Now then kiddie winkies ... behave yourselves.
Now then kiddie winkies ... behave yourselves.
Hi Dave, and many thanks for your help. Hope these will do (they are a little under the full 1500 x 1000, I realised I didn't know how to do an accurate pixel crop in Lightroom!) They are contiguous, with just a view pixels of overlap, I think.Dave, Can you give us a couple of 1500 x 1000 px crops from the full image, so we can see them at 100% without TinyPic downsizing them?
The air conditions were quite complex. It was about 9 in the morning and the air temperature wasn't too high, though the surrounding plains would be warmer. The green patch the birds are heading into is a permanent spring (that's why they fly in) so that air would probably be cooler and moister.
Here are the crops. They are from a RAW .CR2 image imported into Lightroom, then cropped and exported as JPEG, with no sharpening applied.
Thanks again,
Dave
Hello again William, I am sorry you got irritated.
What is "leading edge blur" and what is the mechanism whereby the leading edge of an object becomes blurred in the direction of motion? Does blur also occur at a trailing edge? How does the sensor "know" the difference in a still picture?
A good link would be appreciated.
These are genuine questions - Googling kept showing stuff to do with video and LCD displays.
Just so's you know, I was not "guesing" and neither was I "paddling" - by using such terminology you are descending to my level.Analysis is analysis and proof is proof.
If you do not like dealing with factual analysis and best practice to conclusion and want to paddle in procedures suited more to guesing than actually finding out what is/are the problem(s) - then that s fine by me:
I used the profile tool in ImageJ around the head of a standing bird and found equal blur in the X and Y directions - similarly for the flying birds from which I naively deduced that his shutter speed was fast enough for the shot.
Dave,
Is there any chance of a 100% crop of the two standing birds at lower left?
My apologies to the Forum for ruffling feathers . . .
. . while thinking about the birds, I panned (left to right) across the ISO test chart on my monitor.
Immediately noticeable is the incorrect color rendition at the leading and trailing edges:
Thinking that Mr Bayer was at work, I took a Foveon shot:
So, the question is: if a similar discoloration exists in e.g. the birds' white faces, can motion blur [relative to the camera sensor] be said to be present?
Last edited by xpatUSA; 9th January 2013 at 08:17 PM. Reason: cain't hardly write good English
Hello back to you.
Re your Questions and Statements - here are my responses. Capitals in this post, as with other posts I make are used for EMPHASIS of IMPORTANT or TECHNICAL WORDS – I am not shouting.
One can detect blur at both the leading edge and the trailing edge of an area – for example the Bird’s Wing – or the two edges of ‘things’ – the ear; the finger etc. …
It easier or more difficult to detect, depending upon mainly two factors:
- the light (which in this case is soft and is why I mentioned I could not detect it all over) and
- the colour/ contrast of the edge(s) concerned.
Direction is determined by contrasting and comparing the blurs. It is usually determined as MOTION BLUR by detection of the same SIZE blur at edges which are the same approximate distance from the camera.
MOTION BLUR then can be determined as CAMERA MOTION or SUBJECT MOTION by interrogation of BLURS on known STILL OBJECTS in the frame.
In some cases, with using other information, a good evaluation of speed, of the SUBJECT and or THE CAMERA can also be postulated or even confirmed, with enough data and repetition of the same results.
These are visual and 'hands on' and much easier to be taught face to face and with examples and is quite difficult to detail in words without writing an essay and being very technical: but IMO the above a concise overview in a moderately technical point form.
I have been at times contracted as a Specialist, apropos the forensic investigation of photographs, mostly from surveillance cameras, but other images also: perhaps these phrases, 'Leading Edge Blur' and 'Trailing Edge Blur' are part of a lexicon which is used in a very small circle: but they are indeed phrases, which are used.
Until a few seconds ago I has no idea whether there are any links, or not, if one googles - ‘Leading Edge Blur’. But for fun, I just did exactly that.
On the first page of my browser, this abstract came up as the fifth hit:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2918382/
It appears on first glance to be using leading edge blur in imagery for medical analysis (and maybe on video monitors) – I didn’t read much of it. But is certainly contains images of leading and trailing edge blur, though as I understand the study it is actually detecting how sharp those edges are – so it is looking for the least amount of blur for conclusion – but as I mentioned I didn’t read much of it.
