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07-12-2009, 08:57 PM   #1
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Is sharp images from Post processing?

I always see people with super sharp clear pictures that I can never do. Do they sharpen it while post processing or something? Also I see that the reflection is mad insane, how do I do shots with so much reflection off the car?

Here are some examples of the sharp I'm talking about:



Here is comparing to one of my pictures:


07-12-2009, 10:09 PM   #2
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Try a polarizer filter for reflections. Planning ahead for the right angles will also help.

Sharpness is more of a challenge. Start by taking a photo which can be sharpened: proper depth of field and the right stuff in focus. Make sure you are getting the most out of your lens, maybe using a hood, an aperture in the middle of its range, and focal lengths where it performs well. For example, the kit lens will work better at f11 and 35mm than it will at f3.5 and 18mm. Or you might have the DA35 macro in your pocket to use instead. Camera shake should be eliminated. Exposure should be as close as possible on your subject. ISO should be as low as possible so you don't sharpen the noise too.

I generally try to do all that right so I don't have to be a post-processing sharpening expert. I'll give a few suggestions. Sharpening is usually best if it's done as the last step. If you downsize an image for web use, it usually needs sharpening. (Some programs do this automatically when they downsize.) RAW files need some sharpening because of the construction of the sensor. Software that offers many sharpening options is better than one button that says "Sharpen". Sharpening too much produces annoying artifacts. Don't sharpen twice.

I fooled around with your image and it can stand some sharpening, at least the typical amount I'd apply for a downsized image. It seemed like the exposure tried to keep the streetlights and headlights from blowing out. Changing levels or applying a curve gives a different look which you might like more, overexposing those bright spots but increasing the contrast on the car. A white car on concrete is going to be tricky anyway.
07-12-2009, 10:09 PM   #3
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QuoteOriginally posted by LeDave Quote
I always see people with super sharp clear pictures that I can never do. Do they sharpen it while post processing or something? Also I see that the reflection is mad insane, how do I do shots with so much reflection off the car?
The EXIF data from the first image shows thats its from a P&S camera (Samsung S750) with a 1/2.5" sensor shot at f2.8.

The issue probably relates to the small sensor size and the small lens giving a large DOF - hence the apparent sharpness. Those P&S lenses are easier to manufacture and than a dSLR lens.

To get the same DOF/sharpness on a dSLR you'll need a prime lens (can't see your EXIF data so no idea what lens/camera your using).
The sharpness is a function of the circle of confusion (CoC) - the APS-C sensor has a CoC of 0.0189mm compared to the P&S sensors 0.005mm. The net result is that you need better lenses and smaller apertures to get the sharpness higher on APS-C (smaller apertures decrease the CoC). It gets worse with Full Frame (35mm) at full aperture.

But this CoC issue works to your advantage too - you can defocus objects behind your subject (bokeh) to make the subject stand out.

There are several good articles on DOF/aperture/sharpness/circles of confusion etc. Start with this one on Wikipaedia

Assuming your using a dSLR and the kit lens (18-55mm) then image sharpness will require:
  • a sharp prime lens - most kit zooms are not razor sharp - and the Pentax is amongst the best of them!
  • a smaller aperture (eg f8 to f11) to give you greater DOF
  • probably the right sort of light for the reflections (those shots had a lot more light)
  • more contrast between the reflection and your car (dark cars show reflections better)

Post processing can only partially fix sharpness issues - in the first instance you need good glass to get a good image.

I'm sure someone else will have some more ideas.....

Last edited by MoiVous; 07-12-2009 at 10:33 PM. Reason: added CoC comparison
07-12-2009, 10:38 PM   #4
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Kit lens is supposedly a pretty good lens already, and you should be okay getting what you call "sharp" images with it. Just experiment with it - for example, zoom lens is usually better at its "middle", rather than extreme wide or telephoto lengths. Also, as suggested, use f8 or f11.

Lens aside, sometimes pics need a bit of post-processing to make it "pop". For one, lacking contrast in images may make them look unsharp. Same goes for reflections - your car has reflection on the doors - but you can't see them cuz they don't show that well. The car's hood shows no reflections - since there's nothing to reflect. I did some adjustments like Dave, and I can post or send you the result if you wish.

