Good finderscope for C925

[The_bluester]

OK, I thought I had got out of the recent Vic fires lightly (We live near Kilmore, Forbes to be exact, right in the middle of where the fire crossed the Kilmore-Lancefield road) but recently found one unsuspected damage.

I keep my scope in my main shed and it looked like it had come through unscathed (the fire got to within inches of the shed wall) however the objective cap had dropped off the finder and it took smoke damage. I removed the objective to try to clean it up properly but to no avail and I also managed to damage the rear of the objective with a tool in the process of removing the retaining ring, which was stupidly tight. The finder is now rather like looking through a dewed up SCT (Which having only recently bought heaters is a view I am well familiar with :P)

Thankfully the main scope and all my eyepieces are fine. Except that I seem to have some internal grunge on the corrector developing. I will have to get my bravery out and remove it to clean when it gets a bit worse, I recall seeing someone else post that there was a series of the C scopes known for that and it was there before the fire so I am not concerned about it, it also does not seem to be impacting visual performance yet so best left alone.

SO...... What is a good finder? similar in dimensions to the original Celestron 8 X 50 and with an adjustable brightness illuminated reticle? I am not sure yet if I would make the change to a right angle finder as I can see advantages and disdvantages to that move, the main disadvantage being trying to get my head around not looking where I am aiming!


Regards the rest of the fire stuff, I won't leave people wondering. We lost a hayshed and it's contents (Thousands of dollars worth of really good quality hay) a water tank (Plastic, melted by the heat of the hayshed) and around 4KM of fencing and lots of shade/windbreak/beautification trees. Our livestock (Pony stud) were fine, house is fine and my main shed with all my equipment (Including the scope and my race car) was saved by a matter of inches. We had done a runner hours before the front passed through due to me realistically being the only one who could have stayed and that would be just stupid. My wife and 5 year old obviously had to go and my mother is the wrong side of 70, leaving me on my own, we would have been OK in hindsight but hindsight does not protect your life!

The place looks rather depressing at the moment though at least recent rain might green it up a bit so it looks less decrepit. The tree plantations will tace a decade to look as good and it will still be a year or more before we find out which trees that look OK are not going to make it.

[astro744]

I use a Telrad for aiming plus a Stellarvue F80M RACI finder on my C9.25. I use either a 20mm Plossl or a 16mm T5 Nagler on the finder, (no cross hair or pulse illumination) giving me 4 degree field that matches the outer ring of the Telrad nicely. This combination works well for me.

The F60M2 is also a very good finder from Stellarvue and is very lightweight.

I personally find illuminated cross hairs, whether continuous or pulsed annoying as they hinder my ability to detect faint objects in the centre of field and you'd be amazed at how many galaxies actually show in the 80mm finder. I find it not too difficult to judge the centre of field without cross hairs.

[The_bluester]

Looks like the 80 is discontinued. Replaced by the F80M2? How does it go with a corrected image but right angle? Getting my head around looking at right angles while trying to point the scope is my main concern with a right angle finder.

At the moment I don't use the finder all that much as I have the CPC925 goto so once the mount is aligned electronically I am off for the night and I sometimes even remove the finder completely. But of late I have been pointing the scope manually with the hand controller more and more instead of using goto and obviously a cactus finder makes that a lot more difficult. I am also seriously looking at a wedge to use the scope in an EQ mode so that I can star hop and move it manually with the clutches undone for quick pointing, obviously loosing the goto facility in the process. Again, I am really going to need a working finder for that.

[astro744]

That's why I also have a Telrad for pointing. I found using a straight through finder more of a problem on the C9.25 due to awkward angles at times. My C9.25 is mounted on a Losmandy GM-8 mount.

The rear or the F80M rotates to bring the eyepiece to a comfortable angle but yes I too would want something to aim with and a Telrad is ideal.

I may have an F80M2 not F80M and mine sure looks like the one on the Stellarvue web site. I didn't like the 23mm eyepiece and I feel 4 degree field is more than enough and I also prefer a slightly higher magnification than 13x and the 20mm Plossl gives me 15x and 16mm T5 Nagler gives me almost 19x, (M83 looks good with the latter).

Stellarvue do recommend a highly corrected eyepiece due to the f3.75 focal ratio and the Nagler is ideal but of course makes for one very expensive albiet very stunning combination.

One word of warning though: The helical focuser has some grease and mine was over greased and the bottom of any long barrel eyepiece may come in contact with it. It is easy to wipe away the excess before you start using it but just be aware of this, (it may not be a common issue).

[The_bluester]

Food for thought.

Has anyone had any experience with the ES finders?

[Camelopardalis]

I use a Rigel Quikfinder for pointing and an Orion RACI for the wide view on my C11 :)

Would love one of the Stellarvue finders though. I've not seen the ES finders round these parts, but even in the US if you buy one separately you may as well get the SV for the extra few $$$

[The_bluester]

One thing I might be able to double up with here is I have thought a few times about piggy back mounting a rich field scope on the 925 as it would make two in one views of objects like the Orion nebula or Eta Carina etc possible. I MIGHT be able to justify the stretch to an F80 based finder on the those grounds.

Then the eyepiece hunt would starta again, though even with my Nagler 11mm it would still give around half the power of my longest FL EP in the 925 and a TFOV over twice as large as a Nagler 31mm would in the main scope (And I have not got a Nagler 31!) Pop a nicely corrected EP around 30mm in there with the 2" focusser and it would surely be headed towards the rich field end of the spectrum.

[astro744]

That's exactly the reason I use my F80 on the SCT. The Pleiades is a good example too and they look good in the 80mm finder.

Note you will only get straight through with the 2" option on the finder and using a highly corrected 2" eyepiece will add a lot of weight.

The 24mm Panoptic will give over 5 degree field at 12.5x and 6.4mm exit pupil. It is nice in the F80 as is the 19mm Pan but the 16mm T5 Nagler is my favourite giving me more magnification, a darker background and wider apparent field. Note I usually leave my Meade 4000 series 20mm Plossl in the F80 and it works quite well.

Note if you do order an F80 make sure you get the mounting rings and mounting foot to suit the 'scope you intend using it on. This does add a significant amount to the cost unfortunately.

[The_bluester]

It will be a little while before I do it I think, Just getting a thread up here early to start gathering info. At least I can still see through the old one well enough to align the scope so I can use it, but it is useless for anything beyond that.

Common snese would be to go and buy a Meade finder from Bintel for about $100 and leave it at that. It would probably even fit in the Celestron bracket, though I would love to move it forward on the OTA a little as it can get in the way at times.