Olympus High Resolution Mode test w/60mm macro

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Lou Jost
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Post by Lou Jost »

Thanks for finding your tests. Hmm... here we are comparing a 16Mp image to a 10 Mp image with the same optics. I admit I am a bit surprised by apparent sharper results of the 10Mp Sony crop. Is this from a stack? Are these unsharpened RAW images or did they go through their respective cameras' jpg converters?

austrokiwi1
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Post by austrokiwi1 »

Sorry both are stacks of 4 and 5 images respectively same step increment the sony needed one more step to cover the highest parts of the image. all source images were Jpegs no editing before stacking by Depth map.

I am not surprised at the difference in IQ. Its not just a matter of resolution, dynamic range and noise give the Sony the advantage. I do not know how much the Back illuminated sensor contributes to the image, So far with the Canon Range finder lens I am gaining the impression that it is making light sensing easier. With the other A7 series cameras the micro lenses above the pixels actually reflect light away from the pixels at the edges of the sensor, when RF lenses were used. The A7rII does not seem to have this issue ( to my eyes) so I suspect there is another advantage here
Still learning,
Cameras' Sony A7rII, OLympus OMD-EM10II
Macro lenses: Printing nikkor 105mm, Sony FE 90mm F2.8 Macro G, Schneider Kreuznach Makro Iris 50mm , 2.8, Schnieder Kreuznach APO Componon HM 40mm F2.8 , Mamiya 645 120mm F4 Macro ( used with mirex tilt shift adapter), Olympus 135mm 4.5 bellows lens, Oly 80mm bellows lens, Olympus 60mm F2.8

Lou Jost
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Post by Lou Jost »

I think it is misleading to compare jpgs though. We have no idea what sharpness settings, noise reduction processes, etc were used by these very different cameras. It would have been better to compare identically-processed RAW images. Still, I agree that larger pixels should be less noisy and have more dynamic range. Yet it seems to me that the difference between your pictures is more than can be attributed just to those two factors.

austrokiwi1
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Post by austrokiwi1 »

I take your point on Raw. The different "engines " probably do make the comparison less useful. I will look at repeating it... with Raw and then using the same editing software to convert to Jpeg. that said... there is an ever present difference between the two cameras with the Sony being the much better performer . Given the price differential I would be disappointed if that was the case.
Still learning,
Cameras' Sony A7rII, OLympus OMD-EM10II
Macro lenses: Printing nikkor 105mm, Sony FE 90mm F2.8 Macro G, Schneider Kreuznach Makro Iris 50mm , 2.8, Schnieder Kreuznach APO Componon HM 40mm F2.8 , Mamiya 645 120mm F4 Macro ( used with mirex tilt shift adapter), Olympus 135mm 4.5 bellows lens, Oly 80mm bellows lens, Olympus 60mm F2.8

Lou Jost
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Post by Lou Jost »

I'd love to see additional comparisons if you have more. If it really is so much better, I could switch to that camera for microscopy since I could re-use all my glass (Nikon and M42 tube lenses, and my Oly lenses reversed). I could even still do focus bracketing by controlling the lens with my Oly. But I would still like to see more. Your Oly is an older one that has a lower-res sensor and none of the new tricks of the PEN F.

Lou Jost
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Post by Lou Jost »

Does your Sony allow flash with the silent electronic shutter? I assume it is really silent and not EFCS? That is a huge advantage of the PEN F over most other cameras. An essential feature for me.

lolhonk
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Post by lolhonk »

austrokiwi1 wrote:How I measured the resolution:

Here is a comparison of the oly at 5.25X and the A7rII at the same magnification ( I have cropped the Sony image to the same FOV as the Oly. To my eye the Sony is still producing the better image. Optics are the SK 40/2.8 coupled with an SK 210/5.6 Large format enlarger lens( A very workable combination that happily covers a full frame sensor) Lighting was the same in each case and I set custom White balance separately for each camera.
Hi,

thanks for this comparison! May I aks you why do u use coupled lenses? What's the advantage? Why u don't use the sk 40mm reversed with some extention tubes?

greetings,

Lou Jost
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Post by Lou Jost »

See
http://www.photomacrography.net/forum/v ... led+lenses
For a given magnification, coupled lenses have a lower effective aperture than lenses on extension. The difference is significant at very low m, not so much at m > 3.

Lou Jost
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Post by Lou Jost »

Here is a non- high-res stack, at 10x (Mitu 10x + 200mm Nikon).
Image
Below is a crop of the original image. Same Urania moth as above. In this picture you can see how the curved iridescent scales are actually transparent-- note how the scales underneath them are illuminated through them, with only the denser scale tip casting a shadow. I admit that this is pretty crappy but I think it is due to the crazy iridescence.
Image

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Post by rjlittlefield »

Lou Jost wrote:Rik, I should add that there are other reasons why I switched from Nikon to MFT. I do a lot of field work in remote places that require hiking for many days, and the weight of APS or FF lenses is too much for me. If money were no concern, sure, a nice set of FF gear for microphotography and a nice set of MFT gear for fieldwork would be ideal. But if money is limited, MFT is a good compromise.
Lou, there is nothing in that quote that I would disagree with. I also have no disagreement with your points about vibration control. And I think it's quite possible that the Olympus in hi-res mode can match the per-image-area noise levels of a full-frame sensor. (That's because the Oly gets to empty and refill the sensor multiple times in shooting a single hi-res image, so its total photon capture may match a single exposure from the full-frame.)

