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Forum: General Photography 05-24-2014, 07:51 AM  
Latest Pentax hacking results
Posted By seppstefano
Replies: 43
Views: 5,545
too bad I read only now... else I would have definitely voted.
Forum: Pentax K-30 & K-50 12-31-2013, 11:16 AM  
New Firmware
Posted By seppstefano
Replies: 60
Views: 11,133
Hmm, I wouldn't really know how to perform the upgrade without the SD card slot....

Wish you all a great 2014!

Stefano
Forum: Pentax SLR Lens Discussion 10-26-2013, 12:29 PM  
Lens repair nightmare
Posted By seppstefano
Replies: 17
Views: 2,379
In the USA customers are way safer against such things than in Italy, and I wish you all the best, but for sure those "pirates" shouldn't behave the way you described!
Forum: Pentax SLR Lens Discussion 10-08-2013, 12:20 AM  
Vivitar Series 1 200mm f/3.0 -vs- Pentax-M 200mm f/4.0
Posted By seppstefano
Replies: 25
Views: 13,058
I don't want to hijack the thread but none of my two copies of the K200/4 shows such high PF as that one I can see on these published shots.

But I'm not saying that K series tele are perfect. For example I get PF on the K300/4, while a much humbler Vivitar 300/5.6 has almost none at the price of less sharpness.
Forum: Pentax SLR Lens Discussion 10-04-2013, 12:55 AM  
Vivitar Series 1 200mm f/3.0 -vs- Pentax-M 200mm f/4.0
Posted By seppstefano
Replies: 25
Views: 13,058
Would love to see a comparison with a K200/4. I do really like the shots it can provide, and - within Pentax lenses - some guy considers it only inferior to 200 A* ED Macro.
Forum: Pentax SLR Lens Discussion 10-03-2013, 01:37 PM  
Vivitar Series 1 200mm f/3.0 -vs- Pentax-M 200mm f/4.0
Posted By seppstefano
Replies: 25
Views: 13,058
ok Jan, we'll stay tuned :)

BTW, it would be quite interesting for me to see a shootout with the K200/4. I have it and it surprises me every time I see the world through it.

Stefano
Forum: Pentax SLR Lens Discussion 10-03-2013, 01:18 PM  
Vivitar Series 1 200mm f/3.0 -vs- Pentax-M 200mm f/4.0
Posted By seppstefano
Replies: 25
Views: 13,058
hmm,
it seems to me the Vivitar has a clear advantage in close focus range, while the M performs better on long range.

Thank you for the great work,

Stefano
Forum: Pentax SLR Lens Discussion 10-03-2013, 06:44 AM  
Soligor C/D 135mm f/2 -vs- Vivitar Series 1 135mm f/2.3
Posted By seppstefano
Replies: 6
Views: 15,293
Please, I am interested!

BTW, great work, thank you.

Stefano
Forum: Pentax K-30 & K-50 09-30-2013, 12:54 AM  
How many K-30 owners do we have?
Posted By seppstefano
Replies: 498
Views: 59,509
+1 here
Forum: Pentax K-30 & K-50 09-30-2013, 12:52 AM  
Blue Tint
Posted By seppstefano
Replies: 19
Views: 3,205
Hello,
aside from purple fringing and CA defects, what hurts me more in my shots is the magenta hue which sometimes appears. As many suggested, you can manage it by working with RAW and use the auto white balance settings of your preferred sw.
Forum: Pentax K-30 & K-50 09-30-2013, 12:44 AM  
New Firmware
Posted By seppstefano
Replies: 60
Views: 11,133
Hi there,
just to report another smooth and successful update to v1.05. It seems now my K-30 works better with my Lexar SD card.

Stefano
Forum: Pentax SLR Lens Discussion 03-10-2013, 01:23 PM  
Help on using leica lens on pentax k-r
Posted By seppstefano
Replies: 16
Views: 2,109
gosh!...where are my glasses...?
Forum: Pentax SLR Lens Discussion 03-10-2013, 01:15 PM  
Help on using leica lens on pentax k-r
Posted By seppstefano
Replies: 16
Views: 2,109
...oops, I didn't notice it was a Summaron... thank you Steve and sorry for the misinformation.

