Pentax 8-24 SMC zoom eyepiece

[Richard Hather]

I will soon be the owner of this EP, I was wondering if anyone has any experiences or advise they would care to share.

I like the idea of not having to swap eps, ease of use is key for me, the trade of FOV as far as I can tell but not much else?

I will of course be purchasing fixed eps at a later date, I honestly think a zoom EP will come in handy ☺️

[Dave In Vermont]

I imagine you are thinking of springing for a Pentax, as you titled the thread. By all accounts, these are very good Zoom's and a step-up from less costly Baader Hyperion Mark III 8 - 24mm.

You've also demonstrated 'doing your homework' and are aware of Zoom EP's having a diminished FOV - compared to fixed F.L. EP's. I'll only point out a few other things about these:

The 24mm setting is often too narrow for many people, and experienced folks often recommend one to think of these as really being 8 - 20mm range. Many people - including myself - use these from time to time. I usually carry my Vixen LV - ZOOM 8 - 24mm Zoom for my grab-and-go telescope, an ST80. This works very well, and people enjoy playing 'skydiving-on-the-Moon' with one. I also have this to add - do check for what you're looking for in 'Used' listings, as you might just find one that's a bargain. Us astro-folks tend to keep our gear in excellent condition. The rule-of-thumb in 'used' tends to hover around 2/3rds. new-costs.

Have fun!

Dave

[Richard Hather]

22 minutes ago, Dave In Vermont said:

I imagine you are thinking of springing for a Pentax, as you titled the thread. By all accounts, these are very good Zoom's and a step-up from less costly Baader Hyperion Mark III 8 - 24mm.

You've also demonstrated 'doing your homework' and are aware of Zoom EP's having a diminished FOV - compared to fixed F.L. EP's. I'll only point out a few other things about these:

The 24mm setting is often too narrow for many people, and experienced folks often recommend one to think of these as really being 8 - 20mm range. Many people - including myself - use these from time to time. I usually carry my Vixen LV - ZOOM 8 - 24mm Zoom for my grab-and-go telescope, an ST80. This works very well, and people enjoy playing 'skydiving-on-the-Moon' with one. I also have this to add - do check for what you're looking for in 'Used' listings, as you might just find one that's a bargain. Us astro-folks tend to keep our gear in excellent condition. The rule-of-thumb in 'used' tends to hover around 2/3rds. new-costs.

Have fun!

Dave

Hi Dave, you are right the Pentax is the zoom EP I will be purchasing second hand I mite add.

Im going to be a little more specific with what I plan on using the zoom for which is dso purely visual observations.

How is the detail on dso from what I've read the Pentax is up there with the best with the amount of detail and dark backgrounds achieved?

Richard

[Merlin66]

The Pentax is a great (but big and heavy!) zoom eyepiece.

I use mine for solar observing - no issues, no drama. A great performer.

 

[Richard Hather]

1 hour ago, Merlin66 said:

The Pentax is a great (but big and heavy!) zoom eyepiece.

I use mine for solar observing - no issues, no drama. A great performer.

 

Thank you for your comment Merlin, optically it's meant to be up there with the best, have been you ever used it for night viewing? 

I honestly can't wait to try it ☺️

Richard

[Dave In Vermont]

I've only got 2nd. - hand info on the Pentax. But that which I hear match-up with what Merlin said.

I have the Vixen LV-ZOOM and the Baader Hyperion Mark III. Both work well for me.

Please let us know how it works out for you. I'll toss your report in my files to pass onto curious folks.

Enjoy,

Dave

[Merlin66]

Richard,

I only do solar observing and spectroscopy.

Not enough time in the day/ night for much else.

I'm sure you will find it works well for you.

 

[Richard Hather]

5 hours ago, Dave In Vermont said:

I've only got 2nd. - hand info on the Pentax. But that which I hear match-up with what Merlin said.

I have the Vixen LV-ZOOM and the Baader Hyperion Mark III. Both work well for me.

Please let us know how it works out for you. I'll toss your report in my files to pass onto curious folks.

Enjoy,

Dave

I've heard good things about both those zooms.

Trust me I can't wait to get my hands on the EP and see how it performs ?