There is much to love about the Olympus. The only reason that I haven't bought one yet is because I don't want to get even more distracted away from other things that are already taking far too long to get done.

All that said, I'm still going to push back against what I see as an over-exuberant claim that the camera is great for capturing lots of megapixels.

Theory and your own experiments indicate that to actually use all those megapixels on such a small sensor, the optics need to be running at effective f/4 or thereabouts. That's simple enough near m=0, but quite challenging around 1:1.

Sure, theory says that all you need to do is couple two f/4 lenses in a symmetric arrangement, and you'll have 1:1 at effective f/4.

But in practice that only applies at image center. Away from center, the light takes paths that the lens designers never anticipated or optimized for, and that leads to problems with a wide range of aberrations.

Perhaps I've overlooked something to the contrary, but what I keep reading in your posts are words like "Yes, finding suitable pairs of lenses to couple is a big challenge. But theoretically there could be a big payoff for m less than about 3." And I have not noticed you posting any images -- none at all -- showing high quality, corner to corner, at troublesome magnifications.

Perhaps this is just a perception issue, and in that case I would love to have my perceptions corrected.

So I will ask, quite bluntly... What have you actually found for "suitable pairs of lenses to couple"? What are the details of the coupling, for example added stops? What magnifications do the pairs work well at? And perhaps most important and convincing, what do the images look like, in their corners, with a detailed subject?

--Rik

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Post by Chris S. »

Lou,
Lou Jost wrote:Below is a crop of the original image. Same Urania moth as above.
Did you mean:"Below is a crop of the above image. Same Urania moth as pictured at the beginning of this thread?"

I ask because I was confused when I first read your post.

Cheers,

--Chris

Lou Jost
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Post by Lou Jost »

That's fair enough.
"I think it's quite possible that the Olympus in hi-res mode can match the per-image-area noise levels of a full-frame sensor. (That's because the Oly gets to empty and refill the sensor multiple times in shooting a single hi-res image, so its total photon capture may match a single exposure from the full-frame.) "
Yes, the Oly takes 8 shots per image so it is capturing twice the total amount of light per image area compared to full frame taking an image with the same field of view.
"What have you actually found for "suitable pairs of lenses to couple"? What are the details of the coupling, for example added stops? What magnifications do the pairs work well at? And perhaps most important and convincing, what do the images look like, in their corners, with a detailed subject?"
I have always tried to be careful to say "theoretically"....I don't know if the theory can be realized in practice. I try to emphasize that. But I have gotten encouraging results at m around 1 to 3 (my goal). I did post some results; though they are not good enough, they give me reason to be hopeful.

Here I used a 75mm f/1.8 Oly MFT lens reversed on a Vivitar 135mm lens with a Waterhouse stop to gve a measured EA of about 5.6 on an APS-C camera. Here is a full image:

http://www.photomacrography.net/forum/u ... tack_1.jpg

and here is a 100% crop:

http://www.photomacrography.net/forum/u ... 1353_1.jpg

Note that these are not full stacks because I was just testing. But I did get some of the edges.

I also had decent results with a reversed 50 f/1.4 sigma on the 75mm lens, and several other combos on the PEN F. Here is a -25 PL f/1.4 at f/4 reversed on the Oly 75mm at f/1.8. Again this is a partial stack but I did get some of the edges.

Image

Here is the lower left corner at 100%:
Image
Last edited by Lou Jost on Sun Nov 20, 2016 8:05 pm, edited 2 times in total.

Lou Jost
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Post by Lou Jost »

Chris, it is the same moth but it is an enlargement of the image immediately above it. Sorry for the confusion.

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Post by rjlittlefield »

Lou Jost wrote:I also had decent results with a reversed 50 f/1.4 sigma on the 75mm lens, and several other combos on the PEN F. Here is a -25 PL f/1.4 at f/4 reversed on the Oly 75mm at f/1.8. Again this is a partial stack but I did get some of the edges.

http://www.photomacrography.net/forum/u ... PMax_1.jpg

Here is the lower left corner at 100%:

http://www.photomacrography.net/forum/u ... rner_1.jpg
That looks pretty good at first glance. But when I match the second image to the first one it seems to occupy an area that's about 19.6% x 26.1% of width x height. If that's the whole frame displayed in the first image as 1000x750 pixels, that seems to imply that the crop represents the whole frame at only about 15 megapixels, not 80.

What have I missed? Is the other image not actually the whole frame?

--Rik

Lou Jost
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Post by Lou Jost »

That wasn't a high-res stack. Just a regular one. First round of testing just uses the faster-to-make regular images.

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