Zoom eye pieces, any good. (1 Viewer)

[giosblue]

Just a general question to all the forum members that are vastly more experienced in these matters than me.

After a long absence I'm just getting back into my birding.
All my gear apart from some new bins I have just bought is old. 20/25 years.
Having said that, I'm perfectly happy with the bins, the difference between my old Bausch and Lomb Elite 10x42 and the new Bushnell 8x42 Ed is not that great.
Both are excellent.
The scope is a Optolyth TBS80 HD with the fluorite lenses. I have a 20x 30x and a 22x60 zoom. The 20x and 30x are fine, but the zoom leaves a lot to be desired. Are newer zooms like this, or have there been big improvements over the years? Am I expecting too much at 30x plus magnification?

Ron

 

[mayoayo]

Zooms have been much improved in recent years...new designs in zoom eyepieces have fields of view that at most of their range,rival wide angle fixed eyepieces,with good eye relief,and even weatherproof..Coatings have also been improved,and such complex designs as zooms,with so many glass surfaces ,benefit of such advances in the form of better contrast and brighter images.How much too expect in terms of magnification depends on Your scope,but i would expect a reputable brand ,with 80 mm fluorite objective to be able to handle quite more than 30x with ease.
I have a kowa 823,of similar vintage and caracteristics,coupled with a modern,wide angle zoom,the Baader Hyperion,and use it all the time at powers very close to 60x and excellent performance.I think I have read reports of the Optolyth 100 using the same eyepiece (Baader zoom),so its quite possible that you would be able to adapt one to yours as well..

 

[giosblue]

Thanks for that, I was thinking would it be possible to upgrade the eye piece. The problem is, nobody seems to sell Optolyth in the UK any more. From your experience it seems my 22x60 zoom is sadly lacking.

Ron

 

[mayoayo]

I have seen that zoom,in recent pictures,amd looks like a very nice eyepiece.,excellent coatings and quality build..What is that you dont like about the image,compared with the fixed power eyepieces?

 

[giosblue]

It's not as bright or contrasty Unless it's bright sunlight it just looks flat. The more you zoom out, the better it gets though. Not sure about third party zooms. If it screws in does that mean it's compatible? Mine has a 35mm dia thread.

 

[Tero]

I use a Pentax scope with a Vixen Zoom. It gives me 20x to 49x. Beyond that, the 65mm scope would be too dim to use. For most use I leave my glasses on, going to about 40x. The eye relief on eye pieces is all over the place so check those specs. And for most scopes you are quite limited by branded eye pieces.

 

[giosblue]

I've found that moving my eye further away helps, but the FOV is much less. Trying to get your eye in the middle is hard when your close up to the lens. Optolyth have a new 20x60 eye piece. I wonder if this would be compatible and also an improvement?

 

[jring]

Hi Ron,

in general, the human eye in bright sunlight has a pupil size of approx. 2.5mm. If the exit pupil of your optics (which is calculated by dividing the objective diameter trough the magnification) gets smaller than your eyes pupil size, the image will go gradually darker with decreasing exit pupil size.

So that's why around 30-35x is the optimum for 80mm scopes regarding image brightness. Also there's usually nice wide angle fixed magnification eyepieces at that magnifications which look glorious.

On the other hand there has been quite a lot of progress in zoom eyepiece construction and in coatings in the last 20-30 years, so a current zooms usually are a lot better than the classic examples in many ways: wider field of view, brighter due to better coatings and sharp up to the highest magnification.

On my Kowa body of similar vintage comparing a modern zoom with the old one is like night and day. I cannot comment on Optolyth though, as I haven't used their products.

So as usual - if you decide to give it a try - order from a shop with a good return policy.

Joachim

 

[giosblue]

Anybody on the forum speak German?. Contacted a seller on ebay to ask if the later eye pieces would fit my scope, and this is the reply.

HAllo
Dafür müssen wir die genaue Gerätenummer haben dann können wir beim Hersteller nachfragen.
Mit freundlichen Grüßen

Did it on google.

