Sharpness of Tamron SP 28-75

[Redbird_xo]

The following is a 100% crop, near the edge and off the centre. Was taken at 75mm, f8.0 and ISO200. Is this considered sharp? Or I haven't seen sharpness?

[KevC]

Uhm, it may be the jpg compression artifacting but it doesn't seem too sharp to me...

[Redbird_xo]

Sure, the artifact is pretty bad. Thanks for pointing out. Here is a smaller size with lower compression. Hope it tells a faithful story.

[HKFEVER]

Sure, the artifact is pretty bad. Thanks for pointing out. Here is a smaller size with lower compression. Hope it tells a faithful story.
Please do a 100% corp of the focus point area.

[kawter2]

Tv( Shutter Speed )
1/125
Av( Aperture Value )
16
ISO Speed
200
Image Size
680x600


Based on the exif value it shows f16 @ 1/125 It should be a lot sharper if you shot this jpg large smooth/fine

is this a crop or a resize, is the exif correct @ f16?

It seems to me that something is up (something went wrond in the taking of the picture), because even the worst tamron lenses are still SUPER sharp @ f16

[Redbird_xo]

Tv( Shutter Speed )
1/125
Av( Aperture Value )
16
ISO Speed
200
Image Size
680x600


Based on the exif value it shows f16 @ 1/125 It should be a lot sharper if you shot this jpg large smooth/fine

is this a crop or a resize, is the exif correct @ f16?

It seems to me that something is up (something went wrond in the taking of the picture), because even the worst tamron lenses are still SUPER sharp @ f16

The original was shot in RAW, converted to highest quality JPEG, then cropped. The EXIF that I am looking at shows aperture at f8.

[Olegis]

I'd say that it's quite sharp - and it may be even sharper after some USM, which is pretty mandatory with DSLR. Also, don't forget that the resolving power of the sensor isn't that great with such small-detailed objects.

[Redbird_xo]

The EXIF didn't get through?

[Redbird_xo]

Please do a 100% corp of the focus point area.

Here it this.

[Andy_T]

For a 100% crop, this looks *very* sharp to me. What do you expect? :rolleyes:

This picture seems very demanding to me ... the structures are very small, the distance obviously is considerable, if you have any kind of haze in the air, this could have great impact on the perceived sharpness of the picture.

Best regards,
Andy

[Redbird_xo]

I'd say that it's quite sharp - and it may be even sharper after some USM, which is pretty mandatory with DSLR. Also, don't forget that the resolving power of the sensor isn't that great with such small-detailed objects.

Great idea! USM done. I took a guess on amount, radius, and threshold. How does it look now?

[HKFEVER]

Here it this.

I did not notice that you are located in HK until I saw so many wall mount air-con. unit.

Did you shot this picture in Kowloon size?

The image is a little soft, did you hand held the camera?

1/125 should get you better than this.

Try to have the same setting with tripod in AF then tripod in MF and see the different.

[HKFEVER]

Great idea! USM done. I took a guess on amount, radius, and threshold. How does it look now?

It looks over sharpened.

[Redbird_xo]

...if you have any kind of haze in the air, this could have great impact on the perceived sharpness of the picture.

Best regards,
Andy

There's definitely atmospheric issue in where I live. The daily air pollution index published by the government basically tells people to stay indoor or at your own risk otherwise.

[HKFEVER]

There's definitely atmospheric issue in where I live. The daily air pollution index published by the government basically tells people to stay indoor or at your own risk otherwise.

The pollutant is coming form right across the border's (Chinese border) industrial zone.

I notice than Hong Kong only get clear air whenever China has long holiday.:evil:

[Olegis]

It looks over sharpened.

No it doesn't, at least not to me. If Redbird_xo would be so nice and show us the whole picture after USM (or at least that original 100% crop from the first post), you'd see that it looks just fine.

[HKFEVER]

No it doesn't, at least not to me. If Redbird_xo would be so nice and show us the whole picture after USM (or at least that original 100% crop from the first post), you'd see that it looks just fine.

I agree, show the original first corp and the 100% corp with all the air-con. unit with USM.

[Redbird_xo]

I only did USM on the corner section of the original posted pic after I responded to KevC's comment on the artifact issue. Sorry about that!

[HKFEVER]

I only did USM on the corner section of the original posted pic after I responded to KevC's comment on the artifact issue. Sorry about that!
If the corn is that sharp, wow the center must razor shape.

[Redbird_xo]

Thought I would post another set for comparison. It shows the original 100% crop and the adjusted 100% crop.

[Olegis]

That's also quite sharp, especially after the USM. I suggest to try selective sharpening techniques to avoid sharpening JPEG artifacts or / and noise. I'm using the JB's Custom Smart Sharpener (http://www.pinkheadedbug.com/sharpening/assets/download/JB's%20Smart%20Sharpeners.zip) action which is great.

