Photo sharpness, am I imagining things?

[The_Traveler]

a bit of leveling and you're set.

 

[Peeb]

Glad you're getting better images.

Many of which have already been noted, here are some things that can detract from image quality:

1) motion blur

a) camera shake- too slow shutter speeds (a suspect in your first set of pics)
b) moving subject with too slow shutter​

2) extreme aperture settings (max and min setting each introduce issues)
3) High ISO (not an issue in your images)
4) poor lens, or damaged equipment (a suspect)
5) zoom lenses at the extremes (typically at their worst at max and min focal lengths)
6) filter problems (a suspect for you)
7) focus problems- unlikely in 'landscape' images, but possible
8) Over-reliance on VR - ironically vibration reduction can actually introduce blur if you have a stationary subject and a camera on a tripod and/or adequate shutter speed. While VR can be a godsend, it can also be a culprit. Depends on the scenario.

 

[japvdk]

Yup, first off get the UV filter off and bin it (or use it as a coaster if you really can't bear to throw it out). But even for a superzoom those are off. To me it certianly looks like there's some camera shake in there, but I'd have still expected these to be sharper.

So time for a test. First off get outside when there is good light, get a tripod or a stable platform, enable mirror lockup (or live view) and put your camera on timer. Set the camera to f11 and focus 1/3rd of the way into the image using a single point AF and focusing on a contrasty area. Then take a shot, and you should have a sharp image. If the image still isn't sharp there's an issue probably with the lens, if it is sharp it's your technique.

I think finding the new photos I took better might have been wishful thinking..
So I gave this a try as well . Here is the result. 31mm, f11, 1/160, iso 100. The light might not be optimal yet, if so, i'll try again later.

In my opinion, it is still quite, well, blurry might be a good word.
Hope to get you guys's opinions.

 

[dennybeall]

Let's add a bit too much Hi-Pass sharpening: Now what do you think?

 

[japvdk]

Well, to be honest, I'm still not sure. I mean if this is supposed to be the best sharpness I'm going to be able to get. At screensize, it's really not sharp. In any case, it's not a big improvement over the pictures I posted in the very beginning, still with the filter screwed on, and those weren't made on a tripod nor were the lighting conditions ideal. But maybe I'm imagining things, my thread is called that for a reason

 

[weepete]

Yeah, that one of the trees looks very soft. What did the camera focus on and was there

Here's a website with some sample images of your lens and I'd expect the performance to be similar.

https://m.dpreview.com/reviews/sigma-18-250mm-3p5-6p3-os-hsm-macro/5

FYI diffraction normally starts showing at around f16 and gets worse with smaller apertures. F8-f16 is the sweet spot for landscape photographers.

 

[japvdk]

Yeah, that one of the trees looks very soft. What did the camera focus on and was there

Here's a website with some sample images of your lens and I'd expect the performance to be similar.

https://m.dpreview.com/reviews/sigma-18-250mm-3p5-6p3-os-hsm-macro/5

I focussed on the tree, so I would expect at least that to be sharp. The fotos on dpreview are what I expected when I bought the lens, not the very best image quality, but they are at least sharp. I'm thinking of going back to the store with my problem, do you guys think that will help?

 

[weepete]

Yeah, I'd return it.

 

[mcap1972]

I'm sure it's a combination of few things like bad lens, misalignment, camera shake(mirror slap), post processing. Try doing some comparison tests with a different lens at the same focal lengths.

 

[dannylightning]

I haven't read everything here. you may need a faster shutter speed, the lens may need tuned to get a better focus, some cameras have a focus fine tune, some sigma lenses can be hooked up to the sigma dock so you can really fine tune the focus, I own 3 sigma lenses that can be tuned with the dock, the first one I got was tuned perfect from the factory. the second one i got was a giant mess and i had to fine tune it and now its taking amazing photos, the 3rd one I got was a little off on focus and I tuned it.

so the lens may not have been tuned properly or you are doing something wrong, sometimes you can contact the factory and send the lens to them and they will tune it for you, I have heard of a few people doing this with different band lenses and when the lens came back it was perfect.

it does have a huge zoom range and generally that is not going to give you the greatest image quality. my nikon 18-200mm does pretty well, at times the photos that come out of it are perfect but there have been some bad image too. the photos on dp preview some of them look nice, some of them look soft.

im gonna guess its just the lens its self your better off getting two separate lenses if you care about image quality. sure its nice to only need one lens for most shooting but that usually comes with a price.