Image Quality

[Barry Beckham]

With the debate about image quality raging........... If you want to see quality images, then look no further than the article below

http://www.beckhamdigital.co.uk/articles/B...ck/bassrock.htm

[Ken Cox]

SEE

http://www.miguellasa.com/photos/sspopup.mg?AlbumID=1001578

THESE OSPREYS ARE BEAUTIFUL…THERE ARE 35 DIFFERENT PICTURES,

THE SLIDE SHOW WILL WORK ITSELF…YOU DON'T HAVE TO CLICK ANYTHING...........

ENJOY

think they might be "tuned" a bit

KEN

[Barry Beckham]

I think tuned is the word, I would like to see what proportion of the image was used here. Impressive though when you see it in the slide show

[Ken Cox]

THE WATER DROPLETS AND THE DOUBLE CATCH AMAZED ME:)

[Peter S]

Some very memorable images in both these sequences.

"Tuned" is perhaps a very important word in all these discussions about quality of images. I have seen various figures quoted for the difference in sensitivity between the eye and a digital sensor but there seems some general acceptance that the eye can see some 18 to 20 stops difference, and very rapidly changes its "aperture" to make allowances, while the sensor sees around 9 stops and the camera settles on a fixed aperture.

If a presenter wants to show the viewer of a single print or a slide show something similar to the scene that they saw with their own eyes then they have to make some "adjustment" if there is more than a 9 (some may say 7) stop variation in the contrast. The adjustment may be by the use of filters or via Photoshop.

The bottom line is that "realism" is NOT achieved by simply reproducing the image recorded by the sensor. Neither was this the case with film - a little dodging here a little burning there!

The same applies to some extent with a wide angle view and cropping. There is a discussion on one of the Canon forums as to which lens represents the closest picture to the one seen by the eye. Many seem to suggest 50mm others point out that the eye constantly scans the view while the lens takes a single view.

We also all see colours slightly differently. Some of us even spell the word in different ways! We are always left with somewhat subjective judgments and adjustments.

Most of us can however tell if an image is out of focus or blurred and in my view if we wouldn't print it it does not have a place in a public slide show. Image quality is important when presenting to a wide audience. If the only picture I have of my great grandfather is blurred I'll still hang on to it. It's a great memory but that's a different story.

Kind regards

Peter

[jfa]

Just stunning Ken.

Like Barry I would like to know more of the technical details of the photography, thanks for the link.

[xahu34]

... the difference in sensitivity between the eye and a digital sensor but there seems some general acceptance that the eye can see some 18 to 20 stops difference, and very rapidly changes its "aperture" to make allowances, while the sensor sees around 9 stops and the camera settles on a fixed aperture.

There are more differences between the human eye and the camera's sensor. You may look at the Adobe whitepapers written by the late Bruce Fraser:

http://www.adobe.com/digitalimag/pdfs/linear_gamma.pdf

http://www.adobe.com/digitalimag/pdfs/unde...lrawcapture.pdf

The bottom line is that "realism" is NOT achieved by simply reproducing the image recorded by the sensor. Neither was this the case with film - a little dodging here a little burning there!

I agree, and this is the reason why I like techniques for shadow enhancement and other stuff for contrast regulation.

Best regards

Xaver H,

Munich

[jfa]

The words given to me by an "old timer" when I was just starting in the slide/tape area of photography ring in my mind --

"Your show is only as good as the worst slide in it"

I have come to understand that this mainly applies to the pictorial, (or as some call it "chocolate box"), style of AV and like all rules there are times even there when it can be creatively broken. However as a guide it has been useful for me to remind myself of this often.

We also must keep in mind the medium we are working with is Audio/Video and consists of 3 important components,

-Audio (sound),

-Video (still photography),

-Presentation (the way we tie it all together).

The images may be exceptional but if they are presented in a basic uncreative way the show is in danger of becoming boring. This is partly because the quality of presentation possible, (the creative functions PTE and Photoshop give us), and that being shown, now is of such a high standard that the medium is moving beyond a basic 4 second image with a 3 second dissolve with no variation in the show.

Also if the audio consists of no more than any piece of music at hand, unsynchronised with the images the show can fail no matter how good the images are.

I have seen many shows with high image quality that fall down due to mundane audio and/or poor presentation.

The above quote now should be-

"Your show is only as good as the worst image, the audio or the presentation used in it"

...Edit 9:25....

I must also say that the most creative presentation with the best sound mix will not make a great AV without the appropriate images at the highest possible standard that the particular type of show demands.

[Barry Beckham]

Ifa

Those have been my views since way back when I used to do this with twin projectors, but there are times when images are used that clearly are not really good enough. Your right that this then drags the whole show down.

