Pentax K-5 better than any Canon?

srichards said:
Exposure blending is fine for still subjects but for fast moving one eg speed boat racing on a sunny day then it is not so good. I'd rather have a camera I can hit the shutter button once and get as close as possible to the scene in front of me than have to spend a while in photoshop diddling around. Some people enjoy the diddling process. I don't :)

Also if you have better dynamic range your camera will last longer as you won't have to bracket as much ;)
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But surely you need to "diddle" in Photoshop anyway to take advantage of the dynamic range, even with one exposure?

This thread is quite entertaining, as I'm not even sure we've got to the thorny issue of diffraction on a crop sensor yet :lol:
 
Oggy said:
One of the problems with Pentax in general is the limited range of lenses. More than you could shake a stick at up to 100mm, a few 100-300mm and none greater than 300mm. I also believe the AF does not get near the 7D in speed or sophistication.
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While the Pentax range may stop at 300mm, I'm pretty certain you can get the longer Sigmas in Pentax fit if you need longer.
 
Musicman said:
TBH, while wide DR is a useful thing to have, people successfully shot slide film with only around 6 stops of latitude for many, many years. I still do.

Kodachrome was relatively generous and went to 8 stops. Fuji Velvia 50 will get you about 3.5 to 4 stops of usable range; you treat its exposure with kid gloves, but get it right and the results are worth it.
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I didn't know that Velvia only has about 4 stops. Incredible what it can do with them! This bit of info made me glad I read this blatant trolling thread so cheers! :)
 
Musicman said:
looked at another way, the Canon S95 would win hands down versus with the K5 for something you could slip into your pocket and have with you all the time for when a great opportunity for a picture arises. ;)
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Not so daft. ;)

I have my Pentax for things which aren't moving and aren't too far away. It takes a very nice picture with lots of colour and contrast and not much noise. For something whistling past me at 400MPH, I have the 7D. :)
 
DaydreamJay said:
Sorry, I always sound stroppy in writing, probably because I'm from Yorkshire.

ND grads are great when the horizon is level...
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And softly graduated ND's are great when the horizon isn't.

ND grads IMO are very useful, almost essential for landscape shooting.

Another topic though.
 
manualfocus-g said:
No need for the stroppiness, my reply had a winky ;) To answer your question though, I just use an ND grad filter. Although the 5D has more than enough dynamic range anyway.

As previously stated the K-5 is a great camera, but it won't tempt me away from the lovely full frame viewfinder, sensor and lens compatibility of my 5D. Depth of field at f1.2 on ff is incredible :cool:
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Surely the DoF at equal apertures is the same regardless of the sensor size? AFAIK DoF is not a function of sensor size. With different sized formats you change position to frame the shot and possibly use different focal length lenses and these things affect how you take the shot and how the image is presented and confuse the issue and create the illusion of less DoF with full frame but in reality (again, AFAIK) the actual DoF is the same for all sensor sizes if all other factors are equal.

This is something that you can test for yourself if you have cameras with different sensor sizes. A few minutes testing should show you that DoF is not affected by sensor size as such and if you think about it that's the way it should be.

Or, as Bob Atkins says...

"If you use the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL"
 
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woof woof said:
Or, as Bob Atkins says...

"If you use the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL"
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This is true, but if you are shooting with a FF camera you may as well take a few steps forward and fill the frame a bit more
 
As I said... you take the shot differently.

There seems to be a misconception that FF gives shallower DoF and we see this repeated so many times that I just thought that it was worth saying, politely, that it simply isn't strictly true.
 
woof woof said:
Surely the DoF at equal apertures is the same regardless of the sensor size? AFAIK DoF is not a function of sensor size.
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Here we go again.... try taking the same picture on 6x6 and an m4/3 camera tell me that.

Bob Atkins is right within the precise terms of his example, but the bit you're missing from your equation is that the DoF is different for *the same angle of view*. You'd have to use a shorter focal length lens on the m4/3 body to achieve the same AoV. Or you'd have to step back from the subject. In either case, you're reducing the magnification of the subject.

Since depth of field is a function of magnification of the subject and the aperture of the taking lens in combination with each other (greater magnification reduces the depth of focus which is why telephoto lenses exhibit more 'blur') reducing the magnification with a wider lens increases the depth of focus when the aperture is fixed - more stuff is in focus on a smaller format if you're taking the same picture.

Go play and see for yourself

www.dofmaster.com/dofjs.html
 
This is a very interesting discussion and thank you all for the info provided.
 
