70 replies to this topic

[Charlotteda]

I see that B&H Photo has the Telrad Reflex Sight - whats the difference between the 2" and 4" base - other than 2" of course 

[vtornado]

With a straight finder, one keeps both eyes open and site down the tube, watch the sky and look through the finder

to get the scope initially aligned.

 

With a raci, to look through the finder you are looking at the tube.

 

A red dot/telrad/rigel quick finder (known as reflex finders) gets the tube pointing into generally the correct area.

The process is use the reflex finder to get into the neighborhood.  Next use the finder to get the object or star

patterns into the finder, then widefield eyepiece in the telescope. 

 

I go back and forth between my finder and my map often to verify I am in the right place.  Without the raci,

I would have to crane my neck to look through the finder.  This is uncomfortable if doing it for a long time

and often. 

 

Reflex finders can be uncomfortable too, but they are used for less time than the finder.

Edited by vtornado, 21 January 2023 - 06:56 PM.

[Bistromath]

I see that B&H Photo has the Telrad Reflex Sight - whats the difference between the 2" and 4" base - other than 2" of course 

The difference between the bases is in how far they hold the Telrad sight away from the telescope tube - 2 inches off the tube vs. 4 inches.  Holding the sight away from the tube can make it easier to look through the sight, easing the need to twist your neck to see properly.

[Mike Q]

Maybe look at getting a dual mount and mount a 9x50 RACI and a green laser pointer. I have this set up on my 10 inch dob and it works wonders.  As for a laser, i use Z Bolt green lasers.  They are rated down to 14 degrees and are very easy to see.  They also offer a pressure switch that you push and the laser turns on, let off and the laser shuts off 

[justfred]

It took a few years but I went from a 90mmMAK to a 6"Dob to a 13"Dob to a 20"Dob, back to a 6"Dob,  to an 11"Dob, back to a 6" Dob, back to an 89mmMAK and finally back to a 6"Dob.... put a Rigel Quickfinder on your XT6, get a comfy chair, a copy of Orion's DeepMap 600, a red light, a thermos full of your favorite beverage, go find some clear and dark sky, and live happily ever after. :-)

 

Fred

[Spile]

Spile,  Just not had time to look closely at your comment.  If the Raci means you don't have to bend down - why do you need the Telrad too?

Simply speed. The Telrad gets me to the right part of the sky. I would spend too long getting the RACI aligned but perhaps I need to try harder.

[Dave Mitsky]

Spile,  Just not had time to look closely at your comment.  If the Raci means you don't have to bend down - why do you need the Telrad too?

It's rather difficult to use a RACI finder scope on its own.  A pointing device puts you in the right area quickly as Spile said.  The optical finder scope will then allow precise star-hopping.

[hcf]

If you get a RACI, you do not have to get a Telrad. The simple Red Dot Finder that you already have will work the same way to get you in the general area, after which you can switch to the RACI. Because you will spend a little time with the RDF with this setup, it might not be too tiresome.

 

One problem with Dobs is, that it has only one finder mount. To have both a RACI and a RDF you need a double/triple finder mount bracket. The Telrad base is attached to the scope using double sided tape, so it does not use up a finder mount. To use a RACI+RDF these days you can use a triple finder mount like this one

 

https://www.ebay.com/itm/165806143648

 

which will not only take a RACI and your existing RDF, but also raise the RDF a little which helps.

[starfinder123123]

Nice scope.

May I recommend an adjustable astronomy chair? You mention the calisthenics my Starbound adjustable chair from Amazon was one of the best investments I made. I can be very comfortable no matter the elevation I am pointing at.

Dang! That’s almost as much as the telescope! My best purchase in astronomy was the telescope. You can use whatever for a chair, no need to get scammed.

[Tony Flanders]

Dobs O Fun said:
 

My Starbound adjustable chair from Amazon was one of the best investments I made.

 
And starfinder123123 responded:
 

Dang! That’s almost as much as the telescope! My best purchase in astronomy was the telescope. You can use whatever for a chair, no need to get scammed.

Let me offer an in-between opinion. I can and do use a regular chair most of the time with my 7-inch f/5.4 Dob. However, that Dob was specifically designed for use with a standard chair, which is not true of a standard 6-inch f/8 or 8-inch f/6 Dob.

