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Opinions on the APM Ultra Flat Field 24mm 65deg?

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#1 howardcano

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Posted 02 March 2018 - 10:31 AM

I'm looking for opinions from owners of the APM Ultra Flat Field 24mm 65deg eyepiece.  There doesn't seem to be much chatter about it.

 

I have an ES 24/68, but it has insufficient eye relief for my thick eyeglasses, and shows sustantial vignetting with my Xcel LX 2X Barlow.  Would the APM UFF be a worthwhile upgrade?


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#2 lylver

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Posted 02 March 2018 - 12:09 PM

Visually excellent. It replaces my Zeiss OPMI 10x22B when I need a bigger field.

I only had one issue when using a filter : retaining ring not well machined, should be deeper threaded to avoid this unscrewing event.

 

http://www.astrosurf...comment-1491646

Smartphone images are nice and I compared it with a 20mm Clave : transmission is lower but stars are pinpoint too and contrast is excellent. (tested on a ED 16" dobson and other scopes)

 

A versatile all scope eyepiece with max field for 1"1/4 (can be used daily on spotting scopes)

 

I think a better than FMC coating and a fix about the retaining ring would put it at a top rank class eyepiece.

 

I prefer it over LVW, Hyperion,and maxvision 68° (tried a 28mm and sent it back)



#3 Starman1

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Posted 02 March 2018 - 08:33 PM

https://www.cloudyni...mm-ufs-arrived/


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#4 howardcano

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Posted 03 March 2018 - 10:46 AM

Many thanks to both of you for the info and links!

 

The link that Don provided said that the eye relief was just about right for use without eyeglasses, so that would be a no-go for my thick glasses.



#5 lylver

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Posted 03 March 2018 - 03:17 PM

 fingertap.gif Fold the eyecup

IMG_20180303_211449.jpg


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#6 howardcano

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Posted 03 March 2018 - 04:08 PM

 fingertap.gif Fold the eyecup

attachicon.gif IMG_20180303_211449.jpg

I assume that the reviewer tried that.  The exact quote is: "Eye relief at eye cups.....need to touch brow to get full fov. Not promising for those that need glasses to observe."

 

I don't want to risk getting yet another eyepiece that has insufficient eye relief for me.

 

I've seen the eye relief on this eyepiece specified as both 29mm and 20mm.  I'll guess that the correct value is 20mm.  But I've had eyepieces with longer eye relief specs that simply didn't work out as the eye lens was still buried way down in the body, even with the cup removed.  Or the spec was simply wrong.

 

I currently have a Delite 18 that has a 20mm eye relief spec, and I'm trusting that is correct.  With the cup all the way down, the eye lens is virtually level with the body and eye cup.  But it just barely gives me enough eye relief to see the entire field, and that's with an AFOV smaller than on the APM UFF 24.


Edited by howardcano, 03 March 2018 - 04:10 PM.


#7 lylver

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Posted 03 March 2018 - 04:39 PM

from top of eyecup (big 42mm diameter eyecup) to center surface : 23mm

Cornea is at the limit of the top of the eyecup for me.

My review was done at a club Star Party, not alone...



#8 howardcano

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Posted 03 March 2018 - 05:26 PM

from top of eyecup (big 42mm diameter eyecup) to center surface : 23mm

Cornea is at the limit of the top of the eyecup for me.

My review was done at a club Star Party, not alone...

Thank you for this information.  I didn't see anything like it on the first link you provided, although it could have disappeared in Google Translate (though I did search the original page for "relief", which appears to be spelled the same in both languages).

 

Can you give me the Z-dimension from the highest part of the body to the center surface of the eye lens with the eyecup removed?  (In other words, how far is the center of the eye lens recessed into the metal body?)   I suspect I'll need almost all of that 23mm.



#9 Starman1

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Posted 03 March 2018 - 06:39 PM

24mm, eyecup removed, depth of lens center below top of aluminum body: 10mm

With eyecup attached and folded down, that's 12mm; effective eye relief is 8mm, insufficient for glasses.

I can't even see a 50° field in this eyepiece with glasses on.

It is an eyepiece designed for NON wearers of eyeglasses.



#10 howardcano

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Posted 03 March 2018 - 06:45 PM

24mm, eyecup removed, depth of lens center below top of aluminum body: 10mm

With eyecup attached and folded down, that's 12mm; effective eye relief is 8mm, insufficient for glasses.

