New Zeiss binos 8x40 SFL and 10x40 SFL (2 Viewers)

[henry link]

I wouldn't use these or any other phone-scoped images to evaluate binoculars. Firstly, lateral CA will be heavily influenced the exact alignment of the camera lens and the eyepiece. It's very hard to avoid at least slight misalignment which will likely favor one or the other binocular.

Secondly the true aperture of these phone cameras has become increasingly difficult to discover. It's not in the camera specs, which now call the focal ratio the "aperture" and always give a full frame "equivalent" focal length instead of the true focal length, so the true aperture can't even be calculated from the focal length and focal ratio. This matters because phone lenses all have very small true apertures, typically around 2-2.5mm, so they are inherently incapable of accepting the full exit pupil of most binoculars. A 2.5mm phone lens will stop down every 8x binocular to about 20mm.

 

[pm42]

I wouldn't use these or any other phone-scoped images to evaluate binoculars. Firstly, lateral CA will be heavily influenced the exact alignment of the camera lens and the eyepiece. It's very hard to avoid at least slight misalignment which will likely favor one or the other binocular.

When you get the same result every time, the same as the one you got when using a modern and CA free camera+lens and exactly what you see, one can guess that the protocol is relatively robust.

so they are inherently incapable of accepting the full exit pupil of most binoculars. A 2.5mm phone lens will stop down every 8x binocular to about 20mm.

How does this prevent them to capture the resolution and CA at the center of the image?

 

[Richard D]

Interesting photos - that CA looks quite heavy for an 8x40 at that price. Obviously the naked eye test is the real proof.

 

[henry link]

It's difficult to say what's happening in the Zeiss image. Remember the light that causes the CA is coming from the bright background and bleeding into the dark areas. The lateral(?) color fringe appears to be wider and heaver on the top side of the bottom bright area, suggesting possible vertical misalignment of that image compared to the Swaro image. For this kind of testing I use a static target of alternating black and white bars across the entire FOV with a white cross in the center. That makes alignment issues pretty obvious.

You may be able to accurately photograph the CA of an 8x40 or an 8x32 with a 2.5mm phone lens, but remember the result applies only to center 20mm of both binoculars' objectives when they are stopped down to 20mm.

 

[Troubador]

This is interesting because we clearly do not see the same thing even on a picture. And something that I find obvious is hardly visible to you.
I find this challenging in a good way.

Here is a 500% crop of the same pictures in the same order. Do you see the more yellow and purple CA on the right there?

Now the CA looks about the same in both left and right pics.

Lee

 

[lilcrazy2]

I don't see that Andy, in fact I can barely make out any CA on the right-hand image and so suspect this is the NL.

Lee

Amazing how we all seem to see things differently. To my eyes the pic on the right has more purple CA on bottom of antennae and birds tail. The right pic also seems sharper (birds eye and claws) and has a very slight tint to the overall pic

 

[pm42]

Now the CA looks about the same in both left and right pics.

Ok so we clearly do not see the same things.
I'll be interested to know what you see in the SFL with the naked eye once you get the chance to test them.

 

[james holdsworth]

Looks like two different types of CA in each image, although a photo crop will likely exaggerate anything a hundred fold.

 

[Brummie]

Definitely more CA in the RH image, but it was always going to be the case that the SFL would have more. Doesn't seem like a huge amount on a challenging target. I'd love to see it compared to something I'm familiar with, like a UVHD+ or Habicht 10x40.

 

[henry link]

Looks like two different types of CA in each image, although a photo crop will likely exaggerate anything a hundred fold.

I though the purple might be partly longitudinal CA, but then why isn't it completely surrouding the dark area, rather than appearing only at the bottom.

There's certainly much more purple in the right image of the tail, but then there would be more if the alignment between the camera and eyepieces is off.

 

[Richard D]

It will be interesting to see how the CA is by eye - given these are from the centre which should be the best performing area, the crop suggests it doesn't handle CA as well as the Conquest 8x32, which I thought pretty good for the price, but it is a photo crop... Resolution looks good enough (although again judging resolution from a camera isn't as useful as by eye).

 

[DrewskiMT]

Interesting results, hard to say if they are valid or meaningful if the camera lense isnt capturing the full exit pupil. I’ll defer to Mr. Link’s extensive knowledge base. Also, the CA in conquests and MHGs doesn’t bother me… so I’m guessing the SFL won’t either…

 

[DrewskiMT]

Lugging around 42 Kowa Genesis or Meoptas would bother me….

 

[BryanP]

iPhone 12 pro using the long lens, Swaro on the left, Zeiss on the right, 100% crop of the raw file.

Thanks for these PM42,
Would it be possible to see the full sized un cropped versions for comparisons purposes. I get the sense the 100% crop scale of the bird in the photos verses the scale of the bird while looking through the eyepiece might be skewing my perceptions.

 

[Maljunulo]

I see purple on the right hand image.

At the risk of causing an uproar, if you are older, and/or have cataracts, your vision in the short end of the spectrum is significantly altered. The short end is attenuated and/or scattered.

 

[SUPPRESSOR]

I wouldn't use these or any other phone-scoped images to evaluate binoculars. Firstly, lateral CA will be heavily influenced the exact alignment of the camera lens and the eyepiece. It's very hard to avoid at least slight misalignment which will likely favor one or the other binocular.

Secondly the true aperture of these phone cameras has become increasingly difficult to discover. It's not in the camera specs, which now call the focal ratio the "aperture" and always give a full frame "equivalent" focal length instead of the true focal length, so the true aperture can't even be calculated from the focal length and focal ratio. This matters because phone lenses all have very small true apertures, typically around 2-2.5mm, so they are inherently incapable of accepting the full exit pupil of most binoculars. A 2.5mm phone lens will stop down every 8x binocular to about 20mm.

Once again the voice of reason sheds light when all others are flailing about in the dark😇.
Peter.

 

[pm42]

Would it be possible to see the full sized un cropped versions for comparisons purposes. I get the sense the 100% crop scale of the bird in the photos verses the scale of the bird while looking through the eyepiece might be skewing my perceptions.

Sure. Here it is. And below is a picture showing the whole field of the binoculars, well 90/95% of it.

 

[BryanP]

Sure. Here it is. And below is a picture showing the whole field of the binoculars, well 90/95% of it.

Cheers and thanks for that. Puts the images and ca in context for me.

 

[henry link]

That's a miniature version of the image you would see through the binocular. On my computer screen at my normal viewing distance the FOV circle (without clicking on the + button) subtends about 10-12º. The FOV in the binocular would subtend about 60º. The original image of the two birds on the antenna is about twice life size viewed the same way.

 

[MiddleRiver]

I see the CA diff clearly. I also think the RH image is sharper?