Somewhat muted.

[Papillon]

Hi all. I posted here earlier this year as I was deciding between a Tal100rs and a Skywatcher ed80 that I had been offered. I ended up getting neither and because of a busy working year forgot all about getting a scope. 

Now work has eased off and the early nights have arrived so last week I bought the Tal with an AZ4 mount. I'm pleased I went with this set up, on just the three nights I've had it I've been able to take it outside in between showers and be viewing within seconds of deciding to do so. Last night was the first time I got chance to spend a few hours out there and having never really used a decent scope before, a few things surprised me. 

One was just how much detail can be seen at lower magnification. Jupiter and it's moons was very clear and with two immediately discernable brown belts with the supplied 25mm eyepiece. For some reason I though higher magnification would be needed. The second surprise was when I turned to Pleiades. Rigel, Aldebaran, Betelguese etc. I guess it was silly of me but because they are so visible with the naked eye or with binos but I was surprised that they don't stand out much more than other stars, not like they do through binos.  What did stand out was M42 and Sirius, especially with the supplied 6.3mm eyepiece. Spent a fair bit of time with them, in fact I think the latter twinkler has been my favourite to view so far. 

Obviously I have a lot to learn but there's one thing that puzzles me. The images through the the Tal, although sharp and offer much more detail, seem quite washed out compared to my 8x42 binos. Through the binos the sky is black and the stars very bright. Through the Tal the sky is a dark grey and objects less bright. I just tested it in the daytime and it's the same. I look through my binos and everything is very bright and colourful, I look through the scope and everything is paler, as if the brightness and contrast has been turned down.  I'm focused, images are sharp, just paler and somewhat muted when compared with the naked eye or binos. What I'm wondering is if  this normal or if something wrong with the scope? 

[Peter Drew]

The  25 mm eyepiece gives 40x magnification with the Tal, if you could use 40x on your binocular that too would look dull compared to its usual 8x. As you magnify an image more detail appears but the brightness will diminish. 

[cotterless45]

The TAL is a lovely scope. Targets will pop out , especially if you can get to a dark site.

Nick.

[Papillon]

The  25 mm eyepiece gives 40x magnification with the Tal, if you could use 40x on your binocular that too would look dull compared to its usual 8x. As you magnify an image more detail appears but the brightness will diminish. 

Thank you. Peter,  I never knew that, most helpful, I can now continue in the knowledge all is normal 

Nick, it is rather nice, I've been thoroughly enjoying myself. Lack of sleep may soon become a problem, though. 

[AndyWB]

Magnification decreasing brightness is a useful thing to know about when viewing the Moon. I don't find it too bright at low power - but high power is more comfortable...

[RichM63]

From what you have said, I would deduce that nothing is wrong.

Your wonderful Tal will also show you outlining problems with atmosphere, LP, and the real difference when moving up to higher apparent magnifications.

For me, supplied job lot eye pieces are included as a marketing tool and should not be taken as a real example of what the telescope is capable of.  (unless of course the job lot is Zeiss).

[Blazar]

TAL's.....gotta love them ;-) ...though mine have not been used for a few months! need an AZ4 as well....

[ronin]

Not sure what the eyepieces are - design - would expect plossl's.

One thought is they are not "good" plossl's, as in the lens edges are not blackened and the coatings not up to scratch.

You could be getting light scatter that would make the general background lighter and so the rest is muted.

Any chance of borrowing another plossl, simply to compare things?.

If there is light scatter then the "worst" case is that it is from the internals of the scope, would mean flocking the inside of the tube. However that is doubtful.

Check the performance with other eyepieces then decide if the situation is improved. Scatter in the eyepiece can occur and has in the past. THe original TMB planetary's were terriable for it, that is why they were "improved" and are now TMB II's. On those the coatings were not great, the edges were not blackened and they used a couple of shiny metal bits in the eyepiece. Basically they bounced light all over the place. :grin:  It does happen.

[Carbon Brush]

Excellent advice from all the above. I only add a question. Is the glassware clean?

If you have a 2nd hand scope, it may have picked up a bit of unwanted coating over time that is just taking the edge off performance.

I'm not suggesting a strip down of everything. Just take a look.

If there is any obvious dirt build up, then deal with it (big subject). Otherwise leave alone.

I once bought a 2nd hand frac that had been used more as a lounge conversation piece than for viewing the sky.

There was a good coating of dust inside the objective!

Don't dive in though. Mucky lenses (and mirrors) can give surprisingly good views.

Hope this helps.

[Blazar]

Not sure what the eyepieces are - design - would expect plossl's.

One thought is they are not "good" plossl's, as in the lens edges are not blackened and the coatings not up to scratch.

You could be getting light scatter that would make the general background lighter and so the rest is muted.

The original RS eyepieces were the 25mm and 6.3mm plossl. The 25 is a really nice piece of glass though the 6.3 could be better. I still gravitate back to the 25 (even in my 800Edge now), though that is also one of the Gen2 25's....even better then the new 25mm that comes with the 100RS.. The TAL diagonals were also of good quality.  Might be good to see a picture just to confirm they are TAL EP's though.

[Papillon]

Thanks for all the advice guys. Yes, the glassware is clean and the inside of the tube looks fine. Both eyepieces gave me what I think are great views but bear in mind I'm new to this so I don't know how good, good is. Jupiter was pristine at 155x, so still and clear it could have been a photo. Incredibly easy to track with the AZ4 too, I thought that might be my downfall being a complete beginner but I kept things in the field of view with ease. I must admit, I have glued a small bolt to the underside of the tube just above the focuser to use as a handle as that seems a more sensible place to manoeuvre the tube from. 

No, I can't borrow an eyepiece but I do plan on picking up something that sits between the two supplied. Once done I can then compare. 

I'm afraid I can't provide photos of the eyepieces, far too a technologically bumfangled thing to do someone as "rural" as  I. The 25mm has Super Plossl written on it and the 6.3mm, Multi Coated Super Plossl. 

As for light scattering, I honestly have no idea how to tell if it is occurring. I shall have to do some reading up. 

All in all I'm very happy with the scope, especially now I am a fraction less ignorant. 

[Jim Steele]

Welcome to the tal owners club!!!

She's a really sweet piece of Russian engineering and I have really taken to mine

I've had mine for around 6 months and I can see where your coming from but I think what your seeing is just down to light skies, may I ask what phase the moon was when you made your observations? The reason I ask is that Moon glow really knocks out details I've found.

The tal teloptics Web page is a good resource, they have some images of the plossls in the review section. They have a very distinctive coating colour on them...

The 25mm ep is a real gem, I have bought a 10mm tal ep from here for £10, along with a 2x Barlow top give me a few more options but on the whole i have been impressed by it especially the lack of apparent ca, it's there but hardly noticeable really.

I'm sure you've made a good choice, they really are nice scopes.

Good luck and clear skies

[AndyH]

Here's a link to the site that Jim references - http://www.talteleoptics.com/eyepieces.html

Further inside that site are a few in depth reviews by a respected observer, which has some more nice, close up pics included. Here they are(pdf files) .........

TAL Super Plossl Review.pdf

Here are an other couple by the same bloke, which are Tal related and may be of interest anyway..........

TAL Finders Review.pdf

TAL SWA-UWA Review.pdf

Hope they're of interest.

Cheers,

Andy.

ps: I'm sure users and owners of the 100RS can recommend eyepieces that work well for the scope, especially higher powered ones, bearing in mind you are using yours on an alt/az mount.

pps: I agree that the supplied Tal 25mm is a lovely eyepiece.