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Forum: Pentax News and Rumors 11-13-2013, 08:47 PM  
DA 20-40mm Ltd. By The Numbers?
Posted By tigrebleu
Replies: 184
Views: 25,807
I understand that you wanted to compare lenses with a similar focal length range on APS-C, but comparing full frame lenses with an image circle about twice the surface area of APS-C lenses isn't fair for the full frame lenses to start with, at least in terms of size, weight and filter size. You still have a point in the fact that Canon and Nikon don't have a lot of APS-C options in the range of the DA 20-40mm (the 17-55mm F2.8 lens they both have in their line-up is the only one, actually :lol: ).

To be fairer, you could also have included other lenses with a similar equivalent focal length range, but in APS-C (DSLR or mirrorless) and in FourThirds and MicroFourThirds mount.

So I added a few APS-C and 4/3 lenses to the ones in the original post. And for purposes of a "decent" comparison, I didn't include any lens with a max. aperture smaller than F/4, or any lens with a focal length lower than 28mm or greater than 70mm in full frame equivalent, so that it's close to the limits of the Pentax's 30-60mm in FF equivalent focal length range. Here we go:

- Canon: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- Fujinon: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- Nikkor: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- (Olympus) Zuiko Lens 14-35mm F2.0 SWD
Filter: 77mm — Size (D x L): 86.0mm x 123.0mm* — Weight: 900g* — Weather sealed: YES** — Motor: SWD — Stabilizer: NO, in-camera
*: Plus the length and weight increase of a MMF-2 or MMF-3 adapter when used on MicroFourThirds cameras.
**: Only with MMF-3 on MFT cameras (MMF-2 not weather sealed).

- Panasonic: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- Pentax DA Limited 20-40mm f/2.8-4.0
Filter: 55mm — Size (D x L): 71.0mm x 68.5mm — Weight: 283g — Weather sealed: YES — Motor: DC — Stabilizer: NO, in-camera

- Samsung: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- Sigma ART 18-35mm f1.8 DC HSM
Filter: 72mm — Size (D x L): 78mm x 121.0mm — Weight: 811g — Weather sealed: NO — Motor: HSM — Stabilizer: NO (in-camera on Pentax recent DSLRs)

- Sony: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

- Tamron: no lens in the 28-70mm FF equivalent focal length range and/or with a max. aperture of F4 or faster.

The Sigma 18-35mm beats the DA 20-40mm on aperture speed and wide FOV, but is much shorter at the tele end and doesn't have weather sealing. And it's a LOT bigger than the Pentax 20-40mm.

The other one, the Olympus Zukio 14-35mm F/2 is as big as the Sigma 18-35mm, has similar aperture and size, and is even a bit heavier. But it does have weather sealing.

Still, the DA 20-40mm offers the best option in the pack when it comes to traveling light or using a non-obstrusive lens on your camera, at least in this very limited focal length range.

But...

If I could've included the Fujinon XF 18-55mm F/2.8-4 R LM, it would have been a close call, with the Fujinon having a better focal length range but no weather sealing... Same for Panasonic's Lumix G X Vario 12-35mm F2.8 Asph. / Power OIS lens, with the Panasonic having a faster aperture, wider FOV but shorter tele reach and no weather sealing either. But both go beyond the 28-70mm FF equivalent focal length range.
Forum: Pentax K-3 & K-3 II 10-08-2013, 01:27 AM  
The K-3 finally has what I've been looking for in a DSLR.
Posted By tigrebleu
Replies: 34
Views: 6,340
1. New AF with genuine AF tracking.

Not just the focus, take a shot, re-focus, take a shot... AF-C action my K10D, K-7 and K-5 used to do.

Still have to see if the reality lives up to the promises, but a 27-AF point system is a big improvement over the 11-AF point system used previously, especially if the subject leaves the initial AF point and that the other AF points are used to keep it in focus by means of tracking the subjecy.


2. Better, 14-bit RAW files.

About time. Sure, 12-bit RAW is nice, but 14-bit allows for more color gradients, which helps pulling the most out of your digital image file.


