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Celestron NexStar Evolution 9.25 concerns...


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Hello,

Last summer I bought a Celestron Astromaster 130 to pursue my "astronomy" dreams. I chose the astromaster 130 because it was cheap but not too "limited" in order to see if I had the will and the patience to practice diligently at a small risk (worst case scenario I wasted 200 euros). I proved my self capable of both and also more passionate than expected... hence I now NEED a bigger scope!

I was thinking about the celestron nexstar evo 9.25... it is bigger (in terms of aperture) and I love the idea of controlling it using my iPhon or my iPad (I'm a computer engineer and I'm quite "turned on" by this kind of things).

I have mostly one concerns... the focal length is 2350mm which wold lead more or less to a field of view of about 0.9 degrees using a 40mm eyepiece, which is kinda small compared to the almost 2.5 offered by my celestron with the 32mm eyepiece. Will I have issues finding objects? And what about gazing to bigger things?

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A 40mm plossl will not have a 50 or 52 degree view they are restricted by the lower tube that acts like a filed stop, they are normally stated as 42 degrees. So you would be at about 0.71 degrees. A 32mm 52 degree plossl gives 0.7 degrees.

There are other options but I think 0.9 is not attainable with the non-specialist eyepiece.

The view will be a lot narrower then the 130 and yes it will cause problems, I bought and used a Mak and the first time was a complete waste, I went and bought a 40mm plossl - even that 0.01 degree mattered to me.

Simply a 1 degree object will not fit in, you cannot get a 1 degree object in a 0.7 FoV.

So M42 is too big, M45 and I guess several others. Try reading theought the Wiki list of Messier objects if it has the object size then take note/count of the number that are sort of 0.5 degrees and above.

You can get 2" eyepieces, I have one (not sure how) and boy it is big.

The scope is a goto so it should locate the object and at least put it in view.

It is well suited to smaller objects, planets, M1, M57 should come out well, clusters (most) should be OK

One concern I have is the mount, it looks like an 8SE mount and the 925 could be a bit much. No specific idea if it is the same mount or if it is a beefed up 8SE. I would ask about this aspect if possible.

Also if possible see one, an 8" is not exactly light, believe me I have lifted one several times.

Edited by ronin
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Hi Ya Freedom, even with a degree your going to be able to see the majority of the objects we have in the night sky.  There's only a few objects which warrant a larger field of view, but you can use the 925 with the 130 for larger star fields.  The 925 is a very nice scope - you will have hours of fun on the Planets and the Moon will be just amazing - the level of detail on the Moon alone will keep you going for a few months and its always nice to re - visit our favourites.

A lot also depends on the amount of light pollution you have or if you can get out to much darker skies, not sure but I think the Evo comes with a handset - some have said that the software your supposed to use with the Evo is a little thin on the ground for objects, so you can just use the handset to send the scope to more objects, the GOTO on the scopes is very accurate - the only thing that will be of a problem is the level of light pollution you observe from, I live near a large town and can normally get down to mag 10 - 11 for some of the brighter objects, under light pollution the Galaxies will just be a smudge in the EP - its only when you get under very dark skies that these Galaxies show a little more.

Personally I find my Binoculars better for the large star fields - my 15x70's give nearly 4.5 degrees - so more than enough sky here for the larger star fields and open clusters, you can then use the 925 for objects like M2, M15,M36, M37, M38 - low power will show them nicely in the FOV, you can then increase the mag to go "inside" and have a wonder around - these objects will only show as "misty" patches of light in the Binoculars - so I tend to use different equipment for different objects - but the 925 will excel on the Planets, Jupiter and Saturn will be stunning through it, I can spend a few hours at a time just centreing Jupiter, letting the scope track and keep the object central and just watch the different features cross the Planet, even the Great Red Spot can be seen on the better steadier nights and I can track the progress.

HTH a little Freeedom, I have settled with long focal length scopes and found them to be more than capable for the majority of the objects in the night sky and have learned to live with my local light pollution - if you have a dark sky then this will help you the most - objects will be shown with much more contrast and enable you to search for the really faint stuff.

Regards.  Paul.

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Thanks to you both!

I live on the sea side, although I live near Cannes all the southern half of the sky is on a perfectly dark sea. Usually I suffer from nasty light pollution only when looking at objects W-NW-N-NE-E,  while SE-S-SW is quite good.

I too have a good pair of 15x70 binoculars! Unfortunately I do not have enough space at home to keep both the nexstar and the astromaster... one will go in my cave and will be used just occasionally.

Aren't there any eyepieces capable of giving a FOV of at least 1 degree?

