Ad
Ad
Ad
Pages: « 1 2 [3] 4 »   Bottom of Page
Print
Author Topic: Why full frame for landscapes at low ISO?  (Read 16648 times)
Daniel Browning
Full Member
***
Offline Offline

Posts: 142


« Reply #40 on: October 23, 2009, 05:45:42 PM »
ReplyReply

Quote from: coles
One of the primary benefits for a larger sensor size (or film size) is that an image degradation due to camera or subject motion is less detectable because the amount of enlargement for any given size of print is less (using a tripod does NOT guarantee 0 camera motion).

That is correct when one uses the same focal length on two different sensor sizes. However, it will result in a much different angle of view, of course. If instead you keep angle of view the same by scaling the focal length with the format size, it turns out that motion and subject blur remains the exact same.

In other words, you are correct that wider angles of view have less motion blur, but that is true of all formats.
« Last Edit: October 23, 2009, 05:46:09 PM by Daniel Browning » Logged

--Daniel
coles
Newbie
*
Offline Offline

Posts: 16


« Reply #41 on: October 24, 2009, 06:22:05 PM »
ReplyReply

Quote from: Daniel Browning
That is correct when one uses the same focal length on two different sensor sizes. However, it will result in a much different angle of view, of course. If instead you keep angle of view the same by scaling the focal length with the format size, it turns out that motion and subject blur remains the exact same.

In other words, you are correct that wider angles of view have less motion blur, but that is true of all formats.

Daniel,
I'm not sure I agree. If you have larger-format camera A. with a 20-degree lens and compare it with smaller-format camera B. with a 20-degree lens, at any given enlargement, the amount of camera shake will be more obvious with camera B due the greater degree of enlargement. In order for your assertion to be true, I believer that the enlargement must be proportionally smaller for camera B.

In comparing prints made from both medium format and Pentax k20 cameras, I observe much more motion blur from the Pentax at, say, 11x14, even with lenses of equivalent field of view.
In order to see less motion blur from the Pentax, I'd have to have 5x7 or 8x10 prints.

Scott
Logged
BJL
Sr. Member
****
Offline Offline

Posts: 5128


« Reply #42 on: October 24, 2009, 06:47:37 PM »
ReplyReply

Quote from: coles
Daniel,
... If you have larger-format camera A. with a 20-degree lens and compare it with smaller-format camera B. with a 20-degree lens, at any given enlargement, the amount of camera shake will be more obvious with camera B due the greater degree of enlargement.
I agree with Daniel. The 20 lens on the smaller format has a smaller focal length and so the same angular rotation of the camera moves the smaller image across the focal plane by a proportionately smaller amount, and the size of the motion blur at the focal plane is smaller.  The greater degree of enlargement then just cancels out this and gives the same amount of blur on the same sized print.

Your idea of thinking in angles is a useful one when comparing different formats. Say in each case the FOV is 20 horizontally and the sensor is 4000 pixels across. Each pixel spans 1/200 of the subject: loosely speaking, you have an angular resolution of 1/200. A camera rotation of, say 1/100 moves the image 2 pixels across the image in either case (1/2000 of image width) for the same amount of blur size relative to image size.

This begs the question of how the rotational motion of a camera due to hand-shake might vary with format size. Some say that larger formats benefit from greater mass (really, moment of inertia) leading to slower twisting due to hand-shake, but if so, that depends on camera bulk, not format size directly, so if it is an issue, using a heavier camera is a possible advantage, independent of format. Add "ballast" if you really must; maybe bolt metal plates to the unused tripod socket.
Logged
Daniel Browning
Full Member
***
Offline Offline

Posts: 142


« Reply #43 on: October 24, 2009, 06:48:41 PM »
ReplyReply

Quote from: coles
Daniel,
I'm not sure I agree. If you have larger-format camera A. with a 20-degree lens and compare it with smaller-format camera B. with a 20-degree lens, at any given enlargement, the amount of camera shake will be more obvious with camera B due the greater degree of enlargement.