3. Dual memory card slot.

As a pro photographer, I can't stress the importance of backup, and while it's possible to do that on a computer, there are times when it's not. Having a dual memory card slot is a good way to have my RAW files doubled for safety. Or to shoot RAW and JPEG without having to sort the pictures out in the end, in case my client wants a quick JPEG for press release after the event I shot.


The rest of the K-3's features are pretty much a case of "very good, but not a game-changer for me".

For instance, the wi-fi tethered support is a nice feature to have, but it only works with some mobile phones and tablets, not with computers. I'm still waiting for an USB tethered shooting feature from Pentax for studio use, but it's not like I can't live without this feature.

However, the "simulated AA filter" is a clever way to go around having two separate cameras, one that's AA filterless and the other that has an AA filter. Which one to choose? Hmm... Now you can have both in one camera. Kudos to the Pentax/Ricoh design team.

I'm a little bit disappointed with the new 24 Mpix (bigger files, ugh...), as I would've preferred something around 18-20 Mpix, but I was expecting this 24 Mpix sensor to make it in the K-3 anyway, so it's not like it's gonna be much of an issue. And I'm sure a lot of people will be happy to have more resolution, so the Mpix jump isn't bad at all.

As long as the image quality is at least as good as with the 16 Mpix sensor from the K-5, I won't mind much buying new hard drives, LoL.

Overall, my feelings are that the K-3, while not groundbreaking, is a solid camera that's loaded with great features, and most important, that finally addresses Pentax's main issue with its DSLRs, which is their AF performance, especially on moving subjects. Now if Pentax can just offer improved controls on their video mode, their products will be as good as any Canon or Nikon products, while being smaller, more rugged and offering an extensive line of APS-C lenses.

Yeah, I know. It's not full-frame. I remember a few years ago, I wrote in the Pentax SLR talk dpreview forums that a Pentax FF camera wouldn't be available before 2013-2015. Looks like 2014-2015 might be the time when a FF Pentax camera finally hits the shelves. Even if Pentax releases a K-1 FF DSLR, I'm sure the K-3 will remain the most popular among enthusiast photographers, and some will even prefer it to its FF brother, thanks to its 1.5x crop ratio, very useful for wildlife shooters.

Looks like Ricoh is quite serious about its DSLR products. This new camera is an excellent step in the good direction, and most important, Ricoh/Pentax have been listening to Pentax users who asked for improved AF, 14-bit RAW files and dual card slot, features a flagship DSLR should and must have IMHO.

But for now, I'm okay with my K-5, so I'll wait a bit for the K-3's price to drop before committing to buying this new DSLR, which will require a new battery grip, and possibly some new HDD for those 24 Mpix 14-bit RAW files. That will give me plenty of time to see if the K-3 lives up to its promises as well.
Forum: Pentax News and Rumors 10-02-2013, 12:53 PM  
Promises, promises K3 24mp New tracking AF
Posted By tigrebleu
Replies: 406
Views: 68,764
Here's my two cents on the K-3 AF system rumor. BTW, I don't care about the K-3 being APS-C or FF, or being 16, 20 or 24 Mpix.

As long as the AF tracking can finally match that of a Nikon or Canon DSLR with similar price, I'll be fine. The possible, rumored new 36-point AF system seen on RiceHigh (yeah, I know, it's RH, so anything coming from there has to be taken with a grain of salt, but I'm sure Ricoh wants to improve this as much as we do) could give us just that: quicker AF-S and much more accurate AF-C with more options on where you want to focus, and with accurate, dynamic AFpoint-to-AFpoint tracking on top of that!

Add in an improved flash system with a much more accurate metering and a faster X-sync speed (1/180th can cause problem with freezing a moving subject when shooting in ambient light, so moving to 1/250th of a second would be meaningful improvement for me), and I'll be more than satisfied.