I will most certainly be posting a report on how I think it performs and the pros and cons I can't wait ☺️

Richard

[Richard Hather]

5 hours ago, Merlin66 said:

Richard,

I only do solar observing and spectroscopy.

Not enough time in the day/ night for much else.

I'm sure you will find it works well for you.

 

Merlin,

I think I will enjoy using it and I understand your time woes I'm much the same I struggle to find time myself ?

Richard

[Ricochet]

Congrats on buying a great EP. I considered buying it for my Pentax spotting scope but having decided against it had been willing someone else to take it before temptation overcame me.

You've certainly got a top eyepiece for planetary and double star observation where you can seamlessly adjust the magnification to match the seeing conditions. I've not considered/tried a zoom for DSO observation before but in theory you can do something similar and adjust the magnification for optimum exit pupil for each object. However, this means that you are likely to be using it at the narrow end of the range so I suspect that while it might excel for small DSO's like planetary nebulae and globular clusters large DSO's like diffuse nebulae and open clusters might require you to revert to fixed focal lengths with wider views.

[Merlin66]

 

The photo shows a standard TV 21mm Plossl, TV 8-24mm Zoom and the Pentax 8-24mm Zooooom!

Big, bold and beautiful.

[Richard Hather]

11 minutes ago, Ricochet said:

Congrats on buying a great EP. I considered buying it for my Pentax spotting scope but having decided against it had been willing someone else to take it before temptation overcame me.

You've certainly got a top eyepiece for planetary and double star observation where you can seamlessly adjust the magnification to match the seeing conditions. I've not considered/tried a zoom for DSO observation before but in theory you can do something similar and adjust the magnification for optimum exit pupil for each object. However, this means that you are likely to be using it at the narrow end of the range so I suspect that while it might excel for small DSO's like planetary nebulae and globular clusters large DSO's like diffuse nebulae and open clusters might require you to revert to fixed focal lengths with wider views.

I have to admit it's been on my radar almost since I started out 6 months and finally I'm at the position were my setup is complete and I can focus on eps.

Thats a good point about open clusters which are some of my favourite kind of DSOs.

I do currently own a vixen 40mm EP for this purpose and I will be purchasing a Televue  32mm plossl and a 24mm panoptic for this purpose then of course my Pentax zoom for any sort of magnification if all goes well I'm hoping to have these by Christmas ?

Richard

[Richard Hather]

39 minutes ago, Merlin66 said:

 

The photo shows a standard TV 21mm Plossl, TV 8-24mm Zoom and the Pentax 8-24mm Zooooom!

Big, bold and beautiful.

Wow that really puts it in perspective, it does look beautiful ?

Richard

[F15Rules]

Hi Richard,

Congratulations on acquiring one of the best zoom eyepieces ever made. Only a couple of zooms better it in my opinion, the Aspheric made by Leica and maybe a Nikon one, but these only beat it by having a wider field of view.. on axis it competes with anything.

I owned this zoom until a couple of months ago and sold it to Derek (DRT) on this forum. If you have bought his ep, you are buying mine too!

Again, if you are buying this one, I bought it new from First Light Optics and it will be in mint condition. You can find a thread I started in May here, where I introduced it as part of my Pentax Family of eyepieces...
https://stargazerslounge.com/topic/269416-meet-my-new-pentax-family/#comment-2948933

Sadly I had to let it go for financial reasons but would definitely buy another in the future. I also let the XW 20mm and 14mm go as I found issues with their field curvature and, on the 14mm, kidney beaning. I still have the 5.2mm and 10.5mm Pentax XLs shown, and am delighted with both of them.

 

Back to the SMC Zoom. It might help if I list a few of the pros and cons as I see them:

Pros:

Superb build, better than anything I have seen (including a Leica Vario I used to have).

Heavy - I like this as it matches my other Pentax and Morpheus and ES eyepieces, so little scope rebalancing needed

Water resistant JIS4. Has internal O ring seal to keep out dust and moisture. Not the latest full waterproofing but it's keeping the dust out that I like.

Large eye lens, good eye relief. An amazingly comfortable eyepiece to use for extended periods.

Optics are A1. Sharp in my F7.7 apo right to the edge. What scope will you be using it in?

Contrast- super contrast, almost as good as the XW/XL fixed range eps.

