What makes images sharp?

<p>I take a photo and think - yep, really pleased, then I look at flickr, 500px, photo.net etc and realise that they are not that hot after all.<br>

What makes images really sharp?<br>

- Is it the camera (I have a 15mp Canon DSLR that I thought was the bees knees!);<br>

- is it the lens - I am using a kit lens;<br>

- is it the lighting (I mainly shoot outdoors as I only have the inbuilt popup flash);<br>

- is it the camera settings (I am a newby as you may see from my profile).<br>

- Is it post editing (I am playing with Photoshop CS4 but am no means profficient)<br>

or<br>

is it all of the above and more?</p>

 

What do you mean by "sharp"? Not blurry? Or very stylish and attractive (e.g., a "sharp dressed man")?

<p>Have a look at this article to get some tips on how to get sharper images: <a href="http://photonaturalist.net/7-tips-for-getting-sharper-photographs/">http://photonaturalist.net/7-tips-for-getting-sharper-photographs/</a><br>

I would like to add that DSLR images do need sharpening during processing, especially if you shoot RAW. </p>

<p>I think you're going to find that some peoples ideas of what's sharp differ from others.<br>

To my eyes, many digital photos I see have been artificially sharpened too much (post editing that you mention above) such that they spoil the natural look of the image.<br>

If you shoot jpeg then you're at the mercy of whatever the camera decides to apply to your photo. if you shoot raw images you can control the amount of sharpening applied by post processing.<br>

However you need to start from a good base point, and that means most of the things you mention, although I think most modern camera+lens combinations are capable of an acceptably sharp image.<br>

A point you haven't mentioned is stability - i.e. even the slightest camera shake during exposure will compromise the sharpness of the result.<br>

Be wary of comparing your photos to those of a professional as the pro has undoubtedly spend 10 times as much on his/her kit as you can, so it would be unreasonable for you to expect exactly the same output.</p>

<blockquote>

<p>What makes images really sharp? …<br>

<strong>is it all of the above and more</strong>?</p>

</blockquote>

<p>Yes.<br />Best that you answer Mike’s question to narrow the conversion .</p>

<p>WW</p>

<p>"Sharpness" is a somewhat vague and subjective term that often comprises:</p>

<ul>

<li>the ability of a lens to resolve detail (including aperture, DOF, etc.);</li>

<li>the ability of the recording medium to record that detail;</li>

<li>contrast and, with color photos, saturation, both of which may be affected by flare including internal lens flare;</li>

<li>camera vibration or motion;</li>

<li>subject motion;</li>

<li>and the skill of the person editing and printing the digital file or the darkroom technician printing the negative;</li>

<li>the size of the output/display medium.</li>

</ul>

<p>Perception of sharpness is often subjective and depends on the size of the print or display and proximity of the viewer.</p>

<p>Control all of those and you can be reasonably certain of sharp photos of test charts. The tricky bit is applying that to photographs of things other than test charts.</p>

<p>In very simplistic terms sharpness is often defined as a function of the interaction of resolution and contrast as perceived by the human eye, both of which can be achieved in many different ways. Resolution is the ability to clearly distinguish between two objects (for instance two parallel lines) of equal luminance, whereas contrast maintains equal resolution, but varies the luminance of the object to distinguish it from its background. Maximum perceived sharpness occurs when you have both high contrast and high resolution. So if you think about these two factors and how to achieve each, you can control the sharpness in a shot. For instance...shooting on a foggy day will diminish contrast significantly, producing soft tones, whereas shooting on a sunny day with shadows produces high contrast shots (which often a digital camera can't fully capture the entire range resulting in blocked shadows or blown highlights). On the other hand, if your objects aren't clearly defined or indistinguishable from one another, or your lens exhibits certain elements of distortion, it is hard to achieve high resolution. Likewise, if you have motion in a shot, or fail to properly adjust sharpening and contrast of tones in post processing of digital photos, it may be hard to achieve the sharpness you desire. If you are examining your shots at the pixel level, rather than a print from a normal viewing distance you, may be disappointed in not seeing absolute or even perceived sharpness. Again, there are a lot of ways to achieve "sharpness" which are well beyond the scope of a simple answer in this forum. You might want to start to read up on the subject so you can more fully understand the factors involved, and incorporate them into your work.</p>

<p>It can be all of the above; if you take Lex' list of what may make sharpness, then you may also see the vast array of options that can make a photo seem less sharp. Plus, what others said: some example links would help to fully understand what you call sharp.</p>