And this conversation came up as the eighth hit:http://www.fxguide.com/forums/showth...ion-Blur-Query
I only glance read the conversation, but the simple explanation of ANALYSIS of DENSITY seems valid to me on first glance (for DIGITAL IMAGES)
Maybe my search engine is skewed toward these procedures - I don’t know, but to the best of my memory - I have never searched that term before.
***
Apropos “guessing” and “paddling” – these comments were not emotive but specifically related to your methodology and specifically to what you presented on this thread.
This was:
1. Taking only one small section of the image as the test data presented.
2. Making a conclusion from that one area.
3. (This is a most important bit) – Basing a CONCLUSION upon what was NOT EXISTING.
4. (This is THE MOST IMPORTANT bit) – stating the conclusion based upon the ABSENCE of something is PROOF.
Therefore: ‘living proof’ (your words), derived by that methodology, is indeed “guessing” and “paddling”.
***
Please note: my using the terms ‘paddling’ and ‘guessing’, was not sarcastic and certainly not even close to the arrogant schoolboy sniping, previously direct to me and I totally dismiss any such insinuation: I would be happy for this line of conversation and insinuation to be dropped.
***
Your initial apology that your sarcasm directed at me was unwarranted and irritated me is accepted and I require no more talk of it and if you wish, I am happy for there to be no hard feelings.
WW
ADDENDUM:
You were thinking and writing as I was replying to you.
Your analysis above and using a Foveon-like Image is one technique.
What you have discovered is that the two birds in your sample are moving in (almost) opposite directions relative to EACH OTHER.
Your analysis has not yet determined (though close to it) if there is BOTH CAMERA MOVEMENT and SUBJECT MOVEMENT.
Even from this sample you’ve made, we can strongly postulate that the 1/400s caught SUBJECT MOVEMENT of the Birds which were flying. More samples from FLYING BIRDS would substantiate.
Apropos the Bird which is standing – that HEAD could have been moving – so we are NOT yet at the stage to conclude that there was CAMERA MOVEMENT.
The soft light caused me difficulties – but looking closely at various blades of the GRASS and DIFFERENT AREAS of the STANDING BIRDS (I mean different areas of each bird's BODY) I do still believe that some CAMERA MOTION was captured – but I have not yet - and I don’t have the time at the moment - to interrogate the crops which have been provided with any degree of stamina that would hold water in Court.
Also these notes are directed as much to the OP as to the respondent – and I trust they are useful to both and many others too.
Last edited by William W; 9th January 2013 at 08:49 PM. Reason: Addendum Added
Last edited by xpatUSA; 9th January 2013 at 09:15 PM.
Ted, Bill,
Couldn't the red/gren edges be Lateral CA (chromatic abberation) in the lens?
For the benefit of those who don't know; this can be confirmed (I use the word loosely) IF the errors are concentric about the centre of the lens and opposite on opposite sides.
I lost the plot with which bits of image we were looking at and which directions the errors were
I did study the crops closely but did not come to a firm conclusion on it being CA, so I think I may be mistaken.
Dave,
The only conclusion I have come to on the 100% crops is that the problem IS a combination of various causes;
a bit of camera shake,
a bit of focus error (I do believe the closer birds are a bit sharper),
a bit of subject movement,
a bit of low contrast due to flare and slightly diffuse lighting,
a bit of those coloured edges (CA?).
All these things are contributing to a lacklustre image - I take many myself, so don't feel bad.
I had a go at one of the 100% crops with my 'pet' sharpening regime for such pictures;
Your crop repeated here;
My edit:
This is one occassion when you should just view them here one above the other and not click the image to compare in the Lytebox
Any good?
I only downsized by about 2:1, the full size image will require closer to 3:1, so should look a bit better.
UPDATE:
If you can find a way to get the full size RAW to me (e.g. Drop box or MediaFire, I could have a go and tell you what I did.
Cheers,
Last edited by Dave Humphries; 10th January 2013 at 07:37 PM. Reason: removed error
Yes. And probably some is.
If the edges are seen as "a stand alone" interrogation, then concluding it is "only" CA, could be one possibility.
Note that in my first post I previously mentioned the lighting conditions.
