[osv]

Indeed: Pentax 645Z Ranked Highest by DxOMark - Photo Industry News | PentaxForums.com

how can it be ranked when there isn't any test data? i already posted the sensorgen measurements, you don't need dxo to see some of the comparison data.

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[itshimitis]

no, in the specific scenario you posted above, if the ff sensor/14mm lens is shot in portrait mode it has nearly enough vertical fov(aka width, since it's rotated) to cover the horizontal fov of the 645z/25mm lens... since you can't visualize that, do the math instead... 645z has a .79 focal length multiplier/4:3 sensor, ff is 1:1/3:2 sensor, Angular Field of View Calculator

81.2 degrees vertical(aka width, since it's rotated) for the ff sensor
82.5 degrees horizontal for the mf sensor

so it appears to me that you may or may not be short a degree of fov, depending on how accurate the actual focal length of the lens really is.

---------- Post added 03-19-16 at 05:00 PM ----------



oh? do you see a problem with the math that i posted? the width is almost the same, and you have much better vertical coverage to include both the road and the north star in the shot, which itshimitis could not do with the 645z/25mm combo.

shooting it with the ff camera would have been the better choice, compositionally speaking... cropping it like itshimitis just did does not work at all.

104.3 degrees vertical(aka width, since it's rotated) fov with the ff sensor/14mm lens
66 degrees vertical fov with the 645z/25mm lens

Have you actually looked at the images I posted above at all? Using the 3:2, It would be be too narrow on width. It would not, I believe have the whole of the road in frame, and I need the whole road in frame to use it as a leading line. That scene is now 300 miles away from where I am or else I would take a stroll to reshoot. In any case are you suggesting that a portrait orientated shot would be the same composition as a landscape orientated shot? Really? I didn't and don't want to shoot in portrait orientation for this shot.

[MJSfoto1956]

[re: Panasonic technology] cropping the sensor is no different than cropping the image.

um, this is completely wrong with regard to Panasonic's unique "cropping" feature as used in their P&S cameras: they maintain the diagonal during crop and thus they maximize the number of pixels per crop -- no other cameras have this. You might be thinking about how Nikon (and Pentax) are indeed cropping off pixels -- and with these systems there is indeed no difference between an in-camera crop and a post-processing crop. However, you quoted Panasonic and I have to clear the air here: Panasonic's P&S in-camera cropping is unique, patented, and a really really cool technology.

Michael

[osv]

Have you actually looked at the images I posted above at all?

i tried, but i have no idea what you did there... since there is no a7rii portrait shot, we simply can't make a valid comparison.

the good news is that the math appears to prove that they both have the same horizontal field of view, when the a7rii is in portrait mode... you should be able to see that with test pics, i can see it just by looking at what you posted.

it won't be the same shot of course, due to distortion, but since the camera couldn't be moved, there aren't any alternatives.

[itshimitis]

i tried, but i have no idea what you did there... since there is no a7rii portrait shot, we simply can't make a valid comparison.

the good news is that the math appears to prove that they both have the same horizontal field of view, when the a7rii is in portrait mode... you should be able to see that with test pics, i can see it just by looking at what you posted.

it won't be the same shot of course, due to distortion, but since the camera couldn't be moved, there aren't any alternatives.

Distortion isn't the reason the shot wouldn't be the same. Portrait and landscape orientation are different compositions entirely. Distortion has nothing to do with it.

[texandrews]

how can it be ranked when there isn't any test data? i already posted the sensorgen measurements, you don't need dxo to see some of the comparison data.

Just for the record, DXO HAS apparently tested the Z, as has been posted here and at DPR. I believe the result (a score +, not the full charts) was a leak, somehow mistakenly put in a place where it could be publicly accessed. But what we saw was that the Z was the best sensor tested, including the D810.

That said, there are many good reasons to choose one camera over another.

[narual]

Why don't you lovebirds take the pissing match to pm?

[osv]

um, this is completely wrong with regard to Panasonic's unique "cropping" feature as used in their P&S cameras: they maintain the diagonal during crop and thus they maximize the number of pixels per crop -- no other cameras have this. You might be thinking about how Nikon (and Pentax) are indeed cropping off pixels -- and with these systems there is indeed no difference between an in-camera crop and a post-processing crop. However, you quoted Panasonic and I have to clear the air here: Panasonic's P&S in-camera cropping is unique, patented, and a really really cool technology.

i'm not really clear on how that could work, but it sure sounds interesting.

for a given sensor size, diagonal always changes with fl, so they would have to be effectively changing the sensor width/height directly, to compensate for the change in fl... it seems to me that maximizing pixel count in that situation infers some compromise like interpolation, pixel skipping, etc, which creates it's own set of issues.

---------- Post added 03-19-16 at 06:31 PM ----------

Distortion isn't the reason the shot wouldn't be the same. Portrait and landscape orientation are different compositions entirely. Distortion has nothing to do with it.

cropping changes the portrait/landscape scenario; 14mm distortion has everything to do with how the shot looks.

since you aren't accepting the math that proves that the width is the same, why not do some test pics with ff/14mm in portrait mode, vs. 645z/25mm?

---------- Post added 03-19-16 at 06:41 PM ----------

Just for the record, DXO HAS apparently tested the Z, as has been posted here and at DPR. I believe the result (a score +, not the full charts) was a leak, somehow mistakenly put in a place where it could be publicly accessed. But what we saw was that the Z was the best sensor tested, including the D810.

why do people keep saying "leaked"? like it's tmz or something... how do you know that what we saw was accurate info? what if they screwed up the testing, which is why there is still no data?

do you know who bill claff is, and what sensorgen does? there is accurate measured data out here already, i've posted it... dpr has iso noise pics, whatever dxo finally does isn't going to add much to what we already know.

