Aperture Fever Strikes!

[niallk]

Nice one: enjoy searching out the possibilities

Go as big as you can manage and afford!

I love my 10" 250px: it has shown me so much.  But if a good 12" comes up...

Best of luck,

-Niall

[scarp15]

Good luck in this search Neil, I am quite sure that you will take to it very naturally quickly. A dob is a breeze to use, highly functional and transformational in terms of the views you will encounter at dark sky locations. Some good suggestions made, consider to, ease for setting up, on certain light / compact models, dew prevention such as on the secondary will be a factor. My first scope had been a vintage C8 SCT on a clock drive fork mount. When I was inclined to consider what to go for next in terms of aperture gain, initially I had considered a CPC 925. This abruptly changed as soon as I became a member on here and begun to ask the same question as yourself and focus the search on a dobsonian. I had narrowed the choice between a OOUK VX10 and Skywatcher 12" flextube, in terms as to everyone else's advice, 10" or 12" in the right context will be a brilliant choice for taking along on dark sky trips. For a time I got to use a 12" Flextube, the manual version and became accustomed to traveling to dark sky locations with it, where it was used 90% of the time. A VX10 on a dobsonian mount would be quite superb and yep, do occasionally come up used at very reasonable cost. 

[kev100]

Hi Neil,

I'm sure you've already done this, but just in case, I'd recommend adding the settings for the 10in and the 12in scopes you have in mind into Stellarium (diameter, focal length), along with the eyepieces you have, and comparing the 'views' on some familiar targets ... The extra focal length of a 12 will give more mag with a given eyepiece than you'll get with a 10. That also means a reduction in true field of view. With my 20mm Myriad in my 250PX, for example, I can see pretty much all of the Beehive cluster, and likewise with the Pleiades. With a 12in scope, though, they don't fit in the fov.

In my experience, from a dark site there'll be little to choose between the performance between a 10 and a 12. In fact, I recently did a brief side-by-side comparison between my 250PX and a 14in dob with an OO mirror. I only got to view the Whale galaxy, but I felt it looked better (sharper, clearer) in the 250! Further, in light polluted skies, I'd suggest a 10in would offer slightly better contrast due to the lesser aperture (it would be slight, though). 

Having switched up from a 130/900 Skywatcher Explorer to a 250PX myself, I feel pretty confident in saying that you wouldn't be disappointed making the same leap; the difference is mind-blowing. I've had my 10inch for about three years now, and absolutely love it. Sometimes I think I would get a 12 if buying again, but only ever briefly. 

Kev

[Littleguy80]

31 minutes ago, kev100 said:

Hi Neil,

I'm sure you've already done this, but just in case, I'd recommend adding the settings for the 10in and the 12in scopes you have in mind into Stellarium (diameter, focal length), along with the eyepieces you have, and comparing the 'views' on some familiar targets ... The extra focal length of a 12 will give more mag with a given eyepiece than you'll get with a 10. That also means a reduction in true field of view. With my 20mm Myriad in my 250PX, for example, I can see pretty much all of the Beehive cluster, and likewise with the Pleiades. With a 12in scope, though, they don't fit in the fov.

In my experience, from a dark site there'll be little to choose between the performance between a 10 and a 12. In fact, I recently did a brief side-by-side comparison between my 250PX and a 14in dob with an OO mirror. I only got to view the Whale galaxy, but I felt it looked better (sharper, clearer) in the 250! Further, in light polluted skies, I'd suggest a 10in would offer slightly better contrast due to the lesser aperture (it would be slight, though). 

Having switched up from a 130/900 Skywatcher Explorer to a 250PX myself, I feel pretty confident in saying that you wouldn't be disappointed making the same leap; the difference is mind-blowing. I've had my 10inch for about three years now, and absolutely love it. Sometimes I think I would get a 12 if buying again, but only ever briefly. 

Kev

Thanks Kev. That's a really good idea. I have to admit that I haven't played around the Stellarium to compare yet. Will definitely do that. I hadn't thought about the FOV aspect either. 

