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Forum: Post Your Photos!
04-07-2022, 04:41 AM
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Very nice picture! It demonstrates the advantage of a fisheye lens which produces a realistic foreground. A rectilinear wide angle lens stretches the foreground (particularly around the corners), and that's not always welcome.
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Forum: Pentax SLR Lens Discussion
05-12-2019, 10:40 AM
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My K1-II enjoys the company of the DFA 28-105 very much. If I want to travel light, I also grab the A20/2.8; there aren't many light options at the long end, however. I might take the DA 50-200 (well knowing that the 55-300 would be preferrable if I had one) or the trusty old A*300/4.0 which isn't light at all but long enough for all my purposes. If space and weight permit, I love to add some fast primes.
And there is always an unused corner of the bag where I can squeeze in my ancient 17/4 FE. It's just nice to be prepared for the rare occasions when a fisheye comes in handy, and its weight is not much more than the difference between a full and an empty battery. ;-))
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Forum: General Photography
09-30-2018, 10:26 AM
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On my visit to Photokina (on Wednesday) I wasn't too much disappointed by the lack of new announcements. Pentax may have reasons for holding them back, I guess. I was disappointed, though, by the presentation: Not only was Pentax' booth just a quarter the size of the 2016 one, they didn't have a single K-1 brochure nor a lens and accessories catalogue, and some folks asked for the one or the other even while I was there.There were many lenses available for testing, but no 28-105. The Pentax guys I talked to were very kind and helpful (and one of them really knowledgable) but the rather extreme low-budget approach irritated them too. So no need to panic IMO, but still I'm worried a bit.
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Forum: General Talk
09-25-2014, 01:16 PM
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Fascinating! I had never done any speed reading tests before. I can't figure out the OP's figures, though: 433 wpm can't be 400× faster than average, can it? A factor of 10 missing somewhere, perhaps?
Now that my interest was stirred I took a stop watch and measured the time for reading MK's 2nd posting. Hmm, about 700wpm, probably an average figure … As English is my second language, I reached for the newspaper and read the boring article I had just decided to skip … 520 wpm – what? Reading faster in a foreign language?
I suppose that reading speeds can't be compared between different languages. There are so many short words in an English text (and so many long ones in a German text), it's unfair! ;-)
Afaik reading speed and comprehension are not routinely tested in schools here, maybe for political correctness reasons.
BTW I started reading at the age of 3 (out of curiosity, as I remember). What bugs me most when I'm reading are typos; they always seem to grab my attention (no matter if in a German or English text), and there seem to be more and more of them. Even in so-called quality papers.
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Forum: Pentax News and Rumors
10-01-2013, 09:11 AM
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I haven't seen anyone refer to the hump on the other side of the lens. If I compare the K-3 front view to my K-5 there is definitely more volume between the lens and the grip.
It looks like the left bulge (in the direction of shooting) continues across the lens mount through to the other side.
Now let me speculate before it's too late: I think it is the axis and drive for a second semi-transparent mirror which directs some light onto the AF sensor while the mirror is raised, to enable PDAF in video or live view mode.
It's still dreaming time!
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Forum: Pentax News and Rumors
09-29-2013, 04:55 PM
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As I mentioned before, this is not true. Generally speaking, wide-angle lenses can be built with small rear lenses but telephoto lenses can't. BTW, there is a reason why camera systems with larger image formats do have larger mounts …
Don't know what you call “normal image stabilization”. The Pentax APS-C sensors can move by ± 1 to 1.5mm; a larger format needs larger movements as the same field of view is projected onto a larger area. Therefore the pixel movement is amplified by the crop factor and, accordingly, the sensor has to move more for the same effect: ± 1.5 to 2mm.
It's somewhat unfortunate that a larger sensor, which is heavier anyway, needs larger movements, and explains why there is no IBSR for the 645 format (although the lenses do cover a large image circle of about 75mm while the sensor only measures 55mm diagonally).
