Altair Astro 10x60 finderscope

[bambuko]

For what it is worth (bearing in mind my newb status) - my experiences in using one.

I was quite clear that I wanted decent RACI finderscope for my 6" reflector and I was quite impressed with it when it arrived - beautiful piece of kit!

My problem was with focusing of the supplied 23mm eyepiece. It has a ring for focusing of the reticule and I have found that when reticule was sharp I was running out of focus range in the main helical focuser.

It was OK when I tried it in daylight on distant objects, but at night when trying to focus at infinity the focuser was "bottoming out" and running out of adjustment.

Altair Astro very quickly provided another eypiece to compare (thank you for great customer service!!), but I have found that there was no real difference between the two eyepieces.

I could use/easily focus supplied 23mm illuminated eyepieces providing reticule was out of focus.

I could easily use other 1.25" eyepieces with no problems in focusing.

It seems to me that the scope tube would benefit from being shorter by a couple of mm.

It maybe that it is as it is because of all the other options available for this scope (for use as a guide scope etc).

Other thing that I have discovered was that for visual use (and that is what I do) 23mm eypiece giving x10 magnification was possibly not the best one. OK it is aimed at "...astro-imagers who want to centre an object more precisely in the camera field-of-view, yet the field of view is still very large...", but I found it was far better for my type of use with 32mm eyepiece (unfortunately not illuminated, but this may be another DIY project).

I would love to hear opinions of other users, please.

[Ewan]

For what it is worth (bearing in mind my newb status) - my experiences in using one.

I was quite clear that I wanted decent RACI finderscope for my 6" reflector and I was quite impressed with it when it arrived - beautiful piece of kit!

My problem was with focusing of the supplied 23mm eyepiece. It has a ring for focusing of the reticule and I have found that when reticule was sharp I was running out of focus range in the main helical focuser.

It was OK when I tried it in daylight on distant objects, but at night when trying to focus at infinity the focuser was "bottoming out" and running out of adjustment.

Altair Astro very quickly provided another eypiece to compare (thank you for great customer service!!), but I have found that there was no real difference between the two eyepieces.

I could use/easily focus supplied 23mm illuminated eyepieces providing reticule was out of focus.

I could easily use other 1.25" eyepieces with no problems in focusing.

It seems to me that the scope tube would benefit from being shorter by a couple of mm.

It maybe that it is as it is because of all the other options available for this scope (for use as a guide scope etc).

Other thing that I have discovered was that for visual use (and that is what I do) 23mm eypiece giving x10 magnification was possibly not the best one. OK it is aimed at "...astro-imagers who want to centre an object more precisely in the camera field-of-view, yet the field of view is still very large...", but I found it was far better for my type of use with 32mm eyepiece (unfortunately not illuminated, but this may be another DIY project).

I would love to hear opinions of other users, please.

Sorry to hear your problems with this finder, i to have the same one which i bought for use as a finder but i now use it for guiding.

The finder comes with a fitted diagonal as well dosen't it, bit odd this then as mine is fine, ihave used the recticle in the finder , in the SCT & i now use it on the Triplet for setting up PA, it has a lot of in/out focus & have not had any issues with it.

Thought i would reply & i'm guessing nothing i said will help but keep the thread alive & i am sure more help will follow.

[crashtestdummy]

You could try and see if all the pieces are screwed together as that can throw of focus if one part is unscrewed a turn or two.

[bambuko]

Thank you guys,

It helps, even to know that somebody else didn't have problems

Yes, I had good look at the eyepieces and I have two identical ones from Altair Astro to compare - it would be rather unlucky for both of them to be wrong...

That's the annoying bit about internet buying - it's fine when it works OK, but PITA when things don't quite work.

[lensman57]

For what it is worth (bearing in mind my newb status) - my experiences in using one.

I was quite clear that I wanted decent RACI finderscope for my 6" reflector and I was quite impressed with it when it arrived - beautiful piece of kit!

My problem was with focusing of the supplied 23mm eyepiece. It has a ring for focusing of the reticule and I have found that when reticule was sharp I was running out of focus range in the main helical focuser.

It was OK when I tried it in daylight on distant objects, but at night when trying to focus at infinity the focuser was "bottoming out" and running out of adjustment.