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The Celestron 0.63 Focal Reducer will increase the field of view significantly. A lot of SCT users have this for visual (I have one).

They can be had for only £99 from FLO.

I echo Ronin's concern about the ability of the single arm to solidly support the scope. They didn't offer a 9.25 on the old SE single arm, and even if it is beefed up on the Evo, the 9.25 is 9kg compared to 5.5kg for the C8; a LOT heavier. I'd research carefully before buying.

Rob

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Nice 1 Guys, I didn't comment on the stability of the mount as I've tried to find reviews on the 925 Evo - but there doesn't seem to be anyone posting reviews, over here and on Cloudy Nights - but surely Celestron have had feedback from the SE's - as we all know that the 8SE is on the very limit of the mount, but some have said that its usable - especially for a grab and go.

Not sure but I think that they supply the SAME mount (not tripod - its the beefier CPC one I think for the 925) for the 6, 8 and 925, so, with the difference in weight between the 6 and 925, as said, is considerable ??

It would be nice if someone could give us a review of the Evo 925 - I think there has been quite a few sold over here and in the States - so I can't see why - probably that if it were unstable - If it were your NEW scope - would you post this ?

Regards.  Paul.

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The Celestron 0.63 Focal Reducer will increase the field of view significantly. A lot of SCT users have this for visual (I have one).

They can be had for only £99 from FLO.

I echo Ronin's concern about the ability of the single arm to solidly support the scope. They didn't offer a 9.25 on the old SE single arm, and even if it is beefed up on the Evo, the 9.25 is 9kg compared to 5.5kg for the C8; a LOT heavier. I'd research carefully before buying.

Rob

Great! With this I shouldn't have any problems with the FOV!

Whereas the discussions about the single armed mount worried me a bit!

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Hi Recc, There has been a really long thread on the Evo scopes on Cloudy Nights in the States - those who have bought them have tried to actually weigh each part, the tripod, the mount and the tube separately - from what I can gather the Evo 6 and 8 have the same tripod and the same mount - obviously a different tube assembly.  The 925 on the other hand has a sturdier tripod (I think its a CPC tripod) but the same mount as the 6 and 8 - so the much heavier 925 OTA rides on the same mount as the 6 and 8, but its just the tripod that's beefier.

This is where everyone is trying to find reviews on the 8 and the 925 - as said earlier people are speculating about the mount having to take such a large tube as the 925 when people were saying that the 8SE was struggling on its mount - a single arm mount.

Been trying for ages to find a review of the Evo 925 - but I can't seem to find anything ?

Paul.

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I reviewed mine here

http://stargazerslounge.com/topic/227554-celestron-evolution-c925-first-look-half-light-report/

Since then have used it a few times and it has been very good and a pleasure to use. I haven't used the wi fi side of it as I wanted to try this out on my tablet which has only just received an update to the android software and now connects. My phone worked fine with it though.

Stability is not an issue, the 9 has a very solid tripod, and is very sturdy on the mount, certainly there is a very minor shake after focussing but no different to my small refractor on a push to or many other combos I have used.

The internal battery is excellent, this saves lugging a leisure battery to the dark site. GOTO works a breeze as long as you feed it the right info and choose a good selection of stars for alignment.

Not much to complain about really , lose the rdf for a raci finder and what's not to like ? I think the wi fi aspect is unfinished work but you do get a handset.

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I reviewed mine here

http://stargazerslounge.com/topic/227554-celestron-evolution-c925-first-look-half-light-report/

Since then have used it a few times and it has been very good and a pleasure to use. I haven't used the wi fi side of it as I wanted to try this out on my tablet which has only just received an update to the android software and now connects. My phone worked fine with it though.

Stability is not an issue, the 9 has a very solid tripod, and is very sturdy on the mount, certainly there is a very minor shake after focussing but no different to my small refractor on a push to or many other combos I have used.

The internal battery is excellent, this saves lugging a leisure battery to the dark site. GOTO works a breeze as long as you feed it the right info and choose a good selection of stars for alignment.

Not much to complain about really , lose the rdf for a raci finder and what's not to like ? I think the wi fi aspect is unfinished work but you do get a handset.

Nice report. It does look like a very carefully thought out package with some nice touches. Well built too from what you say.

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Hi Paul,

Yes, I agree with concerns over fork arm but the reviews I read from users in the states etc suggest that on the 8SE it was the tripod that caused the instability. This I presume has been dealt with by installing the CGEM tripod on the 9'25 Evo.

Rick

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Hi Paul,

Yes, I agree with concerns over fork arm but the reviews I read from users in the states etc suggest that on the 8SE it was the tripod that caused the instability. This I presume has been dealt with by installing the CGEM tripod on the 9'25 Evo.

