July 29, 2014, 12:00:28 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - helpful

Pages: 1 ... 10 11 [12] 13
166
EOS Bodies - For Stills / Re: 5D MKIII vs 1Ds MKIII
« on: April 03, 2012, 10:47:37 AM »
tom, I think you should get the 5D3. The other camera you mention was good for its time period. But it's like a Pentium 4 computer vs. a Sandy Bridge computer. I don't know if this analogy rings any bells, but I'm trying to say that the 5D3 is a revolutionary improvement compared to the  1Ds MKIII.

If you were comparing the EOS-1D Mark IV vs. the 5D3, then I would say it is more of a wash, although the 5D3 sensor is twice as good even compared to the EOS-1D Mark IV.

All these people talking about "barely a few stops better" need to realize that even one stop is twice as good, i.e., 100% better. After a week with the 5D3, I would rather have it than any three camera bodies prior to the EOS-1D Mark IV, and it is also easily worth more than the $5,000 EOS-1D Mark IV.

So even for $3,500 (or whatever the price is in your country), the 5D3 is the only choice that I would consider if I were in your situation.

167
EOS Bodies / Re: Shot wedding with 5DIII, dissapointed in AF
« on: April 02, 2012, 06:12:46 PM »
This is not what I am getting. I shot an inauguration on Friday with the 5D3 and autofocus was insanely perfect and snappy down to exposures of 1/30th at f/2.0 at ISO 12,800 with the 135mm f/2.0L.

I also shot a track meet that ran until 1030 pm under poor stadium lights, and tracking was right on, even with runners going in and out of the uneven beams of very dim lights, or backlit in the curves of the track.

The AF of the 5D3 is absolutely incomparably better than the 5D2, and I have loads of experience to be able to make this statement.

BTW, I am using the automatic focus tracking which uses the center spot to lock on and then tracks it to any of the other 61 AF points. It is the mode that shows up with a border around all the AF points and a bold center point, when you are selecting autofocus modes. (I am describing the view through the viewfinder.)

Also, AF worked just as well even if I selected the initial focusing point as one of the other ones rather than the center.


168
Technical Support / Re: Dynamic Range War
« on: March 29, 2012, 03:25:00 PM »
I'd caution strongly against expose to the right

Expose properly, ideally with a well-calibrated incident meter.

If you've still got crushed shadows and blown highlights in critical areas of the image, you either need better light or you need to go to HDR -- and that's assuming that the crushed shadows and blown highlights are a problem in the first place...the kinds of photography where it's a problem but you can't either fix the light or use HDR are basically nonexistent.

Don't forget that there's a great deal more DR to be had in any well-exposed RAW image than what comes right out of the converter with the default settings.




Good points, and actually you have explained very well what the point of ETTR is, which is to maximize the potential of camera sensors, which are capable of far more than what is offered by default exposure settings. The camera sensors are so good that the dynamic range of most scenes is far within the maximum DR capabilities of the sensor. So photographers are faced with a question--use zero exposure compensation, or try to manually expose to get the most detail? Due to the way that data is recorded (2,048 bits of data for the right side in the brightest stop of light), there is much more data recorded on the right side of the histogram.

http://schewephoto.com/ETTR/index.html

There is an amazing example on that page which shows that the little tiny blip on the right side of the sensor (way, way, overexposed, and extreme ETTRing) actually has as much image detail as almost the entire image histogram. That's not what anyone should do. The point is just to show how much more data and details are being recorded for any part of the image that is on the right side of the histogram, compared to the left.


169
Technical Support / Re: Dynamic Range War
« on: March 29, 2012, 03:01:21 PM »
If you want to get the most detail from your images, then the major area of your image's histogram should be towards the right.


Thanks for pointing that out, I only discovered this fact after some try and error - maybe they should have put a  sentence like this in the manual :-p


The concept is termed ETTR.


Great point, I would like to add a link a really cool article on the subject as well:

http://www.luminous-landscape.com/tutorials/expose-right.shtml

In summary,

"For Maximum S/N Ratio [i.e., image quality]

"The simple lesson to be learned from this is to bias your exposures so that the histogram is snugged up to the right, but not to the point that the highlights are blown. This can usually be seen by the flashing alert on most camera review screens. Just back off so that the flashing stops."