Cons:

Heavy - yes, this is both a pro and a con... on the con side, some might find it affects the balance, eg on a Dobsonian, but this was never an issue with my refractors.

Stiff zoom action - this was partly due to it being new, it was freeing up after a couple of months' use. But it's also due to the O ring seal, this means it will always be stiffer than for example a Baader Hyperion zoom. It's just the price you pay for dust and moisture resistance, which I think are good benefits. TIP!! - you can deal with this buy buying a Baader clicklock adapter. This locks the eyepiece very firmly in your focuser, and you will then find the smooth action to be much easier and creamy smooth in use. If you have a 2" focuser (this is a 1.25" barrel ep), you can get one of these: https://www.firstlightoptics.com/adapters/baader-clicklock-2-125-adapter-2956214.html  - not cheap at £55 new, but a great piece of kit. They do come up for sale here and on UKABS for around £35.

Field of View - I agree with what Dave says above - consider this as an 8-20mm range eyepiece. The 24mm setting is only around 40degrees, and if you are getting a Pan 24mm at 68 degrees the Pentax can't compete with that. As you go higher in power, the Pentax will open up in field to a very nice 60 degrees at 8mm, lovely! And all of the field should be sharp, so long as you're not using an uber-short focal length scope under F5 or so.

Light Transmission - wasn't sure whether to list this as a con, I'm being picky now..the light transmission is just a tad less than the fixed length versions. However, the excellent contrast will help you with DSO viewing, so I wouldn't worry about a small reduction in transmission as it would only be visible at the very edge of the scopes light gathering..you might not even notice it.

Price: it's not cheap! But nothing worth having is, and when you consider you are getting almost XW performance albeit with a narrower field, and a very useable range of 8mm-20mm, and the fact that it will literally last longer than you will live, it is good value.

Hope that helps Richard, and enjoy your new toy! - and do let us have your thoughts once you have tried it properly.

Dave

 

[Dave In Vermont]

2 hours ago, Merlin66 said:

 

The photo shows a standard TV 21mm Plossl, TV 8-24mm Zoom and the Pentax 8-24mm Zooooom!

Big, bold and beautiful.

One amusing & true story about that TeleVue® Zoom EP: TV was caught buying the same Zoom as Vixen was selling as their 8 - 24mm LV Zoom. Same factory, same everything - but the price - the TV was more £$€'s. But TeleVue started claiming they always picked-out the "...best one's from the lot..." and blah, blah, blah. But no one wanted to hear it.

TeleVue discontinued offering the 8 - 24mm Zoom as a result. I believe this was the only big 'OOOPS!' TeleVue ever had. The rest of their stuff remains incredibly good.

Thanks for jogging - or jarring - my memory-circuits, Merlin!

Dave

[John]

I still think the 2-4mm and 3-6mm Nagler zooms ming be made by Vixen. TV have used Vixen for a number of products in the past which have had the TV branding. 

More recently TV have had exclusivity deals with their manufacturers so you won't see the same products sold under other branding elsewhere.

I don't think it was a case of being "caught" Dave - it was fairly well known that Vixen produced the 8-24 TV zoom. Most brands gear is made by someone else, has their branding applied and is then sold for whatever the brand thinks the market will stand. Look at the BST Starguiders / Explorers and the Orion Epic II eyepieces - Orion lists the Epic II's at £120 apiece here in the UK whereas the BST Starguiders are £49. Perhaps we should "name and shame" Orion

Alternatively, with the help of forums like SGL, we can be informed buyers

 

 

 

[Telescope40]

2 hours ago, Richard Hather said:

Wow that really puts it in perspective, it does look beautiful ?

Richard

Nice zoom for sure.  Big and bold. I use 2 TV zooms in my binoviewers and  on their own. I'm happy with the views given the above comments and cost to my wallet. 

The Pentax is a big step up in quality. Enjoy, Richard. 

 

Regards John 

[Richard Hather]

8 minutes ago, Telescope40 said:

Nice zoom for sure.  Big and bold. I use 2 TV zooms in my binoviewers and  on their own. I'm happy with the views given the above comments and cost to my wallet. 

The Pentax is a big step up in quality. Enjoy, Richard. 

