

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hi Nick - cheers!

The blinking is adjustable from several times a second to every couple of seconds so this may well work out quite useful.

I'll certainly report back once it's been put through the paces a few more times - if we ever get chance!

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Thanks for the review Shane, it seems that the RA mirror doesn't prove much use in practice and I would be better with just a bog standard dew shield. I might make a DIY one or just end up buying the cheap AE one that keeps popping up of astroboot, that is when it reopens after Christmas.

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I bought the AE one and it looks pretty cool and is a nice fit BUT I don't think it works as well as one you'd make yourself out of foam.

I have one and might ditch it for a foam version. Only cost £3 though so no biggie. May even make a heater with resistors which will solve the problem once and for all.

Edited by Moonshane
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Cool, I'll just use offcuts from the 'scope dew shield that I will EVENTUALLY get round to making just as soon as I find a camping mat that isn't needed any more, I think there is one lying around somewhere in this house that can be cannibalised for this purpose.

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  • 3 weeks later...

not so far, basically because I haven't had chance with the weather and illness.

the mirror is staying out though for sure and the dew shield got in the way on my bigger dob but will be fine on the smaller dob.I may even take the whole thing off and go old school with a home made one (or make a battery operated dew heater).

still a bargain for £25!

Edited by Moonshane
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Was out Thursday night, Temp -4, first time i have used the £3 Dew shield from AstroBoot on the Telrad, conclusion....Honestly....Exellent :).

We were observing for a good 4 hours, and at the end of the session the whole dew shield was covered in frost but the Telrad was performing great....Works for me :evil6:.

Mark.

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I made myself a dew shield for mine, i used a piece of card to form the shape and go around the finder and stuck this on with small velcro pads, i then covered the card with some very thin sticky foam (used for going on pipes, insulation) this is much thinner then a camping mat, i think a camping mat will be to thick and hide the on/off switch within it.

I used it one morning without the dew shield and it dewed up quite bad, used last night in a -1 temp (frost on OTA) with dew shield and not a bit 100% ok, very happy.

For those who wish to see what i done i can put a pic up for you

Edited by bcfcciderhead
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