The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

Mp, sensorsize and shooting hand held - S2 vs D?x

H

HCHeyerdahl

Guest
As I understand, with more pixels, the more dificult it is to shoot handheld (and get sharp pictures).

Now, does this also depend on sensor size?
Will a say 37mp Nikon D?x be more or less difficult to shoot hand held then a leica S2?

Also, I wounder if the current 37 mp of the S2 may be at some kind of sweet spot regarding hand held shooting, and that if an eventual S3 has say 48mp one would more or less loose the current ability to use it as s grab and shoot?


Chris
 

GrahamWelland

Subscriber & Workshop Member
I'd say it depends less on sensor size than it does on sensor pitch.

The smaller the sensor pitch & associated high resolution, the more likely you are to resolve a slight movement into visible blur. When the sensor pitch is larger, the same slight absolute movement of the lens will resolve into a lower resolution which may mask the visibility of the slight blur. For example, if the movement of the lens resolved into say 10um on the sensor, with a 5um pitch you would capture that movement across 2 pixels whilst with an 8um sensor pitch you might only capture that 'blur' in a single pixel and hence not see it as anything other than sharp.

Put another way, when I shot handheld with a D3s vs D3x, I might get away with images that would appear sharper from the D3s vs the D3x under the same circumstances. Down sample the D3x image to the same resolution as the D3s and you'd see basically a similar level of sharpness / lack of blur.
 

coulombic

New member
Your ground sample density is agnostic of your sensor size. It's based purely around the pixel element size, distance to subject, and focal length. To be more specific, you can determine your effective sample resolution with the following equation:

((sensor dimension)/(number of pixels in that dimension) * distance to subject)/focal length.

*All measurements in meters.

This will give you your ground sample density. Knowing this, you can determine how quickly your shutter must actuate to prevent any pixel shifting. This is an incomplete description of the problem, as I am refraining from approximating a human's resting minutes-of-arc ((theta) = s/r, but as it would be varying, it would be a partial-diff). Instead of approximating a partial-diff, we can simply plug-and-chug numbers of assumed human motion velocities. Multiply the shutter interval by your approximated motion. If this number is greater than your GSD, your image will not be critically sharp. It's that easy.
 
Last edited:

dick

New member
Your ground sample density is agnostic of your sensor size. It's based purely around the pixel element size, distance to subject, and focal length. To be more specific, you can determine your effective sample resolution with the following equation:

((sensor dimension)/(number of pixels in that dimension) * distance to subject)/focal length.

*All measurements in meters.

This will give you your ground sample density. Knowing this, you can determine how quickly your shutter must actuate to prevent any pixel shifting. This is an incomplete description of the problem, as I am refraining from approximating a human's resting minutes-of-arc ((theta) = s/r, but as it would be varying, it would be a partial-diff). Instead of approximating a partial-diff, we can simply plug-and-chug numbers of assumed human motion velocities. Multiply the shutter interval by your approximated motion. If this number is greater than your GSD, your image will not be critically sharp. It's that easy.
This is what we call disc of confusion? or square of confusion if you are talking rectangular?

Camera-shake blur depends on:

shutter speed, to the camera's ability to work well at high ISO is a factor.

the ergonomics of the camera

mirror vibration

inertia of the camera/lens/grip combination...

a long heavy lens is more stable, and I could shoot my non-telephoto Novoflex 640mm with shoudler grip at 1/125th (lying flat as you would using a rifle)
 

coulombic

New member
This is what we call disc of confusion? or square of confusion if you are talking rectangular?

Camera-shake blur depends on:

shutter speed, to the camera's ability to work well at high ISO is a factor.

the ergonomics of the camera

mirror vibration

inertia of the camera/lens/grip combination...

a long heavy lens is more stable, and I could shoot my non-telephoto Novoflex 640mm with shoudler grip at 1/125th (lying flat as you would using a rifle)
No, I'm not talking about the Circle of Confusion (CoC), or Airy Disks. I'm speaking very specifically about ground sample distance (GSD). With this calculation, each pixel is representative of specific units of distance. Knowing the distance each pixel represents, you can determine how still you need to hold the camera before pixel-shifting occurs. This has nothing to do with the CoC, DoF, or the resolution between Airy Disks (diffraction).
 

dick

New member
No, I'm not talking about the Circle of Confusion (CoC), or Airy Disks. I'm speaking very specifically about ground sample distance (GSD). With this calculation, each pixel is representative of specific units of distance. Knowing the distance each pixel represents, you can determine how still you need to hold the camera before pixel-shifting occurs. This has nothing to do with the CoC, DoF, or the resolution between Airy Disks (diffraction).
¿The size, at the subject, of each pixel?