 

Regards John 

Thank you John, it will be my first high quality EP and the first zoom I've tried a lot of firsts ?

Thats my thinking at the moment I have plossls and I'm happy with the views I get through those ?

Richard

[Richard Hather]

2 hours ago, F15Rules said:

Hi Richard,

Congratulations on acquiring one of the best zoom eyepieces ever made. Only a couple of zooms better it in my opinion, the Aspheric made by Leica and maybe a Nikon one, but these only beat it by having a wider field of view.. on axis it competes with anything.

I owned this zoom until a couple of months ago and sold it to Derek (DRT) on this forum. If you have bought his ep, you are buying mine too!

Again, if you are buying this one, I bought it new from First Light Optics and it will be in mint condition. You can find a thread I started in May here, where I introduced it as part of my Pentax Family of eyepieces...
https://stargazerslounge.com/topic/269416-meet-my-new-pentax-family/#comment-2948933

Sadly I had to let it go for financial reasons but would definitely buy another in the future. I also let the XW 20mm and 14mm go as I found issues with their field curvature and, on the 14mm, kidney beaning. I still have the 5.2mm and 10.5mm Pentax XLs shown, and am delighted with both of them.

 

Back to the SMC Zoom. It might help if I list a few of the pros and cons as I see them:

Pros:

Superb build, better than anything I have seen (including a Leica Vario I used to have).

Heavy - I like this as it matches my other Pentax and Morpheus and ES eyepieces, so little scope rebalancing needed

Water resistant JIS4. Has internal O ring seal to keep out dust and moisture. Not the latest full waterproofing but it's keeping the dust out that I like.

Large eye lens, good eye relief. An amazingly comfortable eyepiece to use for extended periods.

Optics are A1. Sharp in my F7.7 apo right to the edge. What scope will you be using it in?

Contrast- super contrast, almost as good as the XW/XL fixed range eps.

Cons:

Heavy - yes, this is both a pro and a con... on the con side, some might find it affects the balance, eg on a Dobsonian, but this was never an issue with my refractors.

Stiff zoom action - this was partly due to it being new, it was freeing up after a couple of months' use. But it's also due to the O ring seal, this means it will always be stiffer than for example a Baader Hyperion zoom. It's just the price you pay for dust and moisture resistance, which I think are good benefits. TIP!! - you can deal with this buy buying a Baader clicklock adapter. This locks the eyepiece very firmly in your focuser, and you will then find the smooth action to be much easier and creamy smooth in use. If you have a 2" focuser (this is a 1.25" barrel ep), you can get one of these: https://www.firstlightoptics.com/adapters/baader-clicklock-2-125-adapter-2956214.html  - not cheap at £55 new, but a great piece of kit. They do come up for sale here and on UKABS for around £35.

Field of View - I agree with what Dave says above - consider this as an 8-20mm range eyepiece. The 24mm setting is only around 40degrees, and if you are getting a Pan 24mm at 68 degrees the Pentax can't compete with that. As you go higher in power, the Pentax will open up in field to a very nice 60 degrees at 8mm, lovely! And all of the field should be sharp, so long as you're not using an uber-short focal length scope under F5 or so.

Light Transmission - wasn't sure whether to list this as a con, I'm being picky now..the light transmission is just a tad less than the fixed length versions. However, the excellent contrast will help you with DSO viewing, so I wouldn't worry about a small reduction in transmission as it would only be visible at the very edge of the scopes light gathering..you might not even notice it.

Price: it's not cheap! But nothing worth having is, and when you consider you are getting almost XW performance albeit with a narrower field, and a very useable range of 8mm-20mm, and the fact that it will literally last longer than you will live, it is good value.

Hope that helps Richard, and enjoy your new toy! - and do let us have your thoughts once you have tried it properly.

Dave

 

Thank you Dave for all that information I'm not sure we're to begin with my reply ?

I will start of with the scope I'm using  its a Celestron Nexstar 6se and I've been told many times it's a very versatile scope very easy on eps.

Concerning the click stop baader attachment I've heard about this and as you've pointed out it eases of a bit maybe this won't be an issue I'm sure I will find out ☺️

Finally I will be purchasing your Pentax and I must say I'm very excited to do so ☺️

I saw it up and couldn't resist I remember when you put it up and thought then if only it was a few month from now when I was in a position to purchase eps ☺️

But this chance has come up and I honestly can't wait to look through it ☺️

Richard

[F15Rules]

Hi Richard,

I'm glad my "old" (6 month old!) Pentax is on it's way to you, I think you will like it very much..

Just checking your scope specs online (I think it's the 6" 150mm F10 SCT?), the Pentax would give you a great range of powers from 75x at the 20mm setting up to x187 at the 8mm setting. That's a very useable range on a scope like yours, and probably will take you near to the maximum practical power on planets etc on most UK nights.

As your scope is quite "slow" at F10, the edge of field correction of the Pentax should be nigh on perfect. It will never be a wide field eyepiece, but for ease of use and quality of the views it should please you no end. And your incoming Panoptic 24mm will give you around x63 with a wider apparent field. (By the way, I have the "poor mans 24mm Panoptic", ie the Explore Scientific 24mm 68 degree and it's my most used eyepiece. In your F10 I think it would perform very nearly as well as the Pan, at probably around 40-50% of the price. Just a thought).

If you have a strong clamp on your diagonal you might not need the clicklock, but if you find the whole Pentax barrel rotating instead of just the zoom section, at least you know you can get a solution for it easily :-).

Have fun with it!

Dave

[Richard Hather]

44 minutes ago, F15Rules said:

Hi Richard,

I'm glad my "old" (6 month old!) Pentax is on it's way to you, I think you will like it very much..

Just checking your scope specs online (I think it's the 6" 150mm F10 SCT?), the Pentax would give you a great range of powers from 75x at the 20mm setting up to x187 at the 8mm setting. That's a very useable range on a scope like yours, and probably will take you near to the maximum practical power on planets etc on most UK nights.

As your scope is quite "slow" at F10, the edge of field correction of the Pentax should be nigh on perfect. It will never be a wide field eyepiece, but for ease of use and quality of the views it should please you no end. And your incoming Panoptic 24mm will give you around x63 with a wider apparent field. (By the way, I have the "poor mans 24mm Panoptic", ie the Explore Scientific 24mm 68 degree and it's my most used eyepiece. In your F10 I think it would perform very nearly as well as the Pan, at probably around 40-50% of the price. Just a thought).

If you have a strong clamp on your diagonal you might not need the clicklock, but if you find the whole Pentax barrel rotating instead of just the zoom section, at least you know you can get a solution for it easily :-).

Have fun with it!

Dave

Hi Dave,

It honestly sounds perfect to me fov isn't really to much of an issue for me, I've looked through larger FOVs and honestly they don't do much for me.

Its all about the sharpness and contrast how clear the object is and ease of use.

Concerning the pan I'm sure as the time nears I will decide, the 24mm ES is a quality EP it's just I don't want to always think "what if" lol

Im sure I will have lots of fun thank you Dave ☺️

Richard

[Louis D]

On 8/5/2016 at 05:24, John said:

I still think the 2-4mm and 3-6mm Nagler zooms ming be made by Vixen.

I won't argue who manufacturers these zoom eyepieces, but Al Nagler has been pretty clear in the past that he considers this zoom design to be his proudest eyepiece design achievement, even above all of his wide field designs before Paul Dellechiaie took over designing eyepieces for TV.  Considering no other company has anything remotely like it, I don't doubt him that he designed it.

[Paul73]

Congratulations on what should be a great eyepiece. I was toying with hitting the buy button as I need a second zoom for my solar set-up and thought that a step up from the Hyperion Mk III coukd be good.

I'll probably get another Baarder now. So you have saved me a few quid!

It should work really well in your scope.

Don't forget the first light report.

Paul

[Highburymark]

Top class zoom - and a sturdy SCT like the C6 will handle its bulk well.

[John]

1 hour ago, Louis D said:

I won't argue who manufacturers these zoom eyepieces, but Al Nagler has been pretty clear in the past that he considers this zoom design to be his proudest eyepiece design achievement, even above all of his wide field designs before Paul Dellechiaie took over designing eyepieces for TV.  Considering no other company has anything remotely like it, I don't doubt him that he designed it.

I've no doubts at all about who designed them either