I can't even see a 50° field in this eyepiece with glasses on.

It is an eyepiece designed for NON wearers of eyeglasses.

Thanks, Don.

 

It's a shame, since it sounds like it's a good performer.  I'll keep searching!



#11 Starman1

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Posted 03 March 2018 - 07:09 PM

The 24mm TeleVue Panoptic and 24mm Explore Scientific 68° both have around 13mm of effective eye relief--still not glasses-friendly.

If you're looking for a 68° eyepieces in 24mm with about 20mm of effective eye relief, good luck.

The closest I've found is the 24mm Baader Hyperion, but it's more like 17mm of effective eye relief, not 20.

I can suggest several 22mm, but 24mm is tough.

Don



#12 howardcano

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Posted 03 March 2018 - 09:43 PM

The 24mm TeleVue Panoptic and 24mm Explore Scientific 68° both have around 13mm of effective eye relief--still not glasses-friendly.

If you're looking for a 68° eyepieces in 24mm with about 20mm of effective eye relief, good luck.

The closest I've found is the 24mm Baader Hyperion, but it's more like 17mm of effective eye relief, not 20.

I can suggest several 22mm, but 24mm is tough.

Don

I was hoping to stay around 24 or 25mm.  If I recall correctly (it's been a couple of decades), the Pan 27 didn't have quite enough eye relief, either-- though if it did, I'd be tempted to do that.

 

That said, and with my curiosity piqued, what can you suggest in the 22mm range?


Edited by howardcano, 03 March 2018 - 09:44 PM.


#13 Mike B

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Posted 03 March 2018 - 10:33 PM

24mm, eyecup removed, depth of lens center below top of aluminum body: 10mm

With eyecup attached and folded down, that's 12mm; effective eye relief is 8mm, insufficient for glasses.

I can't even see a 50° field in this eyepiece with glasses on.

It is an eyepiece designed for NON wearers of eyeglasses.

Thanks Don... that pretty well clinches it. I'd wondered about whether folding the eyeguard down, what that netted for ER. Thanks for clearing that up!



#14 SteveG

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Posted 03 March 2018 - 11:23 PM

 

The 24mm TeleVue Panoptic and 24mm Explore Scientific 68° both have around 13mm of effective eye relief--still not glasses-friendly.

If you're looking for a 68° eyepieces in 24mm with about 20mm of effective eye relief, good luck.

The closest I've found is the 24mm Baader Hyperion, but it's more like 17mm of effective eye relief, not 20.

I can suggest several 22mm, but 24mm is tough.

Don

I was hoping to stay around 24 or 25mm.  If I recall correctly (it's been a couple of decades), the Pan 27 didn't have quite enough eye relief, either-- though if it did, I'd be tempted to do that.

 

That said, and with my curiosity piqued, what can you suggest in the 22mm range?

 

If you can use 2" eyepieces, there's nothing better than the Nagler 22T4 for long eye relief. It's my main, low power eyepiece, and mine is fitted with a Dioptrx.


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#15 SteveG

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Posted 03 March 2018 - 11:26 PM

The 24mm TeleVue Panoptic and 24mm Explore Scientific 68° both have around 13mm of effective eye relief--still not glasses-friendly.

If you're looking for a 68° eyepieces in 24mm with about 20mm of effective eye relief, good luck.

The closest I've found is the 24mm Baader Hyperion, but it's more like 17mm of effective eye relief, not 20.

I can suggest several 22mm, but 24mm is tough.

Don

The Meade series 5k 24/68 variant has about 2 more millimeters of eye relief. I can just barely get the entire fov with my Dioptrx sitting on top. It's the best I've come by in 1.25", aside from possibly the Pan 22, which I sold years ago.



#16 Mike B

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Posted 03 March 2018 - 11:40 PM

 

It's the best I've come by in 1.25", aside from possibly the Pan 22, which I sold years ago.

I know, it's a cryin' shame!

 

You want 24-25mm?................we've got that for ya! waytogo.gif 

You want that in 1-1/4" format?......we've got that for ya! waytogo.gif 

You want that in a widefield design?......we've got that for ya! waytogo.gif 

You want that with 18mm or more ER?.......we've got that for ya! waytogo.gif 

 

You want some combination of those?.... what, are you crazy!  ranting.gif 

 

22mm still seems to be the sweet-spot for the combo happy meal....


