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04-04-2016, 10:15 AM   #1
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645Z owners: Will you switch to a Sony 75MP A7RIII?

Sony has made clear their intentions to continue ramping up resolution in their fullframe cameras, and that's their stated reason for introducing the new higher resolution G Master lenses. Now a Japan source source (published on the web today) is indicating the upcoming A7RIII will have a 75-80MP sensor, and improved 5-axis IBIS.

For me, I love extremely fine detail capture for landscape images, as I do print large and I do enjoy getting up close to a fine art print and seeing breathtaking detail of beautiful subjects. I've owned a ton of digital cameras in the last decade and the 645Z is the first that has come close to giving me 40x30 prints that have resolution rivaling prints from 600MB drum scans from 4x5 Velvia originals (and of course the 645Z blows the 4x5 transparencies away in dynamic range).

If I were to switch to the upcoming Sony it would be not only for the additional resolution but also the 5-axis IBIS and small packable size/weight, making it an ideal travel camera. Also, the ability to adapt virtually any lens to the Sony is very intriguing, as I'd love to use the excellent Canon 24mm TS-E II, among others.

And for those who don't print huge, note that the very exacting and picky Lloyd Chambers has shown that oversampling with more pixels than you think you will ever need does produce better IQ in even modest size prints, as it reduces any sign of digital artifacts.

It would be an interesting discussion to see if any current owners of the 645Z think they will switch over to this new Sony? Why, or why not? Obviously there is no right or wrong answer here. I'd love to hear your own thoughts.

Cheers,
Ross

04-04-2016, 10:55 AM   #2
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As a new user of 645Z I would have to say at this time the answer would be no.

75-80MP on FF sensor seems to be pushing ones IQ luck, but who knows until we see a unit in action.

I would generally prefer a larger sensor with slightly larger photo sites as is the case with the 645Z. Although officially only 1.7x FF the 645Z to me preferring 4:3 or 5:4 is around 2x FF.

As Sony also has 100MP FF 6x4.5 sensor and a camera that should take this in the 645Z, without huge tooling changes, I think I would prefer to wait.
Whether I could justify or afford the expense is of course another matter

Cheers
Tony
04-04-2016, 11:11 AM   #3
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QuoteOriginally posted by TonyW Quote
As a new user of 645Z I would have to say at this time the answer would be no.

75-80MP on FF sensor seems to be pushing ones IQ luck, but who knows until we see a unit in action.

I would generally prefer a larger sensor with slightly larger photo sites as is the case with the 645Z. Although officially only 1.7x FF the 645Z to me preferring 4:3 or 5:4 is around 2x FF.

As Sony also has 100MP FF 6x4.5 sensor and a camera that should take this in the 645Z, without huge tooling changes, I think I would prefer to wait.
Whether I could justify or afford the expense is of course another matter

Cheers
Tony

Good thoughts Tony, thanks. No doubt that new larger 100MP sensor when placed in a 645Z mkII would give astounding image quality (as files from the new Phase One 100MP show), and that would be my preferred upgrade from my 645Z unless the price is too high. Still, the small size/weight of a hi-res Sony mirrorless combined with sensor shake reduction for handholding intrigues me for travel photography or difficult hikes where my 645Z system is too much of a burden.

Another factor you brought up: I absolutely am in love with 4:3/5:4 aspect ratios and have been for decades, and I don't relish going back to 3:2 for fine art landscape shooting.

Cheers,
Ross
04-04-2016, 11:40 AM   #4
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Remember, when considering pixels size and light gathering ability, you have to take into account the area of the photosite, not just the crop factor per side

The current 645z sensor has a total area of 1436.64 mm^2 delivering 51.4 MP for a and a photosite density of about 36 kilopixels per mm^2

Say you have a 80MP Sony with a mere 864mm^2. There your photosite density is close to 93 kilopixels per mm^2.