When angle of view is kept the same, focal length cancels out the degree of enlargement as it pertains to motion blur. For example:

80mm lens on 645 Medium Format (56x41.5mm sensor)
8mm lens on a digicam (5.6x4.15mm sensor)

That will give them both the exact same angle of view. To make an 11x14 (336x279mm) print, the 645 only needs enlargement of 6X. But the tiny digicam requires a reproduction magnification of 60X. Now, if there was a blur of 1mm on both cameras, that blur would get enlarged to 6mm on the 11x14 print from the 645 camera, but it would be enlarged to 60mm on the 11x14 print from the digicam. And that's what would happen if both cameras used the same focal length (e.g. 80mm). But if you keep angle of view the same, then you have to use a much shorter focal length.

Say a subject moves through the frame at a speed that causes a blur trail that is 10% of the Picture Height. On 645 MF that translates to a blur on a sensor that is 4.15mm long. But the same exact 10% on the digicam only translates to a blur of 0.415mm. When you add in reproduction magnification, the blur comes out the same on the print: 24.9mm.

Kind regards,
Logged

--Daniel
Ray
Sr. Member
****
Offline Offline

Posts: 8883


« Reply #44 on: October 24, 2009, 07:12:22 PM »
ReplyReply

Quote from: coles
Daniel,
I'm not sure I agree. If you have larger-format camera A. with a 20-degree lens and compare it with smaller-format camera B. with a 20-degree lens, at any given enlargement, the amount of camera shake will be more obvious with camera B due the greater degree of enlargement. In order for your assertion to be true, I believer that the enlargement must be proportionally smaller for camera B.

In comparing prints made from both medium format and Pentax k20 cameras, I observe much more motion blur from the Pentax at, say, 11x14, even with lenses of equivalent field of view.
In order to see less motion blur from the Pentax, I'd have to have 5x7 or 8x10 prints.

Scott

What is perhaps relevant here is the concept that enlargement in the digital domain relates to pixel count, not sensor size. However, sensor size affects FoV. Having adjusted lens focal length to equalise FoV, motion blur of the subject and camera shake should be theoretically the same when using the same shutter speed with both formats. However, camera shake is a variable quantity depending on the weight of the camera, how firmly one can hold the camera and in what manner one holds the camera.

I get the impression that the DSLR pressed against one's face and held firmly with both hands probably has an advantage regarding camera shake.
Logged
coles
Newbie
*
Offline Offline

Posts: 16


« Reply #45 on: October 24, 2009, 10:43:02 PM »
ReplyReply

Quote from: Ray
What is perhaps relevant here is the concept that enlargement in the digital domain relates to pixel count, not sensor size. However, sensor size affects FoV. Having adjusted lens focal length to equalise FoV, motion blur of the subject and camera shake should be theoretically the same when using the same shutter speed with both formats. However, camera shake is a variable quantity depending on the weight of the camera, how firmly one can hold the camera and in what manner one holds the camera.

I get the impression that the DSLR pressed against one's face and held firmly with both hands probably has an advantage regarding camera shake.

Ray,
Even with digital, format size does matter, and not just pixel count. Camera shake, as well as all manner of lens abberation and focusing error are ALL magnified from a smaller sensor, even before one begins to see pixel effect.

Personally, I seem to have a hell of a time holding my DSLR steady. I have much better luck with either my Mamiya 6, Bronica S2, or Leica.

Scott
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8883


« Reply #46 on: October 25, 2009, 06:42:02 AM »
ReplyReply

Quote from: coles
Ray,
Even with digital, format size does matter, and not just pixel count. Camera shake, as well as all manner of lens abberation and focusing error are ALL magnified from a smaller sensor, even before one begins to see pixel effect.

Personally, I seem to have a hell of a time holding my DSLR steady. I have much better luck with either my Mamiya 6, Bronica S2, or Leica.