There are photos of the histograms in the article.

Note that for a dark subject, you still need the image to be darker than for a bright subject, so it is overly simplistic to say "always have the histogram snugged up to the right." But to get the most details out of all the data that is available in the light coming from the subject, that is the way.

170
Technical Support / Re: Dynamic Range War
« on: March 29, 2012, 02:58:46 PM »
The concept is termed ETTR.

While it might not make me seem like a pro (hey, I am not!): I didn't know about that, thanks again dr. neuro!

The only thing left for me to wonder when shooting at low light is if it's better to have a properly exposed histogram at higher iso or a histogram that leans to the left at lower iso. Using lr4 and its smart shadow recovery, I'm tending towards the latter with my aps-c sensor, because higher iso than 800 really ruins the picture while 1ev underexposure does not.


That is a question that there may never be a definitive answer for.

In my experience it depends on the camera. Some cameras whose high ISO modes are just "software enhanced" are better used at lower ISOs with slight underexposure, and then pushed on the comupter with software that is better designed and can increase the brightness without resulting in as much nosie as the in-camera "software-enhanced" ISO boosting.

For other cameras that really do have the ability to increase their light sensitivity, it is absolutely better to increase the ISO to get more bits of detail in the file, and then try to decrease noise later. Underexposing reduces the actual amount of data that is captured in the scene. So in an ideal world, you would get the proper exposure by increasing the ISO, and then reduce the nosie in post-processing, and your image would have higher quality than shooting underexposed and then boosting the ISO with software.

It all depends on whether the ISO level that you are shooting at is provided by the intrinsic analog/physics capabilities of the image sensor physics (in which case you should shoot at high ISO and reduce noise afterwards), or by the camera's image processing (in which case you should shoot at lower ISO and increase brightness afterwards).

Boosting ISO with software always reduces the amount of usable data in the image (which is why the Nikon D4 only has 6-8 bits of DR at ISO 200,000, because it is software boosted). So that is what you always want to avoid.

171
Technical Support / Re: Dynamic Range War
« on: March 29, 2012, 02:26:33 PM »
For the record, slide film has a smaller dynamic range than negative film.

However, it still held at least as much "data" as did negative film.

Therefore, there was much more detail in the image coming from a slide, but exposure latitude was not as forgiving. Blown highlights, and lost shadows were more likely with slide film. Overexposure in particular is much less of a problem with negative film, because there was a lot of headroom with negative film. Not so with slide film.

The way this compares to digital images is as follows:

Approximately the brightest 1/2 of the image data (i.e., the right side of the histogram) represents one stop. Therefore, the most image detail is in this area. Subtle variations between brightness are easily discernable.

The darkest 1/2 of the image data is divided up as if it was another image, like this:

* the brightest 1/2 of the remaining 1/2 of the image data (i.e., the upper half of the bottom half of the histogram) contains another stop of brightness data. There is slightly less detail, since not as much data is used to represent one stop of light.

The remaining quarter of the image data is divided up again, recursively:

* the brightest 1/2 of the remaining 1/4 of the image data contains another stop of brightness. There is significantly less detail, etc.

Let's assume that your image data is stored as 16 bits per pixel, and the primary part of your image is exposed at EV 16.

Then the top 8 bits contain a detailed view of the brightest one stop of the image from EV 16.0 to 16.9.
The  next 4 bits contain a moderately detailed view of the next brightest stop of the image from EV 15.0 to 15.9.
The next 2 bits contain a poorly detailed view of the next brightest stop of the image from EV 14.0 to 14.9.
The final 1 bit contains a very low detail view of the darkest stop of the image from EV 13.0 to 13.9.


This is how it works, simplified, with "linear gamma."

All modern cameras use non-linear gamma systems to expand the dynamic range of linear gamma from the maximum of four stops to many more stops of dynamic range.

But the principle is the same.

If you want to get the most detail from your images, then the major area of your image's histogram should be towards the right.

