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Forum: Pentax K-1 & K-1 II
09-15-2017, 11:56 PM
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Current AF sytem and lenses are so outdated that it is really impossible to shoow moving object or events even with central AF point. The system is responsive on paper but if you compare in real work 5D2 and 70-200 IS L series lens the system lack behind, you just miss 50% of photos you get with Canon. It is even worse with some DA* lenses like 50-135, it takes millenium to focus and the algorithms are really nonsense. It resembles me when Apple lacked RF engineers in house and they designed iPhone antenna - atennegate. Pentax team does not have anyone who knows basic physics and mathematics behind AF systems, they just tune and copy the same old outdated system. Even some compact dual pixel sensors beat them totally.
Worst problem, the pentax system can not predict phocus and can not tell to the lens where to move then, it just tries like CDAF and fails.
It is more wise to get 5D3 and forget all K1 and pentax stuff. There are much better options like Sony or 4/3 systems etc.
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Forum: Pentax K-5 & K-5 II
02-14-2011, 04:50 PM
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Just did two Photoacute profiles for K-5 Sigma 70 mm EX dh macro and samyang 15 mm wide angle, both work great. They should have new version soon with those profiles.
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Forum: Pentax Medium Format
02-06-2011, 03:20 PM
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may be between 20-30 mpix, this is much cheaper than 40 mpix version and there is not too much R&D ahead to change resolution. All MF vendors have different sensors. Theoretically they can add more speed into system in terms of iso and fps.
I do not think they will introduce FF 35mm, this does not make sense anymore except may be marketing. There are few users who win from it, APS-C sensors and glass have evolved to the level allowing print A1 or A2 photos already and the system can shoot in darkness. What magic the FF could give. Of course you get one stop more sensitivity but you have to stop down also your aperture to get same DOF. The system is much more heavier to carry also with FF glass and lenses get more expensive.
With 645D you can just jump to another game, you get much better optics/senors cooperation and huge jump in real resolution.
In MF from the other hand we can see even old lenses capable of resolving new 40 mpix sensor.
If they introduce a 24 mpix FF they must introduce new lenses as well, there is just few resolving such resolution at non center areas. Same story is all the time going on with Canons, they increase resolution and introduce L II lenses.
I conclude that the Pentax pro segment is evolving at 645D not FF, pros are moving from FF to MF anyway soon or they have at least one MF camera, it makes life much more easier. 24 Mpix FF and MF are not compareable in IQ. And it is quite sick idea to compete with CaniKon at the FF pro segment, even Sony is in trouble with its FF there. CaniKon ecosystem is very good and working well in sports, journalism, action, wedding journalism etc, but is is really weak in studio, landscape and fine art segment, most serious studio work is done today already by MF systems.
If they will introduce low spec FF the price could be $6500 25 mpix and they still have good margins.
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Forum: Pentax K-5 & K-5 II
01-02-2011, 09:03 AM
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I have not seen any similar issues like in K20D, K5 is ok in dim or tungsten light. I have sit in physics lab quite a lot an see the testing methods used here are not accurate nor the conclusions.
If the problem is corrected, the CaniKon marketing people still repeat the same pattern and fool people of course will believe it. Everyone can look tests how K5 performs against D7000 and it is not lacking behind much.
I am using DA*55, DA*50-135 amd DA 16-45 quite often, when I shoot 150 photos I get may be 10 misses and this is normal to any camera.
Tungsten shift is totally different issue and this is present with K-x,Kr,K20 and I see it in my K20D, this is systematic error and quite large.
In your test you have to take account that K5 AF areas are quite wide.
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Forum: Pentax Medium Format
12-05-2010, 04:09 PM
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It is really best DSLR (most medium formats are fragile devices and UI-s are quite complicated for wedding shooting) from resolution point of view. 645D goes up to iso 1600 this is not too much and has 1 fps continuous shooting but this is enough for landscapes, group photos, product photos, wedding etc. This quality can not be achieved with any CaniKon camera. If you need high iso, just carry another camera in your bag, other MF cameras do not shine here either.Pentax AF is definitely No 1 in medium format league and brings other features into MF, like P-TTL shoe mount flash.
35 mm FF cameras can not beat 645D at iso 1600, because they loose detail. Imaging Resource has 645D, 5D2 and A900 images. There is nothing to compare here, MF can see fabric thread texture when 35mm FF has even problems with printed textures on the fabric.
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Forum: Pentax K-5 & K-5 II
12-04-2010, 07:12 PM
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Pentax has evolved to the level where more serious work could be done, the camera has excellent dynamic range and in camera shake reduction. All this enables to shoot in various conditions where competitors vibration compensation zoom lenses can not reach due to the large T-Stop values or light loss in the lenses.
I would propose to add some more tools to shoot better still life with K5. We all know that we have only 4 Mpix of RED and 4 MPIX of BLUE sensors in the bayer matrix and the resolution is interpolated.
It is possible to take multiple shots to compensate this color resolution disadvantage of Bayer matrix moving sensor and reading neighboring pixels. Pentax should have tools inside camera to get this done ?
It should be possible to move sensor within pixel resolution but I do not know exactly how accurate the sensor actuators are.
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Forum: Pentax K-5 & K-5 II
12-04-2010, 06:58 PM
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Yes that's true, it is even quite effective shooting from car moving 90 km/h and if car is approaching from opposite direction. I did the test with sigma 70 EX macro which has screw drive but it is fast and quite silent. For me screw drive seems to be faster than SDM but it depends on light also. Thera are also tests at Rice High ultra critical insane site, where K5 performs same level as D7000. I have not been in trouble with K5 AF-C at all.
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Forum: Pentax DSLR Discussion
12-01-2009, 04:48 PM
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At first I saw that AF was out of calibration, mine needed -90 um correction, but there are still some too softy images sometimes.
SR can be the problem as well, I did some tests with DA 21 Ltd and got 100% sharp photos, I do not know why ? But DA*55 and DA16-45 are not doing so good. The problem is not in focus because I checked it with LV.
There is another strange problem, if you shoot with flash at Av, exposure is quite often metered according to the background, i.e something 1/15 to 1/30. This can be tweaked in manual mode only to 1/180 but no other methods exists in my opinion.
In tripod shooting, the camera definitely is vibrating with lighter tripod, the worst case is in camera HDR and there is no mirror lock for HDR or exposure bracketing modes. It gets better with heavy tripod not so easy to carry with.
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