Achieving sharpness and IQ

In the search for better IQ and questioning the need for an upgrade from the kit lens (K20D), my heart sank a little after discovering I have the mkI 18-55:
link

I should say that most images are destined for internet use, I do not often need to print images and even then rarely larger than A4; so my demands are minimal really. The K20D & kit lens are of course a vast improvement over the 4MB compact I had been struggling with previously; noise reduction being the major benefit.
Better IQ to start with has meant less processing time, however there hasn't been the level of improvement in finished images that I could have expected.

A few years ago I moved from CorelPhoto to Photoshop and appreciated a subtle improvement in IQ, a smoothness and more of a quality feel to final images. So now I'm looking at equipment (I don't want to blame it, it's probably me )

I see so many really fine images here and elsewhere, images that "look" like what one would expect of a high quality 300dpi print, but of course they're not, they are are being viewed at less than 100dpi, yet with lovely tonal quality and pin sharp with no hint of acutance.
Occasionally I hit the mark but not often enough, and rarely up to the standard I see here so often.

Sharpening low contrast areas leads to over cooking the high contrast areas, but as I invariably capture at the largest size and highest quality settings and final image often resampled 10% to 20%, acutance gets lost.
But I do wonder if I would be better off with a better lens and then perhaps shoot at an image size nearer to the intended final size.

On the other hand, it's not just sharpness. I know the lens could be better in this respect, but when for example I've taken a shot (with flash) of a full length garment at 18mm and at about 3 to 4 metres distance, then zoom in at 55mm and can see individual fabric fibres, the lens isn't too bad. But there's something lacking!

Any suggestions please.

Don't be despondent about the mark 1 kit lens. It's not as if the mark 2 is DA* standard, although at some point you might want to upgrade to the WR version.

Re image sharpness, are you doing an unsharp mask after resizing?

+1 above.

If shooting subjects that allow, use small apertures, ISO100, solid tripod, mirror up remote control shooting. Oh and a capable, well dispersed flash helps.

I got some very decent A4 prints from GX10 and kit lens.

The user formerly known as Tim mapped his 17-50 Tamron so he knew where the softness appeared and could make allowances.

Dont waste any money replacing the lens, there is nothing at all wrong with it! One of the things lacking in your photography may well be 'but when for example I've taken a shot (with flash) of a full length garment at 18mm and at about 3 to 4 metres distance'That seems to me an inappropriate focal length and too far away as well as using what I presume is the built in flash. It should be considered for use only in dire emergencies.

Sharpness is very much a function of the treatment you give the image for the size you display it at. Many of my IR shots are on the kit lens, the actual resolution can be really quite poor near the edge of the frame. However the final effect for web-sized shots can be of high detail and good sharpness due to the processing.

I use Topaz Adjust to manipulate the local exposure and micro-contrast, plus the appropriate unsharp mask in Photoshop as the final step. There are a myriad of settings to play with, from subtle to very extreme. What Topaz achieves could perhaps be regarded as 'punch' rather than 'sharpness' since it allows you to work with the relationship between colour, exposure and detail at different scales. It is probably worth having a look at the free trial from the Topaz website.

I'm extrapolating here. So you're advising a bigger room and off camera flash/lighting system, keeping what might be a soft lens, and using it at a longer focal length?

Clearly from the OPs description the lens isn't soft, he can see individual fibres. A distance of 4M at 18mm gives a field of view 50% greater than a full length garment so some cropping will be necessary with a resultant loss of quality. 18mm is going to produce some distortion, a focal length of 35mm is more appropriate and as you say may require a bigger room. Yes, some type of lighting other than the built-in flash. In fact, any type.

So forum consensus of the mkII lens being sharper is wrong? It's usually me that goes against forum consensus.


BTW, We used a couple of halogen work lights as a cheap bright studio light once, harsh but good enough.

I don't think anyone is saying anything in particular about the relative qualities of the two 18-55s.

It's more about what the OP needs to do to improve the appearance of his pictures, which is probably more complicated than "get a sharper lens".

