scope shoot out: 120ST v 130 PDS

[ollypenrice]

I'm sorry, I didn't see this earlier.

This looks like a good setup. The only thing I find surprising is that you find it significantly more portable than the 100ED. You find this is so?

Olly

[JG777]

I'm sorry, I didn't see this earlier.

This looks like a good setup. The only thing I find surprising is that you find it significantly more portable than the 100ED. You find this is so?

Olly

It is shorter and slighlty easier to handle. The 100 also lives in an aluminium case, so I would transport it in the case as it is a rather expensive frac, the ST however can stay attached to the mount and be moved around quite easily even in a car once you get the hang of it. The longer tube of the 100 makes that a bit more tricky. The worry factor with the ST120 is a lot less with it being a fairly inexpensive scope when you are moving things around. I really like the combo as I can lift it in seconds and have it up and running outside for quick grab and go. The Mak 127 is good with this as well but obviously needs some time to settle down but the ST is ready to go in minutes.

Rick, how are you getting on with the ioptron? Have you managed any imaging with it?

[Which Star is that]

Hi John,

I quite like the iOptron. It may not be the best Equatorial mount, but the fact that it is designed to be transportable is the clincher for me. I do not use the stock tripod that it came with as it is too long to go in my case even collapsed. It is also a bit wobbly! There is just too much play in the legs when they are extended. For me to use it I would have to strip it down and fit tighter fitting shims round the telescopic legs, then it might be OK.

I simply bought a decent carbon fibre camera tripod (28mm tripo) which is much sturdier than any of the cheap metal tripods I have tried and it mounts straight on to it (standard large size screw - 3/8 UNC I think). It also has the advantage (for me, as I fly with it) that it only weighs 900g!

The only other thing I have found with the iOptron is that although it is technically capable of carrying the ST120, it is probably near the limit. In fact by the time I put the SLR on it it would not balance with the supplied weight. I could have got a second weight, but that seemed to defeat the object for me, so I just made a small 4" extension to the counterweight bar from a piece of tube the right outside diameter and a long bolt. This works for now, but I am thinking of moding it further and making a cradle for some reasonably large lipo batteries that would power the mount and act as the counterweight as well. I don't know why iOptron didn't design it that way as it would have made the mount even lighter for traveling.

I have used the rig a few times for observing and it is great. I have only used it for lunar photography so far and got (for me) what I consider quite good results, but the exposure times were quite short, so not really a good test. I hope to try some deep space object astro soon, but it all depends on weather and where I fly to!

I would like to try it with perhaps a smaller ED80 and use a guide scope plugged into the ST4 port - but I need to get more familiar with the basics before I get that technical. Not enough time in the day - or should that be night!

[ollypenrice]

Batteries as counterwights has to be a good idea. In fact didn't a guest and I invent it over a bottle of wine a few years ago? By gad, I think we did!     (Or was it a bottle of wine as a counterweight??)

Olly

[Which Star is that]

I'm sorry, I didn't see this earlier.

This looks like a good setup. The only thing I find surprising is that you find it significantly more portable than the 100ED. You find this is so?

Olly

It was the length of the OTA that was important for me so the ST120 gave me the best aperture to length to cost ratio. It had to fit into an Airline legal carry on bag. Really the ST102 would have been the sensible choice, but when I was looking to buy it was out of stock and OVL had no estimate for delivery. The 120 was only a few quid more, and buying it in combo with the AZ3 and then selling the mount and other bits that I did not need meant I effectively got the tube for peanuts!

Ultimately my setup has been (and still is) a bit of a test to prove that travelling with all the kit was worth it (so far it has been great) and if it works out I would like to get a quality ED scope and a small guide system and decent astro camera. I would stick with the iOptron as it is designed for travelling and seems to be doing the job so far. Incidentally the iOptron customer service has been great- I broke one of the battery covers and they sent me a new one FOC, and I also did not pack the control box carefully enough once and cracked the LCD and they sent a replacement all the way to the UK at very reasonable cost.

[Which Star is that]

Batteries as counterwights has to be a good idea. In fact didn't a guest and I invent it over a bottle of wine a few years ago? By gad, I think we did!     (Or was it a bottle of wine as a counterweight??)

Olly

Got any available nights at Les Granges in the next 5 weeks as I will be in the alps and have thought of coming down for a night or too? Trouble is if the weather's nice I'll want to be skiing...