Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

Recommended Posts

I use a Telrad spotter on my Orion 6 inch Newtonian reflector telescope. I am considering adding a Sky Watcher ED100 APO 4 inch refractor to my viewing tools and am wondering how well a Tetrad unit would function on this telescope.  Does anyone have experience using a Telrad with a SW ED100 or with another 4 inch telescope?  

Share this post


Link to post
Share on other sites

In my opinion, a Telrad works because it works; it doesn't depend on the scope. Is there any particular reason why you think it might not work?

I use a Telrad with my SW ED120. It works the business. :happy11:

I attach it in a specific way so as to always be able to remove it easily. This is wholly unnecessary, you can attach it any way you like, it will be great.

tmp_10521-DSC_01622111060705.JPG

Block of wood, painted black (thank you, Jagger), serves as base; Telrad riser is screwed onto base. Dovetail clamp screwed to side of block of wood. Dovetail clamp clamps (as it would) to bit of dovetail forward of clamp which holds scope on mount. Recently, I have used an extra tube ring to attach a dedicated short dovetail bar for this purpose.

tmp_24614-DSC_02251658084334.JPG

Alternatively, you could go for a Rigel, which works by the exact same principle as a Telrad, but has a much smaller form factor and fits more easily on smaller scopes:

tmp_27450-DSC_01811492304360.JPG

Here you see my Rigel - with anti-dew band - attached to the TV85 using the same block-of-wood construction. You can also just bolt the base on somewhere convenient:

tmp_6773-DSC_0198-756779906.JPG

DSC_0193.JPG

:happy11:

So if you're worried about a Telrad fitting on the tube, I would advise you to go for a Rigel. Both great finders.

Edited by iPeace

Share this post


Link to post
Share on other sites

Also the Rigel is much lighter than a Telrad, it won't upset balancing your scope to much,

you don't need the extra battery pack because the coin batteries last a very long time, that

is if you remember to switch it off when you are not using it. 

Share this post


Link to post
Share on other sites

The Rigel has quite a small footprint compared to the Telrad and it also comes with a spare base which is handy.

Share this post


Link to post
Share on other sites

I use the Rigel Quickfinder on my 12" dob but it would do well on a much smaller scope too. The Telrad is great of course but it can look a little ungainly on a small diameter tube. The Rigel is a little more resistant to dewing than the standard (unmodified) Telrad as well.

You get 2 bases with the Rigel unit, radiussed for larger and smaller tubes.

  • Like 1

Share this post


Link to post
Share on other sites

I use a Telrad on my 100ED and it's fine. You won't need another Tetrad,  just the base.

I agree that the Tetrad is prone to dew but it is easily wiped. And the batteries do last for ever even if, like me, you always forget to switch it off! I've not tried a Rigel but I did have another red dot finder some time ago and I was always buying batteries for it. The fact that the Tetrad does not use the button type is a big advantage I think. 

  • Like 1

Share this post


Link to post
Share on other sites
2 minutes ago, kerrylewis said:

I use a Telrad on my 100ED and it's fine. You won't need another Tetrad,  just the base.

I agree that the Tetrad is prone to dew but it is easily wiped. And the batteries do last for ever even if, like me, you always forget to switch it off! I've not tried a Rigel but I did have another red dot finder some time ago and I was always buying batteries for it. The fact that the Tetrad does not use the button type is a big advantage I think. 

It is indeed nice that the Telrad takes standard penlight batteries. And I like its extra red circle over the Rigel's two, but this is hardly a deal-breaker. There are dew heaters available for both the Telrad and the Rigel, if, like me, you must have one. My Rigel has taken just as long to drain its coin-sized battery (still using the first one), so that's good. The coin-sized batteries are traditionally not as easy to find as the standard penlights, but recently I seem to be spotting large blister-packs of them everywhere - perhaps becoming more ubiquitous?

:happy11:

Share this post


Link to post
Share on other sites

The batteries for the Rigel are the CR2032's. Available widely I've found and quite inexpensive but they last for ages anyway. My Telrad took a PP3 battery (2 terminals at the top end) rather than penlight batteries.

 

Share this post


Link to post
Share on other sites

?Telrad on a beautiful ED refractor? ?

It could turn your elegant ED into an EEK! D.???

I think telrads are great finders, but they are as ugly as sin and designed to make Dobs look good! :icon_jokercolor:

  • Like 2

Share this post


Link to post
Share on other sites
12 minutes ago, mikeDnight said:

?Telrad on a beautiful ED refractor? ?

It could turn your elegant ED into an EEK! D.???