Likewise, I stand most of the time when using my 12.5-inch f/5 Dob, and I'm perfectly happy doing so for objects more than about 30 or 40 degrees above the horizon.

I recently (a couple of years ago) bought a StarBound chair, and there are plenty of sessions when I don't bring it outside. But there are also some sessions when I do use it, notably when observing objects close to the horizon. In those cases it makes a vast difference. With the 7-inch f/5,4 Dob the only alternative is kneeling, which gets pretty uncomfortable (and often soggy) after a while. And with the big scope there truly is no reasonable alternative.

 

A standard 6-inch f/8 or 8-inch f/6 Dob puts the eyepiece at a truly awkward height most of the time -- considerably too high to reach when sitting in a normal chair, but too low for a typical standard adult. The net result is that most people end up stooping, which is about the worst possible posture. A StarBound chair is truly ideal for such a scope; it means you can always observe in complete comfort, all the way from the horizon right up to the zenith. Yes it's expensive, but it truly is worth almost as much as the telescope itself.

 

A regular chair would only work for objects between about 30 and 50 degrees above the horizon.

 

And whatever else a StarBound chair may be, it's certainly not a scam! An adjustable-height seat is exceedingly useful.

[Tony Flanders]

The difference between the bases is in how far they hold the Telrad sight away from the telescope tube - 2 inches off the tube vs. 4 inches.  Holding the sight away from the tube can make it easier to look through the sight, easing the need to twist your neck to see properly.

I will admit that I've never used a Telrad riser, but I also cannot imagine finding one very useful.

 

Perhaps I'm more flexible than most people here, but I've never had any trouble using a red-dot or red-circle when the scope points less than 50 or 60 degrees above the horizon -- which seems like the only time a riser would make any difference. When the scope is pointing near the zenith, the riser isn't going to make it any higher. Nor is it going to eliminate the need to get my head low and then crane my neck up. So the riser seems doomed to fail in the one and only situation where I really need it.

[Charlotteda]

Thank you all.  I now have a copy of Turn Left at Orion and a red light.  Will probably order the Rigel Quickfinder - hopefully I can figure out where to put it on the scope.  A nice chair for next year maybe?   I appreciate all of your insight.

[Dave Mitsky]

Dang! That’s almost as much as the telescope! My best purchase in astronomy was the telescope. You can use whatever for a chair, no need to get scammed.

An adjustable observing chair can be very useful.  I don't necessarily need to use one with my 6" Dob but it comes in very handy with my larger telescopes.

 

Unfortunately, the prices of these chairs, like many other items of astronomy gear, jumped after the advent of the pandemic.

[Ionthesky]

Thank you all.  I now have a copy of Turn Left at Orion and a red light.  Will probably order the Rigel Quickfinder - hopefully I can figure out where to put it on the scope.  A nice chair for next year maybe?   I appreciate all of your insight.

I'm late to the party (as usual), but welcome to CN and to the wonderful world of ...the universe. 

 

A couple of additional comments:

Dang! That’s almost as much as the telescope! My best purchase in astronomy was the telescope. You can use whatever for a chair, no need to get scammed.

However, you don't need to spend a lot of money if you're reasonably handy with wood projects.  That LYBAR chair is simple, but limited.  Here's a very nice adjustable chair that you can build with moderate skills and a reasonable cash outlay:

http://www.jerryolti...rving_chair.htm

 

As far as drilling holes into the tube goes, its really not a big deal (although I approached it with much trepidation when I first added a Synta shoe (that's what those finder mounts are called, btw) to my old 6" dob.  I currently use a generic RDF and a SvBONY 6x30 RACI on mine, and am very happy with the small RACI.  I do prefer the Rigel QuickFinder to the generic RDF.  I have one on my 5" collapsible dob, and plan to dual-mount it to my 6" and dispense with the cheap RDF.

 

I hope this helps!

 

Regards,

Dave

[Ionthesky]

I just looked at the XT6 on Orion's site and I noticed that you already have a Synta shoe.  The RDF is mounted on it.  So I guess you're all set.  I would remove the RDF, mount the 

RACI finder in the shoe, and mount the QuickFinder with the adhesive mount.  (The QuickFinder doesn't weigh much more than the RDF.)

 

If you do drill the OTA, make sure that you aim the tube horizontal.  That way no chips or filings will fall onto the mirror.  You might also want to attach a few strips of masking tape on the inside of the tube, behind where you intend to drill.