<p>But, a bit off-topic, but since you yourself claim to be a "newbie", it could be of use. Sharpness can be terribly overrated. There are great photos that aren't sharp by any stretch of imagination. And some photos do require a certain sharpness to really shine. The point being that many photographer seem to focus (no pun intended) on getting sharp photos and post-process to make things 'pop' and look sharp. While disregarding throughout the message of the photo - in the end photography is a means of communication, and the effectiveness of the message defines whether the photo needs to be pin-sharp, saturated colours, etc.<br>

An insurance claim or technical manual needs to be written clean, short and factual. A romantic poem or a tragic novel needs a certain verbose (and more indirect) language. Photography is no different. Sharpness is really just one of many factors in that, and the amount of sharpness you need should depend on the photo's content and intent.</p>

<p>Post some examples with descriptions of what you don't like about them. You'll get more specific feedback that way.</p>

<p>Thank you all for your thoughts so far.<br>

I suppose, in some ways, what I am saying is my images look like digital tv whereas so many look HD! Does that make sense? </p>

<p>I would happily post a couple of images and would certainly welcome the feedback - what is the best way to do so? Apologies - I am very much a newbie! :)</p>

<p><a href="

<p>Here is a link to one of my favourite photos - am I allowed to link to flickr? Here goes</p>

<p>You can link to anything legal I think, but only post your own work Much of the picture linked to is soft.. I belive it is desirable that at least some of a picture should be rendered correctly to show you know what you are doing.<br>

I believe that this sharpness thing dates from the advent of colour and then digital when originally only glossy paper was available so everybody unfortunately started in on the sharpness when back with film it was purely the commercial photographer shooting for publication etc ... just a feeling :-)</p>

<blockquote>

<p>I take a photo and think - yep, really pleased, then I look at flickr, 500px, photo.net etc and realise that they are not that hot after all.</p>

</blockquote>

<p>Looked at the full rez version of your flickr link and compared to 100% view of one my own and have to say what you're seeing of your images uploaded to the sites mentioned is output sharpening for downsizing for the web. It helps to test what downsizing does to sharpening and whatever compression by said site does to the appearance of sharpening.</p>

<p>Below is a side by side screengrab of your linked image at full rez @100% view next to one of mine with no sharpening applied in ACR shooting Raw. Yours is not very sharp by comparison because you're viewing the downsized version of the image which tends to look sharper on LCDs. Hope your monitor is calibrated because that has an affect on sharpness appearance as well.</p><div></div>

<blockquote>

<p>“I suppose, in some ways, what I am saying is my images look like digital tv whereas so many look HD! Does that make sense? “</p>

</blockquote>

<p>Yes, it does make sense. Thanks for answering.</p>

<p>On that one particular image of yours, to which you linked -</p>

<p>Notwithstanding Tim’s comments about output sharpening for downsizing for the web; there are other factors which, individually and/or <strong><em>accumulatively</em></strong>, could add to the appearance of that particular image being “Not Sharp”.</p>

<p>Other factors which might make your image appear not sharp, are, but not limited to:<br>

<strong> </strong><br>

<strong>Soft Lighting:</strong><br>

Soft lighting will generally add to the appearance of ‘soft image’.<br>

As there are no hard shadows with soft lighting, the definition of the edges, (acutance), is generally ‘soft’.<br>

Often for soft lit scenes, one can <em>gently</em> boost the MID TONE CONTRAST in post production to make the appearance of a sharper image, whilst maintaining the effect of the soft light.<br>

There are other PP methods also.<br>

<strong> </strong><br>

<strong>The Lens and Aperture:</strong><br>

The image appears to be made with one of the variants of the EF-S 18 to 55 F/3.5~5.6 “Kit Lens”.<br>

The image was pulled at F/5.6 and the lens was set at FL = 55mm.<br>

These Kit Lenses at 55mm are wide open at F/5.6 and you’ll notice that the stonework at the corners (ref: bottom right where the bars are located) are less sharp than the stone work at the centre section of the image – there is noticeable IQ fall off at the edges.<br>

This is peculiar to all the lenses in this series.<br>

I am NOT stating that these lenses are garbage, in fact I am quite an advocate for the kit lens: what I am stating is the lens needs to be understood.<br>

If you shot at F/8 then there would have been a difference; even shooting at F/6.3 could have been useful.<br>

<strong> </strong><br>

<strong>Depth of Field:</strong><br>

I think I see the front edge of the building’s stonework as less sharp than the stones which are behind.<br>

