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02-14-2012, 12:32 AM   #91
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QuoteOriginally posted by DaveBlack Quote
Please don't do it as a 85/2.0. What a waste of R&D resources. Just re-release the excellent FA*85/1.4 as a DFA*85/1.4.

Dave
I don't think that 128 mm is usefull length at APS-C...
105 or 115 mm are better. or 135 mm.

Anyway, as for me - old FA*85/1.4 is not better than FA77/1.8. Faster - yes...But the picture is nothing special...
I'd prefer DA90/2. or DA90/3.5 PANCAKE LIMITED - but there are no such lenses in roadmap

02-14-2012, 01:37 AM   #92
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QuoteOriginally posted by ogl Quote
I don't think that 128 mm is usefull length at APS-C...
105 or 115 mm are better. or 135 mm.
It's actually closer to 130 than 128 (K-5 crop is 1.52, K-7/K20d crop is 1.53) - i.e. close enough to 135, IMHO. Besides, Pentax used to have both 100, 120, 135 and 150mm lenses!
02-14-2012, 06:19 AM   #93
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QuoteOriginally posted by Urkeldaedalus Quote
I want full frame, too, but really if you want a full frame camera you should buy one from a company that already makes one. If you keep waiting for Pentax to do it you'll be bound to be disappointed .....
Not to mention being an annoying dickweed on forums
02-14-2012, 06:23 AM   #94
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QuoteOriginally posted by ogl Quote
I don't think that 128 mm is usefull length at APS-C...
105 or 115 mm are better. or 135 mm.

Anyway, as for me - old FA*85/1.4 is not better than FA77/1.8. Faster - yes...But the picture is nothing special...
I'd prefer DA90/2. or DA90/3.5 PANCAKE LIMITED - but there are no such lenses in roadmap

I would like both a 85/1.4 and a 135/1.8. Still before those two I would love a DA*29/1.4 for a weather-sealed normal lens.

Dave

02-14-2012, 06:24 AM   #95
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QuoteOriginally posted by Wheatfield Quote
Not to mention being an annoying dickweed on forums


Excellent use of dickweed.
02-14-2012, 06:40 AM   #96
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from lenses to dickweed, nice transition !
02-14-2012, 06:47 AM   #97
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QuoteOriginally posted by DaveBlack Quote
I would like both a 85/1.4 and a 135/1.8. Still before those two I would love a DA*29/1.4 for a weather-sealed normal lens.

Dave
Do you think this lens could be small? Why 29 mm, not 28 or 30 mm?
02-14-2012, 06:52 AM   #98
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QuoteOriginally posted by ogl Quote
Why 29 mm, not 28 or 30 mm?
Many people think 29mm is APSC's image circle (K-5's is 28.4mm though).

02-14-2012, 07:21 AM   #99
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QuoteOriginally posted by falconeye Quote
I didn't look it up now. But isn't it rays into the car's interiour which causes heat up? If so, black paint could still heat up much more rapidely than silver. It just wouldn't matter much with a car heating up through the windows. Black paint would even radiate more heat from the car's interiour to cool it down ...
With that illustration I was asking the poster to prove his assertion about white painted lenses by referencing the definitive study. I suspect so many of these assertions are just urban legends.

I found a related article about cars paint colors. The article states the largest controllable factor was whether the auto glass wasd tinted, then the amount of glass in the "greenhouse" Tinted glass or less glass = cooler car.

For this discussion the real question is whether white paint actually reduces barrel expansion at the marginal point of lens alignment deflection, or whether with either color the marginal temperature of the barrel is achieved.
02-14-2012, 07:25 AM   #100
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QuoteOriginally posted by monochrome Quote
For this discussion the real question is whether white paint actually reduces barrel expansion at the marginal point of lens alignment deflection, or whether with either color the marginal temperature of the barrel is achieved.
If you carry it this far, don't you have to take the question of inner-tube air turbulence and their impact on optical performance into account? I know that this is an important topic with scopes which are air-filled (which unlike Hubble, most are ).
02-14-2012, 10:00 AM   #101
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QuoteOriginally posted by ogl Quote
Do you think this lens could be small? Why 29 mm, not 28 or 30 mm?

Because it seems like Pentax likes to use uncommon and different focal lengths. Anything between 28-30 would be ok with me. No this lens will not be small. I will guess a 77mm filter size.
02-14-2012, 08:10 PM   #102
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QuoteOriginally posted by DaveBlack Quote
Because it seems like Pentax likes to use uncommon and different focal lengths. Anything between 28-30 would be ok with me. No this lens will not be small. I will guess a 77mm filter size.
The problem is no such lens in roadmap till 2013 and later.
02-16-2012, 02:55 AM   #103
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Hi,

What will be the Sigma strategy? They were waiting for the Pentax/Ricoh one... but today, will they launch new K-mount lens (that already exists for Nikon, Canon...)?

Regards.

Malsi
02-16-2012, 10:13 AM   #104
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QuoteOriginally posted by Malsi Quote
Hi,

What will be the Sigma strategy? They were waiting for the Pentax/Ricoh one... but today, will they launch new K-mount lens (that already exists for Nikon, Canon...)?

Regards.

Malsi
If it wasn't for sigma we'd have no fast 20-30mm primes available for K mount. As it sits we have 24/28/30/ plus the 85 all fast none of which exist in the Pentax lineup plus the UWA & fisheye primes like the 4.5 and the 10mm
and pending 150 which is also a missing FL (no 135 from anyone )
02-16-2012, 10:50 AM   #105
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QuoteOriginally posted by ElJamoquio Quote
30/1.2? That would need about 86mm front filter or so, correct?
A 30mm F1.2 for APS-C sensor should not need a 86mm filter size since the 30mm F1.4 Sigma only has a 62mm filter the FF/35mm Pentax A 50mm F1.2 only needs a 52mm filter and the Pentax FA 85mm F1.4 a 67mm filter.
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