[normhead]

IN many of your images you are having soft images because of depth of filed issues, not lens softnesss.

An understanding of depth of field and hyperlocal focusing would probably help you out.

The first big improvement I'd go for given you shooting style would be a 100 macro, or a Tarmon 90 macro. That will give you edge to edge sharpness for your longer shots, and detailed borders on your close up images. Either of those will be a great companion for the 18-135. The strength of those lenses being for the type of shot where the 18-135 is weakest. That being said, you're still going to have to learn about depth of field.

The lizard shot would be what the 18-135 was designed for. Excellent sharpness in the centre, smooth soft creamy out of focus areas. What's not to like. To have everything in focus on shot like that, a cell phone would be your best bet.

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Last edited by normhead; 04-29-2017 at 05:43 AM.

[pres589]

Another option would be one of the older 105mm Macro lenses; I'm thinking of the Vivitar / Lester Dine / etc lenses. These are old, only available used, and costs are pretty low compared to something like the DA60-250. Another is the Samyang 135mm that you can buy new. These aren't zooms so not quite as versatile.

Good luck Kerri, glad you are finding the forum useful.

[mikesbike]

Your very good DA 18-135mm lens, which I also own and love, has some weaknesses out at the long end as you indicate. I also have the Pentax DA HD 55-300mm f/4-5.8 WR lens, which is still available new at a reasonable price. I like this lens a lot, even though I have some of those very expensive lenses that have been recommended. It still uses the old screw drive, but so do most of the expensive Limited primes. I find it turns out nice crisp images. Edges are very good, especially if stopped down just a notch. It's AF is said to be slow, but I have been satisfied with its performance. It has a long-turning focus throw, which causes slight delay when going from a closer range to far away, but that is also better for fine-tuning manual focus. I find if not going from an extreme distance to another extreme its focus speed is good. A woman posted some very good moving bird shots a while back that proved this lens can do it with some practice by the photographer.

It does not focus close up, maybe 5 ft or so. But unlike the newer version- the DA 55-300mm f/4.5-6.3 PLM lens, it is not an internal-focus lens, so when dealing with closer subjects like 8-20 ft, you are still able to get a true 300mm shot with the older one. Internal focus lenses tend to shorten their focal length with closer focus distance, sometimes greatly so. The newer lens also requires a firmware update for its full function, which may not work for all camera models. It also has a slower aperture than the older model. My DA 55-300mm HD WR lens can keep to f/4-4.5 out to 200mm when needed to keep shutter speed up. That's only one stop difference from a big, heavy, and expensive 70-200mm f/2.8 lens, and it has more range.

[Des]

The first big improvement I'd go for given you shooting style would be a 100 macro, or a Tarmon 90 macro. That will give you edge to edge sharpness for your longer shots, and detailed borders on your close up images. Either of those will be a great companion for the 18-135. The strength of those lenses being for the type of shot where the 18-135 is weakest.

Another option would be one of the older 105mm Macro lenses; I'm thinking of the Vivitar / Lester Dine / etc lenses. These are old, only available used, and costs are pretty low

+1 to these suggestions.

Norm has made the point elsewhere that when you are on a walk or travelling light (like your cycle touring or bushwalking), and trying to carry the minimum, a prime is only worth carrying and swapping to if it gives you something much better than the zoom for the particular shot. A macro lens does that; so does a special lens like the FA 77 Ltd. I have the DA35 f2.4 which is lightweight, compact and sharp, but even though I often carry it, mostly I don't bother swapping the 18-135 for it, because the zoom set at 35mm gives 90% of the result I can get with the 35 (and sometimes more). But I do find more often that it is worthwhile to swap for the DFA 100 f2.8 Macro, not just for the macro, but because it gives much better results than the zoom at its long end. And there are no bad macro lenses. The manual focus ones will do fine.

If you have a telephoto zoom as well (like the 55-300) you might find it is worth swapping to for the telephoto end. If you don't have one, @mikesbike makes a good case for getting one of the screwdriven 55-300 models (DA-L, DA and DA WR) - they are optically identical except for newer coatings on the WR. The DA-L and DA are good used buys at around $A120-200. They are also about one stop faster than the 18-135 across their common range. It makes a very handy two-lens travel kit with the 18-135.

As @mikesbike points out, the new 55-300 PLM doesn't work with all bodies. The K-30 is not supported at present.

[Des]

My main concerns arise at 135mm or close to that zoom in two circumstances - when the subject is all on one plane in the distance such as the pelicans (135mm, 1/180, ISO 400, f5.6) or all on one plane closer in such as the Christmas beetles (135mm, 1/15, ISO 400, f5.6).

A macro lens would give more edge-to-edge sharpness with shots like these. Although to put it in perspective, most people looking at these shots wouldn't immediately zero in on the edges. They are both visually pleasing images.

But in the absence of a macro lens, you could still get more corner sharpness from the 18-135 by stopping down to say f8. The light would have allowed that with the pelicans with a small compromise on shutter speed. With the Christmas beetles, you were already at 1/15th so narrowing the aperture would have required raising the ISO (unless you were using a tripod). I think I'd have gone for 800 ISO in order to get the aperture down a stop, or even under-exposed a little with a view to bringing up the exposure in PP.

One cheap trick that sometimes works to overcome corner softness is to frame wider and crop the image. Here's an example. Cropped and processed v jpg straight out of the camera.

---------- Post added 05-02-17 at 09:08 AM ----------

Cropped and processed.

[Kerri-Ann]

Thanks again Des, Normhead, Pres, MikesBike et al

Thanks for observations on my pics and further comments and suggestions.

I have been having a busy time test shooting a boring but indicative line of bushes with little shrubs in the foreground and bigger trees in the background to check fstop differences for focus and depth of field at different zooms. A good lesson in taking care to stop down as much as possible but to ensure a fast enough shutter speed to enable hand holding (which I almost invariably do)!

I also pulled out my old Sigma 100-300mm 4.5 - 6.7 lens that I have not used on my DSLR and gave it the same test (also checked out its review here on the site: not too bad for its market positioning). I think it performs better at that 100-135 cross over. But I will need lots of luck or use a tripod more to get sharp shots in low to average light when using longer range.

Without thinking about it, I guess I have already been using the crop in to get rid of the soft edges where necessary!

I'm off overseas next week with my (newly re-loved) 18-135 and will contemplate further options in the future. The forum is providing a great source of info and there seems to be quite a choice of ways to go.

Thanks all
Kerri-Ann

[Des]

Good luck Kerri-Ann. Enjoy your trip. Don't forget to post more photos.