January 28, 2015, 04:24:31 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 - jrista

Pages: 1 ... 67 68 [69] 70 71 ... 326
1021

What camera out there, anywhere, offers any kind of significant advantage (and by that, I mean the 2+ stops DR improvement the Sony Exmor cameras get at ISO 100) in DR over any other camera, AT HIGH ISO? I mean, if such a thing exists...I'd like to know about it...but frankly, aside from the 1D X at ISO 12800, 25600, and 51200 (which is actually less than a 2-stop difference compared to any other camera), I don't think it does.


The goal posts seem to be shifting. The discussion above was about dynamic range in general for wildlife. Not specific brands.

I think developing this tech is just as important (regardless of who develops it at higher ISO's) as IS and other improvements within the context of wildlife photography.

Well, DR discussions usually involve just two or three specific brands, and the tone of the conversation is always the same. I guess I assumed, apologies.

However, you handily skipped past the FAR more important part of the post you quoted. I think it's an important discussion, and I believe your answers are important, because fundamentally, at high ISO, the available dynamic range is ultimately bound by physics, not technology. So, if you don't mind:

Quote
We disagree here. It's as simple as that. I could point you to my own work, at http://jonrista.com (since you insist I make the case myself), as well as the work of numerous professional bird and wildlife photographers who have been using Canon gear for years, and never seem to complain about the lack of DR at the very high ISO settings they use. Not only that, their work is phenomenal.

You have to understand, unless you are talking about shooting wildlife at ISO 100 and 200, there is very little difference in DR at higher ISO settings, with the exception of the 1D X (which has a good stop and a half ADVANTAGE at VERY high ISO settings.) Did you miss my post where I shared the DR numbers from sensorgen for the D810, D800, 5D III, and 1D X? I thought that would have put the issue to rest. Are you talking about wildlife photography shot at ISO 100 or 200, or are we talking about your crepuscular light wildlife photography, at ISO 12800?

Could you answer the questions posed? Are you shooting wildlife at ISO 100 and 200 on a regular basis? If so, how do you reconcile that with your prior comments about crepuscular light and ISO 12800? Is there a camera out there that gets 14 stops of DR at ISO 12800? Is there a camera out there that gets more than 10 stops of DR at ISO 12800?

At high ISO, with the exception of one or two VERY expensive cameras, there is little to no difference in dynamic range! It doesn't matter if your using a D810, an A7r, a or a 5D III. There is less than a stop difference between the lot at ISO 12800. They are all full frame cameras, and in a normalized context, they will all perform roughly the same in crepuscular light for wildlife. You can eek a bit more performance out of a 1D X or a D4, but were still very far from the 2+ stop advantage an Exmor has over most other sensors at ISO 100.

If high ISO DR is critical to your shooting style, I still think Canon has the advantage because of ML. I found the thread that discusses their high ISO DR improvements (which, on the 6D, bring you to 1D X/D4 levels of DR):

http://www.magiclantern.fm/forum/index.php?topic=10111.0

According to this thread, the high ISO DR tweak does NOT use the dual ISO technique that reduces vertical resolution...it uses a tweak of the downstream amplifier to avoid clipping the signal, thereby preserving about 1/2 a stop additional DR at all ISO levels.

1022
EOS Bodies / Re: Canon to Make a Big Splash at Photokina? [CR2]
« on: August 11, 2014, 12:23:22 AM »
Umm...toothpaste? That's where this conversation went? Seriously....?  :o

Is there some variant of Godwin's Law that applies to toothpaste?   8)

Haha, maybe! :D We could call it Orangutan's Law, if no one else has coined it yet. :P

1023
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 11:18:29 PM »
This is curious because sometimes I have 2 or 3 photos out of focus for no reason then. I assume I lock on to the subject by placing the subject in my focus point and depressing the shutter halfway (or using the back button).

If this is the indeed the case, I do have a problem with my 1DX because that is exactly how I do it.



But we are all clear on my 1DX I have to keep my focus point on the subject I am tracking where the A77ii or A6000 I do not?

