Roof prisms (Svbony SV202 10x42) Chromatic aberration, cushioning, blurring at edge - comparison, example pictures? (2 Viewers)

[asphaltradler]

I think that setup with all the houses and windows is a very artificial and not very usefull setting. No bino with pincushion distortion will work very well for looking at architecture.

@Binocollector I agree it's artificial, but because of that I also think it is useful! How can anyone rate pincushioning If i only Look at landcape that is unproblematic for optics?

I want to find out only 1 thing: should I send the Svbony back or not. And up to now I get 50% 'Looks ok to me' and 50% 'Looks horrible, must be faulty item'. Which shows me that we have much too few comparible pics here.
I just want to avoid sending things across the country just to get another one that’s the same. If virtually all roof binos are like that I’d accept it. If I could get better results for say 100-150 eur more, I would rather choose that.
I really don’t quite get why it should be so difficult to achieve geometric acceptable optics in a binocular today, compared to 70s Porros, and shouldn’t CA be less a problem than then also, with better coating, phase correction, and even ED glasses?
None of my cameras shows such distortion, not even the Practica 50mm SLR objective from 1950. I know that complete flatness is not wanted because of the rolling ball effect, but so strong as I see it with the Svbony (and is visible in the shots) it disturbs me. That is too much I think?

 

[asphaltradler]

Ok I saw @Binocollector you edited and expanded your last post and more or less answered my above questions.
Well I would be ready to pay some more. What models do you mean with ‘plastic Nikons’? I assume the P7, I read some good about the Prostaff 7s / P7 models but also that they are rather ‘plasticky’ (by you I think Prostaff P7 8x30 arrived, first impressions). Or could you advise to some other for distortion-phobics like me?
I think you had the Nikon 8x30 and the Svbony 8x32 together, so how did they compare in that respects? I saw very little pin cushioning in your test pics of the Nikon.

 

[tenex]

I want to find out only 1 thing: should I send the Svbony back or not. And up to now I get 50% 'Looks ok to me' and 50% 'Looks horrible, must be faulty item'.

Ah, the online forum experience...
...but actually no one is saying "faulty item", just "lousy cheap binocular". Ignore the nutty online hype about this product ("high resolution, high contrast images virtually free of optical defects like chromatic aberration"!) and spend more for something better. Good luck.

 

[Binastro]

Have a look at some of the 1950s and 1960s 85mm f/2 lenses from Jena and USSR.

Unbelievable pincushion distortion.

Yet some use these lenses now for their so called wonderful rendition.

Some 3 element lenses of about 100mm that cost next to nothing have modern copies that sell for £1,000 for the so called beauty of the image.

Even the Domiplan which I consider to be junk lenses have their followers.

Standard 50mm lenses using the Gauss design have been around for ages and are still good.

It is up to the observer to decide what is acceptable or not.

Greenkat EWA binoculars from maybe the 1970s have tremendous pincushion to give the very wide fields.

I like some pincushion distortion in binoculars, but not extreme pincushion distortion.

I hate the distortion free Komz 7x35 and 10x42.

To ask for numerous photos of binocular images won't help.
It is up to the observer to decide what he or she wants.

Perhaps try various binoculars in a store.

B.

 

[asphaltradler]

It is up to the observer to decide what he or she wants.

Perhaps try various binoculars in a store.

I would like very much but in my city I found exactly one photo shop with exactly 1 brand of (re-labelled I think) binoculars… Ok I’ll retry it in a bigger radius perhaps now. Thought that would be easier :-/

 

[Binocollector]

Ah, the online forum experience...
...but actually no one is saying "faulty item", just "lousy cheap binocular". Ignore the nutty online hype about this product ("high resolution, high contrast images virtually free of optical defects like chromatic aberration"!) and spend more for something better. Good luck.