All this will be great news, provided it works as advertised, which has been Pentax's main issue in the past. I'm tired of the "workaround" solutions to Pentax's mirror slap issues on the K-7 (so many shots lost because of this), poor AF-C tracking and AF-S back focusing, and inaccurate flash metering when using the flash in a bounced position. They're just lame excuses to justify why the camera is not doing its job as it should.

I used the D300, D700, D800, D3X, D3, EOS 7D, EOS 5D Mk II and EOS 5D Mk III on various pro shootings (as a 2nd photographer, you have to use the material the 1st photog wants you to use, so the workflow stays the same). And with the exception of the lame AF on the 5D II when not using the center AF point, all these cameras worked as advertised, without the need for a "workaround solution". Nikon's recent troubles with the D600 (and pretty much its denial of the problem) has proven Pentax is not the only one to suffer from such problems. Nikon's "solution" to the D600 was to have the sensor cleaned, which doesn't solve the problem, as the dust and oil come from within the camera (the mirror box, actually), not outside.

So far, only Canon has always acknowledge such issues and worked to solve them. The only time they dropped the ball was with the 1D Mk III, and they learned their lesson from this (the hard way, for people switched to Nikon and its D3 mainly because of the AF issues with the 1D3).

Canon may not be very innovative (they're actually very conservative), but they understand how important recalling faulty products is for their business. Nikon used to think like that, but now, they will release some SB-910s instead of replacing or recalling faulty SB-900s. Seems the D600 will have a successor, the D610, which will "solve" the issue of dust on the sensor. You just need to buy a $2000 DSLR. Go tell that to the guys who paid the same amount of money for their D600 cameras, LoL. Yet they were able to recall the D800 DSLRs which had fault AF points to correct the problem. Hopefully, Ricoh will act more like Canon and less like Nikon (or the old Pentax) when such issues are discovered. I'm sure Ricoh wants to be taken seriously, and they will if they do their homeworks.

In the past, the only thing that kept me from moving to another brand were financial issues (I had to sell the D700 and 16-35mm F/4 I had bought to cover for major house repairs which wouldn't be covered by the insurance, as they still had some good value, something my old K-7 didn't).

Since then, I have been more into teaching photography then making shootings for a living, so the switch wasn't as important as it was before, especially since I bought an used K-5 for $500 (so much DR and so much improvement over the K-7 in low light).

But if the K-3 lives up to the expectations, I can frankly say I won't have any reason left to switch, and I'll stay with Pentax for good. If they don't come up with an AF system that can at least stand the comparison with Canon (fast, accurate) and Nikon (best tracking ever), I'll have to reconsider again, depending on how I'm making my living as a photographer (mainly teaching or shooting?)

But to be honest, I'd be more happy to see a fast (F/4 or F/2.8) DA* or WR ultra-wide lens announced.

Right now, we can only choose between the overpriced DA*16-50mm (overpriced regarding its optical quality, not its build quality), the good but slow (F/3.5-5.6) 18-55mm WR and the convenient but average and slow 18-135mm WR. None of these lenses are ultra-wides anyway, so it leaves me with few options when shooting wide in harsh weather: stick to the DA*50-135mm or use an ultra-wide lens with a plastic cover on the camera, which collects humidity that eventually can make it into the camera through the lens...

I want a DA12-24mm F/4 WR much more than I want a new K-3, I have to say. :D
Forum: Pentax News and Rumors 09-30-2013, 03:10 AM  
Pentax K3 with 40 MP via sensor shift
Posted By tigrebleu
Replies: 128
Views: 28,821
Using sensor shift to increase resolution through multiple shots isn't new. Hasselblad has a MF digital camera that can take six, 50 Mpix shots and combine them into a single 200 Mpix image by means of shifting its sensor with the help of piezo-electric actuators.

H4D-200MS

The only drawback is that the camera and subject as to be completely still during the shot. The advantages are 1) by shifting up, right, right, down, left and then left (or left, left, up, right, etc., whichever), each photosite can capture all four RGB color components (green is present, which can greatly reduce demosaicing artifacts, and 2) by stacking four images on top one another, noise can be reduced from the signal four times instead of just one. (Unless the noise isn't reduced at all, in which case it would add up with each picture.)