No, you do not. The 1D X will change which focus points are used, because it is tracking for you. You can either use all points mode, or one of the zone modes, and it will use all of the available points in the selected mode. You do not have to do anything as far as keeping any particular point on the subject once tracking has started (and that occurs as soon as the subject is locked for the first frame.)

If that is NOT working for you, then you have a problem with your 1D X.

You keep saying focus point. That makes me think you are using single point AF mode. You don't want to use that mode for sports or any kind of AF that requires tracking. You want to use either AF Point Expansion Mode (which will utilize the 4 or 8 points surrounding the selected point), AF Zone modes (which let you pic a grid of points smaller than every point in the array), or all AF points mode. If you want to have some control over what region of the frame is used for AF, but want to use a lot of AF points for tracking, you should be using zone mode.

If your using a single point AF mode, then that's your problem. You've then configured the camera to use only one single point, and it will only ever use that point until you change it, or choose a different mode.

1024
EOS Bodies / Re: Canon to Make a Big Splash at Photokina? [CR2]
« on: August 10, 2014, 10:47:34 PM »
Umm...toothpaste? That's where this conversation went? Seriously....?  :o

1025
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 10:43:54 PM »
But we are all clear on my 1DX I have to keep my focus point on the subject I am tracking where the A77ii or A6000 I do not?

No, you do not. The 1D X will change which focus points are used, because it is tracking for you. You can either use all points mode, or one of the zone modes, and it will use all of the available points in the selected mode. You do not have to do anything as far as keeping any particular point on the subject once tracking has started (and that occurs as soon as the subject is locked for the first frame.)

If that is NOT working for you, then you have a problem with your 1D X.

1026
Here is a normalized comparison of Alan's lapwing images:



I think the IQ of the 7D image has improved to the same level as the 5D III image for the subject. There is still more background noise, however I averaged the background with a median filter and measured the levels. The 7D image has an average level of 99-101 (RGB channels), while the 5D III image has an average level of 106/125/150 (RGB Channels). The brighter background level is helping the 5D III image a bit from a noise standpoint.

(Note, noise is worth in both images here due to GIF format.)

1027
I actually had at one stage a 5dIII, 70D and 7D (with 300mm f/2.8II+2xTCIII) and tested them in good light by photographing lapwings on a raft at extreme distance. All the following shots are 100% crops, processed identically in DxO and with PRIME noise reduction, that virtually eliminates noise. Top is the 70D, which is 671x711 pixels; middle 7D; middle 7D, which is 643x655 pixels; bottom is 5DII, which is 483x447 pixels. In the next post, the 70D is tested against the 5DIII. Under these reach limited conditions, there seems little, if any advantage of using the APS-C.

Just off a cursory glance, it looks like the 5D III is better lit. If you don't mind, I'm going to downsample the middle 7D bird to the same size as the 5D III bird, so we can compare properly normalized results.

1028

I would say the results of many professional bird and wildlife photographers, who do exactly what you describe for a living, and use Canon cameras to create phenomenal works of art, would prove this post to be fundamentally wrong.

Don't hide behind platitudes, Jrista. Make the case for yourself.

This is your quote:

Quote
Anyway, when it comes to bird and wildlife photography, dynamic range is just not an issue.

It's a huge issue. Unless you're shooting with flash, or baiting animals (two practices I find unethical), DR is going to play a huge role.

We disagree here. It's as simple as that. I could point you to my own work, at http://jonrista.com (since you insist I make the case myself), as well as the work of numerous professional bird and wildlife photographers who have been using Canon gear for years, and never seem to complain about the lack of DR at the very high ISO settings they use. Not only that, their work is phenomenal.

You have to understand, unless you are talking about shooting wildlife at ISO 100 and 200, there is very little difference in DR at higher ISO settings, with the exception of the 1D X (which has a good stop and a half ADVANTAGE at VERY high ISO settings.) Did you miss my post where I shared the DR numbers from sensorgen for the D810, D800, 5D III, and 1D X? I thought that would have put the issue to rest. Are you talking about wildlife photography shot at ISO 100 or 200, or are we talking about your crepuscular light wildlife photography, at ISO 12800?

