68 replies to this topic

[Astronoob76]

I think I'm more alert to it than most. Probably comes from being involved with photography for many years. I find myself looking for faults, and sadly, my Steiners seem to really show that particular fault. Despite being bright and sharp in general.

Once you see it, you can't unsee it. Frankly, I wish I never had heard about this thing called "chromatic abberation". Really spoils the fun with some binoculars.

[ihf]

Every single bino can be made to show visual defects in carefully selected scenes, as image capture and analog signal processing are not lossless. This is really the analog of the audio discussion. One can spend as much as one wants, but money isn't going to fix that inconvenient fact. The saving grace is that binoculars are low magnification and our eyes pretty crappy. Together this hides a lot of optical defects.

[jrazz]

After yesterday I need to add another contender to the "no CA club"

 

The Moon-Star 6.5x32 APO+.

Hard to get but wow is it worth it...

 

Here it is along the Meade 10x56

 

My ranking of "CA" binoculars goes like this:

Leica Trinovid HD 8x42 - Surprising amount of CA for something that costs this much but it is very pleasant to look through.

Oberwerk 15x70 Ultra - Well controlled but still visible. Less intrusive than the Leica.

Meade Masterclass 10x56 - No CA in the center to very little in the outer 20%

APM 34x80 - CA visible only at the extreme edge and even then, you have to be looking for it. For all intents and purposes it is color free.

Moon Star 6.5x32 - Same as above or maybe slightly better.

 

I do have 2 binoculars that are completely color free meaning the CA they produce is simply below my threshold of seeing:

Oberwerk 20x65ED and the BT-100XL/SD.

If you dislike CA intensely and do not want to see it these are the instruments for you!

 

 

I mean if you can find it, the Tax Astronomer should be in a league of it's own but I digress.

[MT4]

 

After yesterday I need to add another contender to the "no CA club"

 

The Moon-Star 6.5x32 APO+.

Hard to get but wow is it worth it...

 

Here it is along the Meade 10x56

 

 

My ranking of "CA" binoculars goes like this:

Leica Trinovid HD 8x42 - Surprising amount of CA for something that costs this much but it is very pleasant to look through.

Oberwerk 15x70 Ultra - Well controlled but still visible. Less intrusive than the Leica.

Meade Masterclass 10x56 - No CA in the center to very little in the outer 20%

APM 34x80 - CA visible only at the extreme edge and even then, you have to be looking for it. For all intents and purposes it is color free.

Moon Star 6.5x32 - Same as above or maybe slightly better.

 

I do have 2 binoculars that are completely color free meaning the CA they produce is simply below my threshold of seeing:

Oberwerk 20x65ED and the BT-100XL/SD.

If you dislike CA intensely and do not want to see it these are the instruments for you!

 

 

I mean if you can find it, the Tax Astronomer should be in a league of it's own but I digress.

 

 

Nice to see that you're enjoying the MoonStar 6.5x32 as much as I am 

 

On the Tak Astronomer 22x60, yes it's in a league of its own.   It's my reference standard for sharpness and contrast.  Any new instrument I get gets compared to the Tak.  If it's at least half as good as the Tak on both counts then it can remain in my collection 

[PhotogTom]

Thanks, everyone, for chiming in. Looks like it's not as simple as it looks. In terms of "bang for the buck", if not for the very annoying CA (and yes, it is annoying), I would be very impressed with my Steiner's. But they are what they are. I've had them for several years, and really didn't use them much until more recently.

 

Looks like I have a few options out there. Mostly pricey, but that's the way it goes with glass.

[astroneil]

CA free binocular that won’t break the bank?
 

Here’s one: the Oberwerk SE 8x 32 ED

 

 

 

 

No visible CA on or off axis - $249.95

 

Superb optics for the money

Attached Thumbnails

• 

[vdog]

The Athlon Midas G2's show little to no CA. The CA in my Vortex Diamondbacks is pretty severe in some situations, where the Midas G2's show none in the same situation. No need to spend an arm and a leg.

This is where my search for a CA-free bino led me.

 

But I agree that no bino is completely free, even this one.  I noticed a color fringe once while looking at a dark bird silhouetted against a bright overcast sky.  But so far, that's it.  Not bad at all for what these go for. 

Edited by vdog, 21 July 2023 - 11:29 AM.

[Rustler46]

CA free binocular that won’t break the bank?
 