Rick

Yes Rick, it seems the 8 version of Evo may not have the beefed up tripod that the 9 has but I cannot confirm that for definite. The manual that came with mine referred to a different tripod to the one I had  so assume it means the 8, and Celestron did not print a 9 version of it. The 9s tripod is pretty hefty to move especially if you leave the tray fixed in.

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I do have another question: how far from each other should be the stars for the star-align procedure? Like Sirio + Capella + Castor would be a fine?

The advice for Evo alignment is practically the same to what you will find documented on various forums for the SE versions. For a 3 star alignment bright stars known to the system should be in a big triangle in the sky, higher than 30 degrees and lower than 70.

Get all the data in correct, tripod level etc. and it normally works fine. A lot of people just use 2 star align which apparently is just as good.

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  • 2 weeks later...

Ok... I did it! I ordered the Celestron Evolution 9.25 at my local shop!

Unfortunately it will only arrive in April since all the models they already had (here in France the evolution line was launched this very month) were either gone or reserved... only evo 8 and 6 are left.

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Freedom - very nice to hear this mate - well done - now the WAIT BEGINS !! - I ordered my CPC and had to wait a few months for it - It drove me mad - if your anything like me it will become a nightmare the longer you have to wait for it - but I think the wait will be well worth it - the 925 is a very good performer on the Planets/moon - It will be a pleasure to use- nice to see John pointing us to the review he had posted for the Evo 925 - very nice and well presented - thanks very much John.
I've been out the last few nights with my little 127 Mak on the CG5, you mention earlier about the alignment procedure - well I have to say that I Have tried various different alignment routines, from an EQ and Alt/Az and have found them to be very accurate, the CPC is a pleasure to use - even the basic 2 star auto align feature works very well on the CPC with all objects accurately aligned in the FOV - then to the CG% with the EQ mount align - its a little more detailed with a 2 star align, you can then add calibration stars - I think up to 4, but even on the 2nd initial alignment star on the CG5 things become very accurate with all the latter calibration stars being smack bang in the Centre FOV of a 40mm EP - I just use the 40mm Plossl for all my alignment routines and find it to be very accurate - I have never felt the need to purchase a reticule EP to make things really precise - I'm mainly visual and find both the routines very accurate and with minimal set up time, Away I GO !!!
Just a point, I always level the tripod before beginning with the CPC and the CG5 - with the CG5 I always sight Polaris through the hole where the polar scope fits - I find this more than accurate for my visual needs - I even tried a solar System Align last night just by sending the scope onto Jupiter - it was a little off, but well within the FOV of the finder, once centred and the "align" button pressed, tracking was very precise.
I hope the waits not too much for you Freedom - your going to love the 925 - Congrats.
 
Paul.

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Ok... I did it! I ordered the Celestron Evolution 9.25 at my local shop!

Unfortunately it will only arrive in April since all the models they already had (here in France the evolution line was launched this very month) were either gone or reserved... only evo 8 and 6 are left.

Congats, you wont be disappointed. I will update my review later as well now that I have used it a fair bit.

Also where you live....if it is sunny and you have loads of Ricard and Gran Cru I can drink I may have to pop by with mine :-)

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Freedom - very nice to hear this mate - well done - now the WAIT BEGINS !! - I ordered my CPC and had to wait a few months for it - It drove me mad - if your anything like me it will become a nightmare the longer you have to wait for it - but I think the wait will be well worth it - the 925 is a very good performer on the Planets/moon - It will be a pleasure to use- nice to see John pointing us to the review he had posted for the Evo 925 - very nice and well presented - thanks very much John.

I've been out the last few nights with my little 127 Mak on the CG5, you mention earlier about the alignment procedure - well I have to say that I Have tried various different alignment routines, from an EQ and Alt/Az and have found them to be very accurate, the CPC is a pleasure to use - even the basic 2 star auto align feature works very well on the CPC with all objects accurately aligned in the FOV - then to the CG% with the EQ mount align - its a little more detailed with a 2 star align, you can then add calibration stars - I think up to 4, but even on the 2nd initial alignment star on the CG5 things become very accurate with all the latter calibration stars being smack bang in the Centre FOV of a 40mm EP - I just use the 40mm Plossl for all my alignment routines and find it to be very accurate - I have never felt the need to purchase a reticule EP to make things really precise - I'm mainly visual and find both the routines very accurate and with minimal set up time, Away I GO !!!