Note also I mentioned the possibility of a filter and also what I thought was an unusual amount of CA for any of the three lenses that I ASSUMED was being used: to ‘eliminate’ as a possibility, it being "just CA", one would have to be reasonably familiar with the lens.
Note I also stated that I am not familiar with that Tamron Lens.
***
However, there are other methods:
PART OF the essence of forensic evaluation of (different) SUBJECT MOTION or establishing SUBJECT MOTION against a STATIC SUBJECT is taking many samples from similar areas and making a contrast and a comparison between EACH OF THOSE SAMPLES.
I didn't look closely at the AREA from which Ted's took those two Sample Birds – perhaps they were in the SAME AREA.
On the other hand, note the samples images I posted where I attributed CAMERA MOVEMENT with the letter “A” – those samples I took from DIFFERENT AREAS of the scene:
***
One (exhaustive) method would be to group the Bird in PAIRS - and then seek out DIFFERENCES and SIMILARITIES between the PAIRED Samples - i.e. that is NOT the differences between each BIRD in each individual PAIR – but the differences (if any), in the similarities and differences between the individual birds in each pair.
Then we will get a matrix of PAIRS; and if there is a TREND we might be able to draw conclusions.
Note that just with FIVE BIRDS (two on the ground and three flying) we get SIX PAIRS to begin our matrix:
***
For clarity - I am not going to bet, nor was it my intention to suggest that I would bet a Mars Bar, that I am 100% correct is saying that there is SUBJECT MOVEMENT and also CAMERA MOVEMENT in the sample image.
It is just my considered conclusion that such is so – and that conclusion drawn from a COMBINATION of many factors NOT LIMITED TO but including the quick but yet 'key-point' sort of detailed analysis of the edge blurring, which I originally made.
***
A point I meant to mention before, but was sidetracked – HEAT HAZE or VAPOUR DISTORTION could well be a factor of the GENERAL SOFTNESS – and I didn’t consider that initially.
***
In any case and taking a really simple standpoint to provide PRACTICAL FEEDBACK addressing the Original Posted Question:
- Tv = 1/400s is generally too slow to stop Birds.
- Tv = 1/400s is generally too slow for Hand Held 300mm lens on APS-C Camera
- The Scene was dim with ‘No Shadows’ – ISO 100 was a poor choice to allow the maximum leverage of Shutter Speed and Aperture.
- F/7.1 was likely ‘just at the edge’ of a ‘sensible’ Aperture for that lens shooting at FL = 300mm. arguably the lens would improve at F/8~F/11.
- Panning the camera, when there are DIFFERENT directions of SUBJECT MOVEMENT – seems an odd choice to make.
- Panning with VC engaged (probably? ? ?) is the wrong choice for that lens – VC should have been turned off ? ? ? (not 100% sure on that particular TAMRON lens but it seems to be a logical statement considering my general understanding of the technology).
- ‘Sharpness’ has many facets and the Digital Image REQUIRES sharpening.
- The 600D probably has about 1 Stop of ‘push’ in it whereby the Highlights can be recovered in Post Production – so learn how to push it, especially in low contrast scenes if you want to maximize the (appearance of) sharpness in the Final Image.
- Understand (and experiment with) how the Canon TTL Metering System works – it was a big broad scene that was being metered “evaluative” – If you want the crispest ‘birds’ then value ‘correct exposure’ for the birds and don’t place so much emphasis about the ‘correct exposure’ for the scene: and certainly do not give total control to the camera, for the exposure.
WW
Last edited by William W; 10th January 2013 at 12:53 AM. Reason: corrected typo - 60D to '600D'
I am not convinced that the original image is OVERexposed.
As per my previous post: I maintain that the sample is UNDERexposed - with respect to ‘correct’ exposure for the MAIN SUBJECT of ‘Birds’ in a Daylight Scene which exhibits the characteristics of EV12 to EV13.
Also as previously mentioned, I believe that this UNDEREXPOSURE is detrimental in so far as it exacerbated the appearance of softness and will LIMIT the real ability to make the final image as sharp as it might be IF the exposure (for the Birds) had have been ‘correct’.
Also as previously mentioned, the 600D will have some head room above what in declares via histogram or blinkies the ‘correct’ exposure. And if pushed and all that head room is used then one can recover the highlights in post production.