Here’s one: the Oberwerk SE 8x 32 ED

 

 

 

 

No visible CA on or off axis - $249.95

 

Superb optics for the money

I just ordered an 8X32 SE ED binocular. It was shipped in less than 1/2 day. Kudos to Oberwerk. Here's a review from the website that reports little CA.

 

Product Review: Oberwerk SE 8 x 32ED.

 

It reports overall "complete lack of chromatic aberration", though on the full Moon there was "the merest trace of lateral colour". 

 

Total cost (including shipping & insurance) was $277. I figure this will be a great daytime bino for birding, etc. My only other high quality bino is another one from Oberwerk - 20 X 65 Deluxe on series 5000 tripod. I've been very pleased with that one. I didn't notice any CA, but haven't been specifically looking for it. One review of that bino speaks well of it.

 

Quality is expensive, perfection is nearly unattainable at any price. I appreciate Kevin Busarow's honest assessment of the products he sells and very useful information on the Oberwerk website.

 

Russ

Edited by Rustler46, 25 July 2023 - 02:49 PM.

[f18dad]

Whirlaway, on 17 Jul 2023 - 4:55 PM, said:
The Athlon Midas G2's show little to no CA. The CA in my Vortex Diamondbacks is pretty severe in some situations, where the Midas G2's show none in the same situation. No need to spend an arm and a leg.

 

This is where my search for a CA-free bino led me.

 

But I agree that no bino is completely free, even this one.  I noticed a color fringe once while looking at a dark bird silhouetted against a bright overcast sky.  But so far, that's it.  Not bad at all for what these go for. 

 

I cannot detect any CA in my Athlon Cronus 8.5x42 ED. Maybe my eyes are bad. I can detect some CA in all my other binoculars, just not this one, even on the Moon.

[vdog]

Whirlaway, on 17 Jul 2023 - 4:55 PM, said:
The Athlon Midas G2's show little to no CA. The CA in my Vortex Diamondbacks is pretty severe in some situations, where the Midas G2's show none in the same situation. No need to spend an arm and a leg.

 

 

I cannot detect any CA in my Athlon Cronus 8.5x42 ED. Maybe my eyes are bad. I can detect some CA in all my other binoculars, just not this one, even on the Moon.

It was just that one time.  Took the perfect conditions, I guess:  background, target, angle.  But there was definitely a narrow, pinkish-purple fringe around those birds.  Hadn't noticed it before, nor since. 

 

It wasn't particularly distracting anyway, more like something you had to try to see.  These are fabulous binos.

[Mr Smith]

I have assumed that all light that travels through a lens exhibits dispersion. Blue light has a smaller velocity to red light.

 

Are achromatic doublets are installed in the high end binoculars to help reduce this?

 

Different quality glass and lens forms can reduce chromatic aberration but the application of a doublet actually cancels out some of the dispersion.

Edited by Mr Smith, 26 July 2023 - 01:07 AM.

[Dale Smith]

CA free binocular that won’t break the bank?
 

Here’s one: the Oberwerk SE 8x 32 ED

 

 

 

 

No visible CA on or off axis - $249.95

 

Superb optics for the money

I’ve been very pleased with mine—they arrived ten days ago, and have provided some terrific views in my Bortle 7 skies. I’ve not been able to detect CA either.

[Rustler46]

I just ordered an 8X32 SE ED binocular. It was shipped in less than 1/2 day. Kudos to Oberwerk. Here's a review from the website that reports little CA.

 

Product Review: Oberwerk SE 8 x 32ED.

 

It reports overall "complete lack of chromatic aberration", though on the full Moon there was "the merest trace of lateral colour". 

 

Total cost (including shipping & insurance) was $277. I figure this will be a great daytime bino for birding, etc. My only other high quality bino is another one from Oberwerk - 20 X 65 Deluxe on series 5000 tripod. I've been very pleased with that one. I didn't notice any CA, but haven't been specifically looking for it. One review of that bino speaks well of it.

 

Quality is expensive, perfection is nearly unattainable at any price. I appreciate Kevin Busarow's honest assessment of the products he sells and very useful information on the Oberwerk website.

I received my new Oberwerk 8X32 SE binocular yesterday, and am finding it to be quite a quality product. It was well packed with nice objective covers and rain caps for the oculars. Also the padded canvas case is good for protection when not in use. So here's my review.

 

First a couple of nit-picks:

• The dual ocular rain caps have side loops to capture the neck strap that don't line up with the straps' attachment points on the binos. Others have mentioned this minor irritant, that will likely be addressed in future production runs.
• The canvas carrying case for the bino has attachment points for the neck strap that are too low on the side of the case. If they had been attached higher up on the side, the case would hang down nicely when supported by the neck strap. In practice this didn't matter a lot, since the case lays flat against the user's body despite a slight tendency to tip to the side.