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#17 Starman1

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Posted 04 March 2018 - 01:35 AM

The Olivon 22 has about 17-18mm of effective eye relief.  Might be a possibility in the lower-cost eyepieces.


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#18 starbase25

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Posted 04 March 2018 - 02:44 AM

Visually excellent. It replaces my Zeiss OPMI 10x22B when I need a bigger field.

I only had one issue when using a filter : retaining ring not well machined, should be deeper threaded to avoid this unscrewing event.

 

http://www.astrosurf...comment-1491646

Smartphone images are nice and I compared it with a 20mm Clave : transmission is lower but stars are pinpoint too and contrast is excellent. (tested on a ED 16" dobson and other scopes)

 

A versatile all scope eyepiece with max field for 1"1/4 (can be used daily on spotting scopes)

 

I think a better than FMC coating and a fix about the retaining ring would put it at a top rank class eyepiece.

 

I prefer it over LVW, Hyperion,and maxvision 68° (tried a 28mm and sent it back)

Just tried to use Google translate for this French site. Won't work right because there is a purple thing stuck over the page which can't be removed. mad.gif LOL.

 

https://translate.go...comment-1491646

 

Can't translate the very last post either. ------>  Text exceeds 3900 character limit

 

Eyecrazy.gif


Edited by starbase25, 04 March 2018 - 04:15 AM.


#19 starbase25

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Posted 04 March 2018 - 04:16 AM

24mm, eyecup removed, depth of lens center below top of aluminum body: 10mm

With eyecup attached and folded down, that's 12mm; effective eye relief is 8mm, insufficient for glasses.

I can't even see a 50° field in this eyepiece with glasses on.

It is an eyepiece designed for NON wearers of eyeglasses.

So glad I read this and found out, as I almost bought one!



#20 howardcano

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Posted 04 March 2018 - 06:42 AM

 

Visually excellent. It replaces my Zeiss OPMI 10x22B when I need a bigger field.

I only had one issue when using a filter : retaining ring not well machined, should be deeper threaded to avoid this unscrewing event.

 

http://www.astrosurf...comment-1491646

Smartphone images are nice and I compared it with a 20mm Clave : transmission is lower but stars are pinpoint too and contrast is excellent. (tested on a ED 16" dobson and other scopes)

 

A versatile all scope eyepiece with max field for 1"1/4 (can be used daily on spotting scopes)

 

I think a better than FMC coating and a fix about the retaining ring would put it at a top rank class eyepiece.

 

I prefer it over LVW, Hyperion,and maxvision 68° (tried a 28mm and sent it back)

Just tried to use Google translate for this French site. Won't work right because there is a purple thing stuck over the page which can't be removed. mad.gif LOL.

 

https://translate.go...comment-1491646

 

Can't translate the very last post either. ------>  Text exceeds 3900 character limit

 

Eyecrazy.gif

 

It was the same for me.  I had to cut and paste each section of text individually.  It took a while!



#21 howardcano

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Posted 04 March 2018 - 06:48 AM

 

 

The 24mm TeleVue Panoptic and 24mm Explore Scientific 68° both have around 13mm of effective eye relief--still not glasses-friendly.

If you're looking for a 68° eyepieces in 24mm with about 20mm of effective eye relief, good luck.

The closest I've found is the 24mm Baader Hyperion, but it's more like 17mm of effective eye relief, not 20.

I can suggest several 22mm, but 24mm is tough.

Don

I was hoping to stay around 24 or 25mm.  If I recall correctly (it's been a couple of decades), the Pan 27 didn't have quite enough eye relief, either-- though if it did, I'd be tempted to do that.

 

That said, and with my curiosity piqued, what can you suggest in the 22mm range?

 

If you can use 2" eyepieces, there's nothing better than the Nagler 22T4 for long eye relief. It's my main, low power eyepiece, and mine is fitted with a Dioptrx.

 

2" is not a problem.  The price tag is a problem.

 

I would also be concerned that, even with the greater eye relief, I still wouldn't be able to see the whole field simply because the field is that much wider.  But that is a problem that I'll never have to face, given the price tag.

 

I'd love a Delite 24, if one existed!


Edited by howardcano, 04 March 2018 - 06:49 AM.


#22 howardcano

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Posted 04 March 2018 - 06:51 AM

Oh, I forgot to mention that I was wondering were all of you guys were!  There were just three of us posting, but the view count was showing much more interest than that! grin.gif



#23 lylver

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Posted 04 March 2018 - 06:52 AM

 

from top of eyecup (big 42mm diameter eyecup) to center surface : 23mm

Cornea is at the limit of the top of the eyecup for me.