I really don't want to spoil the fun, but we shouldn't entertain any hopes that Pentax can do anything that is physically impossible. And whine if they don't.
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Forum: Pentax News and Rumors
09-29-2013, 03:28 PM
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I'd call it a ruler :p
 Quote: Do you realize that the Asahiflex mount had an EXTERNAL diameter of 37mm whilst being a 24x36 mount? And what lenses did they have? Focal length, max aperture??
The inner diameter of the K mount is about 43mm. (I don't have the exact specs at hand, just took a lens and a ruler.) In most long telephoto lenses that I know of the rear lens is pretty deep inside the lens body; look at the L converters, they use this space and protrude into the lens barrel.
Now try to draw a lens diagram where the rear lens sends the light to a 47mm sensor through a 43mm mount and where the distance between lens and mount is larger than the register, the distance between mount and sensor. How large can that rear lens be? For a contrast look into the HD DA 560/5.6 – or at the lens diagram, like myself who doesn't have access to the real one ;).
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Forum: Pentax News and Rumors
09-29-2013, 02:44 PM
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If Pentax/Ricoh decide to go for FF they basically have two options – either reuse the K mount and do SR in the lens (as they did for the 645D), or keep in-body SR as a primary selling point and develop a new mount.
I doubt that the K mount accomodates the 43mm FF image circle plus 1.5 to 2 mm leeway for sensor movement on either side, i.e. a minimum of 45 to 46mm image circle. Most of the existing K lenses wouldn't be suitable for IBSR anyway as they don't cover a sufficient image circle (except for the 28/3.5 Shift …), thus it wouldn't make sense to relaunch the old lenses. There could be adapters for K lenses on a new (“A”?) mount giving the user the choice of turning SR off or shooting with a crop factor of, say, 1.2 instead, but only with a smaller register. How does a FF mirror fit in then?
This looks like Ricoh have a choice between a mirrorless new mount with IBSR and adapters for old lenses (with the option of a redesigned focusing and aperture control), and a fully compatible K mount with no IBSR and mechanical aperture control etc. Anyone see a third way??
Considering these alternatives I feel I understand why they still can't make up their minds … :-o
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Forum: Pentax News and Rumors
09-24-2013, 03:31 PM
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Back in May a source “close to Pentax” (of course!) told me that the next flagship camera wouldn't have an articulated display but a detachable one, with wireless communication … I've been doubtful so far but this would fit in with the currently rumoured K-3. A wireless display could be weather-sealed, better than an articulated one.
Let's see what will remain from all these speculative specs. I'm happy, however, that at last there is some speculation going on again!
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Forum: Pentax SLR Lens Discussion
07-18-2013, 03:01 PM
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Just to avoid any misunderstandings: The FA 77 was built for FF. It fills the frame fully ;) and, with 77 real millimetres, is what you might call a portrait lens, with a 50% longer FL than a standard lens.
AFAIK the 70 is for APS-C only (that's why it is so small). I don't own one but I suspect that on FF the corners would be pretty dark (beyond recovery).
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Forum: Pentax DSLR Discussion
07-16-2013, 07:24 AM
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I don't think this was a deliberate choice on Canon's and Nikon's side. AFAIK they started to offer IS in the film era, and IBIS simply doesn't work with film (well, maybe it could, but probably nobody ever tried …). Pentax was a late-comer (as with AF) and had the option to do IBIS, and this is what they chose. As compatibility has always been a major sales argument for Pentax this was a pretty consistent decision.
With a standard FL I couldn't hand-hold slower speeds than 1/30 on my LX; whenever I did try though, > 90% of the shots were blurred. With my K5 I've had many sharp shots @ 1/4 or even 1/2 s for 28 or 35mm which gives 3 or 4 “stops of improvement”. I'd say the success rate depends a lot on “how steady” you hold the camera: the IS can compensate small recurring movements pretty well but is taken by surprise if you jam down the shutter release.