Scott

Scott,
You've got 3 explanations above why camera shake is not magnified with the smaller sensor provided the focal length of the lens is adjusted to provide the same field of view. However, it is true that increases in pixel count put greater demands on the lenses used. That applies across all formats, including the P65 which has a pixel size similar to that of the D3X.

Years ago, questions used to arise about how the 1/FL rule applies to the cropped format camera. As a guide for a minimum shutter speed without IS, with camera hand-held, it's now a bit out-of-date because it used to apply to 8"x10" prints in the days when 35mm film was not considered good enough for prints much larger than 8x10".

In other words, if one uses an 80mm lens with FF 35mm, a shutter speed of 1/80th should be sufficient to overcome camera shake. However, to shoot the same scene with a Canon cropped format, one would use a 50mm lens. The question thus arises, does the 1/FL rule, as applied to APS-C format, mean that one can use a slower shutter speed of 1/50th?

No it doesn't. The 1/FL rule is really a 1/FL(35mm) rule. Whatever the format, the minimum shutter speed needed to overcome camera shake is '1/equivalent 35mm lens in millimetres', and that I guess would apply even to an 8x10 large format field camera unless there are some other issues relating to the difficulty of holding the camera. In other words, for a reasonably sharp 8x10" print, one could get away with 1/50th sec shutter speed, despite the fact that the standard lens on 8x10 format might be 320mm-400mm.

I think the confusion probably arises because people unwittingly sometimes compare apples with oranges. If the FoV is the same, if the print size is the same and if the shutter speed is the same, then the camera shake will be the same whatever the format, or to put it more precisely, the camera shake will be influenced only by one's ability to hold the camera steady. It might well be the case that a P&S digicam with LiveView LCD screen, held at arms length, will need a faster shutter speed to overcome camera shake, especially if one suffers from Parkinson's.


Logged
bjanes
Sr. Member
****
Offline Offline

Posts: 2793



« Reply #47 on: October 25, 2009, 07:47:57 AM »
ReplyReply

Quote from: coles
Ray,
Even with digital, format size does matter, and not just pixel count. Camera shake, as well as all manner of lens abberation and focusing error are ALL magnified from a smaller sensor, even before one begins to see pixel effect.

Personally, I seem to have a hell of a time holding my DSLR steady. I have much better luck with either my Mamiya 6, Bronica S2, or Leica.

Scott
Since when is your Leica a large format camera?

What you neglect to mention is that none of the cameras you mentioned has vibration reduction/image stabilization. According to the Leica expert Erwin Puts the use of vibration reduction can produce results nearly as good as are obtained through the use of a tripod.

Logged
Peter McLennan
Sr. Member
****
Offline Offline

Posts: 1681


« Reply #48 on: October 25, 2009, 11:53:55 AM »
ReplyReply

I've had a D70, a D200 and now a  D300.  I agree with a previous poster about noisy skies; they're especially evident when extracting a black and white with "black" blue sky areas.  It's not a problem, but it is evident.

For landscape shooting at reasonable print sizes (say 16X20) my experience is that the D300's 12 MP is enough.  Stitching (usually very easy with landscapes) renders this problem moot.  I have lots of 30X17 (stitched) landscape images from the above cameras that look great at any responsible viewing distance. : )

What I want is at least two more stops of dynamic range.  When new sensors offer that, I'm in.  Contrast is a much more difficult problem for photography than insufficient spacial resolution given today's 12 MP DSLRs.  With 14ev of exposure latitude, HDR bracketing and processing shenanigans would be virtually unnecessary.

I'm reminded of the early days of computers when VGA had two resolutions: 640X480 with 16 colours and 320X240 with 256 colours.  The lower-res, higher bit depth images always looked better.  

For nearly all camera markets, the megapixel wars are over.  Let the dynamic range wars begin!

Logged
BJL
Sr. Member
****
Offline Offline

Posts: 5128


« Reply #49 on: October 25, 2009, 01:16:21 PM »
ReplyReply

Quote from: Peter McLennan
... that the D300's 12 MP is enough.  Stitching (usually very easy with landscapes) renders this problem moot. ...