Really interesting comments on performance at a dark site. I guess there's always a point of diminishing returns where you need to make bigger and bigger jumps to get the gains in performance. 

It's great to hear from someone who's made the jump from the scope as me so big thank you for the response  Out of interest, did you go for the solid tube or flextube version of the 250PX?

[kev100]

Hi Neil,

I went for a solid tube. I think flex-tubes are ideal for scopes larger than 10in, but I like the solidity of the 250PX. The primary mirror never dews up, the secondary only very rarely. With the solid tube you don't have to think about getting a shroud either.

Looking at the EPs in your signature, I do feel you'll be looking to change them at some point of you go for the faster 10 inch. It is hard on plossls, and I have tried starguiders with mine, and did see distortion around the edges of the fov. I had a 24mm ES Maxvision for a good while, and though a great EP, I did tire of the pin cushioning after a while (Skywatcher Myriad 20mm is an amazing replacement!). Can't comment on orthos as I haven't tried them with a 250PX, but given the focal length and fov, I shouldn't think edge-of-fov-distortion would be an issue.

Kev

[Stu]

Weight is another thing to consider. The OO dobs are significantly lighter due to their Ali tubes, lifting them is much easier.

I've had a couple of 10" and a 12" f5.3 OO dob and they are lovely scopes, possible to get used within budget. I have a dodgy back and the 10" was definitely much easier to pick up. It was actually only really a problem when keeping it low to get it out of the garage, after that neither of them were a problem.

The 12" is a dream scope really, and I would have another in future, but the 10" just felt a lot more useable somehow, and still gave lovely planetary views.

[JOC]

When I wanted to buy a telescope, someone posted a size comparison chart that I found very useful as a guide.  I was going to post the same for you, but as I searched on Google for 'Dobsonian telescope size comparison' and checked the image search I realised that this seemed a much better plan than a single picture - if you are concerned about the potential size of what you are interested in I would recommend the same search.

[alanjgreen]

27 minutes ago, Stu said:

Weight is another thing to consider. The OO dobs are significantly lighter due to their Ali tubes, lifting them is much easier.

I've had a couple of 10" and a 12" f5.3 OO dob and they are lovely scopes, possible to get used within budget. I have a dodgy back and the 10" was definitely much easier to pick up. It was actually only really a problem when keeping it low to get it out of the garage, after that neither of them were a problem.

The 12" is a dream scope really, and I would have another in future, but the 10" just felt a lot more useable somehow, and still gave lovely planetary views.

The other advantage of the OO dobs is the BASE. It's very nice and it's easy to fit encoders to it later if you want to upgrade to push-to by adding a Nexus unit.

[Saganite]

Hi Neil,

If more detail and fuzzy objects is your desire, you cannot do better within your budget, than a largish mirror, so a dob it has to be. Some great advice has already been posted, and a 10 dob would certainly 'light you up'.The only thing I would add is from my own experience, and that is, after using an 8" dob quite happily for some time, I got aperture fever. I considered a 10" and in fact tried one or two, and they are superb, but I knew that what I really wanted was a 12". I found a 12" Lightbridge for £400 in great used condition and enjoyed what that could do, for a year, but found it too heavy, so changed it for a Skywatcher solid tube 12" @ £300, again a lovely scope.I realized that I had made the correct decision as soon as I owned a 12", as I no longer had/have aperture fever, it felt right.I did however change that scope when a OOVX12L F5.3 came my way, with its superb 1/8th wave mirror, for £600, and now I am perfectly content. It is much the lightest 12" of the three mentioned, easily portable,( I am no 'spring chicken' at 65, but handling it is a doddle) I can almost hear the rumblings of cynicism, but honestly, this 12" scope is IT.

Enjoy your hunting, both for your next scope, and with your next scope. 

[Littleguy80]

Thanks all! There seems to be a lot of love for the OOVX dobs. Being lightweight and solid tube is a real bonus. I know @John has used BST's in his 12" without issue which is also good. The biggest challenge will probably be finding someone willing to sell theirs! If not, I may well follow in @kev100's footsteps with a SkyWatcher 250PX. 