The different reports about how much effect an IS has are probably due to the ways people hold their cameras. There is no standard measurement procedure, and every photographer have their individual ways of rolling and shaking …
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Forum: Pentax SLR Lens Discussion
09-17-2012, 03:01 PM
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I got a WR together with my K5 and I find its IQ amazing, regarding the price tag. It's very sharp–at least if stopped down by 1 or 2 steps, and @55mm and shortest distance it has almost macro lens qualities. Since neither the ALII nor the WR seem to receive as much praise as mine would deserve ;) I'm wondering if I was lucky and Providence picked a good sample? Or has Pentax QC improved lately??
Docrwm, perhaps you could include a test at close focusing distances.
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Forum: Travel, Events, and Groups
09-09-2012, 10:33 AM
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I'll be going on Wednesday (if everything works out as it's supposed to …). You'll recognize me: the (one and only??) guy with a K5, hanging around at the Pentax booth and trying to lay his hands on the K5's successor ;)
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Forum: Post Your Photos!
03-30-2012, 02:07 AM
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The underside of a fairly large leaf (of some plant in the greenhouse).
Yes, it's Scilla, and they grow in the Siberian corner of the gardens :)
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Forum: Post Your Photos!
03-29-2012, 07:29 PM
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One day last week -- when the weather was still fine -- I took my K-5 out for lunch. Or, to be more precise, I went for a stroll through the botanic gardens during my lunch break hoping for an opportunity to exercise my new camera. As my enthusiasm about the latter is still overwhelming, please forgive my shooting mundane subjects like these ... This is also my first attempt at uploading pictures; I'd be grateful for advice how to do better.
The pictures are pure OOC jpegs, only scaled down with the Gimp. (The crop received a bit more attention, which probably made it worse.)
Let's start with a bunch of flowers. Don't ask what they are called -- I'm not a botanist, they just looked pretty.
K-5, DA 18-55 WR, F8, 1/250s, ISO 100
When I pixel-peeped into this picture at home I noticed that this blossom accomodates a few critters; do you recognize them in this 100% crop?
I'm really surprised by the IQ of the kit lens; I think it's very sharp, even in the near-macro range, and in case you're wondering -- the AF is spot-on.
K-5, DA 18-55 WR, F10, 1/250s, ISO 100
K-5, DA 18-55 WR, F11, 1/100s, ISO 1000
Of course I wanted to see how my older glass performs. The subjects are not overwhelming, but the IQ encourages me to leave the old lenses in my bag ;).
K-5, A* 135, F8, 1/125s, ISO 1000
K-5, FA 77 Ltd, F4.5, 1/320s, ISO 100
A single red tulip (hmm, I hope it is one?) caught my eye. It grew on a dry, almost colourless patch. The greens in the corner were actually there but I could well imagine to PP their colour away.
K-5, DA 18-55 WR, F6.3, 1/160s, ISO 100
Thank you for looking -- comments and criticisms are welcome.
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Forum: Welcomes and Introductions
03-27-2012, 02:51 PM
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After having (mostly) lurked for a while I want to say hello to y'all and how much I appreciate this forum's friendly atmosphere.
My first camera was an Asahi Pentax ESII (with a 50/1.4), back in 1974. I not only liked its features; my Dad had an M42 SLR (a Practica superTL) at that time, and with the Pentax I could borrow his lenses, extension tubes and the teleconverter. A bit later, however, I bought some more Pentax lenses (SMC 24/3.5 and, yes, an SMC 400/5.6), and they were so much better than my Dad's stuff that I didn't hijack this any more.
17 years and many rolls of film later I decided to enter the bayonet world. Again compatibility was an issue: With a Pentax camera I could still use my SMCs, and anyway I had been very happy with the Pentax stuff. Thus I bought an LX and pretty soon caught a severe fit of LBA: at last I had access to the world of fast modern lenses, and the A's and particularly the A*'s were so great ...
In the meantime it has dawned on me that the film era is coming to an end (I noticed this when my beloved Kodachrome disappeared from the market ;) ). And the shelves are bursting with so many boxed slides that I don't rejoice in shooting new ones any more.
