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Meade ACF Large CO.

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#1 timps

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Posted 28 March 2013 - 08:18 PM

I have noticed that the secondary mirror on Meade SCTs
seem to be quite large.
The Celestron secondaries seem to be noticeably smaller than the Meade.
Does this mean that the 14" celestron will deliver more contrast than the 14" Meade?

#2 jrcrilly

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Posted 28 March 2013 - 08:54 PM

I dunno. I've owned both and never noticed any contrast difference. Didn't notice any apparent difference in obstruction size either, but I never spent much time looking at that end.

#3 rcdk

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Posted 28 March 2013 - 11:28 PM

If you are looking at the new F8 OTAs, then yes it is bigger. But they are aimed at the imaging market where the benefits of shorter focal ratio outweigh the negatives of larger CO.

The best contrast I have experienced was with my 6" F9.5 dob. Of course, the views in my 12" Meade blow it away no matter the target in spite of having a much larger CO.

There is probably more variation between individual scopes of the same brand than between the two brands on average.

#4 timps

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Posted 29 March 2013 - 03:50 AM

Would you recommend the F10 Meade? They are still capable for photography and probably better then F8 for visual, don't you think?

#5 rcdk

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Posted 29 March 2013 - 08:10 AM

I like my F10 scope, but I would try to look through both. The larger CO bothers me, but I have heard the F8 optics are excellent and give great views. Depending on the size of the scope, baffle arrangement, etc. the difference is probably more academic than the CO size suggests.

I have heard that Meade is planning on offering the ACF only in F8 when they run out of the F10.

For photography I would jump on the F8 OTA, especially if it gave good enough views.

#6 Spacetravelerx

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Posted 29 March 2013 - 08:27 AM

On the 14" the CO is only 13.8%. That is not bad at all.

Combined with the over sized mirror, optical design, coatings etc I think this will be a winner. People are already raving about it.

#7 rtanton

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Posted 29 March 2013 - 08:55 AM

A data point of only one...but several years ago, while employed at Meade, we took both a 14" LX200GPS (f/10) and a 14" RCX (f/8) to Palomar to view Deep Impact. It was my opinion (as well as that of several others including some from OPT) that the impact may have been equal to or slightly more visible through the f/8 scope. Contrast was a key factor for seeing the impact visually.

Russ

#8 jrcrilly

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Posted 29 March 2013 - 09:06 AM

A data point of only one...


I have another such single data point. Had a 12" RCX set up next to a well-collimated 12" GPS model a few years ago. Using eyepieces of the same design but of different focal lengths we matched up the magnification and FOV and scanned the Double Cluster for quite a while. All present agreed that the RCX was showing a few more of the dimmest stars.

#9 timps

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Posted 30 March 2013 - 03:55 AM

13.28 according to Meades website. Even better! Supprising as it looks bigger than that on the pics.

#10 cn register 5

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Posted 30 March 2013 - 05:44 AM

Isn't that the obstruction as a percentage of the area? If so it's about 36% of the diameter.

Chris

#11 Bill Barlow

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Posted 30 March 2013 - 02:09 PM

I own a C14 and the secondary mirror housing is 4.5" in diameter. That calculates to about a 31-32% obstruction when compared to the 14" of clear aperture. Not sure of the Meade f/10, but the f/8 probably has something a little larger than the C14's 31-32%.

bill

Bill

#12 orion61

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Posted 01 April 2013 - 04:24 PM

BUT look at the Meade RCX series, the larger secondary doesn't have to mean worse images, the Meade RCX's were outstanding visually. perhaps a little less bright but compaired to when I got into Astrphotography todays 2 minute exposures are nothing. I used to sit still
for up to an hour, guiding..
I also walked in the snow to School. Up hill Both ways...

#13 thesubwaypusher

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Posted 21 April 2013 - 08:48 PM

I never spent much time looking at that end.


:grin:

#14 thesubwaypusher

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Posted 21 April 2013 - 08:52 PM

If you are looking at the new F8 OTAs, then yes it is bigger.


I noticed that at NEAF.

Another thing that surprised me was the pebbled finish didn't seem to bother me as much this year.

I think it was the MEADE INSTRUMENTS sticker that diverted my attention. :thinking:

That looks kind of kool.

