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03-31-2010, 05:53 PM   #1
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C Net 645D article

Warning:

It'll make you want to drop $9,000+ on a 645D


Pentax reshapes medium-format camera future | Deep Tech - CNET News

03-31-2010, 08:08 PM   #2
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QuoteOriginally posted by Samsungian Quote
Warning:

It'll make you want to drop $9,000+ on a 645D


Pentax reshapes medium-format camera future | Deep Tech - CNET News
Make me want to? Heck, I already want to. I just can't afford to.

But then, I'm not the target market. ;-)

Noticed an error in the piece, though. It refers to "Pentax ... bringing modern amenities such as dust-removing sensor shaking to the medium-format realm". The 645D doesn't have a sensor shift mechanism (not surprising given its large sensor), and hence doesn't use the relatively less effective sensor shaking method. It uses a piezoelectric vibration of the UV/IR cut filter, just like the K-7.

Last edited by knoxploration; 03-31-2010 at 08:14 PM.
04-01-2010, 02:29 AM   #3
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From the article:

QuoteQuote:
One big one is lenses; film-era lenses need updating for digital cameras. One issue is that image sensors don't like light that doesn't travel perpendicularly to the lens, a non-issue with film, and another is that sensors reflect light back out, making ghosting and flare a worse problem.
Not having a digital slr, I'm unaware of this problem. Does this apply to the film-lenses (say, K and M-series) on the APS-C sensors as well?
04-01-2010, 02:45 AM   #4
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QuoteOriginally posted by Smolk Quote
From the article:



Not having a digital slr, I'm unaware of this problem. Does this apply to the film-lenses (say, K and M-series) on the APS-C sensors as well?
It does, but vigneting being some darkening on the corner of the image circle, this is much less a problem than on FF. This problem is more present on wide angle lenses than on tele, hence the upgrade first of wide angle lenses than on tele.

04-01-2010, 07:02 AM   #5
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QuoteOriginally posted by Smolk Quote
From the article:



Not having a digital slr, I'm unaware of this problem. Does this apply to the film-lenses (say, K and M-series) on the APS-C sensors as well?
Yes, in theory.

HOWEVER, one of the primary improvements that other manufacturers made between the old "film" lenses and "optimized for digital" lenses was improved antireflective coatings.

Good film lenses (read: pretty much anything using Pentax SMC) had AR coatings that were up to the task to begin with. It's just that digital forced some manufacturers to raise the bar of minimum coating requirements on cheap lenses.

For example, older Sigma superzooms like a mid-90s 28-200 lens provide AWFUL contrast on DSLRs. Newer ones have better coatings and work much better.
04-02-2010, 06:48 AM   #6
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I was under the impression modern sensors did away with the vignetting on older lenses thing and that by now it was merely a myth.
04-02-2010, 11:03 AM   #7
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QuoteOriginally posted by kristoffon Quote
I was under the impression modern sensors did away with the vignetting on older lenses thing and that by now it was merely a myth.
It's still a problem on Leica M system, even if they have made a specific pattern of microlenses for better focus of incident light, the M9 still need some software correction.

Vignetting is also a "problem" on Full Frame (I'm thinking of the EOS5D mkII, he see significant vigneting with the 28-70 / 2.8 L at 2.8) weither or not it's a problem is up to your photographic style and your taste.
04-02-2010, 07:44 PM   #8
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Cross-fertilisation

Reading the CNet article and then the Luminous Landscape article it links to (Pentax 645D – Fiest Impressions & Interview) got me wondering about the kinds of cross-fertilisation that we can expect to see between Pentax's SLR and MF lines.

In particular, the LL article mentioned that the 645D has no AA filter, a first for Pentax. So I'm now wondering if/hoping that the successor to the K-7 will similarly forgo an AA filter, perhaps offering a "Moire protection mode" to compensate for those occasions where moires start to appear.

That's just speculation, of course, but I think it's almost certain that Pentax has learnt a few tricks in the course of developing the 645D that will be applied downstream, just as some of the technologies developed for SLRs head upstream. All this bodes well for the future of our favourite camera brand.

04-03-2010, 01:25 PM   #9
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Thanks for the link, a good read
04-03-2010, 02:34 PM   #10
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I am truly excited about this camera, I cannot wait until there is a load of sample images and landscape images coming out of Japan (plus the measurbation).
04-04-2010, 05:54 PM   #11
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I still can't get what the no-AA filter is supposed to be about.

Does anyone have handy comparative pics shot on similar cameras with/without an AA filter?
04-04-2010, 06:46 PM   #12
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QuoteOriginally posted by kristoffon Quote
I still can't get what the no-AA filter is supposed to be about.

Does anyone have handy comparative pics shot on similar cameras with/without an AA filter?
The AA filter simply blurs the picture just slightly to prevent moire (especially color moire) from appearing in photos, at the expense of some detail.

At least two cameras spring to mind which were available with user-removable anti-aliasing filters -- the Kodak Professional DCS-760 and Mamiya ZD. I'd guess a search of Google will probably turn up comparison images showing the difference with / without AA filters.

I *think* in both cases the AA filter was an optional extra though, so if it wasn't commonly purchased then the comparisons may be few and far between...
04-05-2010, 02:52 AM   #13
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QuoteOriginally posted by asw66 Quote
the 645D has no AA filter, a first for Pentax. So I'm now wondering if/hoping that the successor to the K-7 will similarly forgo an AA filter, perhaps offering a "Moire protection mode"
Leaving out an AA filter isn't necessarily a good thing.

Leica and Hasselblad claim to have anti Moiré software filters in their firmware. This isn't a feasible thing for all possible patterns of Moiré though.

So far, Pentax did not claim to have such software and we haven't yet seen sample shots, e.g. with fabrics on fashion models in full size. However, Pentax announced that the 645D can be ordered with an AA filter on request.

Add to this that at low ISO, non AA sharpness is easily achieved in AA shots using a sharpening tool while color Moiré easily ruins a 6-15MP shot (less likely a 40MP shot though) then the attraction to remove the AA filter pales.
04-05-2010, 09:27 AM   #14
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QuoteOriginally posted by falconeye Quote
So far, Pentax did not claim to have such software and we haven't yet seen sample shots, e.g. with fabrics on fashion models in full size.
It goes beyond not claiming it - the answer re: moire in Luminous Landscape's interview with a product planner suggests that they don't intend to address it in software themselves, at least automatically:

"Our feeling is that customers who would want to use the 645D for such applications have the level of digital skills required to deal with such issues anyway."

Pentax 645D – Fiest Impressions & Interview
04-05-2010, 07:06 PM   #15
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QuoteQuote:
Pentax has a lot of experience with mass-market cameras.
Had to laugh at that one.
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