 

Regards,

Dave

Edited by Ionthesky, 26 January 2023 - 04:57 PM.

[Spile]

My £20/$26 height adjustable stool is also very light https://astro.catshi...m/denver-chair/

[jrussell]

I'll second the LYBAR as a good place to start as far as a seat since you can make it with basic tools. I built one last week for my newly acquired XT8 and used it last weekend. There were only a couple of times I had to stretch a little extra to get to the eyepiece but otherwise it made viewing much more fun. I do recommend some kind of cushion though. I've heard several recommend those kneeling pads used for gardening. I plan on building one of the Jerry Oltion chairs that Dave recommended, but until then the LYBAR is very handy to have.

[Charlotteda]

I shared the "Jerry Oltion chairs that Dave recommended" with my husband and it thought it was really cool.  He could definitely build one in his little wood shop.

Sorry for the confusion - why would I use both?  RACI finder in the shoe, and mount the QuickFinder with the adhesive mount

[rgk901]

I shared the "Jerry Oltion chairs that Dave recommended" with my husband and it thought it was really cool.  He could definitely build one in his little wood shop.

Sorry for the confusion - why would I use both?  RACI finder in the shoe, and mount the QuickFinder with the adhesive mount

the raci finder is a mini telescope for wide views, but it can't really be pointed at anything just like your big scope. The red dot/tel-rad/quickfinder/green laser basically point both your raci and main scope to desired location...all 3 will be aligned together, but raci gives much wider view to help find things

Edited by rgk901, 27 January 2023 - 02:12 PM.

[Ionthesky]

Sorry for the confusion - why would I use both?  RACI finder in the shoe, and mount the QuickFinder with the adhesive mount

As RGK said, the unity (no magnification) finder gets the scope into the general vicinity, then a magnifying finder (like a 6x30 or 8x50) helps with star hopping to your target.  When you use a magnified finder, you're going to see more stars than with the unity finder, which is basically naked-eye viewing.  They really are complementary functions.  The great thing about the QuickFinder is that it comes with two interchangeable bases, so it can be snapped off of one base and moved to another scope.  The two bases have different radii on the bottom, to accommodate different size OTAs.

 

Regards,

Dave

[Astrodomus]

Charlotteda,

I am fairly new as well as astronomy.  so let me share my lessons I learned along (the harder) way.  completely went through the up and down exercises.  I found the Telrad to be the easier finder scope as it gets you in the area, with practice, you start getting a little closer.  I also got a 4" riser, but found I am only using this for about 5-10 seconds to get me in the general area, so mostly don't use the riser anymore (but it did help with the neck stretch).

 

On mistake I made in attaching the Telrad was the positioning on the scope.  The Telrad base uses double sided stick tape so once it is placed, you cannot move without replacing the double stick tape and getting the glue residue off - and it takes dental floss to break the tape from the Telrad and the telescope - another lesson learned).

 

So before permanently mounting and finder such as a Telrad, suggest to use large zip ties (20-24" long) to hold it down the Telrad temporarily to make sure it is in the best position for you, then once you find what works, cutoff the zip ties and mount to the XT6.  I still use both a RACI in the fixed shoe and Telrad (yes being redundant all over again), but was learning how to use both finders.  

 

Also you have to adjust the Telrad and the RACI to be centered on the scope field of view.  This is easier in the daytime to find an object far away in your scope (through the eyepiece, and then use the two adjust  knobs to reposition the bullseye to match the object in the eyepiece).

 

I found a camp chair good at giving me a comfortable seat (and then I got the adjustable viewing chair), both work fine.

 

Adding eyepieces is where the dollars rack up and this does not have to be a fast race.  I just add a couple or Orion and Celestron plossl of varying power - these are good basic eyepieces to start.  Let your needs and experience guide you to further purchases.  (I am now expanding into 2" eyepieces).

 

I just sold my xt6  Loved how portable is was.  Carry it outside, let it cool for 15-30 minutes.  Ready for viewing.  Speaking of setup, if you setup in grass, suggest to put a tarp down, the bases on the Skyquest are pressed wood, meaning they will absorb moisture.

 

I now have an xt8 and xt10i.  I have one Telrad but a base on each scope - I can move the finder to what ever scope I am using.

 

enjoy your Dob.  It is an easy and fun scope to use.  You made a good choice.