The subject sample resolution (which, I think, is what you are talking about) is obviously related to the CoC, or subject res, as you cannot resolve detail much smaller than your sample frequency or resolution.

...and angular camera shake tends to be more important than lateral shake.
 

coulombic

New member
¿The size, at the subject, of each pixel?

The subject sample resolution (which, I think, is what you are talking about) is obviously related to the CoC, or subject res, as you cannot resolve detail much smaller than your sample frequency or resolution.

...and angular camera shake tends to be more important than lateral shake.
Indeed, angular camera shake (theta = s/r) would prove to be a very difficult calculation to make, as I mentioned before. Nevertheless, the angular velocity can be approximated in a linear fashion, simply making estimates of how much distance the lower and upper limits of the subject movement are. Putting a laser-pointer on the lens while attempting this is a useful mechanism to effectively demonstrate the linear travel.

Essentially, if you do the math, even once, you'll see how difficult it is to obtain sharp focus with a very high resolution camera and a long focal length lens without using a tripod. That is to say, damn near impossible.

I'm not speaking about the CoC. The CoC is the point at which light comes into focus on the focal plane. I'm using "focus" as an axiom. I'm not trying to calculate diffraction, or lines per inch, or anything along these lines. Just the distance per pixel based around the parameters of focal length, distance, and pixel element size.

If I were trying to calculate, say, something related to "deep focus," or hyperfocal focus, I'd naturally need to take into consideration. All matters of DoF are inherently related to the Circle of Confusion. GSD? Not so much.

I believe you're also tangling Rayleigh's Criterion/diffraction into this, as Rayleigh's Criterion is ultimately the max resolution obtainable based around the wavelength of light.
 

coulombic

New member
¿The size, at the subject, of each pixel?

The subject sample resolution (which, I think, is what you are talking about) is obviously related to the CoC, or subject res, as you cannot resolve detail much smaller than your sample frequency or resolution.

...and angular camera shake tends to be more important than lateral shake.
Once again, for everyone's edification, GSD, or ground sample distance, is defined by the following equation:

((pixel element size)*distance to subject)/focal length).
 

D&A

Well-known member
No, I'm not talking about the Circle of Confusion (CoC), or Airy Disks. I'm speaking very specifically about ground sample distance (GSD). With this calculation, each pixel is representative of specific units of distance. Knowing the distance each pixel represents, you can determine how still you need to hold the camera before pixel-shifting occurs. This has nothing to do with the CoC, DoF, or the resolution between Airy Disks (diffraction).
Yes, extremely important. In earlier days of DSLR's, this phenominon was just beginning to be understood (to a degree) with the masses of digital photographers. When Nikon's D1x camera was first introduced, going from 2.7 MP of the original D1 to 6MP of the D1x, people started noticing slightly soft and blurred images from Nikon's 80-400 f5.6 zoom lens. Even though that lens had VR, people used to shoot that lens at rediculous slow shutter speeds and get blur free shots with their D1's. When they upgraded to the D1x (from either the D1 or D1H), people complained that there was some sort of interface issue with using that specific lens with their new cameras whereby images were soft and had elements of blur...at the same shutter speeds they were previously using. The term "digital blur" was often used at that time. Of course this phenominon would occur with any long telephoto, but for whatever reason, it was the 80-400 f5.6 that was often cited as an example. After this, people began to realize that this issue was seperate from "circle of confusion and the rule of hand holding specific focal lengths at certain shutter speeds that they calculated, when using these long lenses on film based cameras. Of course all these other criteria are all taken into consideration when it comes to the bigger picture (no pun intended).

Dave (D&A)
 

GrahamWelland

Subscriber & Workshop Member
It's interesting also because the pixel pitch affects the newer higher resolution 16/24mp consumer cameras such as the Nikon D7000 which means that they're becoming brutal with consumer glass and only perform well with the best lenses.

