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08-09-2009, 12:12 PM   #1
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faster glass?

i put my FA31mm lens up to my 645n and there was no vignetting in the viewfinder...

granted i couldnt focus on anything past 10 inches, but makes you wonder, why dont they bother with faster glass?

08-09-2009, 12:35 PM   #2
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Contax 645 Planar T* 80mm f/2
HC 2.2/100
08-10-2009, 08:28 PM   #3
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Mamiya made and/or makes an 80/1.9, too, one of the things that leaned me toward this system for my MF work. I'd probably have one by now, (mostly more for the ease of viewing and focusing than for the actual speed) if my chance at good digital hadn't come along so soon.

The thing about MF is the DOF starts getting wafer-thin pretty quickly, and film flatness can be a concern, so I guess these things have somewhat limited appeal.
08-11-2009, 10:42 AM   #4
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there is a certain shot that i want to do to take advantage of such a shallow depth of field.

i dont know when exactly though,.. i have to set it up.

but i think such a lens would be the 50 F1.2 equivalent, or the 50 F0.95

BTW, 80mm @ F2.0, shooting something 20 feet away, gives you about 2- 2.5 feet of depth of field, more than enough to fully encompas a person

realistically, you would only need about a foot, even half, to shoot someone standing perpendicular to the camera, at 20 feet, so you could probably get away with F1.4 or less!


Last edited by Gooshin; 08-11-2009 at 10:56 AM.
08-11-2009, 01:37 PM   #5
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QuoteOriginally posted by Ratmagiclady Quote
Mamiya made and/or makes an 80/1.9, too, one of the things that leaned me toward this system for my MF work. I'd probably have one by now, (mostly more for the ease of viewing and focusing than for the actual speed) if my chance at good digital hadn't come along so soon.

The thing about MF is the DOF starts getting wafer-thin pretty quickly, and film flatness can be a concern, so I guess these things have somewhat limited appeal.
Without the film flatness issue, maybe with 645D more fast glass might appear
08-12-2009, 11:34 PM   #6
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QuoteOriginally posted by Gooshin Quote
there is a certain shot that i want to do to take advantage of such a shallow depth of field.
. . . such a lens would be the 50 F1.2 equivalent
The closest thing I can think of would be the pentax 67 105mm f/2.4 on an 645 adapter. The lens is plentiful and relatively inexpensive; the adapter not so much.

Wide open, the 105 is reasonably sharp, with some mechanical vignetting on 6x7 format (see the cat-eye shaped highlights in the image below). Vignetting would of course be less of an issue for 6x4.5.



67II, Pentax 105/2.4@2.4, Ektar 100
08-13-2009, 05:09 AM   #7
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thats awesome man.
08-13-2009, 11:29 AM   #8
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Yes, the 105mm does get good shallow DOF.




Last edited by tuco; 08-14-2009 at 01:18 PM.
08-13-2009, 02:33 PM   #9
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A question when I get back to 645 system in the future... I have heard reports of cheaper chinese made 67 to 645 adapters, but scouring the net gave me no results. Anyone knows where I can find these supposedly cheaper adapters? (And the 645 / 67 to K adapter as well)
08-13-2009, 05:41 PM   #10
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For cheaper 67 to 645 adapters, try Cirrus adapters on ebay. They make adapters to fit 67 lenses to just about everything. They often have a BIN or "make offer" price so you can get them pretty cheap.
08-13-2009, 05:45 PM   #11
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QuoteOriginally posted by Andi Lo Quote
I have heard reports of cheaper chinese made 67 to 645 adapters...
.
I'd want to hear from someone with some field experience with one first before I'd get one of those cheap things. I can only extrapolate but when one of my 35mm adaptors for my video camera was a Canon mount, I had to get a Pentax to Canon adapter. Found one cheap. But its fabrication tolerances were relaxed (hence cheaper to make), apparently, because none of my lenses fit snug at all in both sides of the adapter. And I mean it was so bad it was unacceptable. I had to shim it up with that pipe thread teflon tape until I could find a better one.

I can't say you'll experience that problem but it's food for thought.
08-13-2009, 07:10 PM   #12
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Look for the real thing from Pentax built to Pentax Specs. All the others are measured from the Pentax one and reverse engineered.
They do pop up on eBay, you have to monitor and bid for it. Like everything else that is good but discontinued, it is a seller's market.
The best lens for the 645 in terms of smallest DOF would be the FA150/2.8.
08-13-2009, 11:20 PM   #13
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Hi I got a 67-K mount from a chinese source and can happily say it is superbly made.
It was CNC milled with chromium where the K mount is and aluminium where the 67 lens mount is. Cost was about $75USD.
Cheers Neil

Pentax 67 lens to PK Pentax KM K20D K10D K-7 k200D - eBay Adapters Mounts, Lens Accessories, Lenses Filters, Cameras Photo. (end time 27-Aug-09 14:06:41 AEST)

Pentax 67 6X7 lens adapter to pentax K-7 PK K20D K200D - eBay, Medium Format, Film Cameras, Cameras Photo. (end time 10-Sep-09 21:48:56 AEST)
08-14-2009, 09:12 AM   #14
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Zoerk makes a whole range of adapters; check their web site. They are not cheap, but are beautifully made. I have one that lets me use my Mamiya 645 lenses on my Pentax DSLR/SLR's.
08-14-2009, 03:40 PM   #15
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QuoteOriginally posted by Gooshin Quote
there is a certain shot that i want to do to take advantage of such a shallow depth of field.

i dont know when exactly though,.. i have to set it up.

but i think such a lens would be the 50 F1.2 equivalent, or the 50 F0.95

BTW, 80mm @ F2.0, shooting something 20 feet away, gives you about 2- 2.5 feet of depth of field, more than enough to fully encompas a person

realistically, you would only need about a foot, even half, to shoot someone standing perpendicular to the camera, at 20 feet, so you could probably get away with F1.4 or less!
Well, that means there are few reasons to want a very *fast* lens for the sake of DOF, see?

(I admit a bias toward wanting to get much closer to my subjects than twenty feet, even with a tighter lens. I didn't know it when I bought into Mamiya, but I'm not in a hurry to let this 110 go. By my own internal 'logic' about these things, I treat that 110 much like my favorite 85, only I can have a bit more background. (it's really more like a 65mm by FOV. )
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