I think telrads are great finders, but they are as ugly as sin and designed to make Dobs look good! :icon_jokercolor:

My 100ED is an 'old gold' one that I've had for years and is rather careworn (like me) so the Telrad enhances it! Anyway it's dark and there's only me to see it! But if I had a Tak like you......

Edited by kerrylewis
  • Like 2

Share this post


Link to post
Share on other sites

Taks don't need finders ....... you just whisper gently to them what you would like to observe and they find their own way there :icon_biggrin:

  • Like 2

Share this post


Link to post
Share on other sites

It really depends how you use the rdf. Unless it's a very familiar object I just use mine for initial placement near a bright naked eye star and then star hop with the raci

On this basis I find a telrad works on my big dobs and a baader skysurfer 3 on my fracs.

I am with Mike on fracs and telrads.

  • Like 1

Share this post


Link to post
Share on other sites

I have a Telrad with AAs that corroded in it.  I haven't been able to get it working again even with a new battery holder soldered in.  That happened in well under 10 years.  My Rigel QF still has the same button cell going strong after 12 years and no corrosion evident.

Share this post


Link to post
Share on other sites

I don't think that it's fair to blame a product because it was ruined by failed batteries.

Share this post


Link to post
Share on other sites

So far, it would seem that the Telrad would function just fine, but your setup might get some disapproving looks.

:grin:

  • Like 3

Share this post


Link to post
Share on other sites
1 hour ago, John said:

Taks don't need finders ....... you just whisper gently to them what you would like to observe and they find their own way there :icon_biggrin:

Nice John! Now I want one even more. What use is a pension pot? :happy11:

  • Like 1

Share this post


Link to post
Share on other sites

For me, the great thing about sharing dumb ideas with you is that it helps me reflect on them and improve.

So say you have a frac and a Telrad and you don't mind your frac looking a bit daft because it has to earn its keep and you'd like to attach the Telrad only not permanently and you suspect that repeatedly using the metal screws in the plastic base of the Telrad will eventually ruin it. In addition, you don't like the idea of a wooden block because that's just naff.

Got that picture? Good.

Forget about the base of the Telrad. Just use the riser. Attach a small dovetail to the bottom (which is conveniently flat) with some double sided sticky tape.

tmp_27696-DSC_0402-158310025.JPG

Then attach a dovetail clamp to the scope with a tube ring.

tmp_27696-DSC_04031424472460.JPG

Now you can just clamp the Telrad on when you need it, and it will be up where you don't have to crouch in whatever is down by the feet of your tripod in order to actually use it.

Still ugly, but less so without a wooden block and lighter, too. You can always take it off for publicity photos.

That last sentence sounds horribly wrong. Yes, that's my coat, thank you.

:rolleyes2:

Share this post


Link to post
Share on other sites
4 hours ago, iPeace said:

elrad riser is screwed onto base. Dovetail clamp screwed to side of block of wood. Dovetail clamp clamps (as it would) to bit of dovetail forward of clamp which holds scope on mount.

"Screwed on to a block of wood"...

said the man who claims he doesn't know one end of a screwdriver from another !!!

or did you commission someone to turn said screwdriver ??

?

  • Like 1

Share this post


Link to post
Share on other sites
Just now, Racey said:

"Screwed on to a block of wood"...

said the man who claims he doesn't know one end of a screwdriver from another !!!

or did you commission someone to turn said screwdriver ??

?

I don't remember explicitly making that literal claim, but I understand why you got that impression.

:happy11:

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, kerrylewis said:

My 100ED is an 'old gold' one that I've had for years and is rather careworn (like me) so the Telrad enhances it! Anyway it's dark and there's only me to see it! But if I had a Tak like you......

Youd need two telrads to make a Tak look good! Actually, my Tak isn't much bigger than a telrad!

Actually I don't dislike telrads. I even had one on my 6" achromat about 17years ago and thought it was wonderful.  

  • Like 1

Share this post


Link to post
Share on other sites

If you use a Skytee or similar you don't even have to fit the Telrad on the scope,  just fit it to the other end of the T axis. 

  • Like 3

Share this post


Link to post
Share on other sites
7 hours ago, Moonshane said:

I don't think that it's fair to blame a product because it was ruined by failed batteries.

It is if it uses a power source susceptible to corrosion and there's insufficient shielding between the power source and the electronics to prevent damage due to caustic gasses from the power source.  They could have chosen button cells like Rigel, but they didn't.