The problem with RGB (or RGBG, to be more accurate) Bayer matrix filters, is that a sensor with 20 million photosites doesn't record each of the 3 primary colors on each of its photosites. Instead, 25% of the photosites record the red color, 25% the blue color and 50% the green color. The missing info is then made up by the in-camera software or the RAW converter software the photographer is using, generating false color, demosaicing artifacts and such.

By moving the sensor six times, the sensor used in the H4D-200MS can record all primary color for each photosite, which results in a theorical resolution of 200 Mpix. Of course, the apparent detail isn't increased as much as a 200 Mpix Bayer matrix sensor would provide. But the colors are much more accurate, and artifacts are next to inexistent. Overall, the visual level of detail of that 200 Mpix picture compares to that a 60 Mpix sensor, but with much, much more accurate colors and much less annoying jaggies and other demosaicing artifacts. But this camera is a specialized product, and was design to answer the need of a very specific market (making photos of works of art and other historical artifacts).

(Just like the latest Sigma Foevon sensor (which is made up of 3 layers of 15+ Mpix that add up to 45+ Mpix) can't beat a 36 Mpix D800 in terms of details, it does provide increase detail, up to that of a 24 Mpix sensor, but more accurate colors, less artifacts and less issues with diffraction because of a too high pixel density. While the D800 36 Mpix roughly has the same pixel density has a D7000 16 Mpix, the 24 Mpix D7100 has a higher density then both the D800 and D7000, which leaves you closer to the limits of diffraction. As a result, diffraction can appear at wider apertures on the D7100, like F/8 instead of F/11. Diffraction reduces sharpness and the level of detail, so the higher sensor resolution can prove counter-productive if shooting at small apertures.)

If Ricoh plans to use such a device to increase resolution, the shift maybe won't provide each photosite with a signal for each primary color, but would at least allow to have two out of the three colors, like RGBG being shifted to GRGB for a RG-GR-BG-GB sampling. That would still require some demosaicing, so the gains wouldn't be as impressive as with a full RBG capture per photosite, both in terms of color accuracy and demosaicing artifacts. But it would allow to increase the level of detail capture by a decent margin at a lower cost.

Some will call this a useless gimmick, other will welcome this added resolution, even if it's limited to still subjects with tripod photography.

Now if a manufacturer can manage to get a one pixel shift in four directions on such a large, 50 Mpix sensor like the one in the Blad, I don't see why they couldn't do it on a roughly 5 times smaller APS-C sensor with 2.5 times less resolution. Doing the maths, that's about 33% more linear total resolution per mm to deal with. A bit more challenging, but nothing that can't be handled, I would assume. Especially considering the shift would only happen in one direction (20 Mpix to 40 Mpix) instead of four (50 Mpix to 200 Mpix).

The question isn't can they do it or not, it's more, how much does it cost to implement such a technology into a camera (in short, how much higher must we sell our camera to get this stuff in, and will the camera's price remain competitive if we do so).

And that is a question I can't answer. But maybe some knowledgeable people know more about industrial processes and how such a device can add to the price of a DSLR.
Forum: Pentax DSLR Discussion 06-19-2010, 10:55 PM  
The grass isn't always greener next door.
Posted By tigrebleu
Replies: 7
Views: 3,133
I've been considering moving to the 5D Mk II for its video capabilities for quite a while. I should've made the move some days ago, actually.

But two of the three video projects in developpement I was working on just went dead within the last 3 months. :(

So instead of selling all my Pentax gear and switching to the 5DII, I decided to either rent the body or have it lend to me a few times more before I made my move.

I already had the chance to work with it one time (in the studio only, though, but with awesome results), and I wanted to know more about the camera before committing into a full brand switch.

So a few days ago, I went on an event photography assignement with one of my friend's EOS 5DII with the 24-105mm F/4 IS L and the 580EX II.