Hello
For this we need the exact DeviceNumber have then we can ask the manufacturer.
best regards. Unbelievable.

Ron

 

[giosblue]

Hi Ron,

in general, the human eye in bright sunlight has a pupil size of approx. 2.5mm. If the exit pupil of your optics (which is calculated by dividing the objective diameter trough the magnification) gets smaller than your eyes pupil size, the image will go gradually darker with decreasing exit pupil size.

So that's why around 30-35x is the optimum for 80mm scopes regarding image brightness. Also there's usually nice wide angle fixed magnification eyepieces at that magnifications which look glorious.

On the other hand there has been quite a lot of progress in zoom eyepiece construction and in coatings in the last 20-30 years, so a current zooms usually are a lot better than the classic examples in many ways: wider field of view, brighter due to better coatings and sharp up to the highest magnification.

On my Kowa body of similar vintage comparing a modern zoom with the old one is like night and day. I cannot comment on Optolyth though, as I haven't used their products.

So as usual - if you decide to give it a try - order from a shop with a good return policy.

Joachim

With a 80mm x60 zoom the exit pupil would be 1.33 and 4 for the 20x, so I suppose every 60x would be compromised in poor light. Still don't think mines up to much though.

 

[jring]

Anybody on the forum speak German?. Contacted a seller on ebay to ask if the later eye pieces would fit my scope, and this is the reply.

HAllo
Dafür müssen wir die genaue Gerätenummer haben dann können wir beim Hersteller nachfragen.
Mit freundlichen Grüßen

Did it on google.

Hello
For this we need the exact DeviceNumber have then we can ask the manufacturer.
best regards. Unbelievable.

Ron

Hi,

yes I speak german - so if you have more questions beside the correct google translation, send me a PM.

Joachim

 

[jring]

With a 80mm x60 zoom the exit pupil would be 1.33 and 4 for the 20x, so I suppose every 60x would be compromised in poor light. Still don't think mines up to much though.

Yes, with a current zoom you should get satisfactory image at max magnification from an 80mm body with a fluorite lens. My old Kowa TSN-3 is great with the Opticron EP I put on there (although this combination tops out at 53).

Joachim

 

[mayoayo]

I think the eyepiece i was refering to in my previous post is actually the new zoom...Can you post images of your scope and eyepiece?

 

[giosblue]

Hi. I've taken a picture, but can't find the lead to upload it. I'll try to post it later.

I've seen the new eyepieces, mine aren't like those. I would say mine are about 20 years old.
I've been looking at some scopes and most of them seem to be supplied with some sort of zoom, even the very expensive ones. It looks like I could get a pretty good scope for about £800 c/w 20x60 zoom.

I'm happy with the Optolyth, but not the zoom. I don't mind spending £300 on a zoom if it is significantly better. Reading the reviews, the latest zooms seem ok. Always going to lose some light at the extreme, but apparently, sharpness and contrast are pretty by all accounts.
I've e-mailed Optolyth to see if the latest eyepieces are compatible with my scope. waiting for the reply.
When I bought mine it was £150, still got the price sticker on the box.

Ron

 

[mooreorless]

Hi Ron, To post pictures click the "Go Advanced" beside "Post Quick Reply" below , after you do that look below a little "Manage Attachments" click on that >> a pop up window to the left with "Browse" click on Browse etc. Hope this helps some.

 

[giosblue]

Thanks for all your input chaps, however, I have an update.
The Optolyth zoom is not as bad as I thought. I've not used it for a number of years and the sponge padding that is in the tube had gone sticky and was stuck to the lens when got it out. The eyepiece looked clean and I just fitted it to the scope. It turns out that the sponge had left a residue on the lens, which I didn't see.
Anyway, cleaned and now much improved. still not has good as the fixed optics, but more than acceptable.

The latest lenses do fit my scope and I would love to try one, but nobody sells Optolyth in the UK any more.
The last coupe of days here in the UK have been dull and overcast so I'm not getting the best view, I'll report back when I get better lighting conditions.

