765 replies to this topic

[jrazz]

   

 

You're right!!!

 

I feel so   

[WillR]

To quote myself from another topc:

 

I hand hold the Oberwerks LW 15 x 70 all the time, no problem. I have them on a monopod, and when I lay back and look up, the monopod is not on the ground but acts as a counterweight/stabilizer. I hold the bins in my left hand, and the monopod (collapsed) in my right about 12-18" down.

 

I can easily keep them steady enough for observing. Maybe not steady enough to split a close double star, but steady enough for panning around the sky and picking out Messier objects.

[wrighty338]

Jrazz congrats on your 25x100 do let us know what you think on them compared to the 20x65ED Deluxe 

[jrazz]

Jrazz congrats on your 25x100 do let us know what you think on them compared to the 20x65ED Deluxe 

Will be happy to! (though it's snowing now here so it might be a while  )

[scroff]

Hey - didn't mean to trick anyone! woops  

 

jrazz: the 25x100 binoculars look really awesome

 

fiske: was wondering which of the lot in your post would be your choice if you were limited to one

 

overall: this topic is like crack for astronomy binocular enthusiasts. Thanks for posting!

[Fiske]

scroff,

 

Welcome to Cloudy Nights!

 

 

Having previously started a topic titled If I Could Only Have 20 Binoculars, I am more or less disqualified from the pick one binocular festivities. 

 

And the problem now is that having added some additional binoculars to my collection, I might have to expand that list to 24. 

Edited by Fiske, 20 May 2022 - 07:21 PM.

[WillR]

I wanna play..  How about a 20x monocular? 

 

I use this mainly at 20x for long distance terrestrial close-up views, or covert activities, on the widow sill or steering wheel of a vehicle. 

Not while you are driving I hope! 

[jrazz]

I am forming an opinion...

 

I think I like the OB 25x100. Like, really like. I can't wait for clear dark skies cause so far these are blowing everything else away. They do exhibit some CA but you really have to look for it. It's really not a factor. The 15x70 Ultras have way more CA and even they don't become a nuisance in the dark. As far as sharpness go they are right up there with the 20x65ED and I really can't tell if there's any significant field curvature. They do have a slightly smaller AFOV than the 20x65ED but not to the point I feel I'm looking through a tunnel an the difference in magnification is definitely noticeable. I think that with my sky being as dark as they can be the difference in aperture will make these a blast! Can't wait to check out some of the nicer galaxies.

 

An interesting thing is that they are balanced very "forward" as in close to the objectives. This makes them surprisingly easy to hand hold  ... Yeah, I know! I'm not exactly a weightlifter (I mean I can handle the weight of say - a twig, I guess that kind of weightlifting is fine...) but I found that I can prop up my elbows and hold them near the front. They then become dead stable. Kinda cool!  Probably not for looking at the zenith but for low angle observing this could be done in a pinch. They are definitely easier to hold than the 15x70 ultra which I can hold for all of 30 seconds.

 

I thought long and hard if I want to pursue a BT or get these. In the end I figured I can't justify the money for a BT. If I need the magnification my 10" telescope is a far better choice. My only concerns were edge performance and CA. These binoculars are, thus far, really surpassing every one of my expectations. 

 

Really excited to try these out in the dark.

 

 

p.s. In the picture above the 15x70 and the 20x65ED have a 3d printed dew shield with flip-up covers. That makes them appear longer than they really are. In reality the 25x100 are much much bigger than both.

Edited by jrazz, 21 May 2022 - 06:57 PM.

[jrazz]

So, it's what I expected but not completely. 

 

It's pretty dark tonight but really cold (34°) and I had to shovel some snow away from my deck. Sky is dark and clear(ish) as there are some random clouds that are a pain. Seeing is not amazing but passable. I could only spend an hour outside before coming in to heat up so I think most of this night will be in and out to the chagrin of my dogs.

 

The TD;DR: the 25x100 has not toppled the 20x65ED. 

 

Let me explain. It's a monster. Very bright and the magnification is great! I definitely like it a lot! It's more of a challenge to star hop but that's part of the fun. It's perfect for DSOs like M53 and M63. Both popped out from the background and showed considerable details. It showed so many stars it was impressive. In really dark nights I think this could be a really cool galaxy observer. So, where does it fall short? Honestly? In image quality. It's not bad, far from it. It's superior to the 15x70 ultra and that's a fantastic binocular as well but it just can't compete with the 20x65ED. 

 

It's sharp up to around 50% of the field and then a slight blurriness takes over. It's not terrible at all but you really need to make sure that whatever you're observing is dead center. When it is, it's great! Take STF1633 for example (sep 9.0 mag 7.04,7.13). Very easy to see the split if it's in the center. I think I could probably split something at 5" if the seeing is good. Stray away from the center and that separation is gone. This, I think, is the reason I still like the 20x65ED slightly better. It's just so sharp and flat. It makes observing so easy and fun! There's just a "je ne sais quoi" about it that I absolutely love!