Share this post


Link to post
Share on other sites

Everything Is a compromise somewhere.  Button battery life in a Rigel is about 250 hours. With aas (rigel do sell an option which to Install you have to chip away some of the casing) it's about 2700 hours. I must admit I have never heard of another issue like yours with a Telrad which in my view has a generally better build quality and fixing system. Each to their own :happy11:

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Ardrid
      Hi everyone,
      I was lucky enough to get a 12" Skywatcher Dobsonian (305mm/1500mm) for Christmas. It shipped with a 10mm Plossl and a 25mm Plossl, both 52° AFOV. Finally had a clear enough night to try it out and I absolutely loved it. I researched a bunch over the last year so I knew this was the scope I wanted should someone want to get me a really sweet gift before I grabbed it myself. What I didn't research at the time was accessories and equipment, something I've been doing relentlessly over the past few days.
      I'll primarily be viewing in the backyard until I find a great viewing spot (and a good way to safely transport). Light pollution isn't terrible but I haven't fully gauged its impact on seeing fainter objects. I'm not interested in imagery/photography at the moment. Not foreclosing on the idea by any means but everything I'm looking to add is purely for visual gratification at this point. Hoping the experts out there can lead me in the right direction. Here's what I'm trying to figure out:
       
      1. What eyepieces should I pick up?
      I've read that, generally speaking, you want 2-3 premium pieces in over to cover low, medium, and high magnification. I'm currently looking at the following "sets": 5mm Nagler, 13mm Ethos, 35mm Panoptic or 6mm Ethos, 13mm Ethos, 21mm Ethos. I'm not overly concerned about price. I recognize that there's going to be a premium associated with a brand like TeleVue and with squeezing out that last drop of performance; however, I don't want to throw away money unnecessarily if I'm not going to see a benefit from pulling out the stops. I'm not beholden to TV by any stretch but everyone says they're the gold standard so I figured I'd look there first. I'm not looking to grab everything at once either. Was thinking of starting with the 13mm Ethos since it would fill the mid-range gap between my 10mm and 25mm. 
      2. Should I grab a Paracorr?
      I've read many comments that go back and forth on this but the consensus seems to be that, while it's not crucial at f/4.9 like it would be with a faster scope, it's something I should probably have in the arsenal if I'm using wide field eyepieces, which the ones I'm contemplating are. I couldn't detect any coma with the two eyepieces I currently have but I suspect I probably wouldn't given the FOV and my beginner status. I also think that once I see it I'm not going to be able to unsee it. 
      3. Should I pick up a Barlow?
      This question assumes I'm not getting a Paracorr. I like the idea of essentially doubling the number of eyepieces I have but I'm not too sure of the ultimate utility/necessity of it.
      4. Any other crucial accessories I should have?
      I'm looking at a Cheshire collimator for when the time comes. Aside from that, is there anything else I should absolutely have?
      5. Finally, any suggestions on transporting?
      It goes without saying but this baby is heavy. I don't have a garage, and I'm hesitant to store it in the shed, so what I've been doing is removing the OTA from the base and transporting them separately to the backyard for setup. It's not bad but I can see it getting old after awhile, especially with numerous viewing sessions in a row. After all, I didn't get this scope so it could collect dust; I want to use it as often as the weather lets me. I do plan on replacing the feet with wheels so I can at least roll it, but I'm trying to figure out a good solution to getting it in and out of the house (down 3 small steps) to the backyard without damaging it or breaking my back. 
      I think that's all I have for now. I appreciate any help you all can provide. I'm just trying to learn as much as I can so I can have a great experience and eventually show my little guy all about the joys of astronomy. Thanks everyone!
    • By 25585
      Like many I think Telrads are great scope sites. And want to use mine with different scopes. But I don't want to stick a base to a nice looking OTA.
      All base types seem to be curved so sticking to a flat surface such as an accessory plate is not possible.
      The only option seems to be using two holes in its base, if they line up with those on a plate. Are there any ideas out there, or aftermarket Telrad bases apart from the company ones?
    • By michaelmorris
      I've recently installed a Telrad on my C9.25 scope and immediately run into a problem - dew.
      What products have you found work best at keeping dew off the glass plate?
    • By michaelmorris
      I'm after a Telrad with base.  Must be in good nick.
       
    • By tingting44
      Hi there, selling off the last few bits i have come across of my astro gear.....
       
      here is the RRP and details
      https://www.telescopehouse.com/telrad-red-dot-finder.html?gclid=CjwKCAjwk4vMBRAgEiwA4ftLs3Z_WfmZQRR0rdroNMFPhytFfEyOCgsNel7QfWLAw-m9vsKYK5QLzRoCj7EQAvD_BwE
       
      i would like £25 posted please via bank transfer, or you pay for the paypal fees
       
      thanks for looking
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.