Stefano
Forum: Pentax SLR Lens Discussion 03-10-2013, 11:56 AM  
Help on using leica lens on pentax k-r
Posted By seppstefano
Replies: 16
Views: 2,109
mounts.htm

Leica has 47.00 mm distance while Pentax 45.46, so there should be some room for an adapter...

hth,
Stefano
Forum: Photographic Industry and Professionals 01-18-2013, 02:11 PM  
Noise Reduction Software Giveaway: Let us help you improve your photos! (ended)
Posted By seppstefano
Replies: 382
Views: 38,047
I would like to enter this giveaway.

Ciao
Forum: Pentax DSLR Discussion 12-22-2012, 04:15 PM  
Difference between TTL and P-TTL flash.
Posted By seppstefano
Replies: 46
Views: 42,286
IMO there are no excuse for Pentax. This is a plain removal of a useful feature just to cut industrial costs (of just a few dollars) per camera.

Admitted that Pentax/Ricoh wants loyal customer I think should fill these gaps.
Forum: Pentax DSLR Discussion 12-22-2012, 02:26 PM  
Difference between TTL and P-TTL flash.
Posted By seppstefano
Replies: 46
Views: 42,286
Ben, my old tank (a Canon 30d) even when used with pentax lenses and an adaptor ring (I have neither EF or AF lenses :) ) allows both TTL flash and consistent metering and exposures without any additional "A" pin trick, without any glitch and with 100% hit ratio.

The 30d does have a sensor (although way inferior to that of my K-x) AND is an old camera.

Can't find excuse to Pentax decision on carrying on an obsolete, absurd idea as P-TTL and preventing TTL metering to work without headaches on any lens.

I think its name is just cost-cutting (for P-TTL) and marketing (to effectively avoid people using older lenses).

Richard, I have something like 4 Metz flashes around (or maybe more). Yet the point is that TTL flash was bynow a standard and some marketing genius is trying to let us forget it.

Can't agree less with Pentax on this issue and would ask Pentax to come to its senses. No FF and no TTL on flash? Come on! Look at what other brands are doing!

Stefano
Forum: Pentax DSLR Discussion 12-21-2012, 03:36 AM  
Difference between TTL and P-TTL flash.
Posted By seppstefano
Replies: 46
Views: 42,286
Just resurrecting an old thread, can't understand why a dSLR targeted to professionals like the K5(s) keeps sporting a metering system way inferior than that adopted by old flagship LX.

Pentax LX - How does its metering works

"The IDM system measures the actual amount of light reaching the film plane during exposure, regardless of aperture setting or which focusing screen or viewfinder is being used. Even if light conditions change during the brief moment of exposure, shutter speed is adjusted instantaneously to compensate. When the camera is operated in the automatic exposure mode, the IDM system switches on the instant the mirror flips up and the front shutter curtain begins to move (see illustrations). It calculates the amount of light hitting the film plane and instantaneously controls rear shutter curtain motion for correct exposure. Light values, metered through the actual aperture, are monitored for the duration of the exposure - not the instant before the shutter is released. Thus, shutter speed is correct, even in changing light."

and

"For automatic exposure in the TTL Auto Flash mode, the IDM system measures only light reflecting off the film plane since the flash goes off after the shutter is fully open. The rear shutter curtain closes after the IDM system determines that enough light has reached the film and terminates the flash."

Aside from auto-everything, I would say that this feature would matter.
Forum: Pentax SLR Lens Discussion 11-20-2012, 07:49 AM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
Ok,
here am I. I did take some shots of a grey pavement and I'm just trying to evaluate the shifts among several lenses. BTW how do you "quantify" the histogram shifts on latest Pentax Digital Camera Utility?

Contrary to what I found the night I made my early test, this time I found reasonable differences among metered EVs through following lenses: C/Y P50/1,4, C/Y P100/2, C/Y D28/2,8, M50/1,7, both with M+GB (Green Button) and/or Av mode when lens is not fully locked in (continuous stop down). However this happens IF AND ONLY IF I hear the "swishing" sound after pressing the Green Button.

It seems infact that sometimes my green button doesn't seems reacting to first pressure (even if showed in-finder values do change), and needs a second action to wake up and meter. This happens e.g. after closing apertures from 8 to 11 and not when mounting the lens first time.

Did anyone ever experience anything similar? Does this happen only to my K-x? This doesn't seem a faulty pressure: I got it several times.

