Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-10-2010, 02:14 AM   #46
Inactive Account




Join Date: Nov 2010
Posts: 29
QuoteOriginally posted by falconeye Quote
And as has been said, the technological potential of sensor shift is far superior and the negative impact on optical performance is minimal too. Sooner or later, Canikon will have to go sensor shift. Of course, only after Sony and/or Pentax SR performance has started to run circles around them. Which will happen sooner or later. But not immediately.
Interesting. Why is this potential far superior?

12-10-2010, 04:06 AM   #47
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
QuoteOriginally posted by Pompous Moronox Quote
Interesting. Why is this potential far superior?
Mostly, because the moving mass can be kept smaller.
Currently, the Pentax SR isn't that lightweight actually. The SR unit includes a PCB, filter assembly and metal blades. But I imagine it could be made lighter or the motors could be made stronger.

The gyros are the same and I think their precision will increase over time. It is then a question of how quick and how precisely the counter movement can be driven. For sensor-based, there is no obvious limitation for any of the two requirements.

There is a limit though when the rotation starts to distort the image (toward the image edges). In theory, lens-based could counteract this distortion. But in practise, it doesn't happen and the distortions are neglegible ATM. BTW, this limit goes away if you allow the sensor to tilt as well.

Eventually, the lens method is a trade-off between the optical degradation w/o lens shift and the degradation with, e.g., how many lenses to shift/tilt etc. This results in a limit for the correction amplitude. Or the max exposure time which still works for any given lens. The sensor-shift is limited by the image circle only and mild cropping would be ok for long stabilized exposures, I guess. Esp. as tele lenses have large image circles.

In summary,

The lens-shift method is challenged by two requirements in conflict: the correction amplitude and precision shall increase. And the optical resolution shall increase for the higher MP cameras. At some point, this gets very expensive if not impossible.



EDIT:

Let me add an observation which I don't know how relevant it is. The IS systems (both sensor and lens) require close to 1 sec calibration before they become effective. I assume (I have no hard facts) that the system does a Fourrier analysis of the shake and applies a required negative time shift to the response signal in order to compensate for the latency in the system. I.e., it predicts a future movement. You can see this: don't shake but deliberately move your camera: You'll see a significant delay in the reaction. In order to further improve the performance, it would probably be necessary to reduce the system response latency too. I imagine (again no hard facts) that the response latency for a lens-based system is more challenging to reduce than that for an embedded sensor based one. I.e., I wonder how inertial a lens-based IS system really is.

Last edited by falconeye; 12-10-2010 at 07:35 AM.
12-10-2010, 05:28 AM   #48
Forum Member




Join Date: Oct 2010
Location: des veoux rd west, kennedy town
Photos: Gallery | Albums
Posts: 51
I can only say (using fixed shorter lenses ) that base on how i handle a camera, the SR- "On" if speed goes below 80 and SR is Turn-OFF if shutter speed reach a hundredth of a second and above. And to avoid using NR in computer as noise ninja...etc... have to setup the camera auto-ISO not more than ISO 5000. ( Its really annoying and tiry to always clean pictures every after the shoots.) Only way to avoid cleaning is , Using K-5's (with its remarkable DR) ISO that you think is needn't have NR usage. And that SR also helps more in some situation where in the playing fields is more than just of an accessory.


Pictures by buaobao - Photobucket

...buaobao
12-10-2010, 05:32 AM   #49
Loyal Site Supporter




Join Date: Mar 2009
Location: Southern Indiana
Photos: Gallery
Posts: 14,957
One other thing about in lens image stabilization is it gives one more thing to wear out in lenses. I have had a couple of friends who have had Canon lenses experience some kind of failure with its IS. Unfortunately, they were both out of warranty and they ended up eating the cost. Kind of changes the saying "bodies change, but lenses are forever."