I wouldn't really call them lousy.
The Nikon P7 might be slightly better optically but the build quality is horrible.
I took more pics through the Svbony and noticed another thing compared to the Lux HR (which I think for the current price is hard to beat).
Color fidelity is shifted towards green. Similar to a Nikon action ex BTW which has a color fidelity like a Japanese porro from the 70s.
The colors in the next 2 pics look pretty much like that when using them and the red is definitely diminished in the Svbony.
Lux HR (colors seem pretty accurate compared to what I see with my own eyes):

And Svbony - look at the upper part of that barn wall just below the roof. There is definitely the red missing in the SV202 (and once again - pincushion towards the edge is higher):

 

[Binocollector]

Just for the fun of it -- and mind you, when I use those, non of them seems to have annyoing amounts of pincushion distortion, that is why it's so important to actually look through them.
I snapped a few quick and dirty pics free handedly through the Svbony SV202 8x32, the Canon 8x32WP (one of my favourites), a decent older wide angle (probably made by Kamakura) 8x40 and for the sake of it -- the Komz 7x30 (which has almost no pincushion distortion):
For reference -- this is what zero pincushion looks like (still some mild softening towards the edges due to field curvature), but it has a slight amount of "moustache" distortion. There is a lenghty and useful analysis of the specific distortion profile of the Komz 7x30 on Holger Merlitz's homepage.
Komz 7x30 BPO:

Now in increasing size of the FoV:
Canon 8x32WP -- also a slight amount of moustache distortion probably because of the field flatteners.

Svbony SV202 8x32:

And Kamakura 8x40 wide angle:

The binos involved (forgot to take a pic of the Komz though):

 

[exup]

Just for the fun of it -- and mind you, when I use those, non of them seems to have annyoing amounts of pincushion distortion, that is why it's so important to actually look through them.
I snapped a few quick and dirty pics free handedly through the Svbony SV202 8x32, the Canon 8x32WP (one of my favourites), a decent older wide angle (probably made by Kamakura) 8x40 and for the sake of it -- the Komz 7x30 (which has almost no pincushion distortion):
For reference -- this is what zero pincushion looks like (still some mild softening towards the edges due to field curvature), but it has a slight amount of "moustache" distortion. There is a lenghty and useful analysis of the specific distortion profile of the Komz 7x30 on Holger Merlitz's homepage.
Komz 7x30 BPO:

Now in increasing size of the FoV:
Canon 8x32WP -- also a slight amount of moustache distortion probably because of the field flatteners.

Svbony SV202 8x32:

And Kamakura 8x40 wide angle:

The binos involved (forgot to take a pic of the Komz though):

IMHO the SV202 8x32 is a good image ....... I have one and all the other sizes too and they are good bins ...... especially when the price is concerned.

It will be interesting if Neil English sends the 8x42s to allbinos for testing.

 

[Binocollector]

IMHO the SV202 8x32 is a good image ....... I have one and all the other sizes too and they are good bins ...... especially when the price is concerned.

I think they are pretty good for the money, too. Otherwise I wouldn't have 2.
But they are definitely not free of CA despite the ED-glass. And I have some roof prism binos without any ED-glass that still have less CA.
Color fidelity is also not perfect. The purple coatings look nice but diminish the red wavelength a bit too much for my taste.
But they are certainly not "lousy" like tenex said. Not on the same level though as more expensive models naturally. So claiming "they punch above their weight class" might be a bit overly enthusiastic as are comparisons to the "big 3".
Build quality though -- especially compared to my rather disappointing plastic Nikon P7 -- really good for the money.

 

[tenex]

But they are certainly not "lousy" like tenex said.

I really shouldn't have got involved in discussing such a binocular at all. Carry on...

 

[Binocollector]

I really shouldn't have got involved in discussing such a binocular at all. Carry on...

No, please do indulge us. To how many other binos in a similar price range have you compared your Svbony SV202? Do you even own one? Did you base your opinion on my pics or on the fact that you already "know" a roof prism bino for 190€ "must" be crap? (so much for "reality based") Do tell...
It's basically in the same price range as a low end Nikon. I haven't heard people calling those "lousy" and I guess you're aware that all the low end Nikons are made in China, right?

 

[kimmik]

Lousy I found out when I held two doublet lenses in the air and saw 10degrees of sweet spot with almost no image contrast due to the open barrel lol.

Everything else was remarkably good after that.

 

[tenex]

No, please do indulge us. To how many other binos in a similar price range have you compared your Svbony SV202? Do you even own one? Did you base your opinion on my pics or on the fact that you already "know" a roof prism bino for 190€ "must" be crap? (so much for "reality based") Do tell...

Disingenuous and nasty. You know perfectly well I would never buy such "crap". And it should be obvious that I was judging by the OP's pics through it. Yours do show excessive pincushioning, though not as clearly as his, and are not very useful regarding CA.

