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Author Topic: question for RRS/Acratech (high-end) ballhead users  (Read 3432 times)

emag

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #15 on: May 22, 2013, 06:03:31 PM »
For visual use it may work with your C6 but you might want to consider something better suited for your application.  AP is definitely out of the question.  What is the weight of the largest EP you will be using with the C6?



It's just for visual.  At the same time I have a 60D and C8 on a CG5 shooting fuzzies and galaxies.  I put a 40mm or 25mm in the C6 for folks that want to see the moon or Saturn or whatever.  If it's a very clear night I'll put a 4inch f/5 refractor on there instead.  I was using a Mini-Hitch but sold it and bought the Acratech GP, which is more useful for non-astro photography.  Public stargazes are about the only time the C6 comes out, it was a package deal with the CG5 but otherwise, although it's a fine scope, I just don't have a tremendous amount of use for it.  The small refractor works quite well, I'll probably end up sticking with that and sell the C6.

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #15 on: May 22, 2013, 06:03:31 PM »

noisejammer

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #16 on: May 22, 2013, 07:31:27 PM »
Bear in mind that a C6 with a 25 mm eyepiece achieves around 60x. This makes resolving about 2 arcsec (10 microradians) quite easy (usually atmosphere limited.) If you turn this into an equivalent camera lens, it would be around 1200 mm long. This requires a serious tripod. Of course, the moment of inertia of a C6 is a lot lower which makes things easier, but be conscious that tripod vibrations may dominate things.

That said -

It should be quite easy to mount a Wimberley Sidekick on the Acratech and then attach your C6 to that. This would keep the c/g centred over the middle of the tripod and prevent your scope experiencing deceleration trauma.

I mount a 400/4DO plus 1.4x and 1D4 on a Sidekick on my BH-55. This combination is quite fine. I'll come back a little later and comment on my C5 Mak on the tripod - it has roughly the same focal length.

cycomachead

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #17 on: May 22, 2013, 07:40:02 PM »
I've got an Acratech GP-s and LOVE it!

It's literally one of my favorite pieces of gear! I most regularly use a 70-200 (2.8 IS) + extender + 5D/7D + grip and occasionally a flash. That's in the 8-9lb range (w/o flash) and it preforms flawlessly at every setting. More often than not, I  do NOT lock the head down completely. I get it in that sweet spot where it will stay put, but I can still pretty easily adjust the lens.

I rented a 200mm f2L and a 1D4 (and extender) and used the head and it also performed pretty darn well, even in the gimbal position, but I didn't have much time with it. This is a bit heavier than the 300 mk II. I wouldn't try more than a 400 2.8 on the head, and I'm sure it'd hold steady, but the gimbal would be bit off as others have reported. I haven't had any problems with my head.

Well, I did have one…my panning knob actually got stuck once. Acratech is a short drive from home, and they took a look, replaced the entire panning base and some of the inside rubber all for free! They're an amazing company, and I love their products!

Not many people rent acratech heads, however, they loaned me their long lens head for a couple weeks for simply the cost of shipping. It was great with a 500mm f4.

Side note: The GP series of Acratech heads allow you to mount the clamp on the underside of the ball head, and put it on top of the panning base for panorama work. This is a very handy feature, and while a ball head isn't quite as pleasant to work with upside down (the knobs don't feel right to me), it actually works very well, and saves some extra gear.

If you do get an Acratech head, I strongly recommend paying a little more for the level clamp. It's really handy, gives me a little more confidence, and I think is quicker. (If you don't they usually let you trade in a regular clamp for the difference in price, and that's how I got my lever clamp since it's newer than my head.)

noisejammer

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #18 on: May 22, 2013, 11:54:01 PM »
Results of a brief test
I mounted my Celestron 500/5.6 (circa 1980) on my RRS BH-30. I used a 5mm eyepiece so that the magnification was around 100x. It was carried on a Manfrotto 055CX something or other. For those who are interested, this mirror "lens" is colourful but works as a reasonable spotting scope if you keep the magnification modest.

The combination is a very lightweight ballhead, a medium weight tripod and a moderate load. I found that the combination was difficult to use when the ball head was off to one side, but it was dead easy to us when I installed a Wimberley Sidekick. It seems the cantilevered load increases the stiction in the ball head, and as you try to point the scope, it judders.

The C/G as (as predicted above) a long way from safe. I'd be very uncomfortable using a scope like this and I would not leave it unattended.

I don't know how that compares with the Acratech in terms of carrying capacity but the danger caused by an offset C/G was my main point.

I'll look at tripod vibrations when I find a reticle.

lilmsmaggie

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #19 on: May 23, 2013, 12:45:28 PM »
Thanks for checking this out noisejammer.  I expected as much, especially the C/G issue.  And even though I didn't mention it in my post, your mention of the need for serious tripod support and addressing dampening of vibrations etc. was key.   :)


Results of a brief test
I mounted my Celestron 500/5.6 (circa 1980) on my RRS BH-30. I used a 5mm eyepiece so that the magnification was around 100x. It was carried on a Manfrotto 055CX something or other. For those who are interested, this mirror "lens" is colourful but works as a reasonable spotting scope if you keep the magnification modest.

The combination is a very lightweight ballhead, a medium weight tripod and a moderate load. I found that the combination was difficult to use when the ball head was off to one side, but it was dead easy to us when I installed a Wimberley Sidekick. It seems the cantilevered load increases the stiction in the ball head, and as you try to point the scope, it judders.

The C/G as (as predicted above) a long way from safe. I'd be very uncomfortable using a scope like this and I would not leave it unattended.

I don't know how that compares with the Acratech in terms of carrying capacity but the danger caused by an offset C/G was my main point.

I'll look at tripod vibrations when I find a reticle.
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risc32

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #20 on: May 27, 2013, 10:23:29 AM »
you guys seem to be confirming what i was thinking. that is that when your gear gets to a certain size/weight you really need a gimbal mount regardless of what strengths your head/tripod might have.

neuroanatomist

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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #21 on: May 27, 2013, 11:36:06 AM »
you guys seem to be confirming what i was thinking. that is that when your gear gets to a certain size/weight you really need a gimbal mount regardless of what strengths your head/tripod might have.

There's no question about that, IMO.  My BH-55 can easily handle the 600 II, but if I screw up and let go of the gear without the ball tightened fully, best case the lens slams into a tripod leg, worst case the whole setup takes a tumble to the ground.  With a gimbal, when you let go with everything loose, it just moves to level and sits there.
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Re: question for RRS/Acratech (high-end) ballhead users
« Reply #21 on: May 27, 2013, 11:36:06 AM »