What camera out there, anywhere, offers any kind of significant advantage (and by that, I mean the 2+ stops DR improvement the Sony Exmor cameras get at ISO 100) in DR over any other camera, AT HIGH ISO? I mean, if such a thing exists...I'd like to know about it...but frankly, aside from the 1D X at ISO 12800, 25600, and 51200 (which is actually less than a 2-stop difference compared to any other camera), I don't think it does.

1029
Yes, having more DR can certainly make things easier, but good technique can totally eliminate the need


It can't, unfortunately. Actual wildlife chooses the light. The photog has to adapt to this.

We can do our best to maintain desired angles and minimize the requirement for dynamic range, bu there will always be situations when shooting wild animals where increased dynamic range is beneficial.

And I agree that technique is important. But nature doesn't care what your camera settings are. If you are in the field long enough, she's going to throw you surprises. These are almost always the more interesting photos, IMHO.  Yeah I can spend days filming a hawk's face up close while it perches, or film animals feeding.

But what I really want to capture are those magic moments out of nowhere, the moments that tell a vivid story in one, simple frame. Here, we need all the tools in the tool box, and increased dynamic range can mean the difference between a wall hanger and the delete button.

I would say the results of many professional bird and wildlife photographers, who do exactly what you describe for a living, and use Canon cameras to create phenomenal works of art, would prove this post to be fundamentally wrong.

1030
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 09:38:13 PM »
Maybe I am misunderstanding the Sony benefit but with one in my hand it works much better and faster than my 1DX.

I use Case 5 mostly and if someone gets in the way long enough, it switches to the person in-between. This was not the case with the a6000. That also means you have to maintain your focus point on the subject, this is not the case with the Sony. It passes it off from one point to another. It literally moves the focus points as you track from one side of the EVF to the other side if you get behind or lost tracking your subject. If my 1DX does that, I am completely out of the loop.

If you shoot sports, Case 5 is probably not the best option. That one uses a medium tracking switch rate (the "Tracking Sensitivity" setting), so it's designed to jump shortly after a closer subject moves into the frame. Case 5 and 6 are what I use for bird photography. Birds can and do erratically change direction on a dime...it isn't quite that way with sports.

You want to be using Case 2 if you don't want the camera to switch subjects once it's tracking, as that uses -1 for the Tracking Sensitivity setting. You can edit it and put it to -2 if you want, then it will really stick to a subject, even if multiple other potential subjects pass in front of or near to your tracked subject.

1031
Animal Kingdom / Re: BIRD IN FLIGHT ONLY -- share your BIF photos here
« on: August 10, 2014, 09:07:04 PM »
I think so - at least, there wasn't a body anywhere nearby!

LOL.

Ccoo-coo-oo-woo-woo-woo-crwaak! *shakes head, wobbles a bit* "Aww, man, that messed up my dove-love groove!"

1032
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 09:01:07 PM »
Once you use the Flex point to lock on to a moving subject, you no longer have to keep that focus point on the subject. The flex point passes the focus points off to other focus points across the EVF. You can let the subject move across the FOV and that subject stays in focus. The Flex point locks focus when depressing the shutter button half way. Whatever you pressed the shutter button halfway down on it stays locked on until it exits the screen or it 

This is not the end all be all feature. No, it is not like a 5Diii or 1DX, I have both and can attest to this.

This is far more sophisticated and it is progress by a camera manufacture. Real progress. I really hope Sony pushes Canon and Nikon to up their game, soon.

What your describing is exactly how Canon's 61pt AF system works in all points mode. It does EXACTLY the same thing...it will use whatever focus points, out of the entire grid, to keep the subject it originally locked onto and is now tracking, in focus.

I also own the 5D III...that's exactly how it works for me. So either you are not using your 1D X and 5D III correctly, or your just not using the right AF mode on them.