12-10-2010, 05:51 AM   #50
Pentaxian
Aegon's Avatar

Join Date: Jan 2008
Location: Portland, OR
Posts: 1,410
I'm just jumping in and haven't read all of the previous 49 comments, but here's another advantage to in-body SR:
You can use it on a wide selection of fast primes.

Compare to the Nikon VR lineup:
f/2.0: 200mm
f/2.8: 70-200mm, 105mm, 300mm, 400mm
f/4.0: 16-35mm, 200-400mm, 500mm, 600mm

All other Nikon VR lens are variable aperture, slow lenses. The lenses listed above mostly cost big bucks. With a Pentax you can get stabilization on your 50/1.4 and 85/1.4. That's a big advantage.
12-10-2010, 06:49 AM   #51
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
in a nutshell no, it isn't worth it.

I find Nikon's VR to be every bit as good ( and in some ways better) in comparison to Pentax's in body IS. Granted, there are no VR lenses faster than f/2 and Canon is the same in that regard. With Pentax and Sony having the edge over non-integral IS systems, you can get a 50 year old M42 50mm f/1.4 takumar and have it image stabilized which is a definite attraction of the pentax system. but to me that advantage alone wouldn't be enough to make me switch to another system. But then again I really don't have to switch I already own several Canon,Nikon and Leica camera bodies in addition to my pentax hardware. If I want to do really low light work, I just fetch my Nikon D3s and noct nikkor 58mm f/1.2 and snap away.

Though switching to pentax so you can use the FA31mm f/1.8 Limited is perfectly understandable....

Though Falk as usual, makes some very interesting points about the future of IS systems..

Last edited by Digitalis; 12-10-2010 at 07:05 AM.
12-10-2010, 07:04 AM   #52
Veteran Member




Join Date: Dec 2008
Location: Iowa
Photos: Gallery | Albums
Posts: 1,368
QuoteOriginally posted by Digitalis Quote
I just fetch my Nikon D3s and noct nikkor 58mm f/1.2 and snap away.
Lol, kind of an unlikely option don't you think? What would that combo cost now to buy, $8000?

Although I do understand the point you were making.
12-10-2010, 01:04 PM   #53
Veteran Member




Join Date: Sep 2007
Photos: Gallery
Posts: 975
re: film-days vs digital era sr (nikon/canon being the "dinosaur" film type, pentax & friends being the elegant solution in case of digital): not sure if many people remember, but there was a company named contax some time ago, everybody thought they were crazy (and most everybody loved them). anyway, they actually released a camera with an internal (auto) focusing system. yes, they were moving the film plane, if i'm not mistaking, along with film canister, film transport system and all that. obviously, the mass was huge by comparison (or was it?), and the movement wasn't as high frequency or as fast as sr needs to be. but still, it makes one think..

how hard would it be for pentax to come up with something like this in the digital era? i'm thinking, not full af, just some nice adjustment/af range (which would work with any lens: just find a ballpark focus, like "near" "far" "infinity-far", let the camera finetune. make it quicker than classical af systems too (falk was talking something about quick linear motors and such, some time ago?)

12-10-2010, 01:07 PM   #54
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,168
QuoteOriginally posted by nanok Quote
re: film-days vs digital era sr (nikon/canon being the "dinosaur" film type, pentax & friends being the elegant solution in case of digital): not sure if many people remember, but there was a company named contax some time ago, everybody thought they were crazy (and most everybody loved them). anyway, they actually released a camera with an internal (auto) focusing system. yes, they were moving the film plane, if i'm not mistaking, along with film canister, film transport system and all that. obviously, the mass was huge by comparison (or was it?), and the movement wasn't as high frequency or as fast as sr needs to be. but still, it makes one think..

