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02-02-2014, 08:14 AM - 1 Like   #16
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QuoteOriginally posted by dansamy Quote
Are zooms more susceptible to shock damage than primes?
Not only can I not answer that question, I doubt anyone but the guys at lens rentals.com can, if they chose to.

QuoteOriginally posted by alwaysjerricky Quote
Actually I think it's quite sharp already. Lighting plays an important role IMO. I'm using a 18135 and image quality isn't that great as 16-50/sigma 17-50 but it's very great for such a price. Try not to pixel-peep - it will only make your photography journey more painful.
What the 16-50 and 17-50 give you is 2.8 and probably a crisper focus, I'd e interested in seeing sharpness comparisons at the same FL and Aperture with those 3. If memory serves me well, the Tamron 17-50 is the only one better in it's range than the 18-135 at 24mm. The zooms get stronger and weaker in different parts of their range, and the 18-135 is no different. Assuming the 16-50 or Sigma 17-50 is sharper than the 18-135 around 24mm would be a mistake. Which lens you think is sharper depends on at what focal length you do your shooting.

02-02-2014, 08:19 AM   #17
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QuoteOriginally posted by normhead Quote
What the 16-50 and 17-50 give you is 2.8 and probably a crisper focus, I'd e interested in seeing sharpness comparisons at the same FL and Aperture with those 3. If memory serves me well, the Tamron 17-50 is the only one better in it's range than the 18-135 at 24mm. The zooms get stronger and weaker in different parts of their range, and the 18-135 is no different. Assuming the 16-50 or Sigma 17-50 is sharper than the 18-135 around 24mm would be a mistake. Which lens you think is sharper depends on at what focal length you do your shooting.
Hmm true in a way. Need to research more about this. Thanks for the comment.
02-02-2014, 08:44 AM - 1 Like   #18
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QuoteOriginally posted by alwaysjerricky Quote
Hmm true in a way. Need to research more about this. Thanks for the comment.
To me the whole thing where zooms are not as good as primes is the lazy man's approach, with a prime, you use it, you find out it's characteristics at different ƒ-stops, which can be very different, and you have an idea when you might want to use it. With zooms, you have to do that for every focal length. IN the 18-135, you need to understand 18mm 24mm, 30mm, 40mm, 50 mm, and 70-135 where it's consistently centre sharp but not as strong on the edges. It's a lot more work than getting to know a prime. My wife never got comfortable with the 18-135. Using the Tamron 17-50 simplified things for her, less range to deal with.

A lot of people just say primes are better than zooms... yet almost every zoom has it's strength. Even my much maligned Sigma 70-300 gives excellent results from 70mm to 150mm, very close to some much more expensive lenses. When compared to my Tamron 90, DA*60-250 at 90mm, my $200 Sigma (at 90mm) zoom came in third, but it was a close third. A lot closer than you'd expect based on price. The Tamron 90 won with a bit better micro contrast, but it and the 60-250 were very close to identical.

For every zoom you know, you need to know the conditions for which you should take the zoom off and put a prime on instead. There are times I prefer the look of the 21 Ltd. to the 18-135, not because it's sharper but because it handles out of focus areas better. IN low light I like my FA 50 1.8. It goes without saying nothing the 18-135 can do will match that lens in low light. Typically, with the 18-135 on the camera, I'll have the 21, 35, 40 50 and 60-250 in my bag, and I'll take the 18-135 off the camera in some conditions in favour of one of those lenses. But there are also a lot of days where the 18-135 never comes off the camera.

Last edited by normhead; 02-02-2014 at 08:56 AM.
02-13-2014, 09:51 AM   #19
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This thread helped me understand my low light, misty weather photos better, thanks.

02-13-2014, 10:59 AM - 1 Like   #20
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QuoteOriginally posted by sherrvonne Quote
This thread helped me understand my low light, misty weather photos better, thanks.
Another tip for misty conditions would be, remember that you have two eyes, the camera has one. It is much harder for the camera to penetrate the mist than it is for you. A light mist to your eyes, will be heavy for the camera. A heavy mist to your eyes, will be impenetrable for the camera. If you take your mist images, when the mist is at the point where it's barely visible to your eyes, that will often be the optimum for a misty looking picture.
02-13-2014, 11:25 AM   #21
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QuoteOriginally posted by normhead Quote
Another tip for misty conditions would be, remember that you have two eyes, the camera has one. It is much harder for the camera to penetrate the mist than it is for you. A light mist to your eyes, will be heavy for the camera. A heavy mist to your eyes, will be impenetrable for the camera. If you take your mist images, when the mist is at the point where it's barely visible to your eyes, that will often be the optimum for a misty looking picture.
Thanks for the tip, didn't know that.
02-13-2014, 02:04 PM   #22
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QuoteOriginally posted by audiobomber Quote
My 18-135mm needed +10 AF Adjust before I sent it back for calibration.
A good reason to not evaluate lens sharpness using auto-focus.


Steve
02-13-2014, 03:17 PM   #23
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QuoteOriginally posted by stevebrot Quote
A good reason to not evaluate lens sharpness using auto-focus.