Often we also hear the excuse that, well I wanted to show the images like that doesn't really cut it with me. Generally speaking AV is let down by poor image quality more often than any sound or presentation issues.

That is the area where most attention is needed, forget the all the fancy stuff and get that right first. If your going to show photographs to photographers, then at least edit the images and drop out those that don't belong. I would rather see 6 of your good images, rather than 36 that contain only 6 good images.

The issue is not just image quality, but vision too. The variety of a slide show has to be considered at the time you are taking the pictures. When you are in front of the PC, it's too late.

How often do we see good static slide shows showing movement through the frame (not animation)

A good differentail focus shot, sharp in the foreground and soft in the background and then the other way round, it looks great on screen, but it has to be taken like that.

How often do we see any third image examples and it's much easier now than in the slide tape days.

How often do we see the resized images sharpened before being placed into the show. They need it badly after removing millions of pixels.

These are the issues that need general attention.

[jfa]

I think we are on the same page Barry. My previous post was an attempt to place the image importance within the context of the whole show.

The issue is not just image quality, but vision too. The variety of a slide show has to be considered at the time you are taking the pictures. When you are in front of the PC, it's too late.

A very good and important point. I wonder how many of us create a script or even a story-board before we start to photograph/produce our AVs?

How often do we see any third image examples and it's much easier now than in the slide tape days.

In the twin projectors days we had few techniques available and this was, (to me), the most creative and important of them. Now with PZR, 1,000s of dissolves and many other effects at our fingertips I think we have lost sight of the wonderful effect the third image can have.

[Michel]

How often do we see the resized images sharpened before being placed into the show. They need it badly after removing millions of pixels.

Barry,

can you explain more that ? Do you mean your images are not sharpened ? Do you resize your images before the show (I suppose yes) ?

Thanks in advance!

Note: Look also at Vincent Munier. English Language.

[Barry Beckham]

Michel

I think we have to separate the sharpness issue for images in a slide show/AV from those higher resolution images that we wish to print. We can apply a different thought process to both.

For print purposes I sharpen my images at the very start of the manipulation in Adobe Camera Raw, that's if they need it of course. Not all images do and some need more than others. It depends a lot on your technique, lighting, contrast and even the subject matter. Not all images need to be sharpened and every image I produce, is high resolution at the start.

When we move onto using that same image in our slide show we resize the image and users of Photoshop or Elements will often do this via the image size palette where we would tick the Resample Image box in the image size window. There are other ways to do this as well and one of my favourites is the crop tool.

Example

I have an image on screen in Photoshop that is 49MB and the dimensions are 5120*3407 pixels. I use the preset values in the options of the crop tool to select an image the same size as my monitors resolution. Lets assume that is 1024*768

Once that crop has been made and the physical size of the image has been reduced we have gone from 49Mb at 5120*3407 pixels to 2.25Mb at 1024*768 pixels.

We have taken an image made up of 17.5 million pixels and reduced it to 786,432. If my maths are right we have thrown away 16 million pixels. It doesn't really matter what the numbers are, because any resize from a modern camera will discard loads of pixels.

Now, discarding those pixels is the right thing to do in these circumstances and despite the loss of those pixels the image will still display perfectly at 1024*768 even when we put that same image up on a screen 10 foot accross via a Digital Projector. It wouldn't print very well, but that is not the object of the excersize.

However, despite the fact that I sharpened my image at the start of the original high resolution manipuation, it needs to be re-sharpened now that we have discarded those pixels.

I have come to rely on a particular setting in Photoshop or Elements to do this. In 99 out of a 100 cases, you will find that if you are using unsharp mask, you can apply 200% on the amount slider and 0.3 on the Radius slider, 0 on the Threshold. That setting will give you a marked increase in sharpness, but without over doing things.

Try this on one of your high resolution images and with the unsharp mask window open, look at the image with these settings applied and untick, then re-tick the preview box. You will easily see that this setting works fine for images of 1024*768 or even 1280*1024.

Over sharpening an image should be avoided, but consider this. If we need to push sharpness to much higher levels, we will get away with it far more readily with slide show images then those for print purposes. (As long as don't go too high of course)

The reason is simply because on screen, a slightly over sharpened images tends to look a bit better than when we see it on paper, but the most important reason is that it will only be on screen a few seconds. Everything in moderation of course, but if you need to squeeze more sharpmness into an image for a slide show then try it.

The issue that has to be balanced is when we throw animation into the equasion because of the Moire effect. The moire effect can be increased or even directly created by over sharpening an image.

