p.33 #1 · Official: Sony A7 and A7R Fullframe Mirrorless
Tariq Gibran wrote:
Sony is using some sort of Diffraction-reducing technology as well that takes into account the lens aperture so I'm not sure if that trick will work. That will be interesting to test on these cameras. Some of the samples shot at F16 and F22 look remarkably sharp from the A7's...at 100%!
I heard diffraction tech only for JPEG (suck) and only available for A7R.
p.33 #2 · Official: Sony A7 and A7R Fullframe Mirrorless
The video moire is probably caused by line-skipping.
It shouldn't be much worse in the A7R - the lines they keep are still the same distance apart, which means the spatial sampling rate is the same. The lines will just be thinner. The fact that there are more lines between the ones kept has no bearing. The AA filter that the A7 has will have a blur radius of roughly one line, and going from 6000x4000 to 1080p means you really need a filter 4x stronger than that. So the difference between the A7 and A7R here is essentially that instead of a 25%-effective AA filter you've got a 0%-effective AA filter for video.
p.33 #3 · Official: Sony A7 and A7R Fullframe Mirrorless
Also - an 80MP sensor won't affect video moire at all if they still produce 1080p video by simply throwing away 7 out of 8 lines or whatever.
You need a processor that's capable of correctly downsampling (meaning first applying a stronger AA filter, then throwing away samples and lines) every single frame in real-time.
p.33 #5 · Official: Sony A7 and A7R Fullframe Mirrorless
Taylor Sherman wrote:
The video moire is probably caused by line-skipping.
It shouldn't be much worse in the A7R - the lines they keep are still the same distance apart, which means the spatial sampling rate is the same. The lines will just be thinner. The fact that there are more lines between the ones kept has no bearing. The AA filter that the A7 has will have a blur radius of roughly one line, and going from 6000x4000 to 1080p means you really need a filter 4x stronger than that. So the difference between the A7 and A7R here is essentially that instead of a 25%-effective AA filter you've got a 0%-effective AA filter for video.
p.33 #7 · Official: Sony A7 and A7R Fullframe Mirrorless
michaelwatkins wrote:
Sami: Don't shoot buildings and roofs? ;-)
Here's the A7 and A7r, being shot by one of them, out in the woods.
Here's video output from both the A7 and A7r, just watching it now, not sure if there's a moire issue but maybe a comment to the author can determine if it was a problem
I used to see more moire from an AA filterless 12.3MP GXR and Zeiss lens combo than I see from my D800. Aren't more pixels supposed to help mitigate the issue to some degree?
More pixels on sensor usually mean more line skipping. However, D800 records bit larger frames than 1920x1080 by line skipping and then down samples it to 1920x1080 so it reduces moire and jagged lines for final output. So it is not impossible to create smoother video with high mp sensor compared the one example from A7.
p.33 #9 · Official: Sony A7 and A7R Fullframe Mirrorless
Thanks Taylor for that detail, very helpful.
For my purposes, working around moire in video isn't a deal killer. I'm more interested in how prevalent moire is in stills but am betting that it won't be a big problem for me. Anyone have a tight weave herringbone suit and an A7r to test? The folks at HerringBoneSuits.com really want to know.
p.33 #12 · Official: Sony A7 and A7R Fullframe Mirrorless
I'm expecting the A7r to feel familiar in hand:
Contax 139: 135 x 85.5 x 50 mm; 500 grams
Sony A7r: 127 x 94.0 x 48 mm; 474 grams
Contax N1 152 x 116.5 x 69
The shape is more reminiscent of cameras like the bulkier N1, but size wise not far off the Contax 139. The 139 was my carry around camera for many years. I think I'll get along fine with an A7n in hand.
Sony really has made exactly what I've been looking for all these years, a full frame system camera the size of a small SLR.
p.33 #14 · Official: Sony A7 and A7R Fullframe Mirrorless
JohnJ wrote:
Except the Leica R4, probably on account of them being based on the same body/chassis, but not sure how much if any of that relates to pentaprisms/focusing screens etc. Viewfinder magnification is very similar and larger than most cameras which accounts for the larger image and there fore easier focusing.
I always found the R4 to have one of the best, if not the best, viewfinder for focusing wide angle lenses and especially when fitted with a later focusing screen, from R6/7 bodies which where brighter yet easy to focus accurately. That's why I still have it as it has a place even compared to the R8/9, which is also great for accurate focusing, but with a smaller image magnification. The R4 is a great camera for wide angle lenses that are otherwise harder to focus accurately.
that's why i said dslr not slr. i agree the R4 has a better viewfinder, not sure if it's due to optics or the focus screens (or both).
Tariq Gibran wrote:
I'm not so sure that's the case when it comes to bokeh (the central split image or micro-prism only having a central effect). From your statement then, I take it your XD-11 does indeed have a central focusing aid. If you use a ground glass screen, for instance, the bokeh would not be effected like the Sony example. I'm pretty sure the micro-prism has an effect on the oof areas with regard to bokeh. In any case, this is an advantage of EVF's compared to common focusing screens - perhaps the single instance where reality as seen through the lens is portrayed more accurately than through an OVF. ...Show more →
why would the microprism effect rays of light that don't fall on it? the matte part of my focus screen is ground glass btw. finally, i've changed out split focus screens and replaced them with plain matte screens and everything looks exactly the same. trust me, using a ground glass screen on an slr will look just like this. so will using whatever the plastic matte screens are they put in dslrs these days.
the ways in which reality as seen through a lens is seen through an OVF more accurately than an EVF are color, motion, and brightness. everything else is more accurate through an evf.
p.33 #15 · Official: Sony A7 and A7R Fullframe Mirrorless
michaelwatkins wrote:
I'm expecting the A7r to feel familiar in hand:
Contax 139: 135 x 85.5 x 50 mm; 500 grams
Sony A7r: 127 x 94.0 x 48 mm; 474 grams
Contax N1 152 x 116.5 x 69
The shape is more reminiscent of cameras like the bulkier N1, but size wise not far off the Contax 139. The 139 was my carry around camera for many years. I think I'll get along fine with an A7n in hand.
Sony really has made exactly what I've been looking for all these years, a full frame system camera the size of a small SLR.
p.33 #17 · Official: Sony A7 and A7R Fullframe Mirrorless
After the A700 raw fiasco, which Sony eventually fixed, I can't imagine that they'd mess with correcting raws again, at least not without the choice to turn it off.
p.33 #20 · Official: Sony A7 and A7R Fullframe Mirrorless
sebboh wrote:
why would the microprism effect rays of light that don't fall on it? the matte part of my focus screen is ground glass btw. finally, i've changed out split focus screens and replaced them with plain matte screens and everything looks exactly the same. trust me, using a ground glass screen on an slr will look just like this. so will using whatever the plastic matte screens are they put in dslrs these days.
the ways in which reality as seen through a lens is seen through an OVF more accurately than an EVF are color, motion, and brightness. everything else is more accurate through an evf.
With a full ground glass screen, the light hitting it is diffused and scattered evenly. The effect is that dof and oof areas are accurate. With fresnels, microprisms, bright screens and the like, the focusing screen and or parts of the focusing screen act more like a lens or mini-prisms (the light is scattered/ diffused less and focused more directly into the pentaprism). The upside is a brighter image and the downside is that dof and oof areas appear differently. The downside to a pure ground glass screen though is that it will be dim.
Long story short though is that the EVF indeed is superior in this respect.
) and only available for A7R. 