So you aren't looking at 1.7x the light gathering ability for the Z at a per pixel basis. You are looking at a factor more like 2.6. Hardly "slightly larger." Sony would really have to pull a rabbit out of the hat, therefore to achieve anything like the ridiculous dynamic range that the Z has, especially with a higher res. Also, consider that with the smaller photosites, you are going to be looking at diffraction kicking in at much much faster apertures, so in many cases, especially small apertured landscapes, any perceived resolution gains from added pixels are likely to be more than offset by diffraction blur.

Presuming a future 100MP true 645 sensor model, you are looking at 27000mm^2 of sensor area so 37kilopixels per mm^2, roughly the same as the current Z on a per pixel level, with the attendant light gathering and diffraction advantages but with twice as many pixels as the current models!


Last edited by dcshooter; 04-04-2016 at 11:48 AM.
04-04-2016, 11:41 AM   #5
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Nope! As a tool my camera is a sum of its parts. Having owned an A7 briefly I can safely say there is little chance of me ever owning a sony again. Sony is a multimedia company and their products suit the multimedia generation imho. One look at their menus will confirm that. Nah the next stop for me will be a Hassleblad.
04-04-2016, 12:05 PM   #6
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Landscape? Why not merge in PS....

You can get as much as detail as desired. Take several pictures beside/above each other at exactly the same settings (ASA, shutter, and sweet-spot opening) in RAW and devellop to one super sized picture.


Works fine!
04-04-2016, 12:35 PM   #7
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no thanks. it sounds like a downgrade to me.
04-04-2016, 12:38 PM - 1 Like   #8
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I think medium format IQ will keep up in the long term. If FF can do 80 Mp well, the 645 should be able to do 100+ some day


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04-04-2016, 01:00 PM   #9
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QuoteOriginally posted by dcshooter Quote
Remember, when considering pixels size and light gathering ability, you have to take into account the area of the photosite, not just the crop factor per side[...]
Thank you for that info dcshooter


QuoteOriginally posted by creative69 Quote
Nope! As a tool my camera is a sum of its parts. Having owned an A7 briefly I can safely say there is little chance of me ever owning a sony again. Sony is a multimedia company and their products suit the multimedia generation imho. One look at their menus will confirm that. Nah the next stop for me will be a Hassleblad.
I appreciate that honest opinion. I have felt some of that about Sony and am not convinced it is a brand or a tool that would fit me.
Also love "As a tool my camera is a sum of its parts" - there is wisdom in that view.


QuoteOriginally posted by Henrico Quote
You can get as much as detail as desired. Take several pictures beside/above each other at exactly the same settings (ASA, shutter, and sweet-spot opening) in RAW and devellop to one super sized picture.
Thanks Henrico. I have shot multiple images for stitching several times over the years on various cameras, including the Z, and I realize this works well for many folks, but for my personality I absolutely hate the workflow involved, it disrupts what is for me a very exacting and fulfilling process of creating precise compositions in the field with the 4:3 framing of the viewfinder. I cannot explain this fully, it's just the way I am wired to work in my composing.


QuoteOriginally posted by mikeSF Quote
no thanks. it sounds like a downgrade to me.
Short and to the point Mike, I like that ;-)


QuoteOriginally posted by Adam Quote
I think medium format IQ will keep up in the long term. If FF can do 80 Mp well, the 645 should be able to do 100+ some day
Yes :-)

------------------------------

Thinking on this further as I interact with the thoughts shared here, I believe a hi-res mirrorless system could potentially be a good second camera for me for specific needs such as travel in Europe, but not as a replacement for medium format digital that I use exclusively for landscape work.