***
A quick sample and thumbnail sketch:
The 100% crops provided are ‘without any’ Post Production – so just a quick back of the envelope test, here are three of the same sample – the original 100% crop is on top:
The middle image is a facsimile of an increase in exposure of about ⅔ Stop and (before downsizing and posting) there are no blown highlights.
The bottom image is a facsimile of an increase in exposure of about 1 Stop and (before downsizing and posting) the top left hand bird’s wing is just beginning to blow-out.
*
So taking into account all the ups and downs with web postings and the latitude I expect in the 600D – I reckon there is a safe argument that ‘the Birds’ (i.e. the Main Subject) could have been photographed (in raw capture) with an increase in exposure of about 2 STOPS and the highlight detail of the white could be easily extracted in post production.
i.e. the original was pulled at: F/7.1 @ 1/400s @ ISO100
I am suggesting the ‘correct’ exposure for the Birds would have been closer to: F/7.1 @ 1/400sec @ ISO 400.
I note this in closer keeping with the ‘correct exposure’ for Subjects in a Daylight Scene which is at about EV12~EV13.
Those exposures would range between:
F/8.0 @ 1/400s @ ISO400 for EV13.
F/5.6 @ 1/400s @ ISO400 for EV12.
WW
I was bothered about shooting a monitor image, what with frame rates and stuff that I know little about. So I repeated the exercise, hand-held on a real target. Sigma SD10 with Sigma 70mm EX DG macro, f/8, 1/32 sec, ISO 100.
But first, did a check for CA which which was mentioned in another post earlier:
Sorry about the focus.
And finally a panning result, right to left as if following birds . . .
Not a trace of asymmetric discoloration :-( . . . . I also panned in the other 3 axes but still none.
From which I must agree that asymmetric discoloration in the OP is CA - especially noticeable at high-contrast edges as is the thing for CA. However, there may still be a clue in the degree of CA being similar all over the image as opposed more noticeable around the periphery . .
yours humbly,
Last edited by xpatUSA; 10th January 2013 at 06:15 PM.
I stand corrected Bill,
Having studied all the histo.s on the original image and 100% crops, the highest luminance was between 242 and 246 (out of 255). Thanks for putting me straight.
I have removed the incorrect comment from my post above.
Cheers,
Hello, it's the OP again. I was a bit worried that I had inadvertently started the first Australian/American conflict, but very glad that all now seems smooth.
First, many thanks to everyone who contributed - I certainly didn't expect such a rich thread. I knew that the image wasn't really rescuable (is that a word?), and I did want to know what errors I had made.
So a first thanks to those who showed me that the image could really be improved (I had done, but not posted, some of my own PP - but nothing as good as shown here).
Thanks to Bill and Ted for a very erudite discussion. I could follow some of it, but even as a (long ago) PhD level scientist in a physical discipline, I'd have to go back to school to properly appreciate the points made. Much food for thought there too.
I've certainly learned a lot:
- Most important (which no-one mentioned - I don't think you can see it in the EXIF). NEVER EVER rely on P mode when attempting a difficult shot, and related
- Understand when a shot is difficult, and THINK about what is needed.
Taking some of Bill's points:
- Tv = 1/400s is generally too slow to stop Birds.
Yes, didn't think clearly enough. Although, other bird shots at a similar shutter speed came out far better
- Tv = 1/400s is generally too slow for Hand Held 300mm lens on APS-C Camera
Ditto, though with a functioning IS/VC it should have been OK
- The Scene was dim with ‘No Shadows’ – ISO 100 was a poor choice to allow the maximum leverage of Shutter Speed and Aperture.
Too true - but I didn't choose it. The camera did. See learning point number 1, above
- F/7.1 was likely ‘just at the edge’ of a ‘sensible’ Aperture for that lens shooting at FL = 300mm. arguably the lens would improve at F/8~F/11.
- Panning the camera, when there are DIFFERENT directions of SUBJECT MOVEMENT – seems an odd choice to make.
All the birds were moving right to left, or were stationary. The birds were flying in from the right and I was panning as they came and deciding when to shoot. At this point they were starting to land, but I have other images when they were in flight which suffer from the same issues.
- Panning with VC engaged (probably? ? ?) is the wrong choice for that lens – VC should have been turned off ? ? ? (not 100% sure on that particular TAMRON lens but it seems to be a logical statement considering my general understanding of the technology).