Sony's flex point is no more sophisticated than what Canon introduced several years ago. For that matter, Nikon has been doing this for even longer! And Nikon's AF system, which is also tied into it's high res RGB metering sensor, has a large library of reference images that it uses to identify what kind of subject your tracking (which supposedly gives it cues as to subject behavior...however it still doesn't seem to work as well as Canon's 61pt AF system in practice...both the D800 and D4 these days don't perform quite as well as the 1D X in sports and other high action shooting based on reviews.)

1033
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 08:56:34 PM »
I just watched the video, and wow, what a load of crap! This is what Canon's 61pt AF system (and before that, their 45pt and 19pt AF systems) have been doing for years! This is exactly what Canon's AF systems do in all points mode...they LOCK onto a subject, then track that subject. With the 5D III and 1D X, the AF system is also very highly configurable, and comes with several preconfigured AF modes for different kinds of subject motion, as well as full custom configurability. (You can even assign different AF modes to different custom user dial modes for quick and easy access.)

Canon's system allows you to do full subject tracking in all points mode, but also has several zone modes (where instead of using all AF points, it will just use a selected zone of AF points that you can move around the entire grid), as well as expansion modes (where it will let you pick a primary AF point, and then utilize either the four or eight surrounding points to assist). Canon's tracking is also better than what was demonstrated in the video...the reviewer was trying to say that the camera did not lose focus on the guy in red, but it WAS losing focus...because by the end of the sequence, both the red and black guys who were crossing paths were OOF. Canon has a configurable tracking "switch rate"...it will try to keep focus on it's previously tracked subject (using a hysteresis of the previous AF frames) for as long as you configure it, then switch to a closer subject. You can configure this tracking switch rate from very slow through very fast. Canon wouldn't have lost focus on the red player at all, period.

Another thing about Canon's AF system, especially on the 1D X, it would NEVER lose the subject's face. In the video, the Sony was focused on the guys chest and knees most of the time, but no one want's a knee in focus and the face slightly out of focus. The 1D X ties the meter and AF system together via a dedicated processor that can do face recognition (which, actually, works with birds and dogs as well, possibly other wildlife. ;)) Once the face is identified, Canon can maintain the AF lock on the same subject, and on his face, the whole entire time.

So, I'm sorry, but the reviewer in this video is full of crap when he says this kind of AF system has never been done before. MASSIVE LOAD OF BULL SH*T!!

1034
Jon
I am using the same source of information that you quoted for number of pixels on target - Clark.

http://www.clarkvision.com/articles/does.pixel.size.matter/

Quote: "The images in Figures 10 and 11 illustrate that combining pixels does not equal a single image. The concept of a camera with many small pixels that are averaged to simulate a camera with larger pixels with the same sensor size simply does not work for very low light/high ISO conditions. This is due to the contribution of read and electronics noise to the image. Again this points to sensors with larger pixels to deliver better image quality in high ISO and low light situations."

I think your misinterpreting what he is saying. He isn't saying that read noise increases as pixels get smaller. He is saying that read noise represents a larger percentage of the image signal at higher ISO than at lower ISO, and the higher SNR of larger pixels offsets that. That is a true statement.

There are other factors to consider about high ISO, though. I think it was Lee Jay who stated it earlier in the thread, but read noise is lower with smaller pixels. Look at Sensorgen.info, which is empirical data, and look at the read noise levels (that is ALL read noise...dark current contribution as well as downstream electronics contributions). The 7D has ~8e- RN @ ISO 100, while the 5D III has ~33e- RN @ ISO 100. Since you can fit 2.1 7D pixels into the space of a single 5D III pixel, the "equivalent RN" of binned pixels would be ~16.8e- RN, still half what the 5D III has (I really don't understand why Canon's newer sensors have such high read noise...their RN levels are REALLY bad...but maybe it's a tradeoff they make for their high frame rates for the pixel count or something. I can't wait till Canon moves to an on-die CP-ADC design...) I used the word binned there, because it's important. If you average pixels together in post, the random component of read noise drops. Only the non-random component of read noise will strengthen. Canon in general has a handicap there...they have some strong pattern noise at low ISO on the 7D, and even some still on the 5D III. At least it only really shows up at lower ISO settings.

