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04-07-2016, 03:11 AM - 1 Like   #31
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QuoteOriginally posted by osv Quote
no, it's one of the korean 35/1.4 junk lenses.



no, it's foolish to shoot ff landscape shots at f/16-f/22, because of diffraction losses... for example, this m28/3.5 ooc jpeg shot, taken at f/8 or possibly f/10, are you really going to sit there and claim that it should have been shot at f/16-f/22? blow it up to 100%, and tell us what exactly would be gained by taking this pic at f/16-f/22:

https://www.dropbox.com/s/86ch2xumwhq060r/DSC01364smcm283point5f8.JPG



this was never a discussion about dof, read the thread title: "645z owners: will you switch to sony 75mp a7riii"

i never claimed anything about dof platform comparisons, because it doesn't matter; that was your tangent entirely, my point was field curvature and lens design advantages at wider apertures.



no, whwang for instance was very clear, he said the same thing that i did: "You may say this is not fair, why we have to compare two different F-ratio? This is exactly what the lens company try to achieve. Better image quality under larger aperture. IF a 35mm FF lens can be used at a larger aperture, everything you said will be canceled out."

i'm not sure why you keep insisting that landscape photos must always be taken at diffraction-crippled apertures



only to illustrate the effects of pixel density, remember that it's an article on equivalence, the effects of pixel density are not relevant to sensor size.

everything that he said there about higher pixel density is verifiable with the Diffraction Limited Aperture Calculator Digital Camera Diffraction – Resolution, Color & Micro-Contrast

raise the pixel density on any given sensor size, and watch what happens.
I think OSV, that it is clear that many of the folks shooting 645z cameras are doing so for landscape photography -- a place where maximum aperture is not as important as dynamic range. Increasing number of megapixels -- particularly if the dynamic range at base iso drops -- is a significant negative in this context. There are plenty of other ways to add resolution to an image, but few ways to add dynamic range to image that simply isn't there.

Anyway, I just think that bringing up lack of f1.4 or f2 lenses for the 645z is not particularly relevant to the way many of these photographers are using their cameras.

04-07-2016, 03:56 AM - 2 Likes   #32
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The original question, "will you down grade from a 645z"?, does not sound like a question asked by a photographer. Most photographers probably want access to every format. They don't replace one with another. They select what is appropriate for the image being taken.

Trying to replace format size with some kind of MP comparison, if you don't know why that's wrong, not much can be said to help you with that.
04-07-2016, 07:22 AM   #33
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God I hate seeing posts about DoF and math equations in a format debate.

I shoot medium format for many reasons and the quality speaks for itself. I don't need a math formula to tell me what camera and lens combination to use.

Now is a great time to own a 645z because when the 645x comes out you can use it to offset the upgrade cost. There has never been a better time to shoot medium format. The only thing I want from Pentax are more lenses without greatly inflated prices relative to the body.
04-07-2016, 07:38 AM - 1 Like   #34
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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.

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
Switch? No.
Add to kit? Yep.

I might trade my 645z for a 100 MP version.

04-07-2016, 07:56 AM   #35
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QuoteOriginally posted by normhead Quote
.....Most photographers probably want access to every format. They don't replace one with another. They select what is appropriate for the image being taken.
Trying to replace format size with some kind of MP comparison, if you don't know why that's wrong, not much can be said to help you with that.
That's spot on really. I've just taken delivery of a 645Z to augment my Canon 35mm DSLR's, not replace them.

Bob
04-07-2016, 08:45 AM   #36
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QuoteOriginally posted by rfkiii Quote
Switch? No.
Add to kit? Yep.

I might trade my 645z for a 100 MP version.
+1 from me
04-07-2016, 09:16 AM - 1 Like   #37
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QuoteOriginally posted by SeattleDucks Quote
.....

I didn't realize this was an elitist forum where only those with bountiful supplies of money allotted for new gear were allowed to post...
Sorry, I didn't mean to offend you, or anybody else, with my comments nor did I wish to sound elitist.

Bob

04-07-2016, 09:19 AM   #38
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You asked the question, I didn't.

I notice now you add that you don't have the money for both systems. Put all relevant information in your original post and we won't have these little scuffles. I've always said I won't buy into a new system unless I have a gig that will pay for it. So, I'm hardly elitist.

I'm just pointing out the obvious here.

And, you're getting irritating.

