More HEQ5 Pro Questions

[Krusty]

I have been searching through the posts and have not found answers to a couple of questions I have. I apoligise if my questions have in fact been answered in some previous threads.

I currently have a Celestron Nexstar 5Se scope. I find it to be an easy scope to use but am using it now to it's limits for photography. I would like a better setup for astrophotography. I like the look of the HEQ5 Pro mounts because they are now within my price range.

1. Can someone tell me please what length of exposure people are getting out of these mounts before there is too much drift? And for a lengthy exposure, is using the guide port essential, or is the PEC good enough?

2. I have a permanent pier in my back yard for my scope so I don't need to keep lugging the tripod around. Is there anyway that these mounts can be used on a pier insted of their tripod? I would like to be able to use the mount on the tripod still though, when I take the telescope to a different location.

3. I would originally be using the 5" celestron scope with it. (It is a dovetail mount) My next purchase after the mount would be a guide scope. I have read many threads talking about maximum weight for these mounts. Would this be an acceptable match for long exposures. The camera would be a Canon Eos 400d. I would love to one day get an 8" SCT. Would this mount still handle this, or would I be pushing it pasts its limits?


Also do people feel that these are generally good mounts, or should i be looking for something different.

Any feedback on this is greatly appreciated.

Thanks,
Wade.

[Kokatha man]

Hi Wade, I can't really comment from an astro-imager's experience, because I'm just about to get into this area.

However, I do have a HEQ5 Pro and I have mastered the polar alignment and drift align techniques for it, such that I'm very confident of guiding for shorter durations - my drift is very minimal: have just bought Geoff Smith's short/long exposure webcam as well, so auto-guiding should be further enhanced when I set this up.

PEc should benefit the equation too I imagine, and I am making my own permanent pier that will be bolted to my observation deck.

I too want the option of using the tripod at times, but this is no problems as the HEQ5's mount plate (which doubles as the pier's levelling plate) is a simple piece to fabricate. I had designed this for when I thought someone was fabricating a pier for me; but when that turned out to be a furphy I started my own (far superior imho) pier construction and had the HEQ5 mounting/levelling plate made at my local steel supply shop for $20.

I think I've attached the plans for this plate in this post, if it isn't I'll re-do it later today!

Cheers, Darryl.

[Kokatha man]

Hopefully the attachment's here now!

[Kokatha man]

Once more....!?!

[Kokatha man]

The dotted line indicating the reference radius for the hole that is drilled and tapped to hold a set-screw (ie a hex head "bolt") doesn't necessarily have the hole punched and drilled at "12 o'clock" to the virtual centre of the whole plate.

Depending on what sort of base/ how you fix your pier to the ground you will want this tapped hole in possibly different positions on this "dotted" reference radius circumference line in the plans - mine is at 10.45 (quarter to eleven.)

This is because the set-screw you place in this tapped hole (which could just be a plain hole with lock nuts on either side of the plate to hold the "bolt") is the "spigot" (the projecting bit on the top of the HEQ5 tripod) that allows for fine azimuth adjustment.

Determining how or in what position your pier is fixed to the ground, will determine in which position that set-screw spigot is - ie you try to have it aligned as close to geo south (with reference to the now non-existent centre point of the plate) as you can for minimal azimuth adjusting of the mount.

Cheers, Darryl.

[Krusty]

Hi Darryl,

Thanks for the info. Good to see that it won't be a problem to adapt the mount to a permanent pier. Sounds like we are trying to achieve very similar setups.

What size telescope are you controlling? How much weight?

Cheers,
Wade.

[Kokatha man]

Hi Wade - forgot about load capacity: the HEQ5 is rated to carry 15 Kgm - don't know the specs of your Celestron but would assume it's well within the HEQ5's capacity.

The EQ6 is the biggest of these mounts in terms of carrying capacity, but they certainly start to weigh a fair bit on themselves, for portability requirements. Again unsure of actual weights but would imagine the HEQ5 could handle most probably all 8" scopes with ease.

I only use my HEQ5 with a f8 6" achro refractor: this is why I've made a custom pier that has the mount/leveller plate set at 1350mm above ground to give me good ergonomics. (Looking at objects near the zenith with these on the tripod set-up has your chin on the ground almost!)

The achro plus baggage is about 10 plus kilos, which the HEQ5 does with consumate ease. One of my initial imaging forays is to piggy-back a camera to take wide-angle sky shots using my mount.

I've just purchased a webcam that's modified for use as an auto-guider: my imaging knowledge is non-existant - but I'm sure you'll pick up plenty of sound advice for your requirements on IIS. (put it this way, this is what I'm trying to do myself!!!)

Cheers, Darryl.