Progress with focus through slabs

DUIGUY · March 27, 2008 3:47PM

Still not happy, will try changing light bulbs, not enough true toning .

BECOKA · March 27, 2008 4:00PM

What kind of camera?

DUIGUY · March 27, 2008 4:02PM

<< What kind of camera? >>

Sony Cyber-shot 5.0 mega pixels , Carl zeiss 4X zoom lense.

seemyauction · March 27, 2008 4:09PM

Taking a picture through glass or plastic is not easy for an auto focus camera. The camera tends to focus on the plastic instead of the coin.

If your camera has a manual focus now may be a good time to learn how to use it, get out the user's manual...........

DUIGUY · March 27, 2008 4:35PM

<< Taking a picture through glass or plastic is not easy for an auto focus camera. The camera tends to focus on the plastic instead of the coin.

If your camera has a manual focus now may be a good time to learn how to use it, get out the user's manual...........

>>

I'm pretty sure she is in manual focus,,,,,, but let me double check dat dar owners manual again.

BECOKA · March 27, 2008 5:09PM

<< 

<< Taking a picture through glass or plastic is not easy for an auto focus camera. The camera tends to focus on the plastic instead of the coin.

If your camera has a manual focus now may be a good time to learn how to use it, get out the user's manual...........

>>

I'm pretty sure she is in manual focus,,,,,, but let me double check dat dar owners manual again.

>>

So the Sony lets you adjust focus back and forth? That would be a cool feature on a non DSLR that I have not seen yet.

If this is the case try focusing on the field of the coin instead of the devices, you should be able to get a clean shot through the plastic without seeing any plastic in the photo.

JapanJohn · March 27, 2008 8:07PM

I don't smell a focus problem as much as a sharpness problem. Get the camera further away and extend the lens. There's a sweet spot on focal length and aperture somewhere in the range of the camera.

John

stev32k · March 27, 2008 10:37PM

Does this look more like the coin in hand? I adjusted the curve in photoshop.

tahoe98 · March 28, 2008 12:39AM

here's the solution........................................TAKE IT OUT OF THE SLAB!!!

DUIGUY · March 28, 2008 2:46AM

<< Does this look more like the coin in hand? I adjusted the curve in photoshop.

>>

Thanks Steve!! Thats MUCH closer to the looks of the coin! I will have to play with this "curve" feature.

DJCoinz · March 28, 2008 2:52AM

Duiguy: Is your camera a Sony DSC-V1? That's my camera and it's got the 4x Carl Zeiss zoom and 5.0 MP.

The sweet spot for the zoom is at 2.5x. You should put it in the full manual mode so you can adjust the white balance and aperture. Go to this link for specific instructions on how all the camera's features work: Linky

stev32k · March 28, 2008 7:00AM

I don't believe you have a focus problem. It looks to me like an exposure problem. I'm not familiar with the Sony camera, but if you have exposure compensation control I would suggest dialing in -0.5 to start and take test shots from there. If you can look at your histrogram you will see the image is exposed far to the right with nothing in the far left. Another way of correcting the problem - if your camera has the ability - is spot metering. If you can't do any of the above you can make the corrections in software as shown below:

Your original shot:

After correcting in photoshop

DUIGUY · March 28, 2008 7:07AM

Thanks for the great info Steve. Way over my head at this time.

""look at your histrogram "" Should'nt a Doctor be doing this??

MadMarty · March 28, 2008 7:24AM

<< Thanks for the great info Steve. Way over my head at this time.

""look at your histrogram "" Should'nt a Doctor be doing this??

>>

Only worry if he puts on the rubber glove!!!!

adamlaneus · March 28, 2008 7:28AM

It looks to me like you are picking a great deal of glare from the slab. Yes you can generally use levels to cancel it out, but it definitely affects your dynamic range.

One thing to try is to adjust your lighting. Move the light source further away so that it is more of a point source and not such a diffuse source. That might help to reduce the glare.

Swampboy · March 28, 2008 7:30AM

<< There's a sweet spot on focal length and aperture somewhere in the range of the camera. >>

Thanks for the tip JapanJohn.
I know what I'm going to work on this weekend.

Progress with focus through slabs

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