What I want is at least two more stops of dynamic range. ... Contrast is a much more difficult problem for photography than insufficient spacial resolution given today's 12 MP DSLRs.  With 14ev of exposure latitude, HDR bracketing and processing shenanigans would be virtually unnecessary.
If stitching for increased spatial resolution is "usually very easy with landscapes", I would have thought that HDR bracketing for increased dynamic range could be even easier. No repositioning of the camera, and two frames to blend can be taken within about 1/7th of a second with the D300, so even less problems with slight and slow subject movement, or with shifting light and shadows, which might mess up stitching even with a completely immobile subject. I doubt that any sensor progress can match the DR of even basic two-frame HDR blending, due to factors like flare from bright parts of the scene contaminating the deep shadows.

Maybe good HDR+stitching software, maybe even in-camera, could be the most convenient and cost effective "next big thing" for landscapes.

Or reading several successive frames in rapid succession with the video style rolling electronic shutter and adding the successive outputs at each photosite, so no shutter movement between frames. Four sweeps with 12-bit sensor output adds to 14-bits, or a two stop gain; sixteen sweeps for the Holy Grail of true 16-bit depth.
Logged
Chris Pollock
Full Member
***
Offline Offline

Posts: 213


« Reply #50 on: October 25, 2009, 08:18:09 PM »
ReplyReply

Quote from: BJL
If stitching for increased spatial resolution is "usually very easy with landscapes", I would have thought that HDR bracketing for increased dynamic range could be even easier. No repositioning of the camera, and two frames to blend can be taken within about 1/7th of a second with the D300, so even less problems with slight and slow subject movement, or with shifting light and shadows, which might mess up stitching even with a completely immobile subject. I doubt that any sensor progress can match the DR of even basic two-frame HDR blending, due to factors like flare from bright parts of the scene contaminating the deep shadows.
I've recently been experimenting with HDR and exposure blending using a 5D II and Photomatrix. You're right that it's easy to do - taking the shots is dead easy with a good tripod; working out the optimum settings for blending requires some effort.

The problem is that it's often impossible to avoid some subject movement between shots. One of my favourite subjects is Tokyo streetscapes, which as you can imagine are almost impossible to shoot without getting at least a few people in the frame, who have an annoying tendency to move around. Even if there are no people around, things like lanterns swaying in the breeze can be a problem.

A camera with an extra 4 stops or so of dynamic range would open up a lot of photographic opportunities. A medium format digital back might manage it, but I don't think I could justify the currently exorbitant cost. I'll probably buy one when the price becomes more reasonable, as I'm sure it eventually will.
Logged
BernardLanguillier
Sr. Member
****
Online Online

Posts: 7950



WWW
« Reply #51 on: October 25, 2009, 09:57:46 PM »
ReplyReply

Quote from: Peter McLennan
For nearly all camera markets, the megapixel wars are over.  Let the dynamic range wars begin!

That will be a difficult war to fight... since DR is anyhing but obvious as it manifests itself only in the shadows once correct exposure is applied (ETTR). DR today is mostly a romantic concept.

For DR to be understood, we will first need to make sure that the concepts of correct exposure in digital is understood. For example, all the photoraphers who believe that the device they are using as some sort of headroom towards the highlights has probably not put in place the required basis to understand what DR in the digital world means. Even the Fuji cameras are not exceptions to this rule. This will remain so as long as our sensors stay linear devices.

At the risk of looking again like a D3x fan, I will restate the fact that the D3x is significantly ahead of competition DRwise, and yet is assessed by many key reviewers as being very similar to its competitors.

The reason being that most raw converters apply a default curve to the raw data so as to generate a pleasing result. A pleasant result will determine the extend to which a user will want to keep using that particular raw conversion software and is therefore very important.