how hard would it be for pentax to come up with something like this in the digital era? i'm thinking, not full af, just some nice adjustment/af range (which would work with any lens: just find a ballpark focus, like "near" "far" "infinity-far", let the camera finetune. make it quicker than classical af systems too (falk was talking something about quick linear motors and such, some time ago?)
I remember those Contax cameras well don't know how well they worked but always wanted one
it would be neat to apply the concept here (I'm sure some of the concept is what makes sr work)
12-10-2010, 04:00 PM   #55
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,043
QuoteOriginally posted by eddie1960 Quote
I remember those Contax cameras well don't know how well they worked but always wanted one
it would be neat to apply the concept here (I'm sure some of the concept is what makes sr work)
The AF was a kludge and the camera was a horse. The only thing it had going for it was that it used Contax lenses.
12-10-2010, 04:50 PM   #56
Pentaxian
Ratmagiclady's Avatar

Join Date: Nov 2008
Location: GA
Photos: Gallery | Albums
Posts: 13,464
QuoteOriginally posted by Digitalis Quote
in a nutshell no, it isn't worth it.
I'd have to say that's just not the case for low-light work, (The OP's concern) especially on a street photo budget, and for those purposes, especially in absence of fast stabilized lenses. VR you don't have just doesn't help at all, even if it were marginally 'better' for the purpose.


QuoteQuote:
I find Nikon's VR to be every bit as good ( and in some ways better) in comparison to Pentax's in body IS. Granted, there are no VR lenses faster than f/2 and Canon is the same in that regard. With Pentax and Sony having the edge over non-integral IS systems, you can get a 50 year old M42 50mm f/1.4 takumar and have it image stabilized which is a definite attraction of the pentax system. but to me that advantage alone wouldn't be enough to make me switch to another system. But then again I really don't have to switch I already own several Canon,Nikon and Leica camera bodies in addition to my pentax hardware. If I want to do really low light work, I just fetch my Nikon D3s and noct nikkor 58mm f/1.2 and snap away.
That'd be one of those 'livable options' for me. Beastly. (which doesn't bother me as much as some. ) Costs more than my disposable income for the past *decades,* just to have the one lens, and still is unstabilized, but I wouldn't cry. For that price of admission you get pretty sick high-ISO and I imagine a viewfinder that says, 'Did someone say we needed autofocus at some point?' Still doesn't really add up to 'superior to K-5,' in a lot of ways, particularly in comparing SR systems and all.

QuoteQuote:
Though switching to pentax so you can use the FA31mm f/1.8 Limited is perfectly understandable....
Well, I hope to require some understanding in that regard, one day, not that a switch is needed.
12-11-2010, 02:11 AM   #57
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by Ratmagiclady Quote
I'd have to say that's just not the case for low-light work, (The OP's concern) especially on a street photo budget, and for those purposes, especially in absence of fast stabilized lenses. VR you don't have just doesn't help at all, even if it were marginally 'better' for the purpose
Okay I'll clarify my point, even with Pentax's in body IS you need to have good technique,no? I have seen plenty of examples where people have just let technology to compensate for technique that is just plain sloppy. I can hand hold my Nikon D3s at 1/20th without significant difficulty and still achieve more than acceptable results for 13X19 inch print. Though for serious street work, I use a Leica which is categorically not an option for a photographer of limited income.

With street photography is isn't just about which camera has the best High ISO or which camera has IS or not. If you look at street photography in the 90's people did very well without such things because they learned to use their environment to assist with stabilising themselves when light levels sank. I still use many of the bracing techniques commonly used for cameras without IS and in some cases I simply turn off IS in my K10 or K7. It's takes too long to get it's sh*t together and in street photography a critical moment can pass you by in a fraction of a second.

the reasons why I chose the D3s:
1] the D3s has a HUGE viewfinder it makes details, and facial expression in a scene much clearer.
2] High ISO on the D3s has finely grained noise which at it's highest settings has grain that is reminiscent of Kodak TRi-X in Rodinal.
3] the Noct Nikkor 58mm f/1.2 is a real blast to use on the Nikon D3s, bright viewfinder, manual focusing can be a bit of a pain - but I like a challenge. And it produces nice bokeh, though some people really hate how it renders OOF highlights, I don't care - it's the Noct-Nikkor signature.