[d67]

With the debate about image quality raging........... If you want to see quality images, then look no further than the article below

http://www.beckhamdigital.co.uk/articles/B...ck/bassrock.htm

Tracy Langley and the gannets

"I had taken 3 auto-focus lenses with me for the trip - a 17-55mm, a 70-200mm, and a 300mm. At the time I was using a Nikon D2X digital body which had a DX sensor, meaning an effective magnification of 1.5 times."

17-55mm : 1 400 euros

+ 70-200mm : 2 000 euros

+ 300mm : 4 500 euros

+ Nikon D2X : 4 500 euros

+ Photoshop CS 3 600 euros

Total = 12 500 euros

+ special accreditation to land on Bass Rock and so, take photos on solid land rather then on balancing boat.

+ professional photographer

This may help to obtain photos of good to top quality and images where it is possible to count each hair on the skin !!!

[Barry Beckham]

Patrick

Sorry mate, but I always have a little difficulty grasping the point you are making. Thats down to me not you as I can't speak French, at least you can speak and write English.

I think the point you are making is that these people have some advantage over others because of their equipment and status. If so, I think you under-estimate the equipment used by many amateurs these days. Its much the same as you see listed in your thread. My own and most of my friends have a similar amount of equipment. If you visited many camera clubs as I do there lots of people who have this level of equipment also.

I accept that if you don't have a decent telephoto lens you cannot get some shots, but don't write off the quality you see in those images to the equipment this couple have. They would get great quality images no matter what they used, because their method of going about their photography and attention to detail is what makes the difference. I used to pride myself in winning a club competition with a £35 second hand Fujica camera. There were others in the club who had a mass of top Nikon kit that would cost you thousands, but it was no advantage to them as the had no vision or technical ability.

There is no special accreditation to land on Bass Rock, you have to go there and book a place, that's all.

+ professional Photographer

What does that mean Patrick??

It means that someone earns some money or a living from their photography. It doesn't mean they are particulary good at it.. I know wedding photographers who are exellent, but also others who have little creative merit of technical ability, but they still earn a living and therefore are classed as professional.

If I have understood your comments correctly, you seem to be writing off the image quality you see as unattainable. I disagree and think we should all be striving for that level. Sure, we won't all suceed like all school footballers don't end up at top football clubs, but lets set our sights to a great standard and try to achieve it.

That old saying still holds true, its not the camera, but the person behind it who creates the image.

[d67]

I think the point you are making is that these people have some advantage over others because of their equipment and status. If so, I think you under-estimate the equipment used by many amateurs these days. Its much the same as you see listed in your thread. My own and most of my friends have a similar amount of equipment. If you visited many camera clubs as I do there lots of people who have this level of equipment also.

As for PC equipment you overestimate the camera and lens level used by amateurs !!!!

The majority don't go to a photo club and don't want to compete.

I accept that if you don't have a decent telephoto lens you cannot get some shots, but don't write off the quality you see in those images to the equipment this couple have.

Of course not but this helps !

+ professional Photographer

What does that mean Patrick??

It means that he has probably photography knowledge very few of us have.

I suppose also that he has to take time to get high standard photos... if not he can not expect to live from photos as he probably does.

If I have understood your comments correctly, you seem to be writing off the image quality you see as unattainable.

Yes... a goal unattainable for the vast majority of us

That old saying still holds true, its not the camera, but the person behind it who creates the image.

Absolutely sure !

[fh1805]

Yes... a goal unattainable for the vast majority of us

Just because something is unattainable, it does not mean that we should not strive to attain it. It is by trying to understand how others achieve their results and then adjusting that knowledge to the constraints imposed by our own budgets of time and money that we can advance our own skills.

I may never attain the levels of artistic skill that Barry demonstrates in his work; but that doesn't stop me trying to understand how he does it. Nor does it stop me wanting to raise my own standards closer to his.

[Barry Beckham]

Patrick

If you really feel that attaining a higher standard is unattainable for you, then I can't see a great deal of point in putting forward any work at all for comment. What would be the point as the whole purpose is to learn from what other say isn't it?

I don't think I do over estimate the camera and lens level of amateurs, I do visit many clubs and come into contact with thousands of enthusiasts just like us. So I do have a reasonably good knowledge to make such a statement.

You don't have to spend a £1000 on a lens. I worked for years and competed sucessfully with budget second hand cameras and lenses. Olympus and Tamron lenses was my choice.

Absolutely sure !

Not sure what you mean here, if it is that you agree, it seems to contradict your previous comments. You seem to be saying here that it is the photographer and not the equipment that is the main cause of good images.

If you meant this to be a question as in "Am I Absolutely sure !" Then I would say yes, some people can get interesting images with a disposable camera.