Steve
AF was fine after the adjustment, but you're right, I always cross-check with MF when testing a lens.

02-13-2014, 07:03 PM   #24
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I've taken it out a few times now.. as in outside of my home and I've discovered it is plenty sharp.. especially in the center to about 2/3rd out.. the corners have some noticeable softness (which seems par for the course with this lens)... but I think my copy could be a little sharper than some of what I considered the 'sharp' copies shown here; it is a good one I see now!
02-15-2014, 02:54 AM   #25
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QuoteOriginally posted by normhead Quote
Cross posted from a question in the 18-135 thread.



Maybe you should send your lens in for alignment, but first i'd make sure you can't get good images from it.

There are a few assumptions you're making here which are inaccurate. PP doesn't make an image sharper, it makes it look sharper. Here's a recently posted picture.



And a 1:1 crop from from that picture unprocessed.



You could easily argue, this lens isn't very sharp.

The dog may look sharper in the finished image, but that's not the PP bringing out something that isn't there. This was an overcast dull day with not a lot of contrast. SO two things are done to bring up the level of contrast, I add definition, which is in essence micro-contrast, and I use the sliders in levels to adjust the brightest and darkest levels shown so that I use the full palette of my output device. Neither of those things change the level of sharpness. What they do is they increase the amount of distinction emphasizing differences that are actually there but may not be discernible by the human eye. The fact that you can't see them, the way they came off the camera doesn't mean they weren't there. That is the biggest mistake people who don't do PP make. They assume that the camera recorded it the way it was.

In actual fact, one of the reasons I process as quickly as possible, is because I want to remember how it was, and in PP create what I saw at the scene. People tend to think, it's not like the original image because you processed it. That's exactly backwards, most of us PP so that we bring out in the image what we saw in the scene.

Another factor is this image was hand held. Right off the bat, I have no expectation that this image would be razor sharp. That it's as sharp as it is is a testament to Shake Reduction. If I'd thought this could be a gallery print, I would have set up the tripod and done it right. But, I was out for a walk with 3 other people, so that wasn't likely to happen.

Now another couple of images. These shot with an A-400 on a tripod with 2 sec delay. A much brighter day with more natural contrast

The whole image


1:1 pixel peeper- all sharpening turned off.


This image looks much sharper and detailed, but, I had more light, so the original image had more natural contrast. I was shooting on a tripod, and the subject as well had more natural contrast. All those things combined make this a sharper looking image right off the camera. The reason I don't have similar images from the 18-135 is, I rarely shoot it on a tripod, and it's a walk around lens, so the light is often less than perfect.

Here's the DA 18-135 used on a tripod, on a bight sunny day with some contrast in the subject area. Shot at 18mm, so , not even in the lens' comfort zone. And this is a 1:1 crop. All sharpening is turned off. To me, this 1:1 crop looks as good as many hand held images of the un-cropped images, that have been reduced in size and therefore had their sharpness artificially increased. The pine needles are distinct, the curved lines of the broken pottery are lines are clear and smooth.

The scene


1:1 pixel peeper- all sharpening turned off.


My computer monitor is 92 DPI, and this image was taken with a k-5. So This image would look the same quality as it does in the Pixel peeper, printed at 53 inches wide. With a bit of sharpening applied, it would look even crisper than it does as it is now with sharpening turned off.

So brief synopsis

PP gives you an opportunity to opportunity to make the picture look like what you saw at the scene, and bring out detail that may have been present but invisible in the un-processed print. (And that you may have observed when experiencing the scene live.)
IF you are going to look at lens sharpness, you must work from a sturdy tripod with a 2 sec delay. No, ifs, no ands, no butts.
Images taken of high contrast subjects in high contrast lighting situations will look sharper than images taken on dull days without much contrast even taken with the same lens and camera.

Or to be more blunt, if you haven't tested your lens in good light, on a tripod with a 2 second delay, with a subject with decent contrast, you really have no idea how good it is. You might have some idea about how steady your hand is, but that would be the most you could accomplish.
Thanks for that first and very helpful post Norm.
02-15-2014, 06:30 AM - 1 Like   #26
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QuoteOriginally posted by normhead Quote
PP doesn't make an image sharper, it makes it look sharper.
The distinction escapes me:
Scarlett Johansson (the actress) isn't really beautiful She just looks beautiful.

Last edited by wildman; 02-15-2014 at 07:11 AM.
02-22-2014, 01:35 AM   #27
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Running around today taking snapshots with a K-30 plus 55-300mm lens set at 200mm. Simulating a Kodak Brownie on steroids. Makes a perfect point 'n shoot at 1/1000 and f/8 ... Auto-ISO on TAv. From about 9 AM to 4 PM, in partial-cloud sunlight, it's perfect. But before 9 and after 4, you'll have to start lowering the shutter speed and opening the aperture... always trying to keep the shutter speed as high as possible for maximum sharpness. Below, a train in the shade at 5:45 PM, zoom at 55mm, 1/500 at f/5.6, TAv ISO 1000... undedited, unsharpened. Takeaway -- fast shutter speed is the easiest way to a sharp photo... and at 1/1000 or faster, you can't miss.
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