Just a point, I always level the tripod before beginning with the CPC and the CG5 - with the CG5 I always sight Polaris through the hole where the polar scope fits - I find this more than accurate for my visual needs - I even tried a solar System Align last night just by sending the scope onto Jupiter - it was a little off, but well within the FOV of the finder, once centred and the "align" button pressed, tracking was very precise.

I hope the waits not too much for you Freedom - your going to love the 925 - Congrats.

Paul.

Don't tell me... I already started dreaming about it XD! I'm terrible in waiting! I already have a list of accessories I want to by (like the reduces)!

I just have to calm down (too excited)... which is hard!

Really looking forward to gazing at all the galaxies between Leo and Virgo with this new scope!

Congats, you wont be disappointed. I will update my review later as well now that I have used it a fair bit.

Also where you live....if it is sunny and you have loads of Ricard and Gran Cru I can drink I may have to pop by with mine :-)

It is also quite worm during the winter... between 6 and 10 degrees during the night.

I'm eager to read your updated review!

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Before you worry about buying a reducer, check the actual specification of the 9.25 OTA. If I recall correctly, the 9.25 is the smallest in the range that can take a 2" visual back - it just happens to ship with a 1.25" item.

By swapping to a 2" visual back, you will also require a 2" diagonal, but these aren't expensive if you keep an eye on the classifieds. The important thing is that you are then far less limited by your maximum apparent field of view (aFOV). Take a look at this:

tgnGig.png

The smaller circle is the 40mm Plossl, with it's tiny aFOV 40deg image circle. The big circle is a 2" 38mm EP, that because it isn't restricted by a 1.25" barrel, can achieve a 70deg AFOV. The image is the same size (the magnification hasn't changed) but now you can see a lot more of the area you are looking at. Think of it like looking at the same view, from the same distance, but through a much larger window.

Now look at the same pair of circles, but this time I've added the 0.63x Focal reducer to the 40mm Plossl:

PTxmGg.png

The reducer has allowed the Plossl to cover the same area (actual field of view) as the 2" EP.  What this graphic doesn't show, is that because the aFOV is limited by the EP size, when you look in the EP, that blue circle and everything in it, will only look the same size as red circle.

That's right; In case you haven't done it already, looking down a 40mm 1.25" plossl is a bit like looking down a toilet roll - It's all a bit light at the end of a tunnel

Okay, you have to buy a 2" visual back and a 2" diagonal, but you only have to do this once. Being bigger, it will be stronger and more stable and as they always come with a 2-1.25" adaptor, all of your current 1.25" EPs (barlows, etc) and any you buy in the future, will still fit in it. Likewise, 2" EPs are more expensive, basically because they have larger lumps of glass in them.

But make no mistake; when it comes to maximizing actual and apparent field of view in a long focal length scope, there is no substitute.

Russell

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Hi Russell, this has confused me somewhat! I realise that using a 0.63 reducer will not change the apparent field of view, ie: 40 degrees will remain 40 degrees, but surely it will change the actual field of view, ie: lower magnification means wider actual field of view?

Rob

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Ah i think i understand what you are trying to say, i think the confusion comes from when you say ".......when you look in the EP, that blue circle and everything in it, will only look the same size as red circle"; You are referring to apparent field of view but referencing a diagram which is showing actual field of view? Or am i missing something?

So just to be clear a 0.63 reducer will increase the actual field of view?

Rob

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Ah i think i understand what you are trying to say, i think the confusion comes from when you say ".......when you look in the EP, that blue circle and everything in it, will only look the same size as red circle"; You are referring to apparent field of view but referencing a diagram which is showing actual field of view? Or am i missing something?

So just to be clear a 0.63 reducer will increase the actual field of view?

Rob

The reducer is able to increase the field of view at the expense of magnification because it has to fit a bigger image in the same area (the eyepiece). The 2" eyepiece on the contrary has a bigger area which show the image hence is able to increase the FOV without scarfing magnification. I guess it is like looking outside a window...  if you are looking through a 2m^2 window to be able to fit the same "view" you are able to see within the frame in a 1m^2 window you have di squeeze it!

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Ah i think i understand what you are trying to say, i think the confusion comes from when you say ".......when you look in the EP, that blue circle and everything in it, will only look the same size as red circle"; You are referring to apparent field of view but referencing a diagram which is showing actual field of view? Or am i missing something?

So just to be clear a 0.63 reducer will increase the actual field of view?

Rob

Correct.

Stellarium (free download) has a better scope/ocular/reducer/barlow simulator, but you can't export the images as easily.

i find it very handy for saving my tired brain the effort of working this stuff out. You just have to bear in mind that even that doesn't show the relative changes in image brightness/contrast etc.

Russell

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