Musicman said:
Here we go again.... [/url]
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Deep sigh... Yup. Here we go again... :help: I almost didn't post as I just knew what would happen :)

Of course if you change things (which affect DoF) you'll get a different result. That should be obvious.

Anyway, back to the point. DoF is not affected by format size. That's what I posted and that's what I meant. It's a fact. I thought it was worth mentioning just to clarify things as we see it said that it is time after time after time and in my innocents I thought that mentioning that it isn't might cause some to think and might help some to a better understanding of our hobby. Reading up on it is interesting if rather confusing at times.

As it can be confusing I'll be clear. Format size (by itself) does not affect DoF. You have to change other things too.

I hope that someone somewhere found that interesting or thought provoking :)
 
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DaydreamJay said:
I agree but Ansel Adams went to great lengths to get an extra stop out of his workflow.

I think DR is very important especially as I hate the look of the majority of HDR shots out there done with bracketing.
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There's a difference between exposure blending and HDR.
http://www.flickr.com/photos/sundustphotos/5682813037/in/set-72157625791163035
That's a manual blend of three exposures (you can see down the right hand side where I've moved each exposure slightly to align everything and forgot to crop afterwards). Very different to HDR style photos but does essentially the same job, just without tone mapping.
 
woof woof said:
AFAIK DoF is not a function of sensor size.
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Bizarrely, yes it is...

Plug any value of lens, subject distance and aperture into this: http://www.dofmaster.com/dofjs.html and just change the sensor by changing cameras. You'll see DoF change.

What you have with different sized sensors is different Circles of Confusion. The larger the sensor, the larger the CoC hence the bigger the depth of field everything else being equal.
 
DaydreamJay said:
ND grads in theory are virtually redundant on a K-5.
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Why?
 
arad85 said:
Bizarrely, yes it is...

Plug any value of lens, subject distance and aperture into this: http://www.dofmaster.com/dofjs.html and just change the sensor by changing cameras. You'll see DoF change.

What you have with different sized sensors is different Circles of Confusion. The larger the sensor, the larger the CoC hence the bigger the depth of field everything else being equal.
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No. I don't agree and here's why...

CoC doesn't care about the size of the film or sensor and why should it? What it does care about is what can be resolved but that in itself is nothing to do with film or sensor size as such. With digital the CoC will be related to pixel size but that's nothing to do with the actual size of the sensor.

To quote uncle Bob again...

"...the circle of confusion value must be larger than the smallest element the film or digital sensor can resolve. For example, the pixels on the 10D are about 7.4 microns square, so the use of a circle of confusion value of 18.45 microns is reasonable. Film can resolve detail down to less than 5 microns, so the film numbers are good too, For reference 1 micron is 1/1000000 meter or 1/1000 mm."

Neither DoF or CoC are affected by film or image size in itself.

I agree that in practice, in the real world, DoF appears to be affected by things that in reality don't actually really affect it but I think that it's a good idea to understand what's going on, why things appear to be and what really changes or only appears to change what :)
 
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Alan Clogwyn said:
Because the Dyamic range is so wide it doesn't struggle with blowing skies out I guess?
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There's not a camera in earth with that good a dynamic range!

If there is I'll buy one today!
 
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woof woof said:
No. I don't agree and here's why...
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No, I don't agree and here's why...

When you view an image you are taking the frame the image was captured on and expanding it to a certain size. The larger the sensor, the less you have to expand it by to reach the same size. Consequently, the smaller the sensor, the smaller the CoC is before you notice its effect when you are viewing the picture.

It is precisely this rule that allows images that are otherwise not sharp to look sharp when viewed on a web site at 800 x 600.

CoC is NOT related to the size of the pixels themselves, it's related to the resolving power of the human eye and when we perceive things to be out of focus.
 
Wow!
After reading this thread it seems I am deluding myself and should immediately sell my D700 and lens's and buy a pentax K5......I also suppose I shouldn't be using 50mm lens's for portraiture either :bonk::exit:
 
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ironicall said:
Wow!
After reading this thread it seems I am deluding myself and should immediately sell my D700 and lens's and buy a pentax K5......I also suppose I shouldn't be using 50mm lens's for portraiture either :bonk::exit:
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Do I detect a faint whiff of sarcasm?
Lol
 
photon said:
Very clean shadow recovery from the Pentax in the -4 and -5 stop examples. I haven't had a chance to try a recent Pentax, but the early bodies had metering which always sought to preserve the highlights, requiring more post processing than was perhaps necessary.

