Marianne Oelund

Marianne Oelund

Lives in United States Seattle region, WA, United States
Works as a Electronics Engineer
Has a website at
Joined on Jan 22, 2004


Total: 6, showing: 1 – 6

How about . . .

28:1 with a single (Nikkor) lens and no TC?

(Direct imaging of diffraction rings.)

Direct link | Posted on Dec 3, 2013 at 07:05 UTC as 9th comment | 2 replies
On Homemade rig captures extreme macro shots of snowflakes article (186 comments in total)
In reply to:

Lea5: It's the little things where you can see god's art at best.


Mythology doesn't produce spontaneous supernatural healings and resurrections.

How little you are aware of!

Direct link | Posted on Dec 2, 2013 at 17:22 UTC
In reply to:

moving_comfort: Reproduction ratio of .273 - much better magnification than my Sigma 50-150 2.8. A tad heavier and longer than the 50-150, but much smaller than the 70-200. Looks like I may not be using my 50-150 in DX mode on the D800 much longer :)

That magnification value, at closest-focus of 1m, implies a closeup focal length of about 170mm. This is significantly less focal-length shortening than exhibited by the 70-200 f/2.8 VR II.

Direct link | Posted on Oct 26, 2012 at 00:48 UTC
In reply to:

Octane: Firmware can not change the physical design of the AF system. Most cameras did AF ok in some situations at one f-stop beyond the official limit, nothing new. It's not a matter of software/firmware, it's a matter of physical design. The AF sensors are designed to only see the light from a certain aperture. IOW, an AF sensor that is designed to see at f/2.8 will not see more with a 1.4 lens, nor does it get more light. Of course it will work with a faster lens, but when it comes to slower lenses it's more a matter of generous tolerances.
This firmware update can only allow for some more tolerance, it can't change the design. The AF system was not designed to work at f/8, like for example Nikon did for the D4. Of course that didn't sit well with Canon so they are pushing it now to match it. Real life will show how well it actually works.

Since previous models from Canon have had some f/8 capability in the center AF point, the physical design of the 1DX AF system may very well have already provided for it.
The detail of how the handoff from f/8 arrays to f/5.6 or wider-angle arrays is done during focus acquisition or tracking, would be a matter of firmware. Perhaps the initial firmware release was simply short of the development required for this to happen without issues.

Direct link | Posted on Oct 19, 2012 at 03:42 UTC
In reply to:

Rage Joe: What a cute baby animal :)

Yes, that must be exactly what the leopard seal was thinking about the photographer!

Direct link | Posted on Oct 19, 2012 at 01:49 UTC

A few questions:

Will it be possible to add product tags to our past posts?

Will thread/post voting be available on posts created prior to the forum update?

Search filters I'd love to have: Restrict search to a specific username, and date-range filter. It often happens that an older post I've made will answer a current question, and I'd like an easier way to find them.

Direct link | Posted on Sep 28, 2012 at 09:21 UTC as 216th comment | 2 replies
Total: 6, showing: 1 – 6