I don't sneer at you for buying so many $100 binoculars you might as well have a couple of the best; chacun à son goût. In fact I understand interest in the variety of older bins that offer something modern ones don't, like wide FOV... but not the challenge of seeing how usable cheap new stuff from China can be. I imagine those add about as much carbon to the atmosphere as any instrument I'd use myself.

As I said, I should have left this thread alone and will now... if you will allow me to.

 

[lilcrazy2]

I recently bought an 8x42 SV202 that I got for $113 from Aliexpress just for S&G, and I certainly wouldn't call them crap. Actually, they seem very well built, very smooth focuser, but heavy (nearly 27 oz), and somewhat large/tall. The pincushion is higher than most any other 8x42 I have, but I don't find it bothersome. I find CA and glare to be very well controlled. I do notice a slight bit of a blue ring at the very edge, and at times when looking at the edge it seems to bleed out a bit around the 2 o'clock and 10 o'clock positions, but only when I make an effort to look at the edges. While these are certainly worth the $113 I spent, they are not as good as my Celestron Trailseeker ED's, Celestron Regal ED's, Monarch HG's or EDG II's.
All in all, a very nice bino for someone on a very limited budget, or just knock arounds.

 

[exup]

...... my Celestron Trailseeker ED's, Celestron Regal ED's

I have SV202s, Regals and non ED Trailseekers.

I'd be interested to hear how the Trailseeker ED's compare to the Regals? They seem to be getting a following, whereas the Regals don't, which surprises me.

 

[asphaltradler]

Back again. Some last thoughts:

Definitely more pincushion in the Svbony. But not unlike many other binoculars that I own. Even though pincushion distortion and field curvature are two different forms of abberation, it seems like the flat field binos that I own also have less pincushion distortion in general.

IMHO the SV202 8x32 is a good image ....... I have one and all the other sizes too and they are good bins ...... especially when the price is concerned.

It will be interesting if Neil English sends the 8x42s to allbinos for testing.

Well allbinos gave the Zeiss Jena Deltrintem - which I used as comparison - only 3/10 points in the distortion category, where it seems to me to be the same as the 10x42 Svbony: Carl Zeiss Jena Deltrintem 8x30 - binoculars review - AllBinos.com and 6.5/10 for CA, where it is better than the Svbony.

But I just looked again at @Binocollector 's pics and still I see less pincushion there than in mine. Look at that quite straight line at the left side compared to the pillars in my pic:

I have seen not one line as straight as that. What's funny because the curvature of the roof and the bottom of the house seem similar.
??
But again, you said that pincushion increases with lens diameter, but I see not much difference betw. your pics of the 10x50 in post Roof prisms (Svbony SV202 10x42) Chromatic aberration, cushioning, blurring at edge - comparison, example pictures? and the ones with 8x32. In both of yours the vertical lines seem perfect and the 10x50 has not more pincushion than the 8x32.

 

[Binocollector]

I think it's an optical illusion because the straight line in my pic is shorter.
I'm still not sure what the goal is here? The pincushion distortion seems quite normal. If you want less of it you need to buy another bino.
I really don't think yours is any different than mine or defective. I also don't think there would be this much difference that might be attributed to quality control or anything like that.
If that would be the case I'd expect far different results between two specimen.
Binos with pincushion distortion are just not very useful for looking at architecture.

 

[Binocollector]

One last pic to prove my point. This time I simply put the bino on its side to show that the pincushion distortion is equal in each direction (it can't be any other way unless the lenses would be asymmetrical) and taking a picture of a longer straight line. Distortion looks very much the same as in your pic of the steel beam on the balcony.

 

[asphaltradler]

I think it's an optical illusion because the straight line in my pic is shorter.

Must be right . Or perhaps your camera has some function to correct "stürzende Linien" (don't know how to say that in EN, but your from D anyway?) and is doing that only vertically. Then it would perhaps look different if the camera is turned instead the bin...
I have ordered now another brand bin, let's see how the both compare.
Thank you for all the effort in the meantime!
Regards

 

[Binastro]

What I saw yesterday is that my reading glasses have considerable pincushion distortion 15 degrees off axis.

My distance glasses also have pincushion distortion 15 degrees off axis, but to a lesser extent.

Off course if one directs the central vision to the edge when looking through a binocular there should be no change in the binocular distortion, but if one looks straight ahead the edges in the binocular may look different for someone using glasses.

Regards,
B.