07-12-2009, 11:50 PM   #5
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Sweet! Thanks a lot for the help all of you guys, I now know better. And pbo yes that'd be great if you can send me the image with a step by step on how you done it!
07-13-2009, 09:47 AM   #6
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I'd say there is some pretty obvious stuff going on here that has nothing to do with PP. For one thing, see how much *bigger* the car is in the frame in the first two shots? Bigger in frame = details more clearly visible = sharper looking. The fact that they are physically closer also means there is less concern about the atmosphere itself reducing sharpness, which could be an issue on a day like the one it looks like your was shot. Also, see how much brighter the lighting is in their pictures? Tough to get nice reflections on a car off in the distance on a heavily overcast day that looks about two minutes away from a major thunderstorm. If you want to photograph reflections, step one should be to set up the scene in such a way that you can actually *see* the reflections.

I don't know what shutter speed you used or whether you used a tripod, but those would be the next things to look at if you want to maximize sharpness. Laos make sure you are shooting at an aperture that promotes sharpness - usually around f/8 for most lenses. And finally, I do hope you weren't trying to shoot a car that was actually *moving* and expecting it to be as sharp as the other pictures?

Anyhow, all of these things are far more important than any sharpening you might also do in PP. Although if those shots came form a P&S, they were probably shot as JPEG with a pretty high level of sharpening added by the camera's own processing. You might indeed need to add a bit more yourself because Pentax DSLR's don't typically apply as much sharpening as most P&S cameras do. But that's not going to magically transform poorly-shot pictures into great ones. Get the shot right first, then worry about whether PP can improve it ever more.
07-15-2009, 04:58 AM   #7
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To get that super-sharp look, you need to sharpen pictures after resizing them to web resolution. Look:

Resized but not sharpened:


Resized and sharpened:



This is Unsharp Mask 135%, 0,5 pixels, threshold 1. A bit excessive, but I'm making a point here.

Ideally the picture should have been sharpened well at capture (i.e. in your RAW converter,) then downsampled to whatever size you want, then sharpened again. I don't know how the original capture was sharpened in this case since I just used your web quality JPEG. You could get much better results from the original file, I bet.
07-28-2009, 05:12 PM   #8
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QuoteOriginally posted by Erik Quote
To get that super-sharp look, you need to sharpen pictures after resizing them to web resolution. Look:

Resized but not sharpened:

Resized and sharpened:



This is Unsharp Mask 135%, 0,5 pixels, threshold 1. A bit excessive, but I'm making a point here.

Ideally the picture should have been sharpened well at capture (i.e. in your RAW converter,) then downsampled to whatever size you want, then sharpened again. I don't know how the original capture was sharpened in this case since I just used your web quality JPEG. You could get much better results from the original file, I bet.

Wow, the difference is pretty drastic!

07-28-2009, 05:25 PM   #9
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Plus if you don't pixel peep (as people always do) then most of the photos would be fine (with a little help from PP).
07-29-2009, 05:55 AM   #10
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to me, the white civic is out of focus (or just getting there)
07-29-2009, 05:56 AM   #11
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QuoteOriginally posted by GerryL Quote
Plus if you don't pixel peep (as people always do) then most of the photos would be fine (with a little help from PP).
when you do a portrait, if you cant see a persons pores when you pixel peep, you miss focused.

so sometimes pixel peeping does help.
07-29-2009, 09:01 AM   #12
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Did anyone mention get and use a good tripod? It's amazing what a good quality tripod will do for image sharpness.
07-29-2009, 09:44 AM   #13
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If your taste requires that a car be highly reflective, I suggest taking photos of dark (black) cars, not light ones (like the white civic). Dark cars tend to show reflections much more readily than lighter ones, as their underlying colour does not contribute to nullifying the perception of the reflected light. What I mean here is that when light hits a car, it reflects off the glaze and we perceive it as reflection. When that same light is also bouncing off the light paint, we also see the much brighter white, which is more prominent than the reflection. With black cars, mostly the reflections are visible, as the black paint absorbs light and doesn't reflect much itself. Additionally, having the car in harsh light, or with many light sources surrounding it, will contribute to the effect. The effect is particularly noticeable at night or dusk in an urban environment with many street lights, windows, and marquees surrounding the vehicle. Watch luxury car commercials with a keen eye and you'll see what I'm talking about.

When you speak of sharpness, are you talking about actual image acuity (and accurate focus) or do you have software sharpening in mind? You need to be mindful that users that post images to these boards, and online in general, tend to upload significantly smaller and lower resolution images. When you shrink a huge image into a fairly small file, it will always appear "sharper", as you're down-sampling potentially soft portions, which results in a sharper appearance. Additionally, many programs such as Photoshop and Lightroom automatically sharpen images when they are down-sampled. These default options may be turned off, but when they're not, they do make a significant difference.

Last edited by mischivo; 07-29-2009 at 09:50 AM.
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