I wish to be respectful Patrick and it is easy to get the wrong idea in text, but you do seem to have some issue with image quality and the wish to improve and gain higher standards. I hope it is not because it is me that has said it.

By the way, I thought young Pauls slide show was a very good one, I found the photo quality to be perfectly OK for the style of presentation and he captured a mood perfectly. The show didn't need words as the music and images told the story. Short and to the point as well. I think we all accept that there is a world of difference between a presentation of images on this subject and a pictorial one.

[d67]

If you really feel that attaining a higher standard is unattainable for you, ...

... for the example you give.

Absolutely sure !

Not sure what you mean here, if it is that you agree, it seems to contradict your previous comments. You seem to be saying here that it is the photographer and not the equipment that is the main cause of good images.

Yes, the most important for "good" or pleasant pictures is the photographer's sensitivity.

This alone is of course not enough and there must be some practical knowledge (image manipulation, image rules).

The materiel has its importance but is a major problem for some typ of photos... the example you give.

I wish to be respectful Patrick and it is easy to get the wrong idea in text, but you do seem to have some issue with image quality and the wish to improve and gain higher standards. I hope it is not because it is me that has said it.

You seem to have very elitist thinkings !

By the way, I thought young Pauls slide show was a very good one, I found the photo quality to be perfectly OK for the style of presentation and he captured a mood perfectly. The show didn't need words as the music and images told the story. Short and to the point as well. I think we all accept that there is a world of difference between a presentation of images on this subject and a pictorial one.

Thank you. As fort the others comments about this sequence , I transmit him your comment.

[Barry Beckham]

Patrick

Not elitist, I just feel that if you embark on AV, which is all about image presentation, you MUST get the fundementals right.

[Michel]

There are other ways to do this as well and one of my favourites is the crop tool.

I'm a little curious : do you think the crop tool is better than "to resize" (resample image box) or is it the same ?

[cjdnzl]

Well, they say variety is the spice of life, and there's more than one way to resize an image. I run Photoshop CS2, and, like the Photoshop versions before it, it uses bicubic resampling, whether you do it in image size, or with the crop tool.

Problem is, there are better resampling algorithms than bicubic available these days, and one of the best is the Lanczos algorithm, which is used in Irfanview.

So, I crop my images to a 4:3 ratio for 1024*768 projectors, using the marquee tool in its constrained mode and making the constrained ratio 4:3, then use Image/Crop to crop out the image I want. I might sharpen at that point, i.e. the last action in PS before I save the images. I can generate quite a lot of different sized images doing this, but then I batch resize them in Irfanview.

Irfanview can automatically resize to whatever you specify when setting up the resizng parameters, using Lanczos resizing, and applying a sharpen step after the resize.

I find that not only is it quicker than doing it in PS, the resultant images are better as well. The resizing operation processes about one image per two seconds or so, on a 3.00 GHz P4 processor, so for a 96-slide show I did recently, the resize/sharpen operation took all of about 3 minutes.

Of course, my slr is way over the top for slide images; but even my old 2.1 MP point&shoot gives excellent results with the above method.

Colin

[Barry Beckham]

Colin

How about processing the same basic image twice using both methods you describe and post the resuts so we can take a look.

As you can guess, at the size we use these images at 1024 I am thinking you would have a hard job telling the difference, but I would be delighted if you can prove me wrong. I am always looking for an edge on image quality.

[xahu34]

Hello Colin,

there are some drawbacks with resizing when using IrfanView, a program which I like very much.

1. If you apply it to a 16-bit image (say PNG), the resampled output has only 8 bits per channel.

2. People working with colour spaces like AdobeRGB have the problem that IrfanView does not support colour management. In PS you can resize and transform the images to sRGB in one step.

Best regards

Xaver

Munich

[Barry Beckham]

Xaver

Why would you want a PNG file for a slide show in 16 bit?

I can't see the point and it is not where the focus needs to be applied in relation to image quality. We need to keep it much simpler than that or we just over complicate the simple procces of putting a slide show together don't we?

[xahu34]

Why would you want a PNG file for a slide show in 16 bit?

I can't see the point and it is not where the focus needs to be applied in relation to image quality. We need to keep it much simpler than that or we just over complicate the simple procces of putting a slide show together don't we?

bbdigital

There is no doubt that you are right. I would never use 16-bit images for a slideshow. I think that beamers and standard monitors are not in the position to show 16 bits per channel. I just wanted to point out that one should be careful when using IrfanView (a good viewer anyway). The other remark on colour management is more serious. I have seen it again and again that people work with AdobeRGB and wonder why their images look so strange when projected using an old version of ACDsee, or IrfanView.

Best regards

Xaver H.

Munich