My guesstimate is that, in respect to Horizontal Field of View, the building is about 5 meters, linearly; the Field of View (FoV) of the scene at the Plane of Sharp Focus is about 6 meters (20ft).<br>

And I reckon that the Plane of Sharp Focus was achieved on the stone work, just here:<br>

<img src="http://d6d2h4gfvy8t8.cloudfront.net/17138736-lg.jpg" alt="" width="350" height="250" /><br>

If my assumptions are close correct: then by pulling the shot at F/5.6 - you are very quickly running out of adequate DoF to allow the FRONT of the building to be rendered “suitably sharp” – and I do believe that is what I see.<br>

<strong> </strong><br>

<strong>The Shutter Speed:</strong><br>

The shot was pulled at 1/80s.<br>

Assuming that you had Images Stabilization available and it was engaged OR the camera was on a stable tripod, we can assume that any blur as a result of Camera Movement has been negated.<br>

However, at 1/80s can be too slow to arrest Subject Movement.<br>

Whilst, on a cursory glance I cannot find any evidence of Subject Movement (except for the moving water) it is good to remember that even in a <strong><em>supposedly</em></strong> “Static Scene” any gentle breeze in a shooting scenario such as you have, will be enough to render, for example, the longer blades of grass or leaves “soft”, if you are shooting at 1/80s.</p>

<p>WW</p>

<p>My short list for sharpness:</p>

<p><strong>Accurate Focus</strong> - Focus inaccuracies cannot be fixed in post processing. It's either accurate or it's not. I'll include proper depth of field under this heading. Caveat: Autofocus systems can be out of adjustment, i.e. not as accurate as you think it should be, or it can move away from where you want it to be just before the moment of capture.</p>

<p><em>Resolution:</em> Ensure that your AF is working, or use manual focus with image magnification if available. </p>

<p><strong>Camera Stability</strong> - Any shake, including that caused by the camera's mirror or even the shutter will make an image look softer.</p>

<p><em>Resolution:</em> Shoot with a relatively fast shutter speed, image stabilization, or flash, or alternately mount the camera on a tripod.</p>

<p><strong>Subject Movement</strong> - Quick movements may be rendered as streaks in the photo.</p>

<p><em>Resolution: </em>Use a higher shutter speed. For fast sports action, 1/500s to 1/1000s is the recommended range. People moving casually can typically be shot at lower speeds, e.g. 1/125s.</p>

<p><strong>Light Sources with Contrast</strong> - Soft light shows less apparent sharpness, which is why it's used for portraiture.</p>

<p><em>Resolution:</em> Choose or set up different lighting conditions.</p>

<p><strong>A Proper Sharpening Workflow in Post-processing</strong> - Anti-aliasing filters soften images at capture.</p>

<p><em>Resolution:</em> Careful sharpening is required.</p>

<p> </p>

<p>Don't shoot wide open with a kit lens. They don't like that! lol</p>

<p>(Meaning you should shoot at f8 or f11, if you want to get the best sharpness from lower quality lenses.)</p>

<p>Sharp is a function of many things. Are you shaking the camera, while shooting your photos? Hold the camera still. Maybe put it on a tripod. Are your photos in focus? Good focus makes a HUGE difference. I found that I would not only shake my camera, but I would be shooting photos that were out of focus too. When I fixed both of those problems, I found that I could get even sharper images by stopping down the aperture a little. I found that even on very expensive, wide-aperture lenses (like my Canon 70-200mm f2.8 L IS) stopping down makes images sharper (as long as you don't compromise shutter speed and ISO too much).</p>

<p>Oh, and shooting at lower ISO settings helps to keep images sharp too.</p>

<p>It's a balancing act. If you shoot at high ISO settings, the image looks grainy or muddy (not so sharp). If you open up the aperture too much, so you can lower your ISO setting, the image the lens projects onto the sensor is not as sharp. If you slow your shutter speed down too much, so you can use a low ISO setting and a smaller aperture, you will get motion blur, because your subject moves or your camera is shaking. It just SUCKS! lol</p>

<p>Balance the settings and hold your camera still you must, young paduan.</p>

<p>Oh, and THIS is the bee's knees: http://interestechnology.blogspot.com/2009/09/red.html</p>

<p>Thank you to all of you for your responses and the obvious time you have spent looking at an answering my question.</p>

<p>I am grateful to you all and I look forward to ploughing on in the endeavour to become a better photographer.</p>

<p>Regards</p>