? Eyepiece Upgrade.

[jason.p]

Could I make any significant improvement by upgrading my original 25mm Plossl. I realise my scope has limitations but I would like to be sure I'm getting the very best I can out of it. I've read that BST and Vixen are good, and the sort of price I'd be considering, but only if I'd see a real difference. (My main interest at the moment is DSOs)

Thanks

Jason

[ronin]

The BST's are good and should show an improvement. However the same eyepieces can fall into the catagory that some people like and others dislike.

I would expect you to be happy with an upgrade to BST's.

I was when I changed from "standard" plossl's to them.

TV plossl's may be equally good but thay are now close to double the cost of a BST.

Try the 12mm as I see you do not have a 12mm or get a direct replacement, 8mm or 15mm, and compare.

[crazyjedi]

There was a similar thread on here a little while ago at the conclusion of which the OP upgraded to a Vixen NPL only to come back to the forum to complain that they could see no improvement over their original cheapy standard EP. I was a little surprised at this outcome personally but it probably depends on just how much of an improvement is expected. If you went out and spent £85 on a TV EP you would see an obvious improvement after just a short perioud of use, but if you go for an upgrade to a £30-£40 EP the improvements will be more subtle. It will require a little more use and experience with the EP before the improvements become apparent.

Both the Vixen and BST ranges are good lenses and worth buying as an upgrade over a standard EP so long as miracles aren't expected.

Both brands are very well thought of and will serve you well.

As a way of buying into higher price/quality EP's you could consider buying a second hand TV / Meade/ ES etc EP. Ps there is a Meade 5000 26mm super plossl selling in the classified section for £33 which is a lot of EP for the money - I have several of the Meade 5000 super plossls and they are solidly made and optically very good.

Have fun EP shopping

[Naemeth]

Improvements in eyepieces will result in subtle changes, I upgraded my 25mm to a 26mm Japanese Made Meade Series 4000 Super Plossl, you can see my results here:

http://stargazerslounge.com/topic/157112-skywatcher-25mm-ma-vs-meade-series-4000-26mm-super-plossl/

Bear in mind this was written in July, I'm a little more experience but not much .

[rory]

with my first scope i found the best purchase eyepiece wise was a 32mm plossl of half decent quality,i used it constantly to track down brighter dso's with a wide f.o.v

something like the meade 4000 or 5000 series, or gso. second hand you'll get one for about £20-25 bit more for the 5000 but thats what id go for initially.

i concur though the bst's (starguiders are good value)

the above post seems to agree regarding the meade 's

[jason.p]

There was a similar thread on here a little while ago at the conclusion of which the OP upgraded to a Vixen NPL only to come back to the forum to complain that they could see no improvement over their original cheapy standard EP. I was a little surprised at this outcome personally but it probably depends on just how much of an improvement is expected. If you went out and spent £85 on a TV EP you would see an obvious improvement after just a short perioud of use, but if you go for an upgrade to a £30-£40 EP the improvements will be more subtle. It will require a little more use and experience with the EP before the improvements become apparent.

Both the Vixen and BST ranges are good lenses and worth buying as an upgrade over a standard EP so long as miracles aren't expected.

Both brands are very well thought of and will serve you well.

As a way of buying into higher price/quality EP's you could consider buying a second hand TV / Meade/ ES etc EP. Ps there is a Meade 5000 26mm super plossl selling in the classified section for £33 which is a lot of EP for the money - I have several of the Meade 5000 super plossls and they are solidly made and optically very good.

Have fun EP shopping

I take your point about expectations. That's really why I asked the question. I haven't really spent a lot of time with what I've got, perhaps I should not rush in just yet. I will however keep my eye on classifieds and hold out for something good bearing in mind I may upgrade the scope at some time, and with a birthday and Christmas coming up, who knows

Thanks for sound advice

Jason

[John]

Improvements in eyepieces will result in subtle changes.....

Quite right. The improvements get smaller, the more costly the eyepieces too. When you see discussions about the differences between expensive eyepieces like, say, Naglers and Pentax XW's, what is being discussed are very subtle differences in the viewing experience.