[2351HD]

i'm not really clear on how that could work, but it sure sounds interesting.

for a given sensor size, diagonal always changes with fl, so they would have to be effectively changing the sensor width/height directly, to compensate for the change in fl... it seems to me that maximizing pixel count in that situation infers some compromise like interpolation, pixel skipping, etc, which creates it's own set of issues.

---------- Post added 03-19-16 at 06:31 PM ----------



cropping changes the portrait/landscape scenario; 14mm distortion has everything to do with how the shot looks.

since you aren't accepting the math that proves that the width is the same, why not do some test pics with ff/14mm in portrait mode, vs. 645z/25mm?

---------- Post added 03-19-16 at 06:41 PM ----------



why do people keep saying "leaked"? like it's tmz or something... how do you know that what we saw was accurate info? what if they screwed up the testing, which is why there is still no data?

do you know who bill claff is, and what sensorgen does? there is accurate measured data out here already, i've posted it... dpr has iso noise pics, whatever dxo finally does isn't going to add much to what we already know.

Dude I am keen to know what your apparent problem is with the 645 system and the 645Z (or at least it appears you have a problem).

So it tested on DXO really well, better than the D810 and A7rII, and it would want to due to its specs and price.

Is it that hard to accept it and move forward, or are you just trolling?

[itshimitis]

Why don't you lovebirds take the pissing match to pm?

With respect, while I accept that I've allowed myself to be drawn into a circular argument, I'd have more respect for your request had you actually contributed something yourself to the overall discussion. My apologies if I have missed yours.

[/COLOR]

cropping changes the portrait/landscape scenario; 14mm distortion has everything to do with how the shot looks.

since you aren't accepting the math that proves that the width is the same, why not do some test pics with ff/14mm in portrait mode, vs. 645z/25mm?[COLOR="Silver"]

Getting back to the OP's queries, your suggestion to him when he says that 3:2 doesn't work for him is simply to change orientation from portrait to landscape (or vice versa) and then crop. I'm not sure you're aware how ridiculous that suggestion is. I fail to see (and this will be my last response to you, Halleljah!) how you don't get that changing from landscape to portrait orientation completely changes the composition. Composition isn't simply about fitting things in. It's about flow too. If you got your head out of the charts you might see that.

[osv]

Getting back to the OP's queries, your suggestion to him when he says that 3:2 doesn't work for him is simply to change orientation from portrait to landscape (or vice versa) and then crop.

wrong, i clearly stated "the only really valid point i see is 4:3"

i told YOU to do it with the a7rii/14mm, because you effectively admitted that your pics failed because you couldn't get the north star in the shot with the 645z/25mm.

I'm not sure you're aware how ridiculous that suggestion is.

what was ridiculous was your continued insistence that the a7rii/14mm in portrait mode wasn't "wide" enough, even after i proved that it had the same horizontal fov as your 645z/25mm rig

you could have even made a vertical panorama with the 645z/25mm, replacing the sky portion however you wanted, but you couldn't see that option either, because you've got yourself totally locked into the compositional failures of obsolete print aspect ratios... fyi, this is the year 2016, prints can be done at any size and any aspect ratio.

[itshimitis]

wrong, i clearly stated "the only really valid point i see is 4:3"

i told YOU to do it with the a7rii/14mm, because you effectively admitted that your pics failed because you couldn't get the north star in the shot with the 645z/25mm.



what was ridiculous was your continued insistence that the a7rii/14mm in portrait mode wasn't "wide" enough, even after i proved that it had the same horizontal fov as your 645z/25mm rig

you could have even made a vertical panorama with the 645z/25mm, replacing the sky portion however you wanted, but you couldn't see that option either, because you've got yourself totally locked into the compositional failures of obsolete print aspect ratios... fyi, this is the year 2016, prints can be done at any size and any aspect ratio.

For the very last time, I don't want to have to shoot in portrait orientation to get the certain emollients of the shot I want. That was my whole point. With 3:2 I couldn't even get close. With 4:3 I can look next time at getting only a little further back and still keep the composition I want in landscape orientation. It was you who said to shoot in portrait orientation, not me. And at least I do print my images, not relying on just seeing them on screens. Both me and the OP want to shoot in 4:3 at the shooting distance we want to get the composition we want.

print sizes are only obsolete to a certain extent if you are using a sheet roll feeder - which I can with my R3000. There will always be some form of limit one way or another according to the width of the roll. That's the same in any year.

Now, I'm done, you will be the very first person I have on ignore list. I doubt that I will miss very much.

[narual]

With respect, while I accept that I've allowed myself to be drawn into a circular argument, I'd have more respect for your request had you actually contributed something yourself to the overall discussion. My apologies if I have missed yours.

If I hadn't, I wouldn't be getting constant update emails with you sniping at each other.

[itshimitis]

If I hadn't, I wouldn't be getting constant update emails with you sniping at each other.

My apologies as I said, as I missed yours. I probably glazed over on talk of flash sync, since that is something I have no knowledge on...

[rfkiii]

Since I have been cropping to 9:15 (not a typo), I've grown very fond of the aspect. Both 4:3 and 3:2 now look odd to me for landscape photography. Obviously with this cropping regimen, 4:3 wastes more pixels than 3:2, but having 50 MPs, there are some pixels to burn with either sensor aspect. Because I usually choose a wide angle lens when I hike to cover more compositional possibilities (and lighten my load) while knowing that I can crop to compose, the upside to cropping is that many times, I have extraneous amounts of sky that have to go anyway.