That's it for negatives. The binocular itself feels very solid. The weight of it seems appropriate for the quality of construction. There was no problem at all in holding them up to the eyes for viewing. The 8X power is about the maximum for me in a hand-held optic. When mounted on a HD photo tripod, the view was very clear, probably the best I've seen in a binocular. Viewing an overhead electrical wire against a bright sky showed a bit of chromatic aberration in the outer part of the field. But for less demanding subjects like distant vegetation, the view was superb.

 

At night the large exit pupil allowed for my eye's own astigmatism to become apparent. I usually like to view with glasses off. But with the eyecup twisted down and glasses in place, the entire FOV was visible with no astigmatism. The stars focused down to nice round points. Without glasses the right ocular diopter adjustment was not quite capable of correcting for my -5.5 diopter myopia in the worst eye. So this is another reason for using glasses or contact lenses for daytime viewing. For this my usual use will be for bird-watching.

 

I didn't spend much time at night because of a bright moon. But seeing the Cassiopeia "W" and Alcor/Mizar was nice. When I get some darker skies I hope to further assess the nighttime view. The several days before full Moon was spectacular. All craters along the terminator were very sharp, especially when steadied with the tripod.

 

All in all, I'm very pleased to get this high quality binocular. It was ordered on Wednesday, shipped from Ohio to Oregon arriving on Friday. That is stellar for fast order processing and shipment. The 8X32 SE and 20X65 Oberwerk binos are the best by far in my collection. I also have some old 7X50 and 10X50 binos along with an older German 15X80 bino.

 

Russ

Edited by Rustler46, 30 July 2023 - 01:02 AM.

[Rustler46]

I received my new Oberwerk 8X32 SE binocular yesterday, and am finding it to be quite a quality product. It was well packed with nice objective covers and rain caps for the oculars. Also the padded canvas case is good for protection when not in use. So here's my review.

 

First a couple of nit-picks:

• The dual ocular rain caps have side loops to capture the neck strap that don't line up with the straps' attachment points on the binos. Others have mentioned this minor irritant, that will likely be addressed in future production runs.
• The canvas carrying case for the bino has attachment points for the neck strap that are too low on the side of the case. If they had been attached higher up on the side, the case would hang down nicely when supported by the neck strap. In practice this didn't matter a lot, since the case lays flat against the user's body despite a slight tendency to tip to the side.

That's it for negatives. The binocular itself feels very solid. The weight of it seems appropriate for the quality of construction. There was no problem at all in holding them up to the eyes for viewing. The 8X power is about the maximum for me in a hand-held optic. When mounted on a HD photo tripod, the view was very clear, probably the best I've seen in a binocular. Viewing an overhead electrical wire against a bright sky showed a bit of chromatic aberration in the outer part of the field. But for less demanding subjects like distant vegetation, the view was superb.

 

At night the large exit pupil allowed for my eye's own astigmatism to become apparent. I usually like to view with glasses off. But with the eyecup twisted down and glasses in place, the entire FOV was visible with no astigmatism. The stars focused down to nice round points. Without glasses the right ocular diopter adjustment was not quite capable of correcting for my -5.5 diopter myopia in the worst eye. So this is another reason for using glasses or contact lenses for daytime viewing. For this my usual use will be for bird-watching.

 

I didn't spend much time at night because of a bright moon. But seeing the Cassiopeia "W" and Alcor/Mizar was nice. When I get some darker skies I hope to further assess the nighttime view. The several days before full Moon was spectacular. All craters along the terminator were very sharp, especially when steadied with the tripod.

 

All in all, I'm very pleased to get this high quality binocular. It was ordered on Wednesday, shipped from Ohio to Oregon arriving on Friday. That is stellar for fast order processing and shipment. The 8X32 SE and 20X65 Oberwerk binos are the best by far in my collection. I also have some old 7X50 and 10X50 binos along with an older German 15X80 bino.

Just a quick addition to the above report, I used the binocular with my prescription glasses to view some deep-sky objects in the Milky Way. From my Bortle 5 skies at home on the Oregon coast I was able to easily see open clusters M6, M7 and M11 along with diffuse nebula M8 and globular cluster M22. 

 

The actual true FOV is less than the specified 8.2 degrees, perhaps around 7.5 degrees. I hope to have another go tonight using contact lenses to verify actual FOV. While the entire FOV is visible while using glasses, I prefer not having to press the glasses up to the eyecups. So using contacts lenses will be more comfortable.