Altair Astro very quickly provided another eypiece to compare (thank you for great customer service!!), but I have found that there was no real difference between the two eyepieces.

I could use/easily focus supplied 23mm illuminated eyepieces providing reticule was out of focus.

I could easily use other 1.25" eyepieces with no problems in focusing.

It seems to me that the scope tube would benefit from being shorter by a couple of mm.

It maybe that it is as it is because of all the other options available for this scope (for use as a guide scope etc).

Other thing that I have discovered was that for visual use (and that is what I do) 23mm eypiece giving x10 magnification was possibly not the best one. OK it is aimed at "...astro-imagers who want to centre an object more precisely in the camera field-of-view, yet the field of view is still very large...", but I found it was far better for my type of use with 32mm eyepiece (unfortunately not illuminated, but this may be another DIY project).

I would love to hear opinions of other users, please.

Hi,

Sorry to hear you have such problems. I  bought a used one from a member of the forum  ( it is in mint condition )  a couple of weeks ago and I don't have your issues, but I found that once the illuminator was attached to the EP the resistance of the focuser on the supplied diagonal was not enough to keep the EP from rotating the focuser and it constantly goes out of focus. I may take the focuser out and apply much thicker grease to the barrel to resolve this annoying problem.  The other problem is that my finder guider came with a helical focuser for attaching a guide camera, the helical focuser is not a None Rotating type therefore as he focuser turns so does the guide camera and therefore the FOV, not a big problem but is shows that some corners have been cut to keep the cost down.

Regards,

A.G

[Ewan]

Hi,

Sorry to hear you have such problems. I  bought a used one from a member of the forum  ( it is in mint condition )  a couple of weeks ago and I don't have your issues, but I found that once the illuminator was attached to the EP the resistance of the focuser on the supplied diagonal was not enough to keep the EP from rotating the focuser and it constantly goes out of focus. I may take the focuser out and apply much thicker grease to the barrel to resolve this annoying problem.  The other problem is that my finder guider came with a helical focuser for attaching a guide camera, the helical focuser is not a None Rotating type therefore as he focuser turns so does the guide camera and therefore the FOV, not a big problem but is shows that some corners have been cut to keep the cost down.

Regards,

A.G

Lensman do you mean whenyou bout the AA finder it came with a helical 'attachment' for using as a guidescope ?

I bought the AA attachment on their website specific for this finder, an extender tube with s threaded locking ring as far as i can see & it stays rock solid. Focus as a finder was bang on, you can still use it without the diagonal if your ep is inserted a little less.

[bambuko]

Hi,

... I found that once the illuminator was attached to the EP the resistance of the focuser on the supplied diagonal was not enough to keep the EP from rotating the focuser and it constantly goes out of focus. I may take the focuser out and apply much thicker grease to the barrel to resolve this annoying problem.  The other problem is that my finder guider came with a helical focuser for attaching a guide camera, the helical focuser is not a None Rotating type ....

A.G

I had exactly the same experience with mine - in  some position gravity causes eyepiece to rotate in such a way that illuminator hangs down. PITA with eyepiece going out of focus while you using it - the only thing to do is to loosen screw securing eyepiece in focuser and rotate eyepiece and re-focus it again.

I don't know if there is a way to adjust tension in helical focuser?

Focuser is definitely rotating type. It doesn't bother me but I guess might be an issue for someone using it as a guider?

[Sleepy Kiki]

I have the same AA finder / guider package. Apart from the lack of instructions to swap out the prism section for the helical focuser I didn't have any problems with it as a finder and illuminated eyepiece. It now serves me well as a guide scope though and once its focused it remains locked in place

[bambuko]

I have the same AA finder / guider package. Apart from the lack of instructions to swap out the prism section for the helical focuser I didn't have any problems with it as a finder and illuminated eyepiece. It now serves me well as a guide scope though and once its focused it remains locked in place

Thanks for that Sleepy Kiki,

I guess if you are talking about swapping prism section for a helical focuser than it probably is not exactly the same setup (although the base parts I assume are the same).

Just for clarity this is what I am using:

BTW - is your helical focuser the same as the one used on top 90 deg piece? and is non-rotating or rotating?

