Test my lens and solution required

hey all,

After experiencing alot of problem on sharpness, I have decided to test my equipments. For now, I am testing my lens.

I used the following technique suggested by jlabel. :thankyou:

lens sharpness-how to test

Quote:

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Originally Posted by jlabel

The best way to check technical focus is using your camera on a tripod and focusing and shooting a ruler, chose a number and shoot it if the focus is misplaced it may be a lens problem, some newer cameras have the option to configure this kind of problem, also you will be able to see if your lens is sharp enought for you, you should also use f/5.6 or f/8 for this test.

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Additional info.

I used a tripod, mirror was locked up and all shots were taken using a cable release. The focus point was [20] on all the shots.
No PP what so ever.

My lens is Sigma APO 70-300mm F4-5.6 DG MACRO
My camera is Canon 350D

what do you think?

To me the "20" does not look tack sharp.

What format were they taken in (RAW/JPG)

IF they were shot in RAW, did you sharpen them at anytime before you uploaded them?

IF they were shot in JPG, did you sharpen them at anytime before you uploaded them?

Thx - Marko

Thanks for your reply Marko,

Quote:

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Originally Posted by marko

To me the "20" does not look tack sharp.

What format were they taken in (RAW/JPG)

IF they were shot in RAW, did you sharpen them at anytime before you uploaded them?

IF they were shot in JPG, did you sharpen them at anytime before you uploaded them?

Thx - Marko

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It was shot in JPG. No post processing what so ever done on this pictures. They are just out of the camera. May be only cropped.

The problem with this method is that the target, the [20] is not square to the film plane, so your images are suffering from a parallax error. The best way to do this would be to repeat it, using a series of vertical targets such as matchboxes in a staggered line.

Although T.I. is correct, it would have been better if both camera and subject were on the same plane, I'm not convinced that's the problem.

Do you know if your camera is sharpening the images? There should be a setting in the menu that tells you if any sharpening is going on.

If no sharpening is going on, that may be it. In my experience (though I only shoot RAW) digital images need to be sharpened.

any other opinions? Thx! Marko

Here is a more elaborate test with instructions. Focus Test

I hope this helps

cheers

Quote:

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Originally Posted by EJC

Here is a more elaborate test with instructions. Focus Test

I hope this helps

cheers

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You beat me to it

Thanks all of you.

Quote:

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Originally Posted by marko

Do you know if your camera is sharpening the images? There should be a setting in the menu that tells you if any sharpening is going on.

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There is a setting parameter 1 which has sharpening scale +1. These days, I only use RAW for any purpose.

I tried to use Focus Test but couldn't get it exactly. I will give it a try once more.

I don't understand Yisehaq.

Why did you shoot these in Jpg if you ALWAYS shoot RAW?

We need to eliminate variables 1 at a time for ease. You should test the camera/lens by shooting in RAW because that's the way you normally shoot.

i think there's a strong chance this is a simple sharpening issue.

I'd like to see 2 shots shot in raw and converted to JPG.
- On a tripod with a cable release
- both camera and subject on a flat plane

- 1 shot you'll sharpen (in photoshop or GIMP etc.) and one shot you won't. What PP software do you use?

Thanks Marko

Quote:

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Originally Posted by marko

Why did you shoot these in Jpg if you ALWAYS shoot RAW??

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I didn't know that the file types affect the sharpeness. I shot in jpg because I want the file size to be small to upload without any PP manupilations, RAW conversion etc.

Quote:

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Originally Posted by marko

I'd like to see 2 shots shot in raw and converted to JPG.
- On a tripod with a cable release
- both camera and subject on a flat plane

- 1 shot you'll sharpen (in photoshop or GIMP etc.) and one shot you won't. What PP software do you use?

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I use photoshop CS2

Does both camera and subject on a flat plane mean subject and camera sensor on parallel fields?

I will do that and upload soon.