 

So, where does that leave the 25x100? On my parallelogram of course! It was so much fun finding tight doubles and dim galaxies! Especially for dark nights I think this thing rules! I will keep on switching between this and the 20x65ED depending on the target and the conditions because picking the right instrument is half the fun and because on more than one occasion, when observing with the 20x65ED I wished for more aperture and/or magnification. 

[ECP M42]

There's just a "je ne sais quoi" about it that I absolutely love!

Maybe it's the focal ratio and the darkest sky?
Try masking the 25x to about 80mm, and try again.

[Fiske]

Hi, Jordan. Is your uncorrected vision 20/20? Or do you wear glasses and observe without them? The reason I ask is that refocusing binoculars for nearsighted vision can have surprisingly negative consequences for off axis performance. Don't ask me why. I've just noticed it myself.

 

I can't say I have necessarily tested the off axis performance of the 25x100 with a close double as you describe, so I will do that. I have done considerable observing with both those binoculars, however, and have not noticed a significant difference in edge performance between them. It would not surprise me to find that the x65ED is sharper at the edge. I wouldn't expect a dramatic difference, though.

 

Will follow up on this with comparison observations. 

 

Fiske

Edited by Fiske, 22 May 2022 - 02:15 AM.

[jrazz]

Hi, Jordan. Is your uncorrected vision 20/20? Or do you wear glasses and observe without them?

Slightly better than 20/20 - LASIK. Which might be part of the problem too. I've noticed that really large EPs (above 6mm) can have a detrimental quality effect for me.  

 

And yes, I was surprised at the difference seeing as how good they were in daylight. I'll say it again, the 25x100 are EXCELLENT but still can't match the 20x65ED. Focusing on a star and moving it to the edge shows this really well. 

[Fiske]

Well, the 25x100 is not sharp to the edge, that is certain.  And the 20x65ED undoubtedly has better edge performance. Plus, there are considerable differences between our eyes, given your LASIK enhancement and my -5.50 sphere vision in both eyes and the fact that I observe with glasses. 

 

Nevertheless, I will do the same or a similar comparison with the two instruments and report my (likely similar findings). Also, you are making a wonderful case for building a diverse binocular team. 

[Fiske]

Oh, and what you have noticed about daytime versus night time performance illustrates how difficult it is to evaluate binocular sharpness in daylight conditions and why some alpha binoculars aren't necessarily great astronomy instruments -- they are optimized for daytime use where off-axis sharpness is not particularly noticed or valued. 

 

For daytime testing, specific evaluation target sheets can be used. If I recall correctly, EdZ used them for daytime tests.

[Fiske]

It's [OB 25x100 Deluxe] sharp up to around 50% of the field and then a slight blurriness takes over. It's not terrible at all but you really need to make sure that whatever you're observing is dead center. When it is, it's great! Take STF1633 for example (sep 9.0 mag 7.04,7.13). Very easy to see the split if it's in the center. I think I could probably split something at 5" if the seeing is good. Stray away from the center and that separation is gone. This, I think, is the reason I still like the 20x65ED slightly better. It's just so sharp and flat. It makes observing so easy and fun! There's just a "je ne sais quoi" about it that I absolutely love!

I'm continuing the observing report begun in the topic comparing the APM 16x70 with the OB 20x65ED here with additional details relevant to the 20x65ED and the 25x100 Deluxe comparison shared by Jordan in post #59 above.

 

I found I could resolve STF 1633 in both instruments to about 85% of the field. The 25x100 seems reasonably sharp to about 95% of the field. It softens slightly in the outer 5% of the FOV but not dramatically and the illumination at the edge is good. The 20x65ED does just a tad better, showing a slight amount of softening from say 97% of the field to the edge. The edge performance of both instruments is outstanding and the difference between them in this regard is irrelevant for normal observing.

 

STF 1633 / Coma Berenices

12h20m +27*03'

7.04/7.13 9" pa 245*

 

Why do my results differ from Jordan's? Possible explanations are variation in the individual instruments, variation between our eyes, variation in IPD and focus adjustments (quite small differences in adjustment can have a noticeable impact on levels of detail this fine), or possibly the fact that Jordan's environment was much more physically demanding -- near freezing with snow on the ground where I was observing in 60 degree weather wearing sweat pants and a hoodie. Fatigue can also be a surprising factor.

 

One thing I have found is that impressions of a binocular can change over time, when one has more experience observing with it on many different nights and under differing sky conditions.

Edited by Fiske, 23 May 2022 - 08:22 AM.

[jrazz]

Thank you Fiske!

There’s another factor that might be at play. Experience. I suspect you have much more of it than me. I’m waiting for the sky to clear up and redo. I saw the stars “fuzz” out a bit as I moved them past 50% but yes, it was cold and the setting wasn’t very good.

I’m actually happy to hear this! It shows that observing is a skill and there’s much more to learn. That makes it fun for me

[wrighty338]

The TD;DR: the 25x100 has not toppled the 20x65ED. 