There are any number of things that might be contributing to an unsatisfactory image, from simply being too far away and expecting too much of a 100% crop, to not making the most of the editing process.

We need to know more, really, so an example image would be good. Ideally, the full frame, and a 100% crop of the bits that don't seem to be sharp enough. As well as how the photo was taken, and its EXIF.

Without that, it's speculation really, as to how to fix it.

I too felt my K10D with 18-55mm lens was letting me down. A number of members had commented on "out of focus" or similar.

This was apparent even when tripod mounted. A new Sigma 90mm gave similar results

I've since checked the front/back focus of the camera and adjusted it accordingly and the change is dramatic (to my eyes at least)

I'm far from an expert (some would say barely proficient) but I would check out all parameters before scrapping a lens as it may be another effect showing through

regards
Bernard

IQ isn't just limited to sharpness though - I moved from the standard DA kit lens to the Sigma 17-70 and then to the Pentax 17-70, at each stage I saw an improvement but rather than sharpness it was more regarding colour and contrast rendition, some may say that this can be done in PP but I don't fully agree.

The step from compact to DSLR can be a little disappointing because some compacts have excellent lenses which may well outperform the cheap/standard kit lenses supplied with DSLRs, the Pentax kit lenses seem better than most so I'm not sure if this fully applies in this case though

I do firmly believe though that a lend upgrade can make a significant difference in the quality of your images - technique obviously needs to be good regardless of lens though

Simon

I do quite a few workshops using Photoshop and the most usual problem is how the sharpening is done.

It's worth a full exploration of sharpening techniques, not just a few lines, but Martin Evening's books give us everything we need.

When some users have been shown how to sharpen, they are amazed at how sharp their images really can be.

You can just as easily use a £5 lamp as a £200 flashgun. You get to see what the end result will be like and set (and if necessarily tweak) the white balance to get the colours right. I use a grey-cap (link) to make life easier.

And if the thing you are shooting doesn't move, the bulbs don't need to be that bright. Just stick your camera on a tripod and use a slower shutter speed.

Flash is not an easy thing to master and the vast majority of photographers (myself included) never manage it!

I've been writing a reply during the day, just come back to it, clicked on preview and the whole lot has disappeared!
Start again.......


Getting familiar with the lens' in this category is on the agenda. I've only ever previously use prime lens', but the 18-55 is well suited to most of my needs now and I do use the full extent of the zoom facility all the time so a similar spec. is what I will look for when finances permit. Although that 17-70 does sound .......


Other than for record keeping snaps, I only use the built-in for fill-in and usually about a stop down as I don't like fill-in to be apparent. In the set-up described, I use a pair of flash bounced into umbrellas and a flash bounced into an aluminium shade as a key light. With this set-up it's generally f8-f11 @ iso200.


Yes Chris quite right. I'll see what I can find, but unfortunately once I get an image saved into P'shop I usually ditch all the originals.

Focus accuracy is not in question, I have checked that.
Taking DOF into account and/or selecting the best of a series for the DOF I need, there no issue there. And I've already got the AF in hand - best to let the AF pull in (nearer) rather than push out for most accurate AF.


I was expecting such, and I do agree with you. I had practical experience many years ago with a medium format, the lens' of which were seriously lacking in contrast. Trying to compensate during developing and even using the hardest paper never really compensated and the results were always a lacking.

Yes John, generally a touch of unsharp is par for the course as the last thing done. But when selective sharpening is needed I usually use the high pass filter method and then apply it with history brush. But it would be nice to find an easier one than doesn't effect grain/noise.

Thanks for all the comments.

You want dead sharp shots? Weak AA filter like the K10D or K-r.

Make sure your lens is focusing correctly, do AF adjustments if required.

Am a little disappointed by the AA filter on the K-5. I think the K-20 and K-7 may be similar stronger filters.

A good lens makes a big difference IMHO. The sharpness achievable with my DA* lenses or even the 18-135 is really good. In fact I am rather impressed by the 18-135, a lot better than the 18-55 and 50-200 I had.