The experience on photojournos-style event photography was quite different from the studio use. And a rather mixed one... :hmm:

The image quality is just incredible. We're talking leagues ahead of my K10D and K-7: much, much more dynamic range, much less noise and much better color accuracy. But this was quite expected from a FF sensor... a 21 Mpix FF sensor.

For instance, I used ISO 3200 for almost all of the interior photos, and the noise in these pictures is not more of a problem than with my K-7 at ISO 800-1600. That's a huge difference. By the way, all the photos were taken in RAW with high ISO noise reduction turned off, just like I do with my K-7, since I apply my own noise reduction "solution" in Capture One.

The colors also look very natural, with no tendency to emphasize the saturation of certain colors vs. others, and with just the right amount of saturation (the K-7 could use some improvement, here).

The dynamic range is also much more impressive, as expected. There is almost a full 2 stops of highlight information that can be recovered in the 5DII RAW files at times!

The viewfinder was also a joy to use, but I was expecting this from camera with a FF sensor. Nevermind, it was brighter and easier to use, and this put less strain on my eyes.

The flash system was also excellent and, most important, fast. The 580EXII was recycling faster, was going from its pre-flash to its main flash faster and it was more accurate. Too bad there's no pop-up flash on the 5DII: that's not a simple oversight, but rather a cheap mercantile process.

Overall metering is also quite reliable in all modes (spot, center-weighted and multi-segment), with a slight tendency to overexpose bright areas in certain situations (like most DSLRs anyways).

Also, the IS was at least as efficient as with my K-7 at equivalent ISO and focal length, if not better. Even better, the efficiency of the IS can be visualized in real time and before pressing the shutter release.

The lens was also excellent on most aspects, very sharp wide open, even at wide angle and with little to no CAs.

Finally, the AF was excellent in daylight.

But unfortunately for the 5D2, the list of pros ends here. :(

The AF performance in low light was... worse than the K-7 and probably a bit worse than the K10D!

Except for the center AF-point, all other AF-points wouldn't focus properly, resulting in AF hunting and lost opportunities. Again, I was expecting this, having heard about how the 5DII had a downgraded AF system to keep it well appart from the 1D series.

Well, Canon managed to do this just right... the 5DII AF performance is one of the worse I've experienced in the last 5 years (and I have used or tried the K10D, K100D and K-7, but also the D3X, D700, EOS 30D and EOS 7D during that period). :mad:

The body and lens combo is also quite heavy (especially with the 580EXII mounted on the body), but I guess it would just take some time for me to get used to it. The 5DII being a full frame, I was also expecting this, although I found the whole package a bit heavier than what I wished for. :(

The grip is a bit clumsy as well. I would really need the battery grip attached in order to have a comfortable hand position on this body, making the camera even heavier.

Although very sharp and quite useful with its wide-angle to moderate telephoto zoom range, the EF 24-105 IS has also cons. Distortion at the wide end is huge and the light fall-off is even worse. But many FF cameras have issues with WA lenses, so again, I was expecting this.

But the worse problem of the 5DII were the bad ergonomics and the lack of proper customization possibilities. Except for the AF-ON button which sits right in the good place, most buttons are difficult to reach and changing the settings can become difficult in certain situations, like changing the WB settings, for instance, which requires to move the index finger close to the viewfinder housing, making the grip uncomfortable at best, if not unsafe.

Changing the AF-point was less than intuitive, with all 3 customs selections resulting in the EV adjustment being disabled on the e-dials in Av mode, which I use 95% of the time in event photography. Canon should follow Pentax and Nikon's example here. :p

The e-dials are also not too well located on the body, the front one forcing me to remove the index finger from the shutter release (unlike with Nikon and Pentax bodies, again :p), and the back one being too low to use efficiently while holding the camera.

All this would probably improve over time as I would get used to the camera a bit more, but I found all the Nikon and Pentax DSLRs to be very ergonomic from the first moment I grabbed them, something I was never able to feel with any single Canon DSLR (although I could be luckier with the Rebel series).