I'm really pleased that no one has suggested something other than a dob. I'd recently been wondering whether something more portable would be better but it doesn't sound like portability will be a big issue with a 10" or a lightweight 12" dob. 

Whichever option I go, there will be inevitable eyepiece upgrades. I'm sure that I'll very quickly want a 2" low power eyepiece with a wide FOV. 

[Saganite]

1 minute ago, Littleguy80 said:

Thanks all! There seems to be a lot of love for the OOVX dobs. Being lightweight and solid tube is a real bonus. I know @John has used BST's in his 12" without issue which is also good. The biggest challenge will probably be finding someone willing to sell theirs! If not, I may well follow in @kev100's footsteps with a SkyWatcher 250PX. 

I'm really pleased that no one has suggested something other than a dob. I'd recently been wondering whether something more portable would be better but it doesn't sound like portability will be a big issue with a 10" or a lightweight 12" dob. 

Whichever option I go, there will be inevitable eyepiece upgrades. I'm sure that I'll very quickly want a 2" low power eyepiece with a wide FOV. 

Eyepiece upgrades are more inevitable than aperture fever, but all part of the joy of stargazing . My aperture fever is cured, but I am an incurable ocularaholic.( can't check spelling as word probably does not exist)

[Saganite]

57 minutes ago, kev100 said:

Hi Neil,

I went for a solid tube. I think flex-tubes are ideal for scopes larger than 10in, but I like the solidity of the 250PX. The primary mirror never dews up, the secondary only very rarely. With the solid tube you don't have to think about getting a shroud either.

Looking at the EPs in your signature, I do feel you'll be looking to change them at some point of you go for the faster 10 inch. It is hard on plossls, and I have tried starguiders with mine, and did see distortion around the edges of the fov. I had a 24mm ES Maxvision for a good while, and though a great EP, I did tire of the pin cushioning after a while (Skywatcher Myriad 20mm is an amazing replacement!). Can't comment on orthos as I haven't tried them with a 250PX, but given the focal length and fov, I shouldn't think edge-of-fov-distortion would be an issue.

Kev

Good point.

Apart from the weight, the  light shroud and the dewing was the other reason I changed to a 12" solid tube. 

[25585]

44 minutes ago, Stu said:

Weight is another thing to consider. The OO dobs are significantly lighter due to their Ali tubes, lifting them is much easier.

I've had a couple of 10" and a 12" f5.3 OO dob and they are lovely scopes, possible to get used within budget. I have a dodgy back and the 10" was definitely much easier to pick up. It was actually only really a problem when keeping it low to get it out of the garage, after that neither of them were a problem.

The 12" is a dream scope really, and I would have another in future, but the 10" just felt a lot more useable somehow, and still gave lovely planetary views.

I have a Bresser Messier F5 10 inch dob. It is light and has an aluminium tube. Truthfully I wish for longer FL, but my C8 covers that. 

The OO VX12L 1600mm FL is pricey, and I would be tempted to go for 1/10 mirrors, so maybe next year. 

[JOC]

In terms of portability, I don't think you'd find any issue shifting the OTA, you are used to stretching around a fairly big tube at the moment.  Just a word though about a Dobsonian mount.  Mine is extra heavy because of the motors in it, but, this notwithstanding, it tends on the awkward side of things to shift even for a 8" telescope - it's the width that is main bugbear - Even though mine has several handles you tend to have to hold it either out to one side of you or out and up in front of you so you don't walk into the edge of it.  Short distances is fine, but if I'm getting to above the 50m mark I find myself setting it down for a break as I move it.  If you get anything bigger and cart it to a field to set it up then I guess you will have to bite the bullet and lift it, but if you are storing it at home in a garage with no step access to where you want to put it to view, I can see a dolly with some chunky castors on it coming in handy.