 

[DRodrigues]

Ron,
Is possible to use Baader zooms in some Optolyths scopes but depend on the model and the age. I can use it on my "less old" 100 scope - see about the use of astro eyepieces http://www.pt-ducks.com/cr-telescopes.htm#Our%20experience and compare your serial number to mines.
I remember to look to old Optolyth zooms that were great in your scope but weren't 22-60x. Your starts at 22x? The more recent Optolyth zooms are better but not as good as the Baader or other top brands, although I don't have the last version - after looking to an wide-angled zoom, even the Baader isn't wide enough...
I'm waiting to an astro 1.25" wide angled zoom but still doesn't exist.
By the way, eyepieces are the weakest part of Optolyth scopes and there are wide angled astro eyepieces that work even better than the Optolyth wide angled eps, being some less expensive...

 

[giosblue]

Thanks for that. The reason I'm asking all these questions is because I have a 20 year old Optolyth TBS/80 ED.
I haven't used it for years, but now I'm getting back into my birding I thought it was a good time to look at the gear I have. The 20x and the 30x eyepieces are fine, very happy with those. ( until I see something better) then the card will be out Lol. The zoom isn't that good, I know zooms aren't meant to be as good as prime optics, but from what I'm reading, the newer ones are very good . Still not as good a good prime optic, but not that far behind.
I would really like a zoom because at 61 I'm looking for and easy life. Optolyth make a new zoom, which I believe would fit my scope. The problem is, no one sells Optolyth any more in the UK, so I can't try one out.

So my options are, keep what I have, or upgrade the scope and get a good zoom at the same time.
I don't want to buy a new scope and be disappointed with zoom.

I'm going to Martin Mere tomorrow and I'm going to visit In-Focus, so I should be able to compare old and new.
When I bought my scope, they didn't have all the information you get on the internet these days.

As much as anything else, I'm really curious to see how much optics have improved over the last 20 years or so.


With regards to binoculars, I don't think they have improved much. My 20 year old Bausch and Lomb Elite 10x42 are just as good as my recently purchased Bushnell 8x42 Elites. The Bushnell my be ever so slightly better, hard to tell because, the old Elites are 10x42. Maybe scopes have improved more? I'll find out for myself tomorrow.

Ron

 

[henry link]

I know zooms aren't meant to be as good as prime optics, but from what I'm reading, the newer ones are very good . Still not as good a good prime optic, but not that far behind.

I've tested many zooms and many wide field eyepieces. I haven't found modern zooms, as a class, to be inferior to wide field fixed magnification eyepieces in the basic areas of sharpness, contrast and light transmission. There are bigger differences in those areas among the different designs within both types than there are between the two types. Remember, modern wide field eyepieces are not simple designs and may have just as many elements as zoom eyepieces and sometimes similar designs. I've tested only a couple of expensive zoom eyepieces (both Pentax) that were bad enough to limit telescope performance. In virtually every case a birding scope that performs poorly at 60x has problems in the optics in front of the eyepiece. The eyepiece may get blamed, but it's usually just accurately revealing aberrations that originate in the objective lens, focusing lens and/or prisms.

 

[giosblue]

Well, despite my best efforts I didn't get to the In-Focus shop at Martin Mere. I had a problem with the builder who was fitting a new bath. That delayed me about an hour. I had to borrow my sons car which didn't have any fuel in it. I managed to get to the petrol station, but it was making a hell of a banging noise from the front. As I set off it began to get worse, a mile or so later I had to stop, it sounded like a wheel was loose, and it was. He had, had is wheels painted a couple of weeks earlier and it looks like they left the n/s front wheel nuts loose.
Managed to make to a garage who tightened them up for me. Only done four miles and I'm already £25 out if pocket. Nevertheless I carried on, it was a lovely Autumn day and I was really looking forward to seeing the reserve and checking out the latest gear at In-Focus. When I got to Martin Mere it was absolutely packed to the gills, couldn't even park up. It was half term, a lovely day and every Mum and Dad from the N/W was there with their kids, so I came home I'm planning to go next week when the kids are back at school.
And to top if off! when came home , I was locked out and I didn't have a key, so I went back to work.
Today has been a complete disaster.