The following is a less than perfect diagram (I can't be bothered to draw one) of the sensor pitch/pixel distance issue but you get the general idea:
 

D&A

Well-known member
Graham Wrote >>>"It's interesting also because the pixel pitch affects the newer higher resolution 16/24mp consumer cameras such as the Nikon D7000 which means that they're becoming brutal with consumer glass and only perform well with the best lenses."<<<

Graham, funny (and interesting) you mentioned the "above" example in your statement. There is currently a heated debated with some non pro's, making the case that the # of keepers (ie: sharp images) with their newely aquired D7000, isn't anywheres near the numbers of their former D700 body, without realizing the reasons why and now they are disgrunted.

It's not only with consumer glass but with any good glass where they don't consider the physics of what you illustrated in your diagram...namely the consequence of pixel pitch/density of pixels on their handheld shots, especially with longer focal length lenses....or even simply the shutter speeds they choose to use vis-a-vis the focal length of their lens.

Oh by the way Graham, are you sure your diagram wasn't originally used as an illustration of ICBM's during the cold war era? :)

Dave (D&A)
 
Last edited:
G

GPA

Guest
New to this site, so forgive me for this stupid question. Would shooting with strobes avoid the problem?
 

D&A

Well-known member
Hi,

First welcome to Getdpi. Secondly there are really no stupid questions, when asked with the intent of learning information...and I should know, asking my own share of rediculous questions through the years :).

As a simple answer..."No" or not really. This is about camera movement relative to the subject, not subject movement. If you subject say was a non moving object, like a tree for example. If you shot that tree handheld with a 12MP DSLR, and lowered your shutter speed to the point at which Pixel pitch played a role in softening or bluring the image...adding strobe to the equation would have no effect on changing the dynamics of pixel pitch on camera movement. Simply, the strobe (depending on setting) would only help in freezing motion if the subject was moving and caused subject blur due to it's subsequent movement. This is sort of the "short answer" in a nutshell.

Dave (D&A)
 
Last edited:

D&A

Well-known member
Well that and good support, like using a tripod wherever possible...especially when one is dealing with high pixel densitites. There are a number of variables that affect image quality. Thats why grabbing a 12MP DSLR vs. say a 40 MP (or higher) MF camera or even a 24MP D3x for example, requires "impecable technique" such as proper support, to extract the most out of the imager. This of course goes along with the other usual variables such as using lenses of high optical quality.

Dave (D&A)
 

Guy Mancuso

Administrator, Instructor
Work around when in doubt. Monopod

In situations outside the tripod and hairly on handheld the mono can save the day. It's so overlooked by many.
 
G

GPA

Guest
Dave thanks for your help--Lesson learned, I made a big mistake returning my 80mm LS lens (had 3 defective lenses and gave up)--Using 1/1600 setting would have helped with this problem.

Thanks again.
 

dick

New member
New to this site, so forgive me for this stupid question. Would shooting with strobes avoid the problem?
Hi,
Simply, the strobe (depending on setting) would only help in freezing motion if ...
If blur would have been caused by any movement of the camera and/or subject, using flash would eliminate it, or drastically reduce it if:

The shutter speed was reduced to the point at which continuous light was effectively eliminated (this is not possible, with flash sync, in bright sunlight with a focal plane shutter)

The flash duration was short enough to effectively eliminate blur

So shutter speed is the key element for hand held use?
One of them... the skill and state of health of the photographer are also relevant.

Camera-shake blur depends on:

shutter speed, so the camera's ability to work well at high ISO is a factor.

the ergonomics of the camera

mirror vibration

inertia of the camera/lens/grip combination...

a long heavy lens is more stable, and I could shoot my non-telephoto Novoflex 640mm with shoulder grip at 1/125th (lying flat as you would using a rifle)
Using a tilt lens or tilt adapter gives you more DOF, or allows you to use a faster shutter speed with the same DOF.

Natural light often looks more natural or better than flash... a compromise is a combination of flash and natural light.

With a large subject like a cathedral, lighting the whole subject with flash would be a major undertaking... and a tripod or a high-iso camera might be needed.

You could fit stabilizers to the camera, like those used by archers... but now we have electronic stabilizers... but only on consumer cameras? The assumption is that pros use tripods or flash?

...but the topic is about the extent of the problem, not about ways to avoid it.
 

Dan Santoso

New member
I brought my P65+ and used 150mm a lot for my holiday 2010 travel. That was the first time I shoot ambient light only ( usually in the studio with strobe).

Almost 97% of my images handheld was blur (and i don't even bother to check the focus with the stupid LCD). So yes med format with large sensor is definitely harder.

So tripod is a must.
 
Top