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Visual - Lunt B1200 vs B600

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#1 RGM

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Posted 03 January 2013 - 09:01 PM

Looking at purchasing a Lunt 60mm scope. At the present time I will use the scope just for visual, but in the future might try to take some photos.

I might as well get the scope I need right from the start. If I get the B1200 blocking filter, what advantages does it provide for visual use? Such as higher magnification?

#2 Andrev

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Posted 03 January 2013 - 09:54 PM

Bob

We dicuss about that not long ago. If you do a search in this section, you will find your answer.

As for me a visual observer only using both B1800 and B600 blocking filters, I strongly recommand larger you can get.

Andre

#3 RGM

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Posted 04 January 2013 - 07:12 AM

Andre, When did this thread exist. I tried search and also went back about 6 months searching each page. Found nothing so far.

#4 la200o

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Posted 04 January 2013 - 10:59 AM

It will provide a larger FOV, it has nothing to do with magnification. If you have any thoughts of imaging, I'd surely go with the B1200. Less important for visual, but still nice IMO.

Bill

#5 Andrev

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Posted 04 January 2013 - 11:03 AM

Bob.

I tried to do a search myself and can't find the specific thread. I really hate the search engine because it give anything but what we are looking for.

Well, as for my opinion and experience as a visual observer, larger is the blocking filter more space you have around the sun and brighter is the image. For imaging the sun, you need B1200 or B1800 to catch the full disc. I own the LS152 / B1800 and have plenty of space around the sun. I also own a C80mm with 50mm Halpha filter mounted in front of the scope and a B600 BF.

The problem with the B600 BF is the small space around the sun. It barely fit in the FOV at 85X but when I use the B1800, I have a very nice full disc in a larger area. I'm not an imager, but what I remember from the previous thread, to see the full disc you need at least a B1200 for the same reasons. And because the inside glass is larger, the image is a bit brighter visually.

Andre.

#6 frolinmod

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Posted 04 January 2013 - 11:59 AM

It seems to me that the B1200 (for LS60) and B1800 (for LS80 and LS100) are cost effective, but that the B3400 is "way out there."

#7 Escher

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Posted 04 January 2013 - 02:43 PM

Having used both (I now have the 600)... Its really about the same as having an eyepiece that "kidney-beans"... you have to have your eye placed very carefully with the 600 since the actual diameter of the filter is 1/2 the size. I didnt have similar issues with the 1200..

I plan to upgrade to the 1200 down the road then funds are available...

#8 la200o

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Posted 04 January 2013 - 02:44 PM

I don't think the size of the BF will affect the brightness of the sun per se, but will make the view seem more contrasty because of the greater amount of black around the sun.

Magnification is limited mostly by the seeing conditions, much worse in general during the day than at night. My SM 90 is certainly theoretically capable of high magnification, but if I can get 100x I know it's a pretty good day, and I often observe at 70-80x. Some will probably chime in with reports of high mag observing, but they must have better conditions than I do.

Bill

#9 Andrev

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Posted 04 January 2013 - 02:55 PM

Bill

Larger the scope, higher magnification is possible. As you can see in my sketches, most of the time I observe at 180x to 225x witout any problem and under good conditions I can go up to 300X. 150X is very very easy for my scope.

Andre

#10 George9

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Posted 04 January 2013 - 08:45 PM

Bob, if you ever plan to use a binoviewer with the scope, you may want to go for the larger one. When you add a binoviewer, you usually push the blocking filter closer to the objective lens to achieve focus, making the disk of the sun bigger at the blocking filter and raising the potential for vignetting. Even if you use a Barlow to solve the backfocus issue, the solar disk reaching the blocking filter will still be bigger.

I don't quite understand why imaging demands a larger blocking filter. Is it also because you need more backfocus to reach the camera, so also in this case you are pushing the blocking filter toward the objective? Or is it just because the photograph shows vignetting that your eye won't notice?

George

#11 RGM

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Posted 04 January 2013 - 09:53 PM

George, I do have a binoviewer and plan on using in the future. I guess the B1200 is the way to go.

I was planning on the B1200 anyways, just wanted to make sure I was not making a mistake.

#12 frolinmod

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Posted 04 January 2013 - 10:55 PM

You are absolutely positively not making a mistake.

#13 la200o

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Posted 05 January 2013 - 08:45 AM

Bill

Larger the scope, higher magnification is possible. As you can see in my sketches, most of the time I observe at 180x to 225x witout any problem and under good conditions I can go up to 300X. 150X is very very easy for my scope.

Andre


Andre,

150x and above is very very easy for my scope too; it's the atmosphere that won't cooperate.

Regards,
Bill

#14 George9

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Posted 05 January 2013 - 08:54 AM

Before I bought my LS80, I spoke with Lunt and they clearly recommended the bigger blocking filter for binoviewing. (For the LS80, the choice is B1200 or B1800, so I went with the bigger one.) After I got it, I did some measurements with the binoviewer in place and sure enough the B1800 is ample, but the B1200 may have been too small.

For the LS60, I guess the equivalent big one is the B1200.

George

#15 GooglyEyes

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Posted 05 January 2013 - 12:03 PM


Even with the B1200, it took a bit of practice for me to get my eye perfectly positioned, to see the sun. IMO the B1200 is the smallest usable blocking filter.


And... what everyone else said.


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