Cheers,
Ross
04-04-2016, 01:01 PM   #10
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QuoteOriginally posted by Adam Quote
I think medium format IQ will keep up in the long term. If FF can do 80 Mp well, the 645 should be able to do 100+ some day
Yeah in the long run medium format will ultimately hold an advantage
04-04-2016, 01:08 PM   #11
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I don't own a 645z, so the question is not addressed to me, but adding more megapixels, particularly if dynamic range drops a bit and high iso performance is constant is not particularly appealing.
04-04-2016, 01:55 PM   #12
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QuoteOriginally posted by SeattleDucks Quote
Sony has made clear their intentions to continue ramping up resolution in their fullframe cameras, and that's their stated reason for introducing the new higher resolution G Master lenses. Now a Japan source source (published on the web today) is indicating the upcoming A7RIII will have a 75-80MP sensor, and improved 5-axis IBIS.
link?

---------- Post added 04-04-16 at 02:09 PM ----------

QuoteOriginally posted by Rondec Quote
I don't own a 645z, so the question is not addressed to me, but adding more megapixels, particularly if dynamic range drops a bit and high iso performance is constant is not particularly appealing.
doubling ff sensor resolution to that pixel density would be like putting a smartphone sensor in the camera; much worse than what canon did with their 5ds/5dsr disaster.

sony went from 36mp to 42mp, samsung went to only 28mp with the bsi sensor in the nx1, etc... it would take a big jump in technology to put 75mp in a ff, with the dr/latitude that we've come to expect from sony.
04-04-2016, 05:06 PM   #13
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for me, I dont think i would. besides being a currently new happy 645z owner, i dont think having that many megapixels in a small sensor is really worth it, Im liking the feel and the look of the larger sensor format, and the 645z is teaching me a good amount on technique. The final and the most important for me on the reason why i cant join the mirrorless/sony campaign is the EVF, although it has its benefits, Im not a fan.
04-04-2016, 06:16 PM   #14
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QuoteOriginally posted by Fcsnt54 Quote
for me, I dont think i would. besides being a currently new happy 645z owner, i dont think having that many megapixels in a small sensor is really worth it, Im liking the feel and the look of the larger sensor format, and the 645z is teaching me a good amount on technique. The final and the most important for me on the reason why i cant join the mirrorless/sony campaign is the EVF, although it has its benefits, Im not a fan.
Thanks Fcsnt54, you brought up another good point: EVF. Obviously these work great for many people, and I do use one on my Olympus E-M1, but I greatly prefer the feel of an optical viewfinder and really enjoy the one on the 645Z.

Cheers,
Ross
04-04-2016, 07:00 PM   #15
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QuoteOriginally posted by dcshooter Quote
So you aren't looking at 1.7x the light gathering ability for the Z at a per pixel basis. You are looking at a factor more like 2.6. Hardly "slightly larger." Sony would really have to pull a rabbit out of the hat, therefore to achieve anything like the ridiculous dynamic range that the Z has, especially with a higher res. Also, consider that with the smaller photosites, you are going to be looking at diffraction kicking in at much much faster apertures, so in many cases, especially small apertured landscapes, any perceived resolution gains from added pixels are likely to be more than offset by diffraction blur.
These can be compensated with a lens that delivers high image quality without stopping down much. The larger usable aperture can feed more photons to the smaller pixels, produce shallower focus depth, and less diffraction. All these require large aperture for it to work. This is what drives the latest bunch of lenses from Zeiss, Canon, Sony, and Sigma. Newer lenses have to deliver high IQ at large apertures to make high pixel count sensors really worthwhile.

So, the real question is which one is easier (both technically easier to make and design, and practically easier for users to afford): make a 35mm full-frame lens very very sharp at F2.8, or a cropped 645 lens very sharp at F4? This is for the comparison of 645z and A7RII (both around 40-50 MP).

If we are comparing the 645 full frame and the rumored A7RIII (in the 80-100 MP range), then the comparison becomes 35mm full-frame lens very very sharp at F2.0 vs. 645 full frame lens very sharp at F4. Which one is easier to make/design/afford? The answer to this question will probably determine which sensor is technically superior.

My 2 cents.

Cheers,
Wei-Hao
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