Try taking a photo of a subject with little dynamic range, like a a square foot in the middle of a field of green grass. If the image is underexposed, the histogram will make a narrow band towards the left side. The size of the band represents the detail recorded from the grass.
If the image is properly exposed, the band will be a little bit larger showing that more detail is being recorded in the upper area of the histogram which is more detailed because more bits are used to record each stop of light.

172
5D MK III Sample Images / Re: 5D MK III Images
« on: March 28, 2012, 11:11:02 PM »
This photo was taken with the 135mm f/2.0 L lens, part of the first set of photos taken with the 5D3 that I received today from J&R.

173
EOS Bodies / Re: DPReview Canon 5D mark III noise comparison
« on: March 28, 2012, 04:38:49 PM »


Ok, my point is I'm looking at the DPReview comparisons and actually seeing a better looking image with the 5DII at ISO 800.  And we don't know what they used to do the comparisons, or what settings.

I have a 5DIII sitting at home waiting for me, so I'll do my own test tonight against my 5DII using the ACR RC and Lightroom to evaluate.  Hopefully I get better results than what I'm seeing on DPReview!

Hey, I'm your friend! My camera has arrived today as well! My box arrived at home and I am looking forward to doing the same thing. Hope I can get off work early...

I am sorry as well. I think I was a little too harsh, so my apologies to you.

174
I predict 85-90 for the 5D3.

175
Lenses / Re: Best lens/TC setup for football game
« on: March 28, 2012, 04:06:44 PM »
Whatever you do, don't use the 70-200mm F/2.8L with 2x TC III for shooting football, unless you just want portraits when there is no action happening.

It will be a slow and unwieldy f/5.6 combination that will be less-sharp than the other options. And f/5.6 with a TC is worse in autofocus and several other ways, than f/5.6 is with a single lens like the other two choices.

Like someone said, you won't be able to keep shooting much as soon as it gets near sunset, no matter which of these options you choose. If you get some afternoon games in late season you'll be fine and then my best option would be the 400mm f/5.6. You can wait in the corner about 75 feet back from the home goal line and two feet out of the boundary line, and pretty much cover every play in the field. You can still get tightly-framed pictures of plays near the touchdown line, and looser framed shots of everything else.

176
EOS Bodies / Re: DPReview Canon 5D mark III noise comparison
« on: March 28, 2012, 03:54:16 PM »
Yeah, I know all that.  And you can't compare the JPEG's generated by the cameras, because most people who want quality already know to shoot RAW and have their computer comvert to JPEG.  Comparing in-camera generated JPEG's is not even close to comparing apples to apples if you want to gauge how the new sensor does at differen't ISO's, as the new Digic 5+ processor is some 30X more powerful than the one in the 5DII, and thus has time to do good conversions of the RAW data.

Sorry, I should have been more positive. You are totally right that RAW is the way to make real comparisons.

The truth that I am trying to communicate is that the sharpness of "RAW" images when posted as JPEG images really depends on the processing done to them. The ultimate maximum level of sharpness depends on the sensor and AA filter of course, but I have seen scores of messed-up comparisons where a "better/sharper" camera's RAW images were just over-sharpened, and then compared to under-sharpened images from another camera.

The classic example of dishonesty with sharpening RAW images is to "prove" to newbies that they should "always shoot RAW." They give super sharp screen images produced by Lightroom from RAW images that are sharpened for viewing on a monitor, side-by-side with unsharpened (or even blurred) JPEG images from the camera at the lowest sharpening level. And then they crow about their conclusion that shooting RAW is the only pure way to take pictures, when it was all cooked.

And the very first word of my post was that noise isn't about sharpness.

I'm not sure what point you are trying to get across, anyway. I am defending the 5D3 based on accurate testing done by DP Review, and you are bringing up an irrelevant controversy about whether experienced shooters know how to shoot RAW vs JPEG and the power of the new Digic 5+ processor.