I should add that the example scene isn't one to produce a blown sky.
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May be, but the 100% crops look all blurred compared to the 5D2... All cameras have their strengths and weaknesses...
 
arad85 said:
May be, but the 100% crops look all blurred compared to the 5D2... All cameras have their strengths and weaknesses...
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If the original shots were printed at A3, I estimate the 100% crop samples would be about 2 inches tall. Resizing the the image to 50% to give that dimension, the Canon's shadow noise is still apparent but any discernible difference in detail is debatable. I can't vouch for the accuracy, but the greens from the Pentax are more attractive.
 
arad85 said:
CoC is NOT related to the size of the pixels themselves,
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Sensors with pixels, film, dots on a page or on a screen, it doesn't matter.

Just think about how images are formed and you should see that what can be said to be sharp is related to resolution... if you look closely enough.

As Bob says... "...the circle of confusion value must be larger than the smallest element the film or digital sensor can resolve. For example, the pixels on the 10D are about 7.4 microns square, so the use of a circle of confusion value of 18.45 microns is reasonable. Film can resolve detail down to less than 5 microns, so the film numbers are good too, For reference 1 micron is 1/1000000 meter or 1/1000 mm."

And to reapeat a bit of that... "...the circle of confusion value must be larger than the smallest element the film or digital sensor can resolve."

And remember how we got here?

Bob said... "If you use the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL"

To quote further...

"• For an equivalent field of view, a Canon APS-C crop sensor camera has at least 1.6x MORE depth of field that a 35mm full frame camera would have - when the focus distance is significantly less then the hyperfocal distance (but the 35mm format needs a lens with 1.6x the focal length to give the same view).
• Using the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body, the a Canon APS-C crop sensor camera image has 1.6x LESS depth of field than the 35mm image would have (but they would be different images of course since the field of view would be different)
• If you use the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL
• If you use the same lens on a Canon APS-C crop sensor camera and a 35mm full frame body, then shoot from different distances so that the view is the same, the Canon APS-C crop sensor camera image will have 1.6x MORE DOF then the full frame image."

You have to read that carefully... :) but you should see that in the cases when DoF is different it's because something else also changed. In point 1 he changed the lens, in point 2 the FoV is different, point 3 is point 2 with the middle cut out and in point 4 he changes position.

All APS-C is is the middle cut from a FF image.

I believe that DoF is not decided by sensor or film size but the sensor of film size does lead us to make further and different choices... but I believe that that's a different thing.

That's my last post on this subject as it's up to each of us to decide what works for us.
 
woof woof said:
I believe that DoF is not decided by sensor or film size but the sensor of film size does lead us to make further and different choices... but I believe that that's a different thing.
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Well, yes, you have to make some different choices to avoid cutting Aunt Mildred's head off when you stand in the same position to take a picture of her with a 50mm lens on an m4/3 body instead of a 35mm film body and you're hell bent on preserving the DoF to the exclusion of everything else. :D
 
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woof woof said:
in point 2 the FoV is different, point 3 is point 2 with the middle cut out
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Just re-read that for a second. What you are doing is taking a crop of the centre of an image. Merely by doing that, you are changing the DoF (point 2 and 3 differ over the DoF). You haven't even retaken the picture, all you've done is cut a bit out (which is effectively changing the sensor size). Checkmate I'd say ;)
 
arad85 said:
Merely by doing that, you are changing the DoF (point 2 and 3 differ over the DoF).
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Well, [relatively] not if you then print your cropped version at 6x4 instead of 9x6 for the full frame version :)
 
DaydreamJay said:
No. You said you were wanting to buy a camera where ND grads were virtually redundant.
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So you are telling me that a k5 can perfectly expose a landscape foreground and also the sky in a very bright scene, so much so you see all the fine shadows and detail in both on a very bright day? A shot which contains the same dynamic range as using an ND8 for the same scene??

No chance in hell!!
 
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I'm fairly sure it will have a good go at it Jim. If it's sunny tomorrow I'll take a few shots and post the RAW files on here for you to take a look at.
 
Jay seriously, have you used ND8s? If the k5 can do that I'll not only eat my words, but chop all my Canon gear in for a K5 and lenses, as I'm sure all Nikon, Sony, Fuji etc etc owners would too!
 
ND8 is a three stop filter isn't it Jim? I think I had a Cokin one for a while but returned it due to a magenta colour cast.
 
Yeah it's slightly over 3 stops.
 
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