[bambuko]

I never got any reply from Altair Astro to my further emails asking for help (I guess they must have been busy with pre-Christmas rush and assumed that they solved the problem by sending me another eyepiece to try?)

I also got distracted by trying to use another eyepiece - which actually worked very well (eventually )

So my illuminated eyepieces were gathering dust unused and unloved because of difficulties I had... until today when I had a brainwave

Actual reticule is not two pieces of wire, but two scratches on a piece of plastic.

The scratches are on one side of the plastic, so depending on which way it is fitted, reticule can be closer or further away from eyepiece (by the thickness of this piece of plastic).

I quickly took the eyepiece apart and re-arranged one, and here is the result:

Both eyepieces shown had the reticule focused and you can easily see the difference (between x1 and x2).

This should give me  more than enough room to allow me to focus the eyepiece to infinity in the finderscope, which I couldn't do previously (with reticule correctly focused).

I guess a lot of people wouldn't notice this problem because they do not need to correct for being shortsighted by using the focuser? (hence dismissive comments from those who never had any problems ).

I still need good weather to test properly looking at the stars, but... I am reasonably confident about my solution.

ps apologies for no photos of the eyepieces disassembled, but I was in such a hurry that I forgot - hopefully my explanations are clear enough?

[bambuko]

Last night I was able to test the modified eypiece and can confirm total success.

Case closed.

[A40farinagolf]

Dear Bambuko,

I had exactly the same issue as you, so I searched online and up popped your thread, I've copied you suggestion by turning over the crosshairs on the plastic disc and bingo it works.

Many thanks for brill tip.

Regards,

M

[nonlinear]

I know I'm late to this thread but I had exactly the same problem with the current version of this finder (red anodised trim). Your suggestion worked a treat. I can now get the crosshairs and the sky in focus at the same time.  Thanks!

Stuart

[nutrocker]

Hi,

 

I have been reading all about the focusing problems with the Altair Astre 10 x 60 illuminated finder.

I have always had the same problem and just accepted either having the crosshairs or infinity out of focus.

I like the solution of reversion the etched reticle but am nervous about doing it. Would anybody be prepared to give a more detailed description of how to do it.

I have studied the comparison picture given by one member  but do not quite see what has been done.

Thanks for reading,

 

 

i

[billhinge]

I have one as well (from about 10-8 years ago) but it looks  nothing like the one above, I have the right angle and the extended straight through focuser. I have never had a problem with it, I also have the illuminated eyepiece. I think it gives great views but it now has a guide camera in it

[Gfamily]

20 hours ago, nutrocker said:

Hi,

 

I have been reading all about the focusing problems with the Altair Astre 10 x 60 illuminated finder.

I have always had the same problem and just accepted either having the crosshairs or infinity out of focus.

I like the solution of reversion the etched reticle but am nervous about doing it. Would anybody be prepared to give a more detailed description of how to do it.

I have studied the comparison picture given by one member  but do not quite see what has been done.

Thanks for reading,

I think the poster separated the illuminator and crosshair disc and flipped it, so that it went in back to front.

If you have perfect vision, the final image is meant to be at infinity (otherwise you can get eye strain), but for people with uncorrected short sightedness, the final image needs to be closer than that.

To move the image of the crosshairs hairs closer, you need to shorten the distance between the crosshairs and the eyepiece, and I think lack of focus adjustment made that a problem.

I'd want to know more about the distances involved to be sure, but that's my best explanation from an 1970s A level physics standpoint.

 

 

[Pixies]

OK. I have issues too. It's fine with my specs on (shortsighted) but without. I can just barely get the crosshairs in focus when the finder is at infinity. I notice that when I look through the EP, I have to rotate the reticle focuser to the very end in order to focus on it.

So I thought I'd have a go with the above.

First, unscrew the nose piece:

The plastic reticle is held in place with a lock ring.

 

Undo this using either a spanner wrench (the correct way), a small screwdriver (the risky way) or a long fingernail.

Now the reticle can tip out. The etched cross is on the outside, I flipped it round and reassembled it, which is just the above in reverse.

I haven't used it in the finder yet, but I notice that now I can adjust the reticle focuser and reach focus on the crosshairs (without specs) and still have a little more focus movement to play with.