177
EOS Bodies / Re: Have soft images? This helped me a ton!
« on: March 28, 2012, 03:35:33 PM »
Hooray to this thread! As a past photography instructor I have found the same fact to be true. Whenever soft images come up, 98% of the time it is due to missed focus. Other mysterious factors like "my camera is not sharp" are about as likely to be true as for lightning to strike you.

178
EOS Bodies / Re: DPReview Canon 5D mark III noise comparison
« on: March 28, 2012, 03:28:51 PM »
Unless you shoot JPEG, make sure you select RAW to compare the two cameras.

With RAW selected, and ISO 800, the 5DII actually looks sharper than the 5DIII... I wonder what method they used to do the conversion?

All the images posted to the internet are actually JPEG images (unless the original RAW is downloaded).

So the RAW images in the DP Review comparison tool are actually JPEGs that were processed at unknown settings by the staff of DP Review. The sharpness should not be looked at when evaluating noise.

The sharpness of the RAW images actually depends completely on what sharpness was selected when the images were processed to JPEG. And we just don't know. If you look at the JPEG generated by the camera, then that is at least an apples-to-apples comparison, unless they tweaked the default camera settings, which DP Review claims not to have done.

179
EOS Bodies / Re: DPReview Canon 5D mark III noise comparison
« on: March 28, 2012, 03:22:55 PM »
I'm actually a little disappointed from these noise tests with raw files. It beats the D800, 7D, and 5D mark II but not by much. Looks like the Mark 3 is the best by about .5 stop (and only at high ISO), then the mark II, then the D800, then the 7D which is about a stop below the mark 3. The biggest differences seem to be a usable 12,800 iso vs the other cameras that are not...but on the raw files, the difference isn't huge. This is no Nikon D3S but then again it is 22MP which is still very large.

Are we looking at the same images?  Looking at their 100% crop of the coins... 5D3 at 25K looks about the same as the 7D at 3200.  And, the 5D3 at 12.8K looks much better than the 7D at 3200.

In general, I've noticed that looking at 100% crops of the 5D3 reveals obvious noise at high ISOs, but it's of a much more palatable variety and maintains much better contrast and sharpness than any other camera, especially my 7D.

I see myself using ISO 12,800 regularly and 25K in a pinch on the 5D3 where I am not happy with the noise at 3200 on my 7D and try to stick to max of 1600 ISO there.  That's an effective 3 stop improvement for me.

I agree. I think that there is some confusion about sharpness vs. noise. Sharpness is merely a matter of lenses, focus, and image software processing. The AA filter is not going to play that big of a role in the D800 vs. 5D3 except when it is completely removed. All these images could be made to appear much sharper if someone simply used Lightroom to sharpen for screen display. When strictly talking about noise, someone needs to look at the shadow and the blacks, and at colors for chroma noise (odd splotches of color in areas of a single color, ideally looking at multiple patches of different colors in the image). Sensors always have more green in a Bayer array, so it is better to look at red or blue to see chroma noise. Noise always tends to go down in brighter parts of an image (even at high ISO everything is blown out white with a bright enough exposure, so the noise goes away).

This is a center crop of an image at ISO 4,000 from a Nikon D7000 (night softball game). It is simply to demonstrate that ISO 4,000 of the D7000 is the same as ISO 1,600 of the Canon 7D (basketball game photo). Both of the images are mine--I have obscured the watermark only to keep my privacy.

I have looked at all the samples and as near as I can tell the 5D3 does have at least 2 stops lower noise than the 5D2, and at ISO 12,800 should perform about the same as the Nikon D7000 at ISO 4,000.

For any Canon 7D shooters out there, I would recommend the 5D3 has a must-have upgrade. Anyone wondering whether to buy the 7D or the 5D3 should absolutely go with the 5D3 if you can afford it.

The Canon 7D was simply unbelievable in almost every aspect, and it has filled in just as good as a full-frame camera in many situations for me. It is pretty amazing that another camera came out that was 1 1/3 stops better (Nikon D7000), and it is like a miracle that another camera exists which is 3 full stops better than the 7D (3 stops is eight times better, for those who don't know the vernacular). Don't hesitate to purchase the Canon 5D Mark III!

Pages: 1 ... 10 11 [12] 13