 

 It's superior to the 15x70 ultra and that's a fantastic binocular as well but it just can't compete with the 20x65ED. 

 

Interesting!

 

Excellent input thanks jrazz & Fiske

[Rich V.]

How flat the field appears in a particular bino is not the same for all of us.  Younger eyes with plenty of focus accommodation may very well see a "sharper to the edge" image than older users who are presbyopic and can't focus out the FC with their eyes anymore.  I prefer "flat field" designs because my focus accommodation is limited and the edges of the field look worse than ever if FC is present.   

 

Rich

[Fiske]

How flat the field appears in a particular bino is not the same for all of us.  

Definitely agreed on this. 

 

Of course, flat field elements are less critical for narrower field binoculars, which by their nature exhibit less field curvature anyway. The 25x100 has an FOV of only 2.4 degrees. The 20x65ED has a slightly wider FOV (3.2 degrees) but also a longer focal length which results in a flatter focal plane. These factors help account for their excellent edge performance.

[MT4]

I finally had some half-decent skies tonight after a long spell of rainy and/or cloudy weather.  It still wasn't the right weather to bring out the "big" guns, a.k.a. my 82mm Kowa Highlander Prominar BT and 100mm APM SD APO BT, so I only had my APM 20x70 MS ED and Canon 15x50 IS with me.   The APM 20x70 was set up on an Artesky p-gram mount whereas the Canon was used hand-held.

 

It was absolutely great to be able to see some nice star patterns again.  I kept going back and forth between the APM and the Canon to compare the views in the two instruments.   While the APM has significant advantages in mag and aperture, the Canon has a flatter field and a wider TFOV.  Speaking of the TFOV, the Canon's 4.5-degree field is some 86% larger in area compared to the APM's respectable 3.3-degree field.  That huge advantage in area translated into more stars being present in the Canon than in the APM.

 

How could the Canon 15x50 manage to show me more stars than the APM 20x70?   I think the answer lies in the fact that my night skies are pretty dismal with average SQM readings being in the 17-17.5 range.  Under such poor skies, the APM's twin advantages in mag and aperture failed to trump the Canon's TFOV advantage.  (The Nikon 18x70's 4-degree FOV is about 26% smaller in area compared to the Canon's 4.5-degree FOV.)

 

Long story short, for me and my Bortle-9 skies 15x-20x is the "sweet spot" of the mag range as far as straight-thru binos are concerned.  15x is great for general scanning while 20x is more on the specialized side of things, with the Nikon 18x70 being smack in the middle of that sweet spot.  When I need higher mags and aperture, either of which would translate to more weight for both the instrument and the mount, it'd be time to bring out the big guns with angled viewing.

[Takuan]

Some years ago I spent a night at 2000m (6500ft) with a Nikon Aculon 16x50 and my youth telescope (Vixen 100/1000). From that night, I decided that the two eyes were going to have the maximum role in my astronomical observations.
Many images were recorded in my retinas, after that night with such modest binoculars.

Attached Thumbnails

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[Fiske]

Welcome to Cloudy Nights, Takuan.

 

[jrazz]

Beautiful dark night tonight. Like really dark. I can't measure the sky but given how the dim galaxies popped out and the fact that I could see Mag 13 stars in my telescope I would say tonight was nice.

 

I stand by my assertion. The 20x65ED is nicer to look through, very slightly sharper, and flatter focus plane. The 25x100 however, in this kind of night are the tool to use. Definitely. I could easily resolve doubles like 17 Vir  (STF1636) which while having plenty of separation (21") has a secondary which is much dimmer than the primary (mag 6.53,9.31). This is surprisingly hard to see with the 20x65ED but much much easier with the 25x100. STF 1685 (sep 16.0 mag 7.31,7.78) was child's play to split and was really nice to observe! This pair requires concentration when using the 20x65ED but the 25x100 laughs at it.

 

Best of all were the galaxies!

Sombrero showed significant detail. I could easily see the dust lanes. Ditto M64. M85 was huge and bright! M61 looked like a huge blue orb and M53 was really really bright!

 

So what do I prefer? 

I think that each tool is to be used differently. I think the 20x65ED is better suited for brighter nights when the moon is bright and that the 25x100 are for these kind of nights. I had a blast!

In fact, I'm probably not done. I'll pay for this tomorrow but my neighbor has finally turned off his stupid light so I might be going back!

 

Dark skies, what a concept!

[wrighty338]

Im currently cursed by the great British weather and iv had the moon to deal with since my obies arrived, literally managed a couple of hours...however i spy a 3 hour window of clear sky on Friday and with a waning crescent i may actually get to see something.

 

After that i think its going to have to be a trip into darker skies, its great reading everyone's observations because im hoping to see some galaxies at some point 

[jrazz]

Keep in mind that although we all talk about galaxies like we see them as they are in the pictures, the real view is that of very tenuous fuzzy patches! It takes some time to develop the skill to see them at all and to see any kind of detail. Once you do though, they are everywhere!