[Littleguy80]

32 minutes ago, JOC said:

In terms of portability, I don't think you'd find any issue shifting the OTA, you are used to stretching around a fairly big tube at the moment.  Just a word though about a Dobsonian mount.  Mine is extra heavy because of the motors in it, but, this notwithstanding, it tends on the awkward side of things to shift even for a 8" telescope - it's the width that is main bugbear - Even though mine has several handles you tend to have to hold it either out to one side of you or out and up in front of you so you don't walk into the edge of it.  Short distances is fine, but if I'm getting to above the 50m mark I find myself setting it down for a break as I move it.  If you get anything bigger and cart it to a field to set it up then I guess you will have to bite the bullet and lift it, but if you are storing it at home in a garage with no step access to where you want to put it to view, I can see a dolly with some chunky castors on it coming in handy.

Thank you. I don't think I'd ever need to carry it more than 10 or 20m so shouldn't be a big deal. I'm not planning on a goto version so that will save the weight of the motors. 

[Littleguy80]

1 hour ago, Saganite said:

I did however change that scope when a OOVX12L F5.3 came my way, with its superb 1/8th wave mirror, for £600

If you don't mind me asking, where did you get the OOVX12L? I was thinking I'd post a wanted on ABS but wondered if there are other places I could look?

[Saganite]

On 1/31/2018 at 11:23, Littleguy80 said:

If you don't mind me asking, where did you get the OOVX12L? I was thinking I'd post a wanted on ABS but wondered if there are other places I could look?

The OOVX12L was advertized on this forum, but the only other outlet for used equipment that I use is AB&S. You have nothing to lose putting a wanted ad here and on AB&S, it may take a while but you might be lucky as I was, give it a go. 

BTW, looking at your eyepieces, you won't need to change any of them. I have used all of them at f5 without problem. The ES 24 is a 'peach', don't sell it.

[Timebandit]

 

The OOuk are great scopes IMO. And once you have owned one you realise that they are just that bit better IMO.

Aluminium tubes which means lighter to pick up and move around. Great quality mirrors ,which give that bit extra edge in the optical department and hold collimation well even if moved around.

The only thing against them is the new price. But second hand they are great value. You can pick the OOuk up at bargain prices ,if buying used and that does make them great bang for buck IMO

The problem with OOuk when looking for one they don't seem to come up on the used market. But when you are not looking for one then two or three seem to come up at the same time. I was lucky I was toying with the idea of a OOuk when mine came up for sale. And the used prices were so good compared to  new  And even around the same price of a used SW equivalent on one of them ,that I just had to buy. I have got Two OOuk now a 8" and 14" and a great aperture range for me. I have Never regretted buying these scopes and I don't think you will either if you can find a nice one at sensible money.

Good luck☺?

 

 

[25585]

There was a VX12L OTA on ebay not long ago, but "buyer collects" & too far to drive for me so I passed on it. 

For my dob base I use a sack truck with pneumatic tyres. The tube I carry at present. 

[Littleguy80]

Well, the line has been cast... I'm not in a rush so can afford to wait for the right scope!

 

[cloudsweeper]

Good luck Neil!  This thread has made me change my mind again, and I too now fancy a VX12L.  Better start saving!

Doug.

[Littleguy80]

11 minutes ago, cloudsweeper said:

Good luck Neil!  This thread has made me change my mind again, and I too now fancy a VX12L.  Better start saving!

Doug.

hehe sticking to your choice is the hardest part, Doug! This thread has been really good as I've not ended up with too many options to choose between.

[jetstream]

3 hours ago, Littleguy80 said:

I'm sure that I'll very quickly want a 2" low power eyepiece with a wide FOV. 

Lunt 20mm HDC...

[Littleguy80]

2 minutes ago, jetstream said:

Lunt 20mm HDC...

Having read so many of your reports using that eyepiece it actually is very high on my wish list! 

[jetstream]

4 minutes ago, Littleguy80 said:

Having read so many of your reports using that eyepiece it actually is very high on my wish list! 

If you get one it will release you from the need and desire for 21mm Ethos... it is a superb eyepiece Neil.