What is the real deal on DSLR and lens softness?

[peter_rowe]

Hi,

I have been a film photographer for many years and have moved to

digital with a 20D. Using my 24-70L the images are simply not sharp.

I know, I know, they're supposed to be that way, but it makes my 24-

70 an "average lens (which it is not). On film my images are tack

sharp. I have read all the postings, some claim that the

manufacturing quality is bad and you could have a bad lens, or even a

bad camera and many claim that returning one or the other results in

vast improvements. This is not a focus issue -- I've done all the

tests, the entire image is soft. I know I can fix this in RAW but the

dreaded white halo soon appears, and I like to get it right from the

camera in the first place. I've seen descriptions of how the CMOS/CCD

pixels need perpendicular light and it can spill onto adjacent

pixels. I have read literally thousands of postings. I believe that

many "example" images have been heavily post-processed, like this one

here: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00AmI6.

Below is a 100% crop from a RAW image with no modfications from a 20D

and 24-70MM L. Notice how soft it is, see the bricks!

 

Can anyone provide some real light on this situations, are we all

stuck with bad lenses now!<div></div>

[beauh44]

Hi Peter, as I understand it, some of it has to do with the anti-aliasing filter sitting in front of the CMOS chip to keep undesireable artifacts down at the expense of sharpness. Some digital cameras don't have an AAF and while things are quite a bit sharper out of the camera you can get some other weird things like moire, so it's a trade off. My .02 cents is to not be afraid to use unsharp mask liberally. That said, your example is pretty soft - were you shooting with your lens wide open? Best wishes . . .<div></div>

[albert lui]

To add to what Beau said, here's the link to an EOS-1 class DSLR document:http://www.photoworkshop.com/canon/EOS_Digital.pdf

 

Image sharpness (in-camera settings and post-processing) are discussed. A starting point for USM settings is given.

[kraig_cuddeford]

it's not just the 20D, look at this 1DS shot. http://d6d2h4gfvy8t8.cloudfront.net/3006895-lg.jpg

[chiswick_john]

RAW capture can appear a bit soft but can actualy be of high resolution - sharpness and resolution are not the same thing at all. All that is often needed is a bit of local contrast adjustment to give it a bit of 'bite' The bricks and the render texture are visible - resolution is not the problem here. When you say your film is tack sharp - do you mean looking at hi res drum scans at 100% crop and you know for certain no USM was added in the scanning process ( which often happens) - if not it's not a proper comparison. Having said all this some of my Canon lenses are visibly better than others and although the 24-70 is quite highly regarded it's likely not as good as good prime.

[gaius1]

Note that you should not apply sharpening to an image until immediately prior to final output. The level of sharpening required for a 30x20" print and a 900x600 JPEG for the web is very different, even from the same original file. If you sharpen the original image you are actually degrading it, discarding information. Acutance is only the illusion of sharpness!

[christopher_bibbs]

Let me understand this, you want to shoot in RAW, but you want the camera to do the sharpening for you? That kind of goes against the nature of shooting RAW. By shooting in RAW mode, you are accepting that the camera will not handle the conversion or sharpening processes so that you have the flexibility to do it later as you see fit. If you want sharp images out of the camera, you need to shoot JPEG. This is how it is on my 20D, the old G5 my wife used, and the Kodak DCS back that I used.

 

My favorite part about shooting RAW is being able to apply sharpening at different levels to different parts of the image. Eyes? Tack sharp. Skin? A bit softer. Background? Well I wanted that soft anyway so no sharpening. Result? Exactly what I envisioned.

[steve_unsworth1]

I think Peter i asling _why_ he needs to sharpen with a high res camera.

 

I use the Photokit sharpenner which I have found very useful. One of the options is to apply a very mild amount of sharpening after capturing the image. The final output sharpening performed by the software is very flexible and also subtle. If you want to avoid the halos it may be worth giving it a try.

[gaius1]

There is a difference between resolution and acutance. Understanding that is crucial to working with digital images.

[ron c sunshine coast,qld,a]

This is bizzare .There is no way in h*ll you will get a sharp image from the camera with RAW !