And ergonomics are only a part of the issue. The custom menu is very short (read: limited) on the 5DII, something I was not expecting from a $2500 camera.

If Pentax can allow the user to program the function of e-dials in up to 5 different ways on each one of the 5 semi-automatic exposure modes (P, Av, Tv, Sv, TAv) on a $800 camera (K-7), why can't Canon offer at least half of that customization potential on a $2500 camera? I'm sure the K-x has more custom functions than the 5DII! :lol:

After spending half an hour changing the custom setting on the 5DII, I still I couldn't find a way to taylor the camera to my needs, something I can do easily on the K-7 (and that I could do almost as easily on the Nikon D300, D700 and D3X). :(

The Canon EOS 5DII is an excellent camera with pristine image quality. Its video quality and controls rivals most prosumer vidcams at a fraction of the price, and with the bonus of interchangeable lens and shallow DOF possibilities on top of that, although at the cost of AF and form factor. :hmm:

But although excellent in the studio where it shines like a shooting star (thanks in part to tethered shooting possibilities), the 5DII is not much of an action camera. With the exception of image quality, my K-7 suits that role much better.

Too bad, because the high ISO performance of the 5DII, its dynamic range and its color accuracy beat those of the K-7 hands down. But all these are the result of the excellent full frame sensor and Digic processor used in the 5DII, which push the camera ahead of any other APS-C sensor DSLR, including the K-7.

If I could put the Canon 21 Mpix FF CMOS sensor into my K-7, I'd do it anytime! I'd also switch the flash system to Nikon's excellent i-TTL as well. With the lenses and ergonomics of the K-7, the image quality of a 5DII and the flash accuracy of a Nikon DSLR, I'd have the best camera out there! ;)

The end result is that I've decided to put a halt on my project to replace my K-7 by a 5DII. With many new Canon, Nikon and Pentax DSLRs on their way, I'll wait by the end of 2010 before committing more money into a new body. Until then, I'll invest into new battery-powered studio strobes instead.

If it wasn't for the 5DII excellent video quality (and more important: full manual controls), I wouldn't never have thought about switching to Canon. (I'd rather switch to Nikon anyways, since they make better wide and ultrawide-angle zoom lenses than Canon, IMHO.)

But for now, I'm sticking to my K-7. :)

The moral of the story: the grass isn't always greener next door. :o
Forum: Pentax News and Rumors 05-12-2010, 04:45 PM  
Maybe HD camcorder from pentax?
Posted By tigrebleu
Replies: 28
Views: 6,435
Not impossible, but unlikely.

Building a video camera from scratch is not that easy. And people would expect an interchangeable video camera from Pentax to offer constant AF (which requires contrast-detection AF on the sensor), continuous full HD video, and high quality codec like other manufacturers offer. Now all this means a LOT of electronics, something Hoya is not really specialized in.

Sony, Canon and Panasonic already have EXTENDED experience with video cameras (including HD video), so they already have the electronics basis available and only need to improve on these basis.

On the other way, Pentax, Sigma, Fujifilm, Olympus and Nikon have little or no experience in video cameras. For this reason, they'll need at least 5 years and lots of fundings to catch up with Sony, Canon and Pana, provided they try it on thier own. But if they can strike a partnership with a electronics company that has some experience in video cameras (JVC, Hitachi, Samsung, etc.), they could catch up much faster.

Anyway, in the future, the still camera and the video camera WILL merge into one hybrid camera (except for all but the higher end professional models).

Point & shoot cameras will become multi-function tools: MP3/video player, still/video camera, portable video game system, mobile vidphone/wireless internet browser, etc. The limits are endless. This evolution has already begun.

Photoshop CS7 for mobile devices on a wacom-enabled digicam/mobile phone, anyone?

It's only a matter of time and nothing will stop this. The only question remaining is "how much time before it happens?"

Pentax will have to follow the trend when this happens, or they'll disappear.
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