Has Oly improved its AF?

[wazza]

I could be completely off target here, but, I was under the impression that Oly Cams wouldn\'t AF properly if the max apature was greater than 5.6.

Now if the rumours are correct, they will be releasing a lens with a max apature of 6.3 at the long end to go with the E-500.

So does this possibly mean the AF system has been improved?

Cheers
Wazza

[llpoolej]

I *usually* shoot at 2.8 or 3.5 and never have any problems. Not even on fast moving little nitro cars. Those suckers are hard to catch!

Model: E-1
Size: 800x713
Bytes: 700001
Aperture: f/4.5
ISO: 100
Focal Length: 130mm
Exposure Time: 0.001s (1/1000)
Exposure Program: Manual
http://llpoolej.smugmug.com/photos/26238010-M.jpg

And real Nascars....

Model: E-1
Size: 800x600
Bytes: 151583
Aperture: f/3.5
ISO: 1600
Focal Length: 200mm
Exposure Time: 0.005s (1/200)
Exposure Program: Manual

http://llpoolej.smugmug.com/photos/33964306-M.jpg

I am no pro, and I didn\'t even stay at a Holiday Inn last night. So, the AF doesn\'t work that badly! The nitro cars are TOUGH to catch. And my in focus numbers are over 90%

[First Light]

llpoolej... I think you missed the question. Your camera always focuses with the aperture wide open when an autofocus 4/3rds lens is attached. That\'s why you need to use the DOF Preview button to force the camera to adjust the aperture prior to pressing the shutter button if you want to change the aperture before that.

And don\'t think that you can trick the system into autofocusing (AF) at a higher f-stop by pressing the DOF Preview button while you half press the shutter button. It won\'t work. The camera will momentarily switch to the maximum aperture during AF.

What Wazza is talking about is a new low-end 4/3rds zoom lens which has a maximum aperture of f6.3 when zoomed all the way out. So the aperture will truly be f6.3 when the camera focuses at its maximum focal length.

Will the AF system in the E-1 or E-300 have a problem at this f-stop? No one knows except Olympus because there hasn\'t been a lens before now that enabled anyone to autofocus with such a small aperture.

[wazza]

Exactly...

So can we then expect a firmware upgrade for our \'older\' cameras to cope with this slower lens?

It will be interesting to see how this is tackled.

Cheers
Wazza

[llpoolej]

Your right, I misread what the statement was. I had no idea there was a problem with lenses truly slower than 5.6. Learn something new everyday.

[hammer_400]

i dun think oly ever said the f5.6 was the max.
anyone with the tcon tried it on the slwoer zooms to see how on how slow a lens the af will work on?

[hammer_400]

i dun think oly ever said the f5.6 was the max.
anyone with the tcon tried it on the slwoer zooms to see how on how slow a lens the af will work on?

[llpoolej]

Where did this info come from? Being there is no 4/3 lens slower than a 5.6 max. So, none of this info is from real life experience.

I am just a bit confused

[wazza]

There is info on the Oly web site stating the combo of 40-150 will not work with the 1.4x TC in AF. I have read a post elsewhere where a person had tried this combo, but it was only usable in good light.

My question s releating to the rumour of the new lens with the max apature of 6.3 at the long end. If this is supposed to work you would expect the AF to have to perform better..... hence my speculation.

Cheers
wazza

[Dean]

I\'ve learnt two new things today now :)

Is it normal for a lens to give out a slight yellow cast when using higher apertures? I noticed this in particular when shooting f6.5 or above. My Canon mate always shoots at F8 and all his photos have a bad yellow cast. I noticed this also (but to a smaller degree on my E-300 with 50-200) when i shot at F8. It could just be me, but same shot taken at f2.8 and 3.5 was beautifully colored. Is it just a bi-product of catching less light, or catching the combo of RGB that makes yellow \'quicker\'. If that all makes sense?

[First Light]

Dean wrote:
...Is it normal for a lens to give out a slight yellow cast when using higher apertures? I noticed this in particular when shooting f6.5 or above. My Canon mate always shoots at F8 and all his photos have a bad yellow cast. ...
No, the aperture setting should not change the overall tint of the picture. Only an extremely lame lens would have such a strange problem.

This sounds like a white balance (WB ) issue. Many of the consumer and prosumer dSLR cameras obtain all of their WB data through the lens (TTL). This limits their WB system to just the field of view (FOV).

Better cameras also use an external WB sensor that is sensitive to stray light from a wide angle. The E-1 has such a sensor and is able to do a consistently better job of setting the WB. The E-300 does not.

As for Canon, many of their cameras tend to have a \"warmer\" color temperature. However, this problem is much less in their high-end prosumer and pro dSLRs. (Note: You have to purchase a Canon 1D MkII or 1Ds MkII to get an external WB sensor like the E-1.)

I don\'t care for an artificially warm look. I prefer the look of Olympus cameras much better. Since the early days of digital cameras, Olympus has held a reputation for excellent skin tones.

This is one of the advantages of shooting \"raw\" pictures—you can select the color temperature later when you \"develop\" the picture in your computer. That way, if your camera flubs up, you can straighten the photo out later.

Post edited by: First Light, at: 2005/09/15 23:18