<P>Even if you selected the sharpest in camera JPEG setting there is still much work to be done in most pics

<P>"are we all stuck with bad lenses now?"

<BR>No,we are stuck with post proccessing with DSLR's.You'll just have to get used to it

[hugh_crawford1]

Don't forget that the adjacency effect in film development increases sharpness much the same way that USM does.

[henry_minsky1]

I am getting very sharp images using my 50/1.8 lens on my 20D.

<p>

These are taken handheld, with a 420EX flash, using in-camera sharpening, with the default 20D parameter 1 settings.

<p>

100% crop here

<a href="http://beartronics.dnsalias.net:8800/tmp/20d/IMG_1289crop.jpg">http://beartronics.dnsalias.net:8800/tmp/20d/IMG_1289crop.jpg</a>

<br>

 

Full size image here:

<a href="http://beartronics.dnsalias.net:8800/tmp/20d/IMG_1289.jpg">http://beartronics.dnsalias.net:8800/tmp/20d/IMG_1289.jpg</a>

 

<p>

These were actually taken in autofocus mode to demonstrate some front-focus issue, so they could even be a touch sharper on the eye.

<p>

If I had taken these in RAW mode, and applied my own sharpening, they would probably be slightly better. I try to never ever oversharpen anything, and I think that the 20D's default JPEG sharpening is a pretty good first cut at typical sharpening needs.

<p>

I expect to apply my own sharpening to any RAW conversion.

<p>

Your 100% crop example looks a little out of focus to me. Perhaps you need to get your camera calibrated by the manufacturer. You used a tripod or something to steady the camera when you shot that, right?

[chiswick_john]

I set sharpening to minimum on my 20D - Photoshop does the job much better.

[steve_mitchell2]

I am glad that I am not the only one that expects sharp, in-focus images from a $3000 camera lens combo. Don't get me wrong, I love the features of this camera and have learned to work around the soft focus quirks of the 20D.

 

My little P&S, however, presents images that are quite sharp and there is no "halo" from post processing. I know, I know. P&S cameras sharpen the image internally. However, the data in the image appears complete and matches the object of which the picture is taken.

 

From my experience, once an image is "softened", there is absolutely no way to un-soften the image and achieve the same level of detail as one might have if the softening was never applied. Hence, is there a relatively easy way to get rid of the anti-aliasing filter?

 

It would be very nice had Canon given the user the option of having the filter in place.

[henry_minsky1]

Given that the aliasing filter is a more or less well behaved linear convolution, the sharpening operation can be an inverse transform and you get back pretty much close to the theoretical sharpness. There are some losses in practice of course, but you need to understand a little about systems theory before assuming that it is an all or nothing operation. That is why sharpening is not just a gimmick, it is really recovering actual image information.

[PuppyDigs]

Perhaps you should stop pixel peepin' and start using your 20D as it was intended,

e.g., to produce photographic prints. If you view a neg or slide under a high power

loupe it will look soft as well. A 4000 dpi scan viewed at pixel level looks terrible as

well. Yes, my lowly 10D looks soft when I pixel peep but 8 x 12 prints sure do look

sharp. Heck even 12 x 18 prints look tack sharp at normal viewing distances.

[doug_landrum]

I think that Puppy Face is on the right track. First of all, what do you mean by a 100% crop?

 

Sizing an image by various means affects perceived sharpness a lot. If I want a print from RAW from my 20D that fits on 8-1/2 X 11 paper (about a 10 inch image on the long side), then I open in CS with Photoshop's camera raw 2.4 beta at 350 ppi. If I want a 4X6, then I open at 584 ppi. I use unsharp mask a bit and print. My prints are tack sharp from my only Canon lens - the 24-70 f/2.8 L.

 

If you size for the Web, then you are sizing an image at 72 ppi and making it very small and, in the process losing a lot of information.

 

As far at pixels go, I scan film images with a 2900 ppi scanner and get very fine prints to at least 12 X 18. My film images are all taken with Leica M & R. Scans - from a Nikon Coolscan IV - yield images with pixels at about 2667 X 4080. That multiplies out to about 10.9 megapixels.

 

With the 20D I get images about 2336 X 3504 pixels. That gives me a pixel field of 8,158,344 pixels.