OT:
QuoteOriginally posted by eddie1960 Quote
I remember those Contax cameras well don't know how well they worked but always wanted one it would be neat to apply the concept here (I'm sure some of the concept is what makes sr work)

I always loved the construction of their camera bodies, the lines of the cameras themselves. you don't see that these days, Canon are going all smoothly shaped, Nikon are softening some of the harder edges with curves and Pentax is going for a more angular appearance. Sony are (thankfully) keeping the boxier appearance of the Minolta cameras( I regret never buying a Minolta 7D, I actually really liked that camera) and Leica is sticking to a camera body design that was developed in the 1950s.

I have a few contax 35mm cameras in my collection, I also have a Contax 645 tucked away. I used it with a Leaf 22MP back several years ago while I was in new zealand - it was great fun.The AF was as slow as the glaciers I was photographing though.
12-11-2010, 02:42 AM   #58
Veteran Member
philippe's Avatar

Join Date: Apr 2008
Location: Flanders Fields
Posts: 463
QuoteOriginally posted by Wheatfield Quote
There is actually more to this than just shake reduction, though I think the advantage goes to Pentax and it's in body SR because of the increase in lenses that have it available (anything that will mount to the camera).
Night street photography tends to involve street lights and the like in the picture. This can be a real problem, as flare rears it's ugly head.
Pentax lens coatings are still quite a bit ahead of Nikon in this regard, it is very difficult to ruin a shot with flare with a Pentax prime lens, and I rather imagine that Pentax zooms are well ahead of Nikon in this regard as well.
Pentax cameras also tend to be more compact than Nikons, which can be a bonus if discretion is required. The K5 is somewhat smaller than the D7000, though I don't know if it's enough smaller to matter.
Talking about lens flare, I am a little worried about the kind of conditions I have to shoot in like the one you seen in the attached photo. More and more, candle light is what I am asked to shoot in (if I want it or not)...

P.S. This posting might be in the wrong tread, but I taught the remark by Wheatfield was an occasion...

Last edited by philippe; 12-09-2011 at 09:35 AM.
12-11-2010, 06:29 AM   #59
Loyal Site Supporter




Join Date: Mar 2009
Location: Southern Indiana
Photos: Gallery
Posts: 14,957
This is a photo taken with my K7 at iso 1600, 1/8 second, f4 with the DA 35 limited. Certain of Pentax lenses hold up really well to flare, mostly the primes. The DA * zooms do flare quite a bit more.

12-11-2010, 07:26 AM   #60
Site Supporter
Douglas_of_Sweden's Avatar

Join Date: Apr 2008
Location: Stockholm
Photos: Gallery
Posts: 3,347
QuoteOriginally posted by philippe Quote
Talking about lens flare, I am a little worried about the kind of conditions I have to shoot in like the one you seen in the attached photo. More and more, candle light is what I am asked to shoot in (if I want it or not)...

P.S. This posting might be in the wrong tread, but I taught the remark by Wheatfield was an occasion...
Oh, the wonderfull stars of the DA15ltd...
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, d700, dslr, k-5, k-5 ii, k-5 iis, k5, light, nikon, pentax k-5, results, time
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax Low Light Focus indy1984 Pentax DSLR Discussion 15 02-17-2010 09:42 AM
Pentax AF vs Canon AF vs Nikon AF (In low light contitions) karq Pentax DSLR Discussion 110 01-13-2009 04:49 AM
Low light shooting capabilities GX20 at low ISO cabstar Pentax DSLR Discussion 1 12-04-2008 11:01 AM
Pentax can't do action or low light... mcleoud151 Post Your Photos! 33 10-02-2008 04:58 PM
What is the Best Low Light Pentax 50 ? daacon Pentax SLR Lens Discussion 18 01-06-2008 02:15 PM



All times are GMT -7. The time now is 10:57 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top