My review was done at a club Star Party, not alone...

Thank you for this information.  I didn't see anything like it on the first link you provided, although it could have disappeared in Google Translate (though I did search the original page for "relief", which appears to be spelled the same in both languages).

 

Can you give me the Z-dimension from the highest part of the body to the center surface of the eye lens with the eyecup removed?  (In other words, how far is the center of the eye lens recessed into the metal body?)   I suspect I'll need almost all of that 23mm.

 

I did not speak about eye relief in my review, we did it "blind" at night, so it was or was not comfortable to see in the eyepiece. As everyone used it without questionning we did not mesure. In fact, I swap it in the focuser with the Nagler 31T5 and had got the member impressions.

I redid the check, from center to top aluminium M43 thread : ~10mm (not touching lens)

rubber eyecup to top of aluminium M43 thread ~16mm -4mm -> 12mm

So from top of the rubber : 22 to 23mm as I checked last time

 

When folded, the rubber is still 3 to 4mm over the top aluminium part (you cannot touch aluminium : a thin rubber protection avoid it)

so 13 to 14mm over the center of the eye lenses when using my eye glasses

I can see all the field with eyeglasses when folding the rubber eyecup, image is clean. (I still have a little margin outside the field stop and the visible eye lens part is around 35mm diameter)

We did not questions this point when whe tested it at night : was considered eyeglasses friendly

IMG_20180304_123329s.jpg

IMG_20180304_123408s.jpg

Ergonomy of this eyepiece is good : better than LVW, Hyperion, Morpheus, Zeiss OPMI 10x22B i have

I never believed to given datas about eye relief.

It depends much on your physiology.


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#24 howardcano

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Posted 04 March 2018 - 06:55 AM

The Olivon 22 has about 17-18mm of effective eye relief.  Might be a possibility in the lower-cost eyepieces.

Thank you.  I'll see what reviews or other info I can find on it.

 

Is the field stop accessible?  I have no qualms about adding a somewhat smaller stop if it gets rid of aberrations.  I have virtually no accommodation, so field curvature is a particular problem for me.


Edited by howardcano, 04 March 2018 - 07:13 AM.


#25 howardcano

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Posted 04 March 2018 - 07:18 AM

 

 

from top of eyecup (big 42mm diameter eyecup) to center surface : 23mm

Cornea is at the limit of the top of the eyecup for me.

My review was done at a club Star Party, not alone...

Thank you for this information.  I didn't see anything like it on the first link you provided, although it could have disappeared in Google Translate (though I did search the original page for "relief", which appears to be spelled the same in both languages).

 

Can you give me the Z-dimension from the highest part of the body to the center surface of the eye lens with the eyecup removed?  (In other words, how far is the center of the eye lens recessed into the metal body?)   I suspect I'll need almost all of that 23mm.

 

I did not speak about eye relief in my review, we did it "blind" at night, so it was or was not comfortable to see in the eyepiece. As everyone used it without questionning we did not mesure. In fact, I swap it in the focuser with the Nagler 31T5 and had got the member impressions.

I redid the check, from center to top aluminium M43 thread : ~10mm (not touching lens)

rubber eyecup to top of aluminium M43 thread ~16mm -4mm -> 12mm

So from top of the rubber : 22 to 23mm as I checked last time

 

When folded, the rubber is still 3 to 4mm over the top aluminium part (you cannot touch aluminium : a thin rubber protection avoid it)

so 13 to 14mm over the center of the eye lenses when using my eye glasses

I can see all the field with eyeglasses when folding the rubber eyecup, image is clean. (I still have a little margin outside the field stop and the visible eye lens part is around 35mm diameter)

We did not questions this point when whe tested it at night : was considered eyeglasses friendly

attachicon.gif IMG_20180304_123329s.jpg

attachicon.gif IMG_20180304_123408s.jpg

Ergonomy of this eyepiece is good : better than LVW, Hyperion, Morpheus, Zeiss OPMI 10x22B i have

I never believed to given datas about eye relief.

It depends much on your physiology.

 

Thank you for taking the time to take these measurements.

 

It's interesting that your experience when using eyeglasses is so different from Don's.  I've read other posts by Don regarding the general subject (with other eyepieces), and it seems that his glasses must be just as thick as mine!




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