 

Russ

[astroneil]

Just a quick addition to the above report, I used the binocular with my prescription glasses to view some deep-sky objects in the Milky Way. From my Bortle 5 skies at home on the Oregon coast I was able to easily see open clusters M6, M7 and M11 along with diffuse nebula M8 and globular cluster M22. 

 

The actual true FOV is less than the specified 8.2 degrees, perhaps around 7.5 degrees. I hope to have another go tonight using contact lenses to verify actual FOV. While the entire FOV is visible while using glasses, I prefer not having to press the glasses up to the eyecups. So using contacts lenses will be more comfortable.

 

Russ

Dear Russ,

 

I'm very glad you found the Oberwerk SE 8 x 32 ED to your liking!

 

I recently conducted some measurements of the field of view on this instrument, and found its true field to be 7.48 angular degrees, in good agreement with your estimation!

 

With best wishes,

 

Neil.

[Rustler46]

Dear Russ,

 

I'm very glad you found the Oberwerk SE 8 x 32 ED to your liking!

 

I recently conducted some measurements of the field of view on this instrument, and found its true field to be 7.48 angular degrees, in good agreement with your estimation!

 

With best wishes

Thanks Neil for your report. I just returned from a week camping at 7400 feet (24K+ meters) under Bortle-1 skies. The skies were spectacular on the west slopes of Steens Mountain in southwest Oregon. One night I was privileged to observe using a binocular telescope with dual 17-1/2 inch mirrors. The view was of course quite spectacular. I also observed on two other nights with my Oberwerk 20X65 Deluxe and 8X32 SE binoculars. 

 

Under such skies the binocular views were of course impressive. But I truly enjoyed what the smallest aperture showed. The 7-1/2 degree FOV allowed for expansive views of many Milky Way DSOs in context, showing them in relation to other nearby objects. I have been more than pleased with my purchase of the Oberwerk 8X32 SE. For daytime viewing, there's no need for heavier 7X50s or 10X50s, which I have at my disposal. My own eye's pupil stops down the larger apertures to about what the 8X32s provide with much less weight. 

 

For nighttime viewing I've been pleased with what it provides. The outer 15% of the FOV shows some degradation. But perfection isn't possible, at least for the price I'm willing to bear. The vast majority of the FOV gives quite sharp definition with minimal to no chromatic aberration.

 

All the Best,

Russ

Edited by Rustler46, 22 September 2023 - 12:41 PM.

[gwlee]

I have never encountered any binocular that doesn’t exhibit some chromatic aberration under some circumstances, but more expensive binoculars, including the most expensive SW binoculars are better than most in this respect. Lower magnification binoculars usually show less magnification than higher magnification binoculars. 

[astroneil]

Thanks Neil for your report. I just returned from a week camping at 7400 feet (24K+ meters) under Bortle-1 skies. The skies were spectacular on the west slopes of Steens Mountain in southwest Oregon. One night I was privileged to observe using a binocular telescope with dual 17-1/2 inch mirrors. The view was of course quite spectacular. I also observed on two other nights with my Oberwerk 20X65 Deluxe and 8X32 SE binocular. 

 

Under such skies the binocular views were of course impressive. But I truly enjoyed what the smallest aperture showed. The 7-1/2 degree FOV allowed for expansive views of many Milky Way DSOs in context, showing them in relation to other nearby objects. I have been more than pleased with my purchase of the Oberwerk 8X32 SE. For daytime viewing, there's no need for heavier 7X50s or 10X50s, which I have at my disposal. My own eye's pupil stops down the larger apertures to about what the 8X32s provide with much less weight. 

 

For nighttime viewing I've been pleased with what it provides. The outer 15% of the FOV shows some degradation. But perfection isn't possible, at least for the price I'm willing to bear. The vast majority of the FOV gives quite sharp definition with minimal to no chromatic aberration.

 

All the Best,

Russ

Awesome report Russ: thanks for sharing!

Neil

[Terra Nova]

I’ve been using my Maven C5 18x56 ED and my Oberwerk 20x70 ED Ultras quite a bit over the past weeks to observe both Saturn and Jupiter at night and Venus in the morning and I have been very impressed at how well they control CA- no color fringing and no color sparkling what so ever and only the very slightest purple haze out away from the object in the surrounding dark sky, and only when you purposefully look for it and use averted vision. In other words, pretty much the same apochromatic performance you would expect from a short (<F6) apo telescope.