From a read noise standpoint, the 7D is actually very good. Some of the BEST ultra low noise CCD astro sensors on the market, one of which is the Sony ICX694, have ~5e- RN. At 5e- RN, that is one of the lowest read noise levels on the planet. There is a table of read noise levels on an astro site somewhere (I don't have the link handy now), and the lowest standard-gain RN I've ever seen was 4.5e-. Most DSLRs seem to bottom out at around ~3e- at high ISO (at least, according to Sensorgen.info...Clark's results are a little more linear, and his results indicate RN levels drop to as little as ~2e- at their lowest). Regardless of whether RN is 3e- or 2e-, it's EXTREMELY LOW, and a minor contributor to overall high ISO noise in general.

Larger sensors perform better at high ISO because they have the potential to gather more light in total. This thread is all about the reach limitation, in which case, framing identically is not an option. When framing identically is not an option, ** assuming all else is equal ** (I'm REALLY trying to emphasis this point, because the 7D and 5D III are not "all else equal"...the 70D and 5D III would be on more equal technological footing), then pixel size does very little to nothing to improve IQ. There is the fill factor issue to consider...at some point, you reach a small pixel size where, even with a small transistor/wire size, the sheer number of pixels necessitates contributing a meaningful amount of sensor space to that wiring unless you use a BSI design. If the small pixels are small enough that fill factor reduces total photodiode area by a meaningful amount, then averaging pixels is not going to be completely capable of normalizing noise.

The primary reason full frame cameras do better in low light is because they can gather more light in total. If I frame my subject identically with an APS-C and FF camera, then the FF camera is gathering more light in total for my subject. Once normalized, the noise will be lower with the full frame sensor. Because the subject is relative to the frame, instead of absolute within the frame. I could use two full frame cameras, one with larger pixels and one with smaller pixels. So long as I frame identically, all else being equal, the normalized results will exhibit the same noise. The only difference would be that one image is crisper and sharper than the other...and that would be the FF sensor with more, smaller pixels.

I kind of wish I had a 70D at my disposal now, so I could demonstrate with equipment of equivalent technology generation. The 70D has about 6000e- more FWC than the 7D, which is significant, considering the 7D only had about 20ke- to start with. (It's a 30% increase.) Averaging a 70D image to the same size as a 5D III image should have the effect of reducing noise to very similar levels...close enough that you would have to scrutinize to identify any differences.

+1 My biggest mistakes are when my camera is set for point exposure for birds against a normal background and one flies by against the sky and I don't have time to dial in +2 ev to compensate or vice versa. Two more stops of DR would solve those problems.

This is a case where you want more DR to eliminate the need for the photographer to make the necessary exposure change. If you encounter this situation a lot, I highly recommend reading Art Morris' blog, and maybe buy his book "The Art of Bird Photography". He has an amazing technique for setting exposure quickly and accurately, such that making the necessary change quickly to handle this situation properly would not be a major issue.

Personally, I wouldn't consider this a situation where more DR is necessary. It might be a situation where more DR solves a problem presented by a lack of certain skills...but it is not actually a situation where more DR is really necessary.

Autofocus is not necessary, automatic metering is not necessary, IS is not necessary. The fact is that having those features makes it a lot easier, and having an extra couple of stops of DR would also make it easier. It is not a question of lack of skill but having a camera that eliminates one more variable.

Well, I think were getting into semantics now, so I won't really press the issue. Yes, having more DR can certainly make things easier, but good technique can totally eliminate the need, and can be just as easy in practice. That's what I was trying to say.

1035
Third Party Manufacturers / Re: Sony A77II
« on: August 10, 2014, 07:39:28 PM »
I'm not sure WTF Canon and Nikon are doing but Sony is innovating to the point I am becoming VERY tempted to completely jump ship.

An A77ii and A6000 look really good and I could afford to purchase a new body every year.

Don't forget that Sony uses a lossy "raw" file format. Their technology is good, but currently they are gimping it with a crappy image file format (which, given that it is lossy compressed, cannot legitimately be called "raw").

Pages: 1 ... 67 68 [69] 70 71 ... 326