[tim]

I'm not impressed by the sharpness of that picture, but I can't offer one from my own lens as a comparison, sorry. I do have some test shots (http://mrwild.co.nz/ExperimentalGallery/Tests/index.html) on my website, which you might like to look at. There's also a very long running thread on the sharpness of this lens on the fred miranda forums - many people returned there's to be calibrated and were happy with the results afterwards.

[Olegis]

Well, when the details are so small, they are of "high-frequency" nature, and are being filtered by the low-pass anti-aliasing filter in front of the sensor (that's why they put it in in the first place - to avoid the high-frequency abberations as moire). I still think that these images are acceptably sharp and you have nothing to worry about - just go out, shoot and then apply some post-prosessing as levels, curves, colors and of course USM. Levels and curves adjustments often increase the contrast in the image - making it to appear sharper.

[Persian-Rice]

That is not sharp for a that lens. You have a problematic copy. It took me 3 tries to get a good one. Even with JPEG conversion it should not be that soft. The Tamron is a pretty sharp lens.

Here is an example at F/3.2 with an untouched RAW conversion. Messed up the shot, focus was on mouth, so that is the sharpest point. Now my F/3.2 57mm is much sharper then your f8. It shouldnt be

[drisley]

I'd say that it's quite sharp - and it may be even sharper after some USM, which is pretty mandatory with DSLR. Also, don't forget that the resolving power of the sensor isn't that great with such small-detailed objects.

I agree with this statement 100%

[ToddMorris]

That is not sharp for a that lens. You have a problematic copy. It took me 3 tries to get a good one. Even with JPEG conversion it should not be that soft. The Tamron is a pretty sharp lens.

Here is an example at F/3.2 with an untouched RAW conversion. Messed up the shot, focus was on mouth, so that is the sharpest point. Now my F/3.2 57mm is much sharper then your f8. It shouldnt be

Hi,

I think you might be jumping the gun a bit here to say that his lens is a "bad copy". Of course there will be a difference in sharpness between the examples you posted, and the ones he posted. Yours are of a person right in front of you, and his are of buildings that appear to be quite a distance from the camera.

I do have a quick question for redbird ... are you happy with the pictures you're getting from this lens?

If the answer is yes, then stop doing lens "tests" and take it out to get some real pictures ... isn't that why you bought your camera in the first place?

Just my two pennies,
Todd

[Redbird_xo]

Hi,

I think you might be jumping the gun a bit here to say that his lens is a "bad copy". Of course there will be a difference in sharpness between the examples you posted, and the ones he posted. Yours are of a person right in front of you, and his are of buildings that appear to be quite a distance from the camera.

I do have a quick question for redbird ... are you happy with the pictures you're getting from this lens?

If the answer is yes, then stop doing lens "tests" and take it out to get some real pictures ... isn't that why you bought your camera in the first place?

Just my two pennies,
Todd

Understood. But don't you notice I'm not taking pictures of resolution chart or something like that nature? The pictures that I posted are from my collection of landscape pictures. ;)

[Redbird_xo]

That's also quite sharp, especially after the USM. I suggest to try selective sharpening techniques to avoid sharpening JPEG artifacts or / and noise. I'm using the JB's Custom Smart Sharpener (http://www.pinkheadedbug.com/sharpening/assets/download/JB's%20Smart%20Sharpeners.zip) action which is great.

I've taken many pictures from my digital P&S and DSLR, but I've only started post processing them recently. In the past, I didn't even do USM as a minimum. I was actually inspired by another forums member to shoot RAW and do post processing.
Thanks for the advice.

[Olegis]

You welcome ;)
Are you using some kind of UV or haze filter on your lens while shooting pictures like this ? These filters can cut the haze quite a lot and make the picture clearer and sharper. The polarizer filter can also be helpful with this task, it will also enhance the blue sky (making it darker) and eliminate some of the reflections from the buildings.

[Redbird_xo]

You welcome ;)
Are you using some kind of UV or haze filter on your lens while shooting pictures like this ? These filters can cut the haze quite a lot and make the picture clearer and sharper. The polarizer filter can also be helpful with this task, it will also enhance the blue sky (making it darker) and eliminate some of the reflections from the buildings.

Yes, I have a Hoya multi-coated UV filter on the Tamron. I don't have any polarizing filter yet but I'm almost certain that I will get at least one...for the Tokina ATX Pro 17. I placed an order for the Tokina at a local dealer. I primarily use the Tamron for portrait indoor.

[Redbird_xo]

Thank you all for dropping in and contributing one way or the other.

[tim]

The UV filter makes things sharper sometimes? I have an expensive hoya pro filter that I recently took off because I figured it probably wasn't helping the image quality. You think it's better to leave it on?

[Olegis]

The UV filter helps to reduce the haze sometimes when shooting outdoors, it won't be effective indoors. You can see some examples and more detailed explanation here (http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/filter/filter-UV.html) and here (http://www.photo.net/equipment/filters/) .