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Pentax 2X vs. 1.4X test


michael_reichmann1

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I have just published a test of the Pentax 67's 2X Extender vs. the 1.4X Extender. The test was done with the Pentax 400mm f/4 ED(IF) lens. What made the test interesting as well as problematic was the expected Pentax 67 problems of shutter vibration, and the need for approriate support when shooting with such very long lens combinations (800mm).

 

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http://www.luminous-landscape.com/p-ext.htm

 

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Michael

 

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The Luminous Landscape

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Michael,

Another EXCELLENT commentary. Thanks once again. You mention in your

summary that you had used a similar/same combination in Yellowstone in

the winter. If you don't mind me asking, and I don't mean this to

sound in any way insulting, or stupid, but do you know how much all

your usual field gear weighs? Also, and again if you don't mind

saying so, do you transport it all yourself? Just curious. It sounds

like it would require at least two fit people to get it to a remote

location.

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Michael,

One question on your test; You are talking on heavy tripods and

vibrations. To me it looks as if you are using the onepoint

technique. The lens/camera are only fastened in one point - the

tripods head. Using long lenses I do always try to get as much

support as possible. Best support is simply laying the camera

on

ground. Landscapes like yours testsite I always try to get support

from the tipod and an additional point (I love viewpoints with a

sturdy banister)

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Carl,

 

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My camera kit depends on the type of shooting I anticipate doing,

and I have a few different packs to use based on whether I'm mostly

shooting from a vehicle or doing extensive hiking.

 

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For day hikes I try not to carry a camera backpack weighing more

than about 20 lbs, excluding the tripod which is carried with a

shoulder sling. This means something like a Lowepro Mini Trecker.

I'm middle aged, but in reasonably good shape, and can hike for

hours with such a setup. It means leaving something like the 400mm

f/4 at home though.

 

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The MiniTrecker is an airplane carry-on, and the tripod goes in a

dufflebag with my clothes.

 

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For my recent Yellowstone shoot ( http://www.luminous-

landscape.com/yellowstone-winter.htm ) for example, where most of

the shooting was from the vehicle, I use the Lowepro Roadrunner AW,

a large rolling backpack style bag, which held everything I needed

for a week-long shoot, including 2 MF bodies and 5 lenses, one of

which was the Pentax 400mm f/4 ED(IF).

 

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The bag weighed 55 lbs (I know because the airline weighed it). I

could pack it for a few hundred yards, and did, but that's about it.

It's sturdy enough to be checked as lugged and because it has wheels

as well as a pack design, can be wheeled through airports rather

than carried.

 

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If I'm using this bag and need to hike I simply take what I need and

put it in the pockets of my shooting vest. The camera and one lens

goes over my shoulder with the tripod on its sling as always.

 

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Hope this helps.

 

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Bert,

 

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You're quite right. But, if you go back and re-read the article

you'll see that I did use, and also mentioned, the Manfrotto 359

Support Arm, which is a must for this type of photography.

 

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http://www.luminous-landscape.com/359.htm

 

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Michael

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Many people tried the Pentax 67, and gave up, saying that the images

were not sharp. I found it was true if I used a lesser tripod, say,

a Bogen 3021 which I did try out. The shutter shock problem of the P67

demands much heavier support, even with the mirror locked up,

especially when shooting horizontals. The movement of the shutter mass

creates an internal torque about the camera's mass center, so it

actually twists during the shot. This is much less a problem for

verticals, since ironically since we need to flip it to the side of

the ball head the torque now has to fight with a much more rigid

tripod axis. Try to twise your 3021 the both ways, and you'll

understand what do I mean. It is by some means a handicapped system,

on which one can't fire at 1/8 and 1/15, and for which a Grizo 1548 is

absolutely necessary, even it costs a fortune and offsets a very cheap

MF system otherwise. However counting in the $1k for the 1548 the

system is still inexpensive, cheaper than many of my friends 35mm

outfits. I also use a short aluminum center column with the setup, on

which I drilled three holes across the center so that whenever I shoot

I stick through a philips screw driver I always carry, and hung my 25

lb. (at least) Domke Outpack backpack to weight down the tripod. It

will look funny, but as a physicist I found nothing substitutes the

physical weight in the role damping out the shutter vibration,

especially when shooting horizontal, even the carbon fiber (or wood)

legs do absorb the vibrations much better than the metal ones. The

Domke bag is of a "vertical" design so that I can access my gear while

it is on the center column, very convenient. I would feel unsecure

whenever my set up is not weighted down by the heavy bag, especially

in windy days. The results? I routinely enlarge my 6x7cm chromes to

24x30 on Lightjet, still with details to be seen inches away (many

viewers sware they are from 4x5 originals), and publications including

two covers last year. I have found my 200mm plue 2x images sharp

enough for 16x20s with this set up.

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