I started shooting more often with my compact camera (an Optio A40) but missed the VF and the IQ of an SLR. I then borrowed a K7 for a few times and saw how well my lenses still performed (or most of them, at least). When I got my hands on a K5 at Photokina 2010 I knew this would be my ideal camera: The moderate sensitivity and the often visible noise were the only gripes I had with the K7, and the K5 ideally addressed these issues ...
On the last day of the recent K5 cashback action I ordered one and have been very happy with it. I simply can't believe how well my ancient glass still performs! So be warned that you will be shown loads of ordinary everyday pictures that this DSLR newbie is excited about and feels are a revelation that he must brag about!
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Forum: Troubleshooting and Beginner Help
05-31-2011, 09:56 AM
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I suppose that as for a hand-held shot the SR can still leave a visible error of a, say, 1-pixel blur, this is in most cases better than no SR at all. And not every hand-held shot is totally sharp, is it? The same could happen when using SR with a tripod, but then it's more of a nuisance as the blur wouldn't have been there without SR in the first place.
Therefore I think it's a good idea to turn SR off when the camera is on a secure rest just to cut out one possible source of (even a minute) error.
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Forum: Troubleshooting and Beginner Help
09-29-2010, 08:28 AM
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Just for the record (and not implying that this is new information ;)) -- all the old MF Pentax wide-angle lenses have orange marks on the aperture and focus rings indicating a medium aperture and its associated hyperfocal distance.
Just select these positions and shoot in Av mode, and everything will be sharp. From about half that distance to infinity. (Unless the shutter speed is too slow or the subject moves too fast, of course.)
Not that I loathe the bokeh -- not at all -- but sometimes this is useful for quick or candid shots.
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Forum: Troubleshooting and Beginner Help
09-23-2010, 02:30 AM
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... and resolution. With infinite resolution (which my cameras don't have ;)) there would be zero DOF. The actual DOF depends on the pixel density in the sensor (and that of the printer or screen, if it's limiting) because you can't see a difference between the in-focus and the slightly-out-of-focus areas of the image if the pixel raster cannot differentiate between them.
And then there is the resolution of the spectator's eye: Depending on the viewing distance, there is an "acceptable circle of confusion" -- we won't see any degree of sharpness smaller than that. For analog photography where there is no fixed pixel pitch, the DOF table calculations are based on this.
Many compact cameras don't show a pleasant bokeh also because the IQ is lacking: the resolution is not fine enough to show a smooth transition from "sharp" to "blurred". And this can't be cured by more MP's alone...
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Forum: Photographic Technique
09-23-2010, 01:54 AM
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Think of the precise date and time of exposure, maybe even GPS location. Perhaps you were supposed to be somewhere else at that time -- in the office, for instance ;)
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Forum: Pentax DSLR Discussion
09-23-2010, 01:44 AM
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Thank you, this is very useful!
A few minor comments though:
- At least the K-r does have front/back focus compensation. I was shown this yesterday on Photokina because I had asked whether it can do this. Other than the K5, however, there is only one global setting, no lens-specific data can be stored. (A side note: The service rep told me that front/back focus is generally a camera and not a lens problem which they can fix in the camera. Therefore the focus correction is just meant as a quick-and-dirty workaround until it gets fixed. Can't judge that myself.)
- According to the specs (in the Photokina brochure), the K-r definitely doesn't support power zoom.
- The K-x's autofocus system is named "Safox VIII" (IIRC).
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Forum: Pentax DSLR Discussion
09-06-2010, 08:52 AM
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The 67 lens will basically behave like any other lens of the same focal length. The main difference is that the 67 lens draws a larger image around (and outside of) your sensor -- which gets lost(*).
You'll gain, however, some IQ because you only use the very centre of the image where lens correction etc. is best, even more so than with a FF lens.
(*) the extra image area gets lost, not the sensor ;)
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