A pleasing result is one that has enough contrast, in this case global contrast since raw converters for DSLRs do not apply automatically local contrast enhancement, although their highlight/shadow recovery tools often do.

So the bottomline is that good or bad DR can only be assessed by looking at the shadows of a file after application of various methods to lift them.

Pretty often, tapping into the actual DR of a camera like the D3x can only be truly done by using some form of tone mapping, something that few photographers are willing to do on a regular basis.

So unless raw converters become smarter at making DR available, real DR we will remain difficult to sell beyond its romantic appeal. Look at how little recognition Nikon has gotten for their outstanding job with the D3x.

Cheers,
Bernard
Logged

A few images online here!
Josh-H
Sr. Member
****
Offline Offline

Posts: 1907



WWW
« Reply #52 on: October 25, 2009, 10:21:35 PM »
ReplyReply

I totally agree that improved DR in a DSLR is a very difficult concept to sell to anyone other than a professional photographer who understands the benefits.

The marketing departments of major camera manufacturers know this - they also know its far easier to market a camera as 'new' and 'improved' because it has 6 mega pixels instead of 5. Thats something every consumer understands on the basic level that '6' is better than '5' (hey this one has volume that goes to 11!).  

Its the same in the display market - the marketing dept. of major display manufacturers knows that the purchaser understands that 'X' display has more pixels than 'Y' - but the punter most likely wont understand the benefit of a larger gamut; even though the larger gamut will give them a better more accurate picture. Hence, gamut is rarely if ever mentioned in a displays specifications.

Ultimately this all means that the marketing dept drives manufacturing to a large degree (duh....). Which means the MP wars are not over (or at least not over as far as the marketing dept. wants you to believe). The marketing depts' will continue to flog this dead horse for as long as they can sell cameras. And improvements in DR will come as part of natural progression - but they will be glossed over by the marketing depts.
Logged

Chris Pollock
Full Member
***
Offline Offline

Posts: 213


« Reply #53 on: October 25, 2009, 10:57:17 PM »
ReplyReply

Quote from: Josh-H
The marketing departments of major camera manufacturers know this - they also know its far easier to market a camera as 'new' and 'improved' because it has 6 mega pixels instead of 5. Thats something every consumer understands on the basic level that '6' is better than '5' (hey this one has volume that goes to 11!).
I think you're probably right, unfortunately.

One factor that a lot of people perhaps overlook is that improvements sensor in resolution are becoming increasingly difficult to take advantage of in practice. Even a small amount of camera shake, focusing error, subject movement, or optical aberration can reduce a 21 megapixel photograph to less at 12 megapixels of information. With each improvement in resolution, the photographer has to take extra care (and perhaps use better lenses) to get the benefit from it.

Improved dynamic range, on the other hand, would not require any improvement in photographic technique to get improved results.
Logged
BernardLanguillier
Sr. Member
****
Online Online

Posts: 7950



WWW
« Reply #54 on: October 26, 2009, 05:02:33 AM »
ReplyReply

Quote from: Josh-H
I totally agree that improved DR in a DSLR is a very difficult concept to sell to anyone other than a professional photographer who understands the benefits.

Considering that many MFDB owners boast about the highlight headroom of their sensors, I am really not sure that being a pro is a sufficient condition to understand this. The truth is that many of the top shooters have developped their skills in the film days and measure light with their back the way they used to measure with film, meaning that in essence they go for the 18% grey card or measure incident light on the subject.

The digital device they will like is the one providing them a safety margin in these conditions, meaning perceived highlight headroom, which means under-exposes relative to an ideal ETTR digital approach. The back histogram and raw conversion software (mostly proprietary with backs) is calibrated in such a way that this impression is maintained. Put it otherwise, the whole chain is calibrated to simulate negative film.

This is possible because of the good DR provided by backs, shadows remain reasonnably clean even with limited under-exposure that it not perceived anyway since the raw conversion software compensates for this when applying the camera curve.

