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sparkie1263
07-24-2008, 08:29 PM
Why is it not sharp right from the camera? I have to use contrast adjustment to get it sharp.

http://i305.photobucket.com/albums/nn219/sparkie1263/Sony%20A100/DSC07419.jpg

DonSchap
07-24-2008, 09:01 PM
I have often wondered that, myself ... so help me God, it's in the glass.

After shooting through the Zeiss 135mm f/1.8 ... it just doesn't need that kind of adjustment. I know it is maddening, but it's true.

I cannot compare the 17-50mm to it, but I can the 70-300, set at 135mm and shoot identical images. The CZ will lay to waste anything the TAMRON can even hope do, on a good day! Of course, there is a significant price difference here ... but, that's what you get. Kick-rump images. Right out of the camera. No PP at all! There are darn few images that I have had to adjust, off the CF card. It shifts your photography to a whole new and refreshing level.

Of course, if you shoot it wrong ... it's still wrong. But, if you shoot it right ... you're pretty much done! Sharpening ... a true waste of time.

I know that is not satisfying to consider, on a reasonable budget, or what you had hoped to know, but the truth isn't always the news you want to hear, it just is what it is. Once you use a lens of this caliber, it is like finding religion. It makes your "standard" image taking EASY.

A wise man will not shoot this lens ... because it devilishly shifts your paradigm in expectations. What you believed was tolerable, no longer is.

To answer the question ... it's not sharp out of the camera ... because it wasn't sharp when it got to the sensor. The optics did their magic ... and came up shy.

Here's a side-by-side, at 100% The sharper focus is apparent. That's what is missing.

38264
Both images were taken with the A100 at exactly the same settings. No alteration ... just a clean crop.

Photography ... a ongoing journey, eh?

sparkie1263
07-24-2008, 09:04 PM
This is my Tamaron 70-300. I do get super sharp images on some shots. I will look and post another that is good.

http://i305.photobucket.com/albums/nn219/sparkie1263/Sony%20A100/DSC06195.jpg

I did bump the sharpness in the camera up one notch. Should I try to mess with the contrast also?

One other question on a different topic. How come sometimes the camera does not lock on focus and I cannot snap the picture?

DonSchap
07-24-2008, 09:48 PM
Frank, it is a "built-in" safety with using "AF". You ought to try doing it indoors, with a 70-300mm ... no flash. It'll be cruising back and forth, and probably never acheive focus lock ... unless you find a high contrast point of light, hence the use of "modeling lamps."

ANYWAY: If you go to "MF" ... it WILL trip the shutter, no matter how bad the focus is.

"MF" is kind of like the "trump" setting in the camera. Like saying, "You will do it ... and like it, too!"

dr4gon
07-24-2008, 09:58 PM
Were you on spot focus? It's not a bad picture, just a bit dark (I'm assuming it was a nice sunny day at the beach).

DonSchap
07-24-2008, 10:24 PM
dr4gon is right, though ... the image is a full f-stop underexposed.

This is where "Spot-metering" excels ... because, it will narrow the exposure meter reading to the center of the frame, instead of "Multi segment" or "Center-weighted" measurement.

On the A100: If you turn the right "function" knob clockwise, to the limit, that is metering mode selection. Give it shot ... and see if it improves the exposure for you.

sparkie1263
07-25-2008, 04:47 AM
Maybe I was using the wrong word when I said sharp. I think what I meant was not clear. If you take the image of my granddaughter and use auto contrast it will clear right up. If you take the image of the dove and use auto contrast there is little to no difference in the image.
Thanks Frank

P.S. I do see a big difference in the glass.

David Metsky
07-25-2008, 06:34 AM
Maybe I was using the wrong word when I said sharp. I think what I meant was not clear.
No, what you meant was underexposed.

sparkie1263
07-25-2008, 03:08 PM
So I should not use spot meter or is it better to be underexposed? What is the best metering mode to use?
Thanks everybody for your detailed explanation.
Frank

DonSchap
07-25-2008, 03:27 PM
Frank,

In my experience, when you are shooting subjects to be in the center of the image ... SPOT metering. Obviously you want to get the best exposure for faces that you can, fighting shadows and what not. Always try to meter for the shadows, not the highlight. In the first posted shot, I would have tried to meter for her forehead, on her right side.