g._cheng1

IMO, Provia 100F is slightly more contrasty than Astia with stronger blues and greens. It is less contrasty than the older Provia.

The 1.4X does not work with 75mm or 150mm without interference from the back elements of these lenses. It was mentioned that the 1.4x may not work with the 120mm macro. In my P645 Interchangeable Lenses manual it does say the 1.4X can mate with the 120mm lens (as well as the 200mm, and 600mm lenses). I've been using this combination to get an even greater macro effect, and as far as I know I haven't encountered an incompatibility problem. As I am writing this I'm moving the focussing ring on the 120mm from infinity to 1:1 back and forth and I don't get any interference. This is the first I've heard that the 1.4x didn't work with the 120mm, especially from a Pentax rep. Now with 120mm AF macro or any of the AF lenses, that is a completely different story. I don't know what compatibility issues exist with the new AF lenses.

Just curious, any reason you bought the P645N before you found the answers to your questions? There may be other camera models that would be a better fit for you, such as the upcoming Mamiya 645AF. This camera has interchangeable backs. The P645N doesn't. In general, using the camera differently than what the manufacturer (Pentax in this case) specifies, i.e. loading 120 film on a 220 insert, midroll film change, is a somewhat risky proposition.

IMO opinion you will notice a slight loss of contrast when using the 1.4X on the P645 120mm Macro and the 200mm lens. I don't know about the 2X teleconverter, but I doubt if you're going to get BETTER image quality over the 1.4X. The 1.4X only mates with the 120mm, 200, 300 and 600 mm lenses because if you try anything else, the 1.4X flange may ram into the rear element of these other lenses.

Using the 1.4X on lenses other than what Pentax says can fit may pose

a problem. The 120, 200, 300, and 600mm designation applies

primarily to manual focus lenses. It may fit on some autofocus

lenses (I don't know which ones). However, it may damage the rear

lens element of the 150mm lens if you try to jam it into the

teleconverter.

Excellent sharpness and resolution are a given for this lens. There

are no infrared focus distance marks for this lens. Also the focus

adjustment from 10m to infinity is usable but small. Great for

portraits, but the lens can be hefty when hand carried with the

body. However, it's very solid and mostly metal in construction - no

cheap materials. For the price, it's a bargain among medium format

1:1 macro lenses. Technique is a far greater factor in image quality

than the optics of this lens when creating macro images.

From my observation, MS 100/1000 is a extremely fine grained film at

ISO 100. I've also used it pushed two stops (E.I. 400) and it looks

more saturated than when used at E.I. 100. It almost gives the

appearance of Velvia when pushed. With an 8X eye loupe, grain is

still very fine, but noticeable. Contrast is also increased. E200

also is very fine grained, but it's less saturated than MS100/1000.

E200 also pushes very well and it is comparable to MS 100/1000 in

sharpness and resolution. Try it out yourself and see which palette

you like.

I'm not sure what you mean by the Mamiya lens 'lacking perspective'. It's difficult to give an objective comparison just from user reports, and for that matter even lens tests. FWIW, the people I've heard that used the Mamiya 45mm lens have found it to be an outstanding lens - sharp from corner-to-corner.

 

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The P645 45mm lens is also an acceptable lens. Check out recent issues of Photo-Life (Canada) and the cover of Outdoor Photographer Mar. 97. for example exposures using the P645 45mm lens.

 

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My personal opinion is only with the P645 45mm lens. It is solid and well made. The images are contrasty, and with an 8X loupe, sharp from corner-to-corner. The only things I have to watch out for is stacking more than two filters (possible vignetting), and that the depth of field scales are rather generous. At F/22, the scales suggest that the image is sharp from 4ft. to infinity. IMO, it is more like 6ft. to infinity.

 

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I wouldn't decide between the M645 and P645 on the quality difference of their respective 45mm lenses. Sorry, don't know anything at all about the zooms.

 

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G.

The P645 and the new P645N do not have interchangeable backs. If this is important to you then the M645 Pro would be your choice. Cost differential between the Mamiya lenses and Pentax lenses apparently is dependent on what part of the world your in. In the States, Pentax lenses in general, are somewhat less expensive new in equivalent focal lengths. Mamiya has many high speed lenses which Pentax does not have, and if you have the need and the money, Mamiya would be the way to go.

 

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IMHO, the P645/645N cameras were more designed for field work than studio use. It is an integrated camera with the AE meter built into it. It approaches most of the 'fast' handling of a 35mm system camera, while using a larger negative. The M645 has interchangeable finders/backs with Polaroid capability. This modularity can give the user more choices in how one photographs, especially in the studio. A lot photographers find this modularity useful in the field also.

 

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See if you can rent both cameras before you make your purchase. When it comes to handling, this also comes down to personal preference.

The P645 has only a center-weighted metering PATTERN. What the P645 does have is two aperture-priority metering modes.

 

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G.