 

The files from the 20D in RAW (with the 24-70 f/2.8 L) are much easier to deal with and result in images that are at least as apparently sharp as scanned images from film (usually Provia 100) exposed with a Leica R7 and 100mm f/2.8 APO-Macro-Elmarit-R - one of the best lenses ever made.

 

I am tickled pink with the 20D and 24-70 combo. Did I also reveal that the 24-70 has as the abilty to focus as close as the Leica Macro?

 

Will I give up on Leica - NO. Do I like the Canon - Yes.

[peter_rowe]

Thank you all very much.

This has been a helpful discussion where many views are seen. Some (probably rightly) believe that I just need to live with the soft images. I must say I agree with others though that once the information is lost, it's diffiucult to get it back (an analogy would be that it's hard to make a poor lens look great, or how many times have you tried to recover an out-of-focus shot and had it work -- never for me!). The example shots from Beau and Henry tell quite a different story than what I see from my camera and this is hard evidence. Beau's shot (see above) is taken with no sharpening and it is pretty darm sharp, although coming through the camera as a jpeg (not RAW). Henry is on parameter 1 which is the first notch of sharpening and is very sharp too. All I know is that I cannot touch this kind of sharpness with my camera and lens combo (even with a closed down lens on a tripod using mirron lockup), I can't even touch this with my camera set on the highest sharpening level. I don't wish to do any processing in the camera -- I would prefer the editing flexibility of RAW and 16-bit if needed where recovery is so much easier without distroying the histogram. I guess I'm now stuck with my worst fear that my camera combo takes much softer photos than other similar setups. I'm off to check out Photokit and see can if it can sharpen without the ugly artifacts (USM is not good at this). Incidently, I can almost always identify a digitally sharpened image -- it has that "look" of starkness and white "speckling" (you can't really see the halo unless it is on a monitor at 100% or is grossly overdone). I'm still in a quandry over having good "L" series lenses that fall on a sensor that softens them -- it just still seems fundementally wrong to me. Remember the days we used blur filters because our lenses were too sharp! Printing is not a solution for everything, soft images still look soft when printed, perhaps there is something to be gained from scaling down the size of the image that compresses the soft edges but I hardly think we should be relying in this to correct a problem.

 

Thanks again.

[coconutdaydream]

now that you've jumped into the digital world, with a computer and some kind of image

editing program on your side, get ready to have COMPLETE CONTROL of your images!

there is no lab to do that for you, no negative to mask! unless you just request the lab to

post-processing for you, which would be very expensive!

[kraig_cuddeford]

so how come the raw file isn't 120+ Megabytes for a 16bit per pixel 8million pixel file.

[chiswick_john]

"Incidently, I can almost always identify a digitally sharpened image " - perhaps you should say a poorly sharpened digital image? - done correctly it's not detectable.

[steve_mitchell2]

regarding the image size: 16 bits per pixel and 8.2 million pixels per image equates is follow: 8 bits per byte, hence 16 bits per pixel equals 2 bytes per pixel / with 8.2 million pixels per image equals 16,400,000 bytes per image / 1024 bytes equals 1 kilobyte thus 16015 kilobytes per image / 1024 kilobytes per megabyte gives approx. 15.6 megabytes (MB) per image not counting any EXIF data.

 

Side note: for computers, kilo-, mega-, giga-, tera-, etc. are 1024x the previous prefix which comes from 10-bit binary or 2 to the power of 10. 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024. 16-bit color will yield 65,536 different color possibilities. 24-bit color will result in 16.7 million different color possibilites.

[kraig_cuddeford]

oh yeah, 8 bits per byte, sorry I'm still having a bad day.

[astcell]

We used to let the photo labs worry about this. I also feel my L lenses are soft but once in a while I get lucky. And the DOF is not forgiving, I need as much as I can get.

[gaius1]

All you people ought to just set sharpening in-camera and shoot JPEG! Quit worrying about it, go out and shoot!

 

If are are still worried, do like I said and learn the difference between resolution and acutance. There are loads of articles on the web - Thom Hogan, Moose Peterson, etc have all written about it.