edwardkaraa wrote:
I think it's interesting that someone earlier made a remark about the difficulty of focusing manually with peaking. Indeed I went back to my GXR files and there is definitely a high percentage of missed focus shots, some of them really critical. So I'm a bit unconvinced about the usefulness of such cameras with RF lenses unless one has the time to use image magnification for critical focus. I think the best way to go is with native FE lenses, Which by the way are superb, perhaps using RF and other alternative glass as a fill gap until more focal ranges are introduced....Show more →
michaelwatkins wrote:
Edward, certainly no matter how proficient I was, or wasn't, with manual focus lenses and focus peaking on the NEX or GXR, spending most of the last year with the D800 convinced me of the same.
Now that Sony has in effect guaranteed the longevity of the E mount, I'm less concerned about vendor lock in and the breadth of available optics. High quality lenses should naturally follow from Sony and others -- assuming of course the market for a higher end FF ILSC remains robust enough for Sony. I think it will - if they cannibalize DSLT and NEX APS-C sales to some degree, so be it.
BenM wrote:
I agree with you both. I find that to ensure I have critical focus on what I want, I have to use the focus zoom functionality on my NEX 7. Focus peaking isn't accurate enough.
philber wrote:
And, since FF has less DOF than APS-C, focusing only with peaking is even less likely to be adequate on the A7.
I've had consistently good results with a 25mm + 50mm combo on two NEX-5N bodies: using zone focusing for the 25mm and focus peaking (with and without image magnification) for the 50mm.
There is a great discussion about AF vs. MF in the Zeiss Otus 55/1.4 thread. The general consensus is that AF and MF require different skill sets.
No doubt accurate MF will be more difficult with a 36 megapixel FF sensor but lots of people seem to be getting excellent results -- for relatively static subjects -- using 35mm and 50mm Summicrons (for example) with the OVF on the D800/D800e.
I'm not suggesting that MF lenses on the A7/A7r will be great for shooting sports or kids but for for lots of subjects I can't see how it will be inferior to a D800. If that were the case, does Zeiss expect that the Otus 55/1.4 for Nikon and Canon DSLRs will only be used for landscape and still life photography?
Since we don't have the original un-touched image file, nor do we have seriously test result, all we can know for now is something like OK or Not OK, isn't it?
Not really. Color shift is largely not a big deal and is fixable. Leica fixes it with software for most of their lenses. Smearing is the real killer.
It seems to me that the "issue" with WAs when it shows up on A7(R) is rather different from what I have observed on NEX. On the latter, it looks like a vertical magenta shift on both sides of the image. On the A7, it looks like a corner-based issue, and very dark in color, which is why it is called vignetting, although it would be sensor-based vignetting rather than the common lens-based vignetting.
So I am not sure we can easily transpose the ailments and cures from NEX to the A7, as it might be a different variety of gremlin.
philber wrote:
It seems to me that the "issue" with WAs when it shows up on A7(R) is rather different from what I have observed on NEX. On the latter, it looks like a vertical magenta shift on both sides of the image. On the A7, it looks like a corner-based issue, and very dark in color, which is why it is called vignetting, although it would be sensor-based vignetting rather than the common lens-based vignetting.
So I am not sure we can easily transpose the ailments and cures from NEX to the A7, as it might be a different variety of gremlin.
vignetting shows up more because fullframes shows the real corner of the lens rather than just the apsc crop. Keep in mind that the biogons has quite heavy vignetting itself on ff, more than 2 stops afaik. I would say
Edgar M wrote:
Correct me if I'm wrong...but a canon mount will be using a much thicker adapter, compared to an M-mount or other RF lens/mount. The thinnest mounts will be that of RF's.
If you want "tiny," then I'd cancel my order asap and order an m-mount.
I'm not concerned about a thicker adapter, its mostly the weight that concerns me. And this way I can use the lens on my 6D as well. Plus, I got a good deal on it on the B/S here.
If I absolutely love the A7 then I would consider selling my 6D and then I might move to RF lenses, but for now I'll stick with SLR lenses for the A7 - I've got plenty that are small enough.
It isn't fair to compare the behavior of a lens in a FF camera with the same lens in an APS-C camera. The field of view is 1.5x wider. It would be fairer to compare a 24-25mm. on a NEX to a 35mm. on the A7/A7r or 15mm. on NEX to 21mm. on FF.
Besides, Nanh is right, a near symmetrical design like the Biogons have significant vigneting for themselves, specially the shortest focal lengths.
Last, the CV 15/4.5 is not very good in FF. We've seen that with the Leicas M9/M240. Too much field curvature and so-so corners, I would use it only on APS-C cameras.
Sorry if I missed the answer to this, but how would WA SLR lenses be? Would they be subjected to the same color smearing, etc as RF lenses? I was thinking about getting an 7r as and adapter to use with my Canon EF and Zeiss ZE lenses when I dont want to lug the DSLR around. If it is going to smear things like my 17mm tse then might as well forget the idea.