What kind of person, basically bragging on a forum that he has a $15,000 system, calls someone who doesn't own $10,000 in camera gear altogether an elitist? You have it backwards. You've got the elitist $15,000 system, and you ask 40,000 site members who will never face that problem to think about your little conundrum.

I guess you have no sense of how ironic that is.

OK ya, I'm an elitist, I admit it. So sue me.

And there is nothing I can do to stop you from posting... so quit your "poor me, I'm a victim" whining.

Post whatever you want. It's a public forum, I can comment if I choose.



Sheesh.
04-07-2016, 09:25 AM   #39
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QuoteOriginally posted by Rondec Quote
Anyway, I just think that bringing up lack of f1.4 or f2 lenses for the 645z is not particularly relevant to the way many of these photographers are using their cameras.
fast glass doesn't have to be used wide open, that's a logical fallacy.

the priority is to get a lens that can take a landscape shot at a wider aperture: "Better image quality under larger aperture. IF a 35mm FF lens can be used at a larger aperture, everything you said will be canceled out."

modern fast glass has less vignetting and fewer aberrations all the way up thru f/5.6 at least, so it should always be evaluated for landscape shooting.
04-07-2016, 09:32 AM   #40
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QuoteOriginally posted by itshimitis Quote
If you could get your head from the computer screen you would realise there are many reasons for landscape photographers to shoot with small apertures.
oh? do you have any pics to back up that claim? i think not
04-07-2016, 09:35 AM   #41
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QuoteOriginally posted by SeattleDucks Quote
WOW!

And this is why I rarely get involved with photography gear forums, because there is always one or two folks who seem to relish being rude.

Take care all, I'm out.

Best,
Ross
Or maybe it's just you.
04-07-2016, 09:38 AM - 1 Like   #42
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QuoteOriginally posted by osv Quote
oh? do you have any pics to back up that claim? i think not
Have a look through my many photos on the post your photos shoots and see my ratio of small apertures. The largest I go is f/8. My last batch were f/8 but only to keep the shutter speed up, as though I was with a tripod I was on a heavily used bridge that vibrates when people run or walk on it. Plus I didn't have need of close things being pin sharp.

Also go to M Salon in Vienna and you will see more than 20 photos of mine in an exhibition and the shots there will be nearly all f/11 to f/16.

I have absolutely nothing to prove to a pixel peeper as that is not what photography is about. It isn't about specs, but about something that you can't put on a resolotion chart...

The thing I see too much on gear forums are people shooting with an f/1.2 and with an orgasmic cry shout: "Look at this it is wide open". Big whoops. You see a photo where nothing is actually pin sharp and the device of wide open hasn't been used for an aesthetic purpose but for the purpose of online willy waving.

Not for me, thank you.
04-07-2016, 09:56 AM   #43
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QuoteOriginally posted by itshimitis Quote
Also go to M Salon in Vienna and you will see more than 20 photos of mine in an exhibition and the shots there will be nearly all f/11 to f/16.
with what camera? because f/11-f/16 on mf does not have the same dof/diffraction problems as f/11-f/16 on ff... that's not pixel peeping either it's something that every photographer should know.

your claim was that there are multiple reasons why a lens should be stopped down well into the diffraction range, and that remains unsubstantiated.

but i'm trying to keep an open mind the only reason that i can see for hitting f/16 on ff is because of a foreground object that's way too close to the lens... or maybe to darken the image, when you don't have an nd filter, but that's questionable.
04-07-2016, 10:33 AM   #44
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Sony need to go so much further than the sensor. It can be the best sensor ever, but if it's in a "computer lens attachment device" rather than a really great to use camera . . .
04-07-2016, 10:38 AM   #45
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QuoteOriginally posted by osv Quote
fast glass doesn't have to be used wide open, that's a logical fallacy.

the priority is to get a lens that can take a landscape shot at a wider aperture: "Better image quality under larger aperture. IF a 35mm FF lens can be used at a larger aperture, everything you said will be canceled out."

modern fast glass has less vignetting and fewer aberrations all the way up thru f/5.6 at least, so it should always be evaluated for landscape shooting.
The point is that you are saying that full frame with high megapixels is better than medium format with fewer megapixels because faster glass is available for the full frame camera than for the medium format camera. But if you are shooting at f5.6 on full frame and f8 on medium format, then I really think using a f1.4 lens is probably wasted and going to give you a lot bigger piece of glass than you really need.
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