Stefano
Forum: Pentax SLR Lens Discussion 11-16-2012, 07:51 AM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
Thank you Lowell,
as soon as possible I'll take the shoots for the test you're suggesting.

Honestly I'm actually finding no less than unacceptable these wildly wrong evaluations given by Pentax meter.
I remember when LX exposure system was one of the best of its time, and I am missing its accuracy and simplicity.

I'll be back with some more data...

Stefano
Forum: Pentax SLR Lens Discussion 11-16-2012, 01:29 AM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
Sorry for late reply, due to intercontinental time-shift :D

1. all tests were made in M mode, as written, and lens effectively stopped down (I mean the image in the viewfinder is darker than at full aperture :)). With Av I keep getting underexposed, "inaccurate" metering, as declared by Pentax herself. With M mode, shutter time evaluations get clipped when f/stop is smaller than f/5.6 and can't understand why.
2. no, the lens is already stopped down to the desired aperture, before metering. I seem I remember body does not show any f/ info.
3. yes
4. yes
5. N/A. See point 1, I did shot in M mode.

I'd love to know if other Pentax users do always get good exposures even e.g. at f/11 as per Pentax officially method (custom menus properly set, M mode, green button) with stopped down lenses (e.g. old M42).

In test the clipped evaluated shutter time was blinking even if the value was quite far from metering limits. For example it blinked at 1/10.... while the effective light was demanding longer shutter speeds. It seems that the shutter speed which is set (and showed) doesn't match with the low light blinking warning. It seems there is "something" externally clipping the shutter value.

Thanks for your time,

Stefano
Forum: Pentax SLR Lens Discussion 11-15-2012, 05:23 PM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
Jim thanks for answering.

But what you're writing is valid in case di lenses in continuous stop down?

The linearity variation from M to A series of the aperture lever doesn't seem to me influent in this case, does it?

I mean that all the lenses I tested and reported had their diaphragm already stopped down when I metered, exactly as you write at #2, yet I'm getting that strange behavior...

Stefano
Forum: Pentax SLR Lens Discussion 11-15-2012, 04:57 PM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
As promised, for who cares, here's my followup.

I'm finally starting getting more consistent exposure results with my K-x and "strange" lenses :)

Quick and dirty, I placed a "C" shaped aluminum foil covering (shortening) all pins on camera lens mount, so any foreign lens was "sensed" like a M42 (of course with metal mount). The pattern is 111*11, the camera therefore should consider the mounted lens as with [1.2 - 22] f/stop range.

I fixed ISO (6400), set M mode, SR on, MF, and metered (the mirror did flip this time :) ) with Green Button (or EV button) and took some shots. Some data:

- P50/1.4 - Good exposures from 1.4 up to f/8, value from which I started getting underexposure and the metered shutter value was blinking.
- P100/2 - Good exposures from 2 (perhaps a bit bright) up to - again - f/8 where I got underexposure and the metered shutter value was again blinking.

Then I did the same with my SMC-M 50/1.7 in stop down mode (not fully locked in) - Good exposures (perhaps 1.7 and 2.8 a tad brighter) but - again - at f/8 I started getting underexposure and shutter time showed in the viewfinder was blinking (we're talking of 1/5 sec, far from the limit of the lightmeter)

Anybody caring to explain me what can be the reason of this strang behaviour?

Kind regards,

Stefano
Forum: Pentax SLR Lens Discussion 11-15-2012, 04:11 AM  
Converting K/M lenses by adding an A pin?
Posted By seppstefano
Replies: 57
Views: 11,207
After several tests of yesterday evening, perhaps I found the existence of a possible solution to my issue on non pentax lenses (of course on pentaxforums :) )

It's here: the lenses I tried have black painted lens mount...

https://www.pentaxforums.com/forums/pentax-beginners-corner-q/137718-manual-a...etering-2.html

I'll report after this evening's test :)

Ciao,

Stefano
Forum: Pentax SLR Lens Discussion 11-13-2012, 01:45 PM  
Anyone tried Carl Zeiss Planar T 50mm f1.4
Posted By seppstefano
Replies: 19
Views: 13,191
This may be a couple of interesting links, too.

test_zeiss50

http://forum.mflenses.com/viewtopic.php?t=13521
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