Yep. I'm pretty sure this was a poor choice. I plan to do some experimenting.
So thanks again, lots to think about, and bye for now.
Dave
AH! Thank you.My words – [The Scene was dim with ‘No Shadows’ – ISO 100 was a poor choice to allow the maximum leverage of Shutter Speed and Aperture.]
That explains a point I couldn’t unravel – the EXIF on my reader seemed to indicate ‘P Mode’ – but I wasn’t sure – and I forgot to ask.
Two further points are:
IF the camera selected the ISO ‘automatically’ that was not because you had P Mode selected, but rather because you had ‘AUTO ISO’ selected in the menu – the two functionalities are separate.
Also, please take time to digest what was written about the TTL Metering: it is more about the understanding and the interpretation of the TTL Metering System and not so much about the Camera Shooting Mode selected.
Please note that - The Photographer has as just as much control over the exposure when using: P Mode; Tv Mode; Av Mode - as if he were using: M Mode.
It is just when one is using any one of the three mentioned ‘Automatic Modes’, the TTL Meter chooses the initial exposure: the Photographer can always manually override, that initial choice.
WW
PS - Ted seems a very nice Bloke - I wouldn't worry about what was then . . . this is now: life's too short to stay cranky for more than a nanosecond. I enjoyed our discussion, also.
Hi Dave,
OK got the CR2 RAW via DropBox ...
Opened in Photoshop CS5 (because my Elements ACR version is too old for a Canon 600D).
In ACR (Adobe Camera RAW 6);
Used straighten tool to level the 'horizon' and get trees vertical.
Used Auto, which added +0.80 stop, supporting Bill's opinion.
Used recovery slider at 40 to save the by now blowing highlights on the top of some wings and give room to apply LCE later.
Moved Blacks ot zero for same reason.
Found the most suitable "Tamron 70-300mm" lens profile, but decreased the CA adjustment to 70 to minimise left/right CA at either edge. This seemed to leave some in an up/down direction, but I couldn't seem to affect that, so if necessary, I'll deal with it later.
All ACR Sharpening/Detail set to 0 except a bit of colour noise reduction (20, Det 40).
WB "As shot" was 5150 and *2, after playing around with the dropper tool and presets, I reckon this wasn't far wrong (maybe you used a WB card), anyway I eventually settled on 5100 and +8. ( tad less green and a tad more red).
Saturation Vibrancy and Clarity left at 0.
Opened in Photoshop.
Cropped - took off the grass in front of the track and little from left and right (now 4595 x 2534 px).
Cloned out a 'part bird' on right edge of frame.
Levels; input Grey 1.1, output Black 5.
LCE: with USM 20% 250px 0 th.
Cloned out three very distant birds in sky and done on left against grass.
Cloned out two stumps on left.
Saved as psd.
Down sized to 1600 x 882 px.
Set zoom to 100% (Ctrl+Alt+0)
Duplicate layer, working on this;
USM Sharpen 1: 40%, 1.5px 1 th.
USM Sharpen 2: 70%, 0.7px 1 th.
USM Sharpen 3: 90%, 0.3px 1 th.
Decide that this level of sharpening has led to some unnatural artefacts by comparing with unsharpened layer.
View to fit screen (Ctrl+0)
Erase top (sharpened) layer where I don't want sharpening, zoom right in where necessary to get a good fit around bird against trees/sky.
This is also a graded erase, between 20% opacity and 100%, depending upon content.
And the result (compare in Lytebox to see sharpening to best effect)
Original above and Edited below:
Hope I'm not disappointed when I see them side-by-side!
Update:
Oh bu**er, just realised I was looking at the EXIF for the wrong picture when I determined it must be a Tamron 70-300mm lens (doh)
I'm sure others, using their own pet techniques could do just as well or better, it's OK, but I'm hungry
Hope that helps,
Cheers,
Last edited by Dave Humphries; 12th January 2013 at 07:10 PM.
Thanks, Dave, what an improvement. That's well beyond my PP abilities, but it gives me something to aim for. I'll study the steps in more detail, and see how well I can work out what is affecting what. You are right, I don't have CSn, just PSE10 and LR.
And you did choose the right lens it is a Tamron 70-300 (the latest version).
Dave
Very, very nice work DH.
WW