The above does not deter some large investment in eyepieces though - see this thread for the evidence :

[Naemeth]

Quite right. The improvements get smaller, the more costly the eyepieces too. When you see discussions about the differences between expensive eyepieces like, say, Naglers and Pentax XW's, what is being discussed are very subtle differences in the viewing experience.

The above does not deter some large investment in eyepieces though - see this thread for the evidence :

http://stargazerslou...ye-piece-cases/

I personally feel the best way to go about things is get a good (but small) range of eyepieces (either Plossls or LER Type Plossls like TMB/HR Planetary if you need long eye relief etc.) around £30-£40 that suits your needs, and slowly when you feel you're ready you can upgrade. I feel I've got a hole of one eyepiece in my collection, somewhere around a 19mm (Barlow for 9.5mm, I can't get on with the Skywatcher 10mm MA), but I will be happy to fill that with a fairly cheap eyepiece.

Just don't rush things, take some time and enjoy the eyepieces you have .

[jason.p]

The above does not deter some large investment in eyepieces though - see this thread for the evidence :

http://stargazerslou...ye-piece-cases/

Now that's scary

[LukeSkywatcher]

The biggest difference i noticed right away between the Vixen NPL's and standard EP that come with scopes, was that the Vixen's offer much better contrast. I also thought they gave a sharper view, but this point could be debated.

[alan potts]

I would go for something around 32mm as well. I would also try and find something secondhand, that way if you do not like it you will not have lost a great deal if you sell if, maybe you would loose nothing.

A televue 32mm Plossl will hold it's value and is difficult to better in this range of eyepiece. Alao the Meade 5000 Super Plossl with a 60 degree field is very well priced now if you can find one.

The Meade is a 2 inch eyepiece though.

Alan.

[alan potts]

Jason,

I have just noticed a 26mm Meade S Plossl in the classified adds, now i don't know if you can use these as you are new to the site, but I can't see you break any rules if you send a personal message to the person selling.

This is a good eyepiece, I sold mine on site only 10 days ago it came as a standard eyepiece with my LX 200, but this is an expensive scope so it is not a cheap and cheerful eyepiece. This may well be worth a punt.

Alan.

[crazyjedi]

There is something very addictive about EP shopping that is bad for the health of your bank account

[Moonshane]

there's an old adage that if you are poor you cannot afford to buy cheap. it seems counter intuitive but in my experience if you buy the best quality you can then you won't be constantly upgrading with a subsequent loss each time you do. buying top quality need not be expensive. I am dedicated to Televue as I feel they offer quality that cannot be beaten. There are some eyepieces that are as good but different but I don't think 'better'.

A used Televue 15mm plossl would be around £50. This will give a view every bit as good (bar a miniscule amount and with a smaller field) as even an Ethos costing 6-7 times as much even used.

If you can, buy used great quality and you won't regret it. I always say try before you buy if you can and this is equally appropriate here so try to join a local club or attend a star party and compare a few eyepieces with your own.

[crazyjedi]

there's an old adage that if you are poor you cannot afford to buy cheap. it seems counter intuitive but in my experience if you buy the best quality you can then you won't be constantly upgrading with a subsequent loss each time you do. buying top quality need not be expensive.

Agree totally with this - This is exactly my thinking too.

I'm not totally dedicated to any specific brand (though TV are one of the best) but any of the top brands are very close in performance; ES, TV, Pentax, Meade are all right up there and stand out above other brands.

There are other brand series that are much loved. Many people are extremely fond of Baader Genuine Orthoscopic EP's for short focal length planetary EP's. Ortho's are different to plossl's and have fewer lens elements and a tighter FOV but are carefully designed to exploit the minimal layers of glass to enhance the light transmission - improving sharpness in short FL

lenses. (put in lay mans terms I'm afraid)

So there really is a wealth of good quality lenses out there provided by a few top end manufacturers (i'm sure others will chip in with further recommendations) and I, like Moonshane would recommend saving a little more and going for the best quality you can get - even if it is second hand

Happy shopping

[AndyH]

Could I make any significant improvement by upgrading my original 25mm Plossl..............

Possibly Not *

* It depends on the condition of yours. I've noticed that some old Tal 25mm's have a tendency for the optical cement in the pair of doublets to 'go off', which affects the view.

