TAL 100 RS
Posted 16 November 2003 - 07:15 PM
My question is this, I have seen a russian TAL 100RS (4" F10, fl 1000mm)refractor on a Synta EQ5 mount for £500. Is this a good scope for planets in my backyard with some light pollution?
I spent the last 2 weeks looking through websites and I think that the EQ5 is a good mount that I could re-use if I wanted to change the scope. I live in Scotland and my budget is limited because I am disabled, so is my choice of scope. Any advice?
Posted 16 November 2003 - 07:20 PM
Posted 16 November 2003 - 07:28 PM
Posted 16 November 2003 - 07:42 PM
Here is what they liked
*Excellent optical quality (for an Achromat)
*Rugged metal construction
*high quality 6X30 finder
Did not like the 1.25 inch focuser (had limited travel and accepted only special accessories). So you may want to make sure you are getting the model with the 2 inch focuser.
Posted 16 November 2003 - 07:51 PM
The 100RS has a 2" extended focuser with a 2" to 1.25 adapter on the star diagonal. I noticed that many people here replace the star diagonals with better quality one. What make should I look out for?
Posted 16 November 2003 - 07:55 PM
Posted 16 November 2003 - 10:28 PM
Posted 17 November 2003 - 04:36 AM
Although I never looked through one, I've the tendency to agree with Blair. Viewing conditions seldom allow these mags (240x) in a 4" F10 achromat on Jupiter, on Saturn it is possible in perfect seeing conditions. I still think the Tal should be a little better than my Sky Watcher 4"F10. I don't think you can go wrong, so I'd go for it. The EQ5 is a perfect match for that OTA too.
Posted 17 November 2003 - 07:34 AM
Buy the way what is APO and OTA?
Posted 17 November 2003 - 08:19 AM
The experts will without doubt give you a good description of an APO refractor. OTA means optical tube assembly. Sorry if this confused you.
The 120 F8.3 can be a very good perfomer and would still match the EQ5 mount well. 5" versus 4" makes a noticable difference in both resolving power (planets) and light gathering (deep sky). It wouldn't be too clumbsy to move around too. Although I find my 4" a very satisfying instrument for planets and brighter deep sky objects. So, maybe you could look out for a used 5" Helios Evostar (most common in Scotland?) too.
Posted 17 November 2003 - 10:05 AM
I used to live in north east Switzerland (Near St. Gallen). The night sky was amazing, how is it where you are? Here in Scotland (North of Glasgow) the weather changes very fast and the seeing at the moment is a bit unstable. Get a bit misty when it is clear and cold. Although 10 days ago got a great view of the Northen Lights!
Posted 17 November 2003 - 10:22 AM
Posted 17 November 2003 - 01:04 PM
I can imagine that the sky in Switzerland is awesome. It's not too bad in my backyard with a zenith limited magnitude of about 5. I think that the Tal still is an excellent choice for your budget, sky and weather conditions. Anohter pro for a refractor is little cool down time. That's something that has to be considered as the weahter can change rapidly, especially where you live.
Anyway, keep us posted about your choice. Looking forward to your first observing report .
Posted 18 November 2003 - 04:07 AM
Posted 18 November 2003 - 11:29 AM
Posted 19 November 2003 - 01:45 PM
I now own a Vixen fluorite and altough the quality of the apo is much higher(as well as the cost ;-) ) I think that the Tal is an exellent beginers instrument. It will give you much pleasure now and once you have it you can learn observing and all that and save some money for an apochromat in the future (that's what I did). Those apo's are real stunners you know especially on the planets and the sun ort the moon,....
Posted 19 November 2003 - 04:11 PM
Posted 19 November 2003 - 05:14 PM
Ron the 4-inch Tall Evangelist B[ee]
Posted 20 November 2003 - 12:14 PM
Posted 21 November 2003 - 07:55 AM
Be warned - it is bigger than I expected - 1 metre off OTA plus Dew shield needs careful manouvreing through doors. The OTA is light enough to carry one handed which helps.
One thing to note if it is not too late. The EQ5 it is sold on is I think the HEQ5 anyway (the one with the stainless steel legs). It might be cheaper if you order them as a unit rather than separately.
Bin the solar eyepiece filter as soon as you receive it - they aren't safe. The moon filter is fine and essential at full moon :-)
I recommend buying a couple more eyepieces or a barlow to give you intermediate magnifications. I bought the Tal 17 and 10mm Plossl's and have added an Orion 32mm for wider field work.
Hardest point has been getting used to using an equatorial mount and finding things. I strongly recommend buying or borrowing "Turn Left at Orion" (see the review in Cloudy Nights) as it gives you eyeball, finderscope and eyepiece views of the objects are looking for.
My favourites so far :-
Mars in August (SPC and some Maria resolved)
Saturn at the moment. Can split Cassini at *100 and I can make out faint belts etc.
M42/43 in Orion. Perhaps the most stunning of all so far.
Dumbell and Ring Nebulae
M31 - Andromedae and M32 (managed M110 once - faint but satisfying).
Globulars - especially M13 in Hercules (and M15 in Pegasus)
Various Double Stars - especially Albirea, Sigma Orionis and Gamma Andromadae.
Final note - have fun reading the manual. The English is very entertaining. I still want to know what slushing is in the certificate.
Posted 21 November 2003 - 09:56 AM
Posted 21 November 2003 - 11:23 AM
1) Make sure you have at least one reasonably wide field eyepiece e.g. a 25mm. The Tal is an f/10 so your field of view is only 1 degree even with the 25mm. Then you can :-
- find things in the finder
- make sure you can see it in the 25mm
- up the magnification if appropriate.
Without goto you'll be struggling with just a 12.5 as your widest field.
I think you get a TAL 25mm ep with the OTA anyway. As far as I can tell it is a good eyepiece. I've seem good reviews of it elsewhere. Certainly the one I use most - especially for Deep Sky (or as much Deep Sky as I can see from my rather light polluted garden)
Posted 21 November 2003 - 11:50 AM
I also have a TAL 100 RS OTA. I think the optics are exellent. In the often steady skies of Arizona I can use 250x with no image breakdown. That is impressive for a cheap 4" achromat. I have it on a Universal Astronomics Unimount and surveyor tripod. I srongly recommend a Minus Violet filter to get rid of the chromatic aberration.