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Old Apr 15, 2012, 12:01 PM   #11
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If I could in any way find it in my budget, I would order the 645D today. Unfortunately, paying bills comes first, and a couple hospital stays have done in some plans. Go for it, Dawg. If you put it off, something could get in the way, as it has with me.

Scott: I beg to differ, strongly, with your contention. I still have my 5MP Minolta D7hi, as well as the Pentax *istD. The vertical resolution on the sensors is nearly identical (1920 pixels vs 2006 pixels) I took some test shots a few years back, when both cameras were fairly new, with equivalent focal lengths and under the same lighting conditions, There is much better detail with the *istD. Viewed at normal screen sizes, it is evident, and even when printed at 4"x6", the difference is visible. Sensor size is still probably the most significant factor in IQ.

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Old Apr 15, 2012, 12:25 PM   #12
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Thanks to everyone who has responded and given an opinion and advise. I do appreciate it very much. The sensor size of the 645 is not quite up to the 645 dimensions but the image detail is there. Printed from raw it can go to 4 feet on the long side and be sharp with very little pixelization if any. Try that with even the best 35mm full format digital camera and the difference would really show up.

Am I planning on printing that large? Probably not but the detail difference would show even in 8x10's. I really want to shoot more landscapes. You good folks see my small bird photos and think that is what I like shooting...I enjoy that but my passion is for landscapes and medium to large format is best for that because of the detail they offer in photographs shot with them. 35mm is alright but not the same. I've experienced the difference in film and from the reports and reviews it seems that sensor size ..Even with digital...Does matter when going for the most detail in a photo.

Shoot Nikon or Canon? No just not for me...I'm too happy with Pentax and will probably stay that way. Just a Pentaxian thing I won't give up now late in life.

Again thanks for the advice.
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Old Apr 16, 2012, 9:42 AM   #13
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Like others have said, if you won't suffer financially, then go for it, you know what you want and getting something different just won't feel right.

I have been going in the opposite direction lately, I have been stockpiling film (my fridge is stuffed with dollar/pound store 35mm Kodak film) and messing around with developing my own film with alternative (cheap) chemistry.
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Old Apr 16, 2012, 3:40 PM   #14
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On one hand – it's an awful lot of money. That's also what I think when I look at what I have spent on camera equipment (even if my total is still below the price of a 645D body).

But then I remind myself (and my wife) how much some people spend on a motorcycle, a sailing boat or a sports car. In that light, a 645 isn't that much! (If you have the money at all, that is.)

Recently I bought a Wimberley Gimbal II head and a top notch heavy duty carbon fibre tripod (Feisol) to go with it. With this I spent a year's lunch box savings – I spent nearly precise the same sum a friend spent on a new exhaust pipe for his bike :-) If I could afford that bike I'd surely buy myself a 645 instead. And a nice bunch of 645 lenses to go with it. And still have money for an ice cream.

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Old Apr 16, 2012, 5:54 PM   #15
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Quote:
Originally Posted by VTphotog View Post

Scott: I beg to differ, strongly, with your contention. I still have my 5MP Minolta D7hi, as well as the Pentax *istD. The vertical resolution on the sensors is nearly identical (1920 pixels vs 2006 pixels) I took some test shots a few years back, when both cameras were fairly new, with equivalent focal lengths and under the same lighting conditions, There is much better detail with the *istD. Viewed at normal screen sizes, it is evident, and even when printed at 4"x6", the difference is visible. Sensor size is still probably the most significant factor in IQ.

Hi Brian,

I'm not trying to be contentious, but your test, while certainly valid for your purposes, cannot really be generalized when attempting to compare the differences in IQ in the current larger sensor formats. It's really apples and oranges, IMO.

Your Minolta uses a 2/3" sensor (@ 8.8 x 6.6mm with @ 58.1 mm˛ area and a 3.9x crop factor). Your Pentax D uses an APS-C sensor (23.5 x 15.7 mm, with an area of @ 369mm˛ with a 1.5x crop factor) so the Pentax sensor is larger by a factor of @ 6:1.

The difference between 135mm (24 x 36mm, with an area of 864mm˛) and a crop 645 (44 x 33mm and 1452mm˛) is considerably less (1.68:1), and differences in IQ are also mitigated in some respects by the technical differences between CMOS and CCD sensor design.

Compare 4/3 with APS-C or APS-C with 135mm Digital, (both have @ 1.5:1 sensor area differentials), and the IQ differences are considerably smaller, and technical development levels in the sensors can make for more difference than sensor size. Since the APS-C sensors are more advanced than the other two formats, the gap is wider compared to 4/3 and smaller compared with 135mm Digital.

I don't consider DXOMark scores as the definitive measure of IQ, since image quality is subjective and really can't be quantified, but their tests show that the D800 sensor can produce 25.3 bits of color depth with 14.4 Ev (stops) of DR. The 645D, tested at 24.6 bits of color depth and 12.6 Ev of DR. Given only a 10% difference in resolution (36 MP for the Nikon, and 40 MP for the Pentax), The differences in IQ should not be that significant, from my experience (after going from 6MP to 10, 14, and now 16 MP in APS-C format bodies), unless one's primary aim is very large format prints or high magnification pixel peeping.

Given the relatively small difference in IQ potential on a sensor only basis, and now knowing that Dawg is looking at landscape performance, I'd go with the 645D. Lens performance will make the difference though, not sensor performance. The 645D is a crop sensor Medium Format, so will use the "sweet spot" from all the lenses, making every lens perform better. The 800D will suffer with glass not optimized for digital at the edges and corners since it uses the full image circle. Also, the 645D will be able to use the SR advantage with all lenses, while with Nikon, you'd have to get premium current VR lenses to get this level of performance, and the extreme expense for the glass would close the price gap for the total system quickly.

Personally (and theoretically only), I'd still go with the Nikon, but my performance and size priorities are different. . .

Scott

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Old Apr 19, 2012, 8:19 AM   #16
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Hi Dawg,
Remember what Mr Nike said,

JUST DO IT!

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Old Apr 20, 2012, 3:59 AM   #17
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Or as the Pink Fairies said on the opening track of their début album in 1971:

"Do It!"
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Old Apr 22, 2012, 7:14 PM   #18
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Definitely do not feel qualified to give an opinion on this one, but somewhat hoping you will be able to get the 645D, because it would be so great to see the amazing landscapes you'll photograph with it...
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Old Apr 25, 2012, 12:32 PM   #19
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Quote:
Originally Posted by simowills View Post
Hi Dawg,
Remember what Mr Nike said,

JUST DO IT!

Simon
I'm with you!!
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Old Apr 25, 2012, 12:33 PM   #20
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Quote:
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Or as the Pink Fairies said on the opening track of their début album in 1971:

"Do It!"
Selling my collections as we speak!!

eskin09m4 on Ebay!
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