#15 Bill Barlow

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Posted 22 April 2013 - 03:37 PM

Did you ask Meade if they were ever going to bring back the smooth/glossy blue paint finish on their SCT's? I had one of the textured/pebble finished 12" ACF and didn't like it much, but now they have decals on them, so that might offer a better look than the naked tubes.

Bill

#16 thesubwaypusher

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Posted 09 May 2013 - 01:45 AM

Hi Bill:

No, I didn't ask them, as I assume they are set on not making them anymore. In one of the other threads, you can see how Lenny's new scope looks a lot better with the decals. But as I sit here looking at my 12" glossy finish, I can't imagine having one of those textured jobs in my living room. It's just not as elegant. In the garage, okay...

I also dislike those goofy stars that they put on the forks. I was looking at them at NEAF and just wondering what Meade is thinking with these toy-like ETCHED emblems on serious scientific instruments that sell for thousands of dollars. It would actually prevent me from buying one.

Thanks, Chris

#17 Spacetravelerx

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Posted 09 May 2013 - 02:06 AM

Chris, et. al.,

I have had the blue glossy tube for a long time (10" LX200), however I like the new textured look of the LX850. I am fine with it in my living room, though (a) it is a bit huge for there, (B) I would rather have it outside or in an observatory!

#18 rcdk

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Posted 09 May 2013 - 06:53 AM

I buy scopes to look through, not at.

As long as it isn't a maintenance problem, I don't care what the paint looks like.

#19 Whichwayisnorth

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Posted 09 May 2013 - 10:54 AM

Supposed to reduce the appearance of finger prints and other smudges. Personally I think they couldn't get the factory down in Mexico or the body shop in TJ to paint without runs or dirt specs so they gave up and went with the rough finish. Just my opinion though.

Keep in mind that they have other tubes that are painted smooth gloss but I wonder if those are done in Mexico or China.

#20 nitegeezer

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Posted 09 May 2013 - 01:15 PM

I guess I would have to agree with rcdk. My scope sits in the case when it is not in use. I would not care if it was hot pink with runs all down the sides. As long as it functions well then I am happy.

Having said that, my opinion has changed over the years. Since the first thing you see when you open the box is the paint job, I can understand a disappointed reaction.

#21 thesubwaypusher

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Posted 09 May 2013 - 06:51 PM

Hi guys:

I can understand the, "It's just a telescope" way of thinking. For me though, I keep my equipment in my living room as a symbol of serious scientific research, or just observing for fun- The telescope symbolizes something much more important to me. As we all know, it is a time machine. How many folks have time machines in their living room? AND, I get real joy from it being around me when I am here. Just looking at it gives me a good feeling.

And while I am on the subject, what is Meade thinking when they DO NOT put a handle on the new 10" f.8s? How do you lift it out of a carrying bag, or mount it? And still no fans- or vents???

Thanks, Chris

#22 Bill Barlow

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Posted 09 May 2013 - 08:23 PM

Wow, I didn't realize that the new f/8 OTA's don't have at least one carry handle. How can you manage the M14 f/8 OTA without a handle? I would have thought that Meade would have added two handles for the 14" and 16" scopes. The C14 has two handles that are lifesavers when moving that scope around.

Bill

#23 Spacetravelerx

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Posted 09 May 2013 - 11:41 PM

Bill,

That is not true - the Meade 14" f/8 does have handle on it. I am getting pretty good now putting it on the mount on my own or with only a little help.

#24 Spacetravelerx

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Posted 09 May 2013 - 11:50 PM

Chris -- I have had my telescope in the living room off and on, but to be honest my LX850 is going into an observatory this August.

Then I just look out my window, see the panorama of the mountains with the dome just 30 yards away.

Mounting the OTA is pretty easy. When my son is helping, I grab the end where the ep goes, lifting by the handle, with my other hand/arm wrapped around the base of the tube. My son grabs the dove tail and tube front. We then bring it to the mount, and I just slide it on the LX850 mount and then tighten it up. Pretty easy.

#25 Bill Barlow

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Posted 10 May 2013 - 06:50 PM

Well that is good to hear..it is a must-have for a scope that large and heavy.

Bill0






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