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08-10-2015, 05:09 PM   #46
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QuoteOriginally posted by Lacunapratum Quote
I am worried that the current execs at Ricoh treat the Pentax camera business like their copy machines.
In which case, all should be well.


Steve

08-11-2015, 01:13 AM   #47
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QuoteOriginally posted by bmw Quote
Well, I understand about the DoF and bokeh. This question is less about that -- though it's a minor concern -- it's more about the fact that there will be over a stop less light when I'm focusing on a distant model who is lit only by modeling lamps. This is already an issue for me, especially as I generally resort to manual focus to avoid hunting and slow AF speeds under low light.


I have f5.6 and f8.0 lenses plus older lenses that need adapters for use on modern cameras. with sunny and bright days I have no trouble focusing. a well lighted studio should pose no problem.
08-11-2015, 07:42 PM   #48
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QuoteOriginally posted by Kolor-Pikker Quote
At equal focal lengths the detail difference may be small enough so as not to be important, but the Z will offer a wider field of view.

Well, the DSLR is going to be the lighter and more flexible option, plus you'll get in-lens stabilization. Sure has it's merits.
If you're going to get a 5DsR anyway just to use the 11-24, there's really no reason to also get the 645Z.


Thanks for the response but I already own the 645z, 28-45, FA 45-85, 55mm, A 120mm macro & FA 200mm. My intention is to replace my 5D3 & 6D with a 5DsR and acquire the 11-24L. My understanding is that the FOV of each of these systems with the equipment listed in this paragraph would be complementary to each other with very little overlap. My question regarded what FOV & reach I would get by adding the FA 400mm to my kit for use on the 645z relative to the D800E and 150-600 since I am visually familiar with this particular FOV and reach. You introduced some math that I was trying adapt to the D800E example. I came up with 1.18x. Can you confirm or deny this multiplication factor? Or can you confirm that the 400mm would be like a 339mm lens on the D800E (sort of in line with what you said in your first sentence). Hate to appear as if I am backing you into a corner. If the equivalent FL is indeed 339mm, that would not be enough reach even with some judicious cropping to satisfy my itch and I would be better off adding a Canon-mount Sigma 150-600 to the Canon side of the kit.
08-12-2015, 12:52 AM   #49
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QuoteOriginally posted by rfkiii Quote
You introduced some math that I was trying adapt to the D800E example. I came up with 1.18x. Can you confirm or deny this multiplication factor? Or can you confirm that the 400mm would be like a 339mm lens on the D800E.
Yes, you're exactly right, pixel for pixel the D800 has 1.18x subject magnification compared to the 645Z. You would actually need a 500mm lens on the Pentax to get closer to the FoV you're looking for.

08-12-2015, 03:25 AM   #50
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QuoteOriginally posted by Kolor-Pikker Quote
Yes, you're exactly right, pixel for pixel the D800 has 1.18x subject magnification compared to the 645Z. You would actually need a 500mm lens on the Pentax to get closer to the FoV you're looking for.


Awesome. Thanks. On this site, the longest lens listed in the database is 400mm. On eBay, there are several Pentax 645 600mm lenses such as this one:


Pentax 645 P A 600mm F 5 6 Ed If w Case Very Good from J 5377 | eBay


Is there any reason why I should not consider this lens for the 645z?
08-12-2015, 06:55 AM   #51
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QuoteOriginally posted by rfkiii Quote
Is there any reason why I should not consider this lens for the 645z?
I've heard good things about the 600mm, some people have theirs mounted to rigs to support the lens and camera: http://www.flickr.com/photos/21294128@N08/8535691606/
And I can see why, it's an enormous piece of glass that may prove a challange to use with regards to vibrations. There's no reason not to get one if you know what you're getting into though.
08-12-2015, 08:34 AM   #52
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Anyone had any luck with the 400mm plus the 1.4 converter?
08-12-2015, 02:05 PM   #53
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They aren't here because no one is willing to pay $15 000 for a 3kg 28-45/2.8 lens!

08-13-2015, 05:40 AM   #54
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QuoteOriginally posted by Kolor-Pikker Quote
I've heard good things about the 600mm, some people have theirs mounted to rigs to support the lens and camera: http://www.flickr.com/photos/21294128@N08/8535691606/
And I can see why, it's an enormous piece of glass that may prove a challange to use with regards to vibrations. There's no reason not to get one if you know what you're getting into though.


Good God. That would take a hand truck to move. My interest in the lens has been duly dispersed. Thanks.
08-13-2015, 05:49 AM   #55
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I'm starting to really regret selling my Mamiya 645 with 85/1.8 prime....
08-14-2015, 07:30 PM   #56
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QuoteOriginally posted by algrove Quote
Anyone had any luck with the 400mm plus the 1.4 converter?


That's a good question.
08-14-2015, 10:28 PM   #57
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Many of the Pentax lenses are descendants, in terms of design, of old German designs that were never really 'fast' e.g. around f2.8; more likely you will find lenses from f4, f4.5, f5.6 or their ilk. Distagon designs are still common throughout the lens line up. FYI, Pentax does have a couple of very popular studio-worthy primes of f2.8: the 90mm f2.8 (and the LS version) and the brutally snappy 75mm f2.8AL.
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