Some horrifically so eg: one of my gen II's

The generation I Tal plossl, has the same glass as in the series II & III, perhaps with lesser coatings though. It's a cracking eyepiece and I've tried quite a few in or around that focal length, over the years.

There are other things to consider.

You have a 1.25"/31.75mm focuser(well actually, yours is 32mm ), so you can't use 2" eyepieces to get wider views.

The widest field stop(FS) you can get in 1.25" 'pieces, I think, is 27mm. In simple designs the FS can be seen(On Tal 25mm's, it's machined into the barrel or may be a sprung ring) and measured up inside the barrel.

So............your scope has a focal length(FL) of 1200.

Max field of view(FOV) you can get is (57.3 x 27) / 1200 = 1.29° ----- doesn't matter if the eyepiece has a FL of 25 or 32 etc, if the FS is 27mm, the FOV will be 1.29°. Only the magnification will differ.

FOV with a 24mm FS = 1.15°

FOV with a 21mm FS = 1.00°

So I'd measure your 25mm's FS & check it's optical condition before splashing out the dosh on a repacement.

I would however think of upgrading & expanding the other eyepiece's, to give a nice range of magnifications, up to around the 200x area.

Andy

edit: ** note my terribly scientific term 'go off'..... hehehe. I think it might be called delamination of the optical cement, used to bond the doublets.

[jason.p]

Thanks Andy for a thoroughly comprehensive reply. I can see what you mean. One thing I had failed to mention to my great embarassment is that I dropped the 25mm EP on a totally unforgiving patio slab and bent it so that it's very difficult to push it into the focuser without losing my place I've tried to round it off again but so far can't quite get it right. I don't think the lenses have been damaged, but can't be sure. So really I'm looking for a replacement/upgrade. As you say my focuser is 1.26mm, but I've fitted a locking thumbscrew and 1.25mms can be held OK.

Thanks

Jason

[AndyH]

Hi Jason.

Reg your 25mm - How does the barrel connect to the body of the eyepiece? Screw in? Any wee setscrews holding it in?

[jason.p]

Hi Andy. I can't see any screws so I guess it may be screw in.

[AndyH]

Check and see if the barrel screws off from the body. If it does, I have a plan.

Andy.

[Marc1980]

I would say buy second hand then if you dont like it you can sell it on with little or no loss. Am I right in thinking that Skys the limit offer a try before you buy service. Another option perhaps.

Sent from my galaxy s3 using tapatalk 2

[jason.p]

Check and see if the barrel screws off from the body. If it does, I have a plan.

Andy.

Hi Andy. From what I can see the barrel is a one piece construction. I've tried to unscrew but without resorting to grip tools there is no movement.

I've managed to winkle out a split ring sleeve from inside and under that is a retaining ring which holds the lens in. This obviously unscrews.

Thanks

Jason

[AndyH]

Mmmm. I didn't realise the Gen I 25's were a 1 piece construction. That pic sure looks like it. I've got a Gen I varient that is 32mm diameter, super low profile and it's barrel comes out.

The bash on it. Is it at the end/top of the pic? If so, extreme careful tapping with a small hammer, at various points around the circumference may help bring it true again. Don't know if you've tried that already?

Andy.

[AndyH]

I think that split ring that you've removed acts as the Field Stop for the lens. Gen II versions on, use a machined stop in the barrel itself.

[jason.p]

Mmmm. I didn't realise the Gen I 25's were a 1 piece construction. That pic sure looks like it. I've got a Gen I varient that is 32mm diameter, super low profile and it's barrel comes out.

The bash on it. Is it at the end/top of the pic? If so, extreme careful tapping with a small hammer, at various points around the circumference may help bring it true again. Don't know if you've tried that already?

Andy.

Yeah, the damage is on the rim at top edge of pic. If I could find a suitable size mandrel to fit inside I'll tap it gently back into shape. So far I've been tweaking it with a small pair of pliers, but as you can imagine, a tweak in one place just move the dint somewhere else

I've also been smoothing it with a bit of wet and dry (desperate measures).

I suppose it will teach me to be more careful in future. Perhaps I should put down some of that rubber matting they have in kids playgrounds

Thanks again

Jason