You will have to use your imagination sometimes when using google translate however it appears that results are not as good as I had hoped. Surprisingly and I could be wrong here they seem to be saying that the A7R has more problems with red shift than the A7
The optical projection of the lens will always be the same, whether you put it on an APS-C or FF ... all the APS-C has done is crop away the bad stuff. Thus, the whole APS-C equivalency comparison @ fair is a moot point at whether or not the A7R with it's offset sensor will address the color shift that occurs from the additional angles of refraction imparted by the microlens redirecting the light onto an RGB bayer array.
The theoretical hope that an offset sensor would result in a lesser amount or refraction required from the microlens to direct the light onto the sensor appears to have little impact (from the magenta sides image and from the comments regarding by others).
The optical projection is designed to have the light converge to align wavelengths at a given point. Having those projections converge (from differing angles) to a point that is then subsequently being refracted is always going to have a detrimental effect on the aligment/divergence. I think that the preliminary results of that magenta shot coupled with the comments by others early experience with a given lens likely tells the story that the offset sensor is no "magic beans" to address the microlens refraction.
While we can clamor over this lens vs. that lens and discount the negative results from a given lens in hope that it will work better for a different lens to our liking, it may be a bit folly.
Light is an energy, a force that is being redirected onto our sensor/film. As such it is a vector quantity. The vignetting that we see from those steep angles is a product of the trigonometry from the projected image. As long as the microlens exists in the same film plane, the angles from the projected image to the microlens will remain the same for a given distance from the optical axis.
On film, will don't have the bayer array to contend with. While the "offset sensor" sent hope that it might have some ability to contend with the color shift imparted by the microlens refracting the converged light, these early images and comments at the A7R make me think that as long as we are using a bayer array in the same film plane, we'll get the same results. The subsequent diffraction of an otherwise properly converged light wavelengths only serves to separate those wavelengths from proper alignment. As that angle of refraction increases (corresponding to the steeper angles of incidence), the degree of separation likewise increases.
As such, I'm inclined to think that unless a Foveon approach (or Canon's "tiered Foveon") is utilized where there is no subsequent refraction to re-separate the properly converged light ... the color shifts will always occur for the steep angles in conjunction with a micro-lens Bayer array. Unless the film plane itself is modified, so that the amount of refraction imparted by the microlens remains below the (visible) threshold for producing that separation, it is physically destined to remain a byproduct of the micro-lens refraction imparted onto the properly converged light.
Let the bashing begin ... but I'm no longer holding my breath that the A7R's offset sensor is going be the "magic beans" that I was very much hoping. Sigma needs to bring out a FF mirrorless Foveon, or Canon needs to finish their "tiered Foveon".
Imo Bayer array and micro-lens refraction is not the answer for UWA steep angle color shifts. The only way that it could be is if a lens was designed to strike the microlens with a non-convergent light, that would subsequently be refracted by the micro-lens to proper convergence. This of course would be most suitable to a fixed mount lens ... like the RX1. As such, that would still mitigate the use of rangefinder glass. UWA, rangefinder glass on Bayer micro-lens for color isn't something I'd hold my breath any longer. Even with SLR glass, it isn't an ideal approach. Thus ... I better get more adept at software correction/profiling for my UWA's until we have a FF non-Bayer/microlens solution. That, or look UWA glass designed for APS-C for Sigma's Foveon (which is rather limited in choices).
You will have to use your imagination sometimes when using google translate however it appears that results are not as good as I had hoped. Surprisingly and I could be wrong here they seem to be saying that the A7R has more problems with red shift than the A7
Foveon isn't the answer to steep angles. Besides, Foveon struggle with color shifts all by itself without RF lenses to induce it. I think you mean organic sensors. That is what will alleviate the steep angles. I doubt we'll see these sensors for at least 5 years or more.
You will have to use your imagination sometimes when using google translate however it appears that results are not as good as I had hoped. Surprisingly and I could be wrong here they seem to be saying that the A7R has more problems with red shift than the A7
Maybe it's because they use the D800E method of AA un-filtering. It actually adds to sensor thickness.
Foveon is just a stacking of RGB sensors on top of each other. The problem is each layer below receives less light and certain wavelengths are filtered before reaching the lower layer (thus Foveon's struggle with color shift).
From what I understand, there are two types of organic sensors being developed. The most interesting one is where the organic material makes up the photodiode. It'll be more lenient on light angles like film. You can google Fuji organic patents. There are a lot of info out there. Right now, I think the three primary companies working on it are Fuji, Panasonic, and Sony. Fuji seems furthest along, but my bet is that Sony will get there first. I don't know, Sony just seems unstoppable in the area of sensors.
Thanks for the link. There are some A7r samples presented as being from the G45. They look gorgeous. What's odd though is that the EXIF shows 45mm - not sure how that's possible since there's no electrical connection to the lens. Maybe they edited the EXIF? Anyway here are the full 36MP samples:
And here is an A7r gallery with what looks like the G21. Reading the rough google translation of that thread is like reading this thread from a parallel universe