DSLR like the D3x are typically calibrated in such a way as to behave like slide film, meaning that the histogram shows something that is extremely close overall to the actual level of clipping in the raw file. It results in totally clean shadows, but often un-satisfied users since blown highlights show up more often (and with less pleasing transitions on some of the DSLR due to a lower real bit depth). In a way DSLR manufacturers are over-optimistic about the actual abilities of their photographers.

Do pros needs to care or be aware of these aspects? Probably not, they are paid for their shooting, artistic and Mgt abilities, not for their understanding of the technology.

Cheers,
Bernard
Logged

A few images online here!
Ben Rubinstein
Sr. Member
****
Offline Offline

Posts: 1733


« Reply #55 on: October 28, 2009, 06:05:20 AM »
ReplyReply

Tonality, Tonality, Tonality.

Oh and Noise, DR, etc. Did I mention diffraction?

I own both crop and FF BTW....
Logged

Daniel Browning
Full Member
***
Offline Offline

Posts: 142


« Reply #56 on: October 28, 2009, 11:33:43 AM »
ReplyReply

Quote from: pom
Tonality, Tonality, Tonality.

Oh and Noise, DR, etc.

I agree with you on those ones.

Quote from: pom
Did I mention diffraction?

Diffraction is actually the same on crop and FF. That's because diffraction scales with *DOF*, not sensor size. For example, f/22 on APS-C has more diffraction than f/22 on FF, *but*, it also has more DOF. You only need f/14 on APS-C to get the same DOF as f/22 on FF. Then diffraction becomes the same.
Logged

--Daniel
BJL
Sr. Member
****
Offline Offline

Posts: 5128


« Reply #57 on: October 28, 2009, 01:11:55 PM »
ReplyReply

Quote from: Daniel Browning
Diffraction is actually the same on crop and FF. That's because diffraction scales with *DOF*, not sensor size. For example, f/22 on APS-C has more diffraction than f/22 on FF, *but*, it also has more DOF. You only need f/14 on APS-C to get the same DOF as f/22 on FF. Then diffraction becomes the same.
Thanks; this needs to be said so many times to people stuck on comparing only at equal aperture ratio and equal ISO speed.

It would be nice to have a "format comparison myth-buster" web page hosted by someone credible, with this sort information.
Next item: why comparing cameras in different formats with lenses of different minimum f-stops at equal ISO speed and shutter speed and thus equal f-stop is not very illuminating ... (It's partly a DOF thing, again.)
Logged
Chris Pollock
Full Member
***
Offline Offline

Posts: 213


« Reply #58 on: October 28, 2009, 02:47:56 PM »
ReplyReply

Quote from: Daniel Browning
Diffraction is actually the same on crop and FF. That's because diffraction scales with *DOF*, not sensor size. For example, f/22 on APS-C has more diffraction than f/22 on FF, *but*, it also has more DOF. You only need f/14 on APS-C to get the same DOF as f/22 on FF. Then diffraction becomes the same.
However, a lot of landscape shots will be taken with everything at or close to infinity, so there will be no need to stop down for DOF.
Logged
BJL
Sr. Member
****
Offline Offline

Posts: 5128


« Reply #59 on: October 28, 2009, 02:59:32 PM »
ReplyReply

Quote from: Chris Pollock
However, a lot of landscape shots will be taken with everything at or close to infinity, so there will be no need to stop down for DOF.
And in that situation, the apertures are large enough that diffraction is not a problem. With SLR formats, diffraction only comes into play when one stops well down from wide open for the sake of DOF control. The practical rule of thumb seems to be that diffraction only has a significant effect on resolution when the aperture ratio is about twice or more the pixel spacing, so f/8 and beyond with the smallest current DSLR photosites (The 18MP EF-S 7D and 12MP 4/3). If you are worried about diffraction hurting the fine detail in your landscapes and your lens fails you as soon as you open up a bit beyond f/8, then a decent lens would probably be the first upgrade to consider!
Logged
Pages: « 1 2 [3] 4 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad