Explore Scientific 92/100 or APM

[Don Pensack]

Moved to relevant thread.

Edited June 9, 2020 by Don Pensack

[Stardaze]

On 09/06/2020 at 09:20, Ships and Stars said:

I can't tell you about the ES offerings, but used to own the Tele Vue 21E and 13E  (and a Leica ASPH zoom) and subsequently replaced those with the APM 20mm, 13mm and 9mm XWAs. I use them in both f4.9 and f3.95 scopes (12" and 20" SW dobs)

Before I sold the 21E, I spent hours one night swapping back and forth, over and over, between the 21E and the 20APM, to the point I couldn't remember which one was in the focuser without feeling around in the dark. The 21E had a slightly wider FOV than the one mm difference suggests, and seemed to snap to focus slightly easier than the APM. The TV eyecup is softer and lower profile, I have to kind of lean in a bit with the APM eyecup or fold it down.

The 20mm APM is c.33% lighter at 680g vs 1020g for the 21E. There is a corresponding size difference as well.

Optically, I could see no discernible difference between the 21E and 20APM side by side, even viewing stars at the extreme edge of the FOV at f4.9. The APM did not seem better than the Ethos optically, but it's close, very close in my humble opinion. By the way, I was using an ES HR coma corrector, the CC settings for the 21E and the 20APM were virtually identical. 

The 20mm APM is £240.00. The 21mm Ethos is £819.00 as you are probably aware. That is a huge difference.  Like ES, I suppose with the APM XWAs there is the ethical question of copyright and/or copying TVs design, but I don't know to what extent the designers of APM have done this. 

After testing the 20APM, I ordered the 13mm and 9mm siblings the following morning and the 21E went on ABS. I wasn't sure at first about ordering the 9mm, but it turned out to be a great move. It's killer on small galaxies, PN and lunar, and I've used it a lot more than I thought I would.

If I had a home obsy, I might have kept the 21E and 13E, but I'm always dragging my scopes around Scotland in a rush to various dark-sky spots and the thought of dropping the 21E some night after tripping on a rock, or even losing it somehow when packing up and heavily fatigued in the dark was a constant point of concern and stress which took away from the experience. At 1/3rd to 1/4th the price, I do not have that stress with the APMs!

While I do not have anywhere near the overall experience as John, Don and Gerry, et al have, I don't regret for a second buying the 20/13/9mm APMs. They are my go-to eyepieces. 

 

Going slightly off on a tangent now, but interested to hear about you dragging your dobs around to dark sites. Appreciate the 20” is a totally different animal, but how do you go about the 12”? Is it an Orion dob? Mines a Bresser and hoping to replace the mount with an Orion version which I’m hoping will make it slightly easier to cart to a site. Interested to know how you go about it. 

[John]

At some point hopefully the SGL star party will start up again. It's held near you and while the skies are not perfect they can be pretty good. I've had some great fun there with 10 and 12 inch scopes (and even with smaller ones - the skies can be quite a bit darker there than they are at home)

[Stardaze]

6 minutes ago, John said:

At some point hopefully the SGL star party will start up again. It's held near you and while the skies are not perfect they can be pretty good. I've had some great fun there with 10 and 12 inch scopes (and even with smaller ones - the skies can be quite a bit darker there than they are at home)

That would be pretty good John 👍

How do you find carting your 12” around? 

Edited June 10, 2020 by Stardaze

[John]

1 hour ago, Stardaze said:

That would be pretty good John 👍

How do you find carting your 12” around? 

My 12 weighs about the same as a Skywatcher / Bresser 10 so it's not too bad. The tube section just about fits into the car with one half of the rear seat folded flat. The base goes next to it in the boot. The car is a medium hatchback.

 

[Stardaze]

1 hour ago, John said:

My 12 weighs about the same as a Skywatcher / Bresser 10 so it's not too bad. The tube section just about fits into the car with one half of the rear seat folded flat. The base goes next to it in the boot. The car is a medium hatchback.

 

Do you wrap the tube in a duvet? Remember seeing a dob with a seat belt mark in the classifieds and thought, there’s a warning right there. 

Edited June 10, 2020 by Stardaze

[John]

2 hours ago, Stardaze said:

Do you wrap the tube in a duvet? Remember seeing a dob with a seat belt mark in the classifieds and thought, there’s a warning right there. 

Actually I wrap it in an old childs sleeping bag that was my daughters when she was a lot younger. I don't use a seat belt on it though - it neatly fits between the end of the boot and the rear of the passenger seat of the car so it's not going anywhere.

 

 

[Stardaze]

1 hour ago, John said:

Actually I wrap it in an old childs sleeping bag that was my daughters when she was a lot younger. I don't use a seat belt on it though - it neatly fits between the end of the boot and the rear of the passenger seat of the car so it's not going anywhere.

 

 

Do you get out regularly with yours John. Really looking forward to taking mine for a few trips, will just have to prepare a few things ready. Haven’t got an old suitable duvet really. A cheap kids sleeping bag will probably still work out cheaper than a dedicated bag.

[John]

35 minutes ago, Stardaze said:

Do you get out regularly with yours John. Really looking forward to taking mine for a few trips, will just have to prepare a few things ready. Haven’t got an old suitable duvet really. A cheap kids sleeping bag will probably still work out cheaper than a dedicated bag.

A few times a year to society outreach events but not this year so far, for obvious reasons.

I do most of my viewing from my back garden which is not too bad for light pollution although there is some.

 

[Stardaze]

13 hours ago, John said:

A few times a year to society outreach events but not this year so far, for obvious reasons.

I do most of my viewing from my back garden which is not too bad for light pollution although there is some.

 

Do you use a coma corrector for your dob John? Be interesting too see how going to 100 deg will affect this aspect for me. 

[John]

2 hours ago, Stardaze said:

Do you use a coma corrector for your dob John? Be interesting too see how going to 100 deg will affect this aspect for me. 

No. I guess there is some coma visible at the field edges with my F/5.3 dob and the very wide angle eyepieces but I've not noticed it so far. Astigmatism from the eyepiece bothers me much more.

100 degree eyepieces are not something that everybody gets on with to be honest with you, regardless of how well they perform. Quite a lot of folks prefer the 68/70 degree apparent field, some are very happy with 40/50 degrees.

At least we have the choice these days

 

 

[Timebandit]

17 hours ago, Stardaze said:

Do you get out regularly with yours John. Really looking forward to taking mine for a few trips, will just have to prepare a few things ready. Haven’t got an old suitable duvet really. A cheap kids sleeping bag will probably still work out cheaper than a dedicated bag.

 

A Dark site really is worth the effort especially for the fainter DSO. Where a true Dark site will bring out the best on the aperture of your scope. Fainter DSO where you may just see, or possibly not see in light pollution areas will start to pop to your eyes. It really is a woow moment and certainty worth the time and effort for fainter DSO targets 

As I see you are not far from the usual SGL star party event. Then you will have to try and pop across, so many people with so much knowledge on this forum. I am sure yo would find it most interesting and helpful

Also when transporting my scope, I put some old camper foam type sleeping mats on the boot floor first, then an old duvet on top and wrap the scope up , so its safe and does not move around. Look after the kit and the kit looks after you. 

 

 

 

16 hours ago, John said:

A few times a year to society outreach events but not this year so far, for obvious reasons.

I do most of my viewing from my back garden which is not too bad for light pollution although there is some.

 

 

Like you John, because of numerous factors at the moment, then a Dark site trip has not been possible this year, and I do miss the fainter DSO woow factor at a Dark site.

But even in light pollution areas, then there are luckily the Luna, planetary targets and double stars to have a crack at . So it is still possible to enjoy the hobby from home with light pollution issues.

 

 

[Stardaze]

3 hours ago, Timebandit said:

 

A Dark site really is worth the effort especially for the fainter DSO. Where a true Dark site will bring out the best on the aperture of your scope. Fainter DSO where you may just see, or possibly not see in light pollution areas will start to pop to your eyes. It really is a woow moment and certainty worth the time and effort for fainter DSO targets 

As I see you are not far from the usual SGL star party event. Then you will have to try and pop across, so many people with so much knowledge on this forum. I am sure yo would find it most interesting and helpful

Also when transporting my scope, I put some old camper foam type sleeping mats on the boot floor first, then an old duvet on top and wrap the scope up , so its safe and does not move around. Look after the kit and the kit looks after you. 

 

 

 

 

Like you John, because of numerous factors at the moment, then a Dark site trip has not been possible this year, and I do miss the fainter DSO woow factor at a Dark site.

But even in light pollution areas, then there are luckily the Luna, planetary targets and double stars to have a crack at . So it is still possible to enjoy the hobby from home with light pollution issues.

 

 

I can't wait to get out to a darker site. Ironically, I've been looking at areas not too far West of yourself! Look forward to an SGL get-together whenever that's feasible, there's surprisingly no friction I've seen on here yet, which is a nice refreshing change for a forum. 😀 

Edited June 11, 2020 by Stardaze

[Timebandit]

2 minutes ago, Stardaze said:

I can't wait to get out to a darker site. Ironically, I've been looking at areas not too far West of yourself! Look forward to an SGL get-together whenever that's feasible, there's surprisingly no friction I've seen on here yet, which is a nice refreshing change for a forum. 😀 

 

 

I think a lot of people would love to get to Darker Sky's at the moment, with the lock down that has been in place. We are missing our fix of Dark Sky's😱

 

On SGL we do have our little banter going on at times especially around refractor v reflector posts and the Tak club 😁.  But mostly taken with a pinch of salt and a smile👍

 

 

[bomberbaz]

I have to throw Nikons into this discussion. I have researched these a lot both before purchasing and since. Most commenters shade the views through them at just edging it over the Ethos. Not massively but it's apparently there none the less.  I do occasionally and unashamedly congratulate myself over taking the plunge and shelling out on these 

I have not yet had opportunity to run a comparison to the Ethos and with the current situation that is unlikely to change in the near future. I am looking forward to running them side by side when the time comes.

Weight wise they are quite a lot lighter than the ES, especially the 12.5mm. The 17 is 950gm but the 12.5 is a mere 672gm. 

The 17 is a 2" fitting and takes 2" filter, however the 12.5mm which is also 2" has a 1.25" nose and so only accepts the same filters. However I use a coma corrector which accepts 2" threads so it's not a huge issue.

I am by no means a EP expert, many on here have far more experience in comparing and dissecting glass results. But all i will say is that as long as my eyesight allows, there is no way on earth I would part with them. 

[John]

The Nikon NAV HW's cost around £980 each I believe. The ES 92's cost £379 each. £600 quid per eyepiece is quite a difference

I didn't mention the Ethos equivilents in this thread because I thought that their price tag would cause a stir.

I'm glad that the NAV HW's are so good

 

 

 

 

 

[bomberbaz]

18 minutes ago, John said:

The Nikon NAV HW's cost around £980 each I believe. The ES 92's cost £379 each. £600 quid per eyepiece is quite a difference

I didn't mention the Ethos equivilents in this thread because I thought that their price tag would cause a stir.

I'm glad that the NAV HW's are so good

Wow it is a huge difference in price, if I were starting from fresh then I would certainly be factoring that into a new decision.

Although I forgot to add that each eyepiece comes with an EIC (read mini barlow) so you get two eyepieces for the price of one.

BTW I didn't realise they had increased so much in price.

Also i would like to, if possible run a comparison between these and equivalent ES.

Edited June 12, 2020 by bomberbaz

[Louis D]

@bomberbaz How of the field of view is visible when wearing eyeglasses in the NAV-HWs?  I would estimate about 80 degrees or so.

[bomberbaz]

I don't wear my glasses when viewing @Louis D, I use a dioptrix which gives a few extra millimetres ER than when using glasses.

Below a 3mm exit pupil I don't bother with anything. My astigmatism doesn't bother me at this point. I have tested several times and I should theoretically use it to 1.5mm exit pupil but like I say, at 3mm and below I don't need it as there is nothing there that I can notice. 

As for what FOV, you have to move your eyeball around to get the full field of view, but your guess at 80 is probably close to it. However from what I have read this isn't native to just the nikons, I believe all ultra wide (+100) eyepieces have the same issue.

Still feels like your falling into it when you put your eye up against it though, exquisite. 

Steve

[Stardaze]

8 hours ago, bomberbaz said:

Wow it is a huge difference in price, if I were starting from fresh then I would certainly be factoring that into a new decision.

Although I forgot to add that each eyepiece comes with an EIC (read mini barlow) so you get two eyepieces for the price of one.

BTW I didn't realise they had increased so much in price.

Also i would like to, if possible run a comparison between these and equivalent ES.

I just can't see how they justify that price tag against ethos? Bonkers. A quality fast prime lens from Nikon isnt too much different to that price point and arguably, there's a lot more glass to them. You pays your money I guess...

Edited June 12, 2020 by Stardaze

[bomberbaz]

10 minutes ago, Stardaze said:

I just can't see how they justify that price tag against ethos? Bonkers. A quality fast prime lens from Nikon isnt too much different to that price point and arguably, there's a lot more glass to them. You pays your money I guess...

I didn't pay the price they currently go for thankfully. However to buy the 3 ethos that the two nikons cover would cost you over £1700. 

I have had these for 4 years now, I think I will still own them in another 10. In that case to me it's money well spent. 

[John]

I only bought one of my Ethos new. The 21mm cost me less than 50% of the current list price, thank goodness !

 

[Timebandit]

 

 

 

Wooow . I thought my Pentax XW , Nagler and Vixen LVW  were not the cheapest eyepiece's (and purchased used). But they look a complete bargain compared to the Nikon. Good job I have not got a taste for 92/100 wide angle eyepiece's 😱. 

 

 

 

[jetstream]

1 hour ago, Stardaze said:

I just can't see how they justify that price tag against ethos

Just look through one...

In comaparison to my 17E the Nikon 17 HW offers a more contrasted view on nebula which is quite a feat actually. The Swan, through the 17HW is a stunning stunning sight, filtered or not.

Thing is you get both a 17mmm and 14mm for the huge price... I bought mine directly from Japan when our dollar was more friendly to the Yen and did not pay near the quoted price in this thread.

And yet! the 20mm Lunt can hold its own in this crowd...

[John]

@Stardaze there you go - you start a thread on the merits of £200-£300 eyepieces and end up getting recommended £1000 ones !

As Gerry / @jetstream says though - your original shortlist are hardly shabby in any way and will show fabulous views