Is my 16-35 a bad copy?

[Deleted User]

In this case I'd be very surprised if this were on the lens - as a general rule 'crap' on the lens tends to resolve itself as areas of softness in the image - seeing rubbish this clearly indicates, to me at least, dust or debris actually on the sensor. The f/22 + wide angle test will confirm this of course.

Msmoto

@ TriShooter

I would not worry so much about the sharpness of the lens, which looked good in the large image, but the large number of spots on the sensor needs correcting. At night the flare around the light sources may appear soft as this is going to not record as a sharp point unless the exposure is reduced.

Clean the sensor, then do some HDR of the same image.

TriShooter

@Msmoto

I agree with you on on the spots but chakoo said that he had dust on his sensor, and apologized for it being there in his first post. In my book Nikon should be doing the apologizing, not chakoo. chakoo was concerned about the sharpness of the photo, and he is right to be concerned about it because it impacts the shot. I am guessing that he has seen that dust in other shots using different lenses so knows that he has to clean the sensor. The comments on adding low center of gravity weight to his tripod, waiting for heavier vehicles to pass by, taking off the camera strap etc. are good suggestions because it will improve this type of photo substantially.

I was not looking at light flare. There is definite motion blur that varies between 2 to 4 pixels in his Atlanta Skyline Shot which is shown clearly in this section of his original picture below of the right side of the second building from the left.



At its longest range the pixel motion is about 2 pixels, while the foreground shift is about 4 pixels. The lens, and or, the sensor may have dust, but the blur he was worried about is motion related as you can see below with a compromise adjustment of 3 pixels for motion and zero sharpening.



The sharpness of the lens looks fine to me.

TaoTeJared

+1 with Trishooter - it's looks like classic camera shake to me. Add some structure, a bit of sharpening and it will be a great image.

TriShooter

@TaoTeJared thanks for your confirmation on the camera shake.

This thread will benefit anyone that uses a tripod substantially, or may wonder why their tripod is not giving them motion free shots. I took the time to shift the motion blur for chakoo because I too liked his image, and thought it was worth trying to save for him.

I remember starting to use a tripod on a panorama shot of the New Orleans skyline. On an impulse I slid into a turn-around next to friendly state trooper, and pleaded with him to let me take a set of shots. about four miles out on the Causeway Bridge from the New Orleans side. I started to set up my tripod before realizing my feet were tingling like I was standing on foot vibrator. The best shots were taken by hand which damped the bridge vibration using my body.

chakoo

Thanks a lot guys for detailed analysis and suggestions. I agree f/22 is definitely causing diffraction, I confirmed it in my tests I did at home. f/8 is the sharpest and f/11 is sharp enough.

I also compared it with relatively cheap 24-85 VR for the shared focal lengths (24mm, 28mm and 35mm). My 24-85 is sharpest at f/5.6 and it beats 16-35 f/8. I will post my test images later tonight.

chakoo

@TriShooter - Thanks for your work. How did you correct pixel shift? Was it done in Photoshop or LR?

chakoo

I uploaded test images to my Google+. Compared it to 24-85 at 24/28/35mm and f/8. Test chart was lit by the window from left side and no other extra lighting was used. Camera was on tripod and triggered by remote with mirror lockup. Shot in RAW, unprocessed and exported it to JPG in LR4. Framing was bit uneven between 16-35 and 24-85 as I moved back because 16-35 is lengthier than 24-85.

https://plus.google.com/u/0/photos/100994177861402107208/albums/5836058564869027825#photos/100994177861402107208/albums/5836058564869027825

You can download original image from Google+ by going to Options > Download full size.

My observation is 24-85 looks sharper to me at 24mm and 35mm. 16-35mm is sharper of the both at 28mm. Also left side of the image looks soft and loosing resolution compared to right side. I observed it with all focal lengths of 16-35. Can this be attributed to window lighting from the left side? Let me know what you think of my tests.

chakoo

I got Lee CPL and GND, went back to the same spot. This time I deliberately not exceeded f/11 on my 16-35. Still had to shoot at 32mm to exclude distractions which on either side of the frame



D600 | 16-35 | f/8 | 20 | ISO 100

Msmoto

Just a note on edge sharpness....a flat chart may not show this accurately due to curvature of field.

[Deleted User]

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chakoo

@darkslide - Nothing wrong with the above, it is sharp. I learnt my lesson on how to use 16-35. Shoot f/8 or f/11 and don't go beyond f/11.

proudgeek

Your second image is miles ahead of your first

chakoo

@proudgeek - Thanks for your comments. I reposted the image after correcting vertical distortion.

Golf007sd

@chakoo Well done! I'm very pleased with the way you stayed committed to your objective. You are on the right path. Looking forward to more of your pictures. Cheers