06-02-10 – Macro Bugs

/how many cars will I need to sell before I can even breathe in the same room as a nikon equivalent.

None. There isn’t a Nikon equivalent 🙁

Also, orionid: You weren’t the only one caught up in the “swapped image” thing…Procedural Texture lost some images too. Dunno what’s up with that, but hopefully neither of you lost too many votes in the process

don’t know about swapped images but i’m sure i lost at least 50 votes while my images were down. and that’s per image 🙂

/how many cars will I need to sell before I can even breathe in the same room as a nikon equivalent.

None. There isn’t a Nikon equivalent 🙁

Boo.

Well, while I’m making that PK-Nikon conversion ring…… Might as well shoot for canon, too…… Oooh, the possibilities there… Imagine the strange looks I could get from purists on either side of the aisle walking around with flashy-white L lenses on a nikon….

Well hm..on further reading of that lens review, it mentions the effective apperture is quite a bit smaller than stated aperture. I’m not sure how that works, or how that works without introducing a boatload of diffraction softening by f/5.6 or f/8. Damn all this math…

Yeah, the thing is that people talk about changes to “effective aperture” when talking about macro lenses, but that can actually be quite misleading. When you focus closer by moving the lens further away from the camera, you lose light due to extension (the lens is projecting a bigger image circle, so there’s more light getting lost inside the lens, and less light falling on the sensor/film). People tend to call this a change in the aperture because they’re used to dealing with exposure in terms of three variables and it clearly doesn’t fit into shutter speed or ISO, but it’s not actually affecting your DOF or diffraction the way an actual change of aperture would, it’s really just light loss due to extension (it’s called “bellows factor” in large format shooting: www-unix.oit.umass.edu/~rbhome/bellows15.pdf).

This doesn’t necessarily apply to internal focusing lenses though. They’re focusing by changing the optical formula of the lens which can alter the effective aperture (as well as shortening the effective focal length in many cases).

Well, so much else on that lens is counter-intuitive, and non-standard, I can only guess that it’s simultaneously internal and external focus and the rear element approaches the sensor as you magnify. This would compensate for some light dropoff, but not much. At that level of magnification though, a DOF of even a millimeter would be huge, so, I’m leaning towards just declaring it PFM.

What’s funny is that I bought her a set of clubs for her birthday…

Congrats justkat!

Congrats justkat (and to olavf for the two of you with the husband/wife 1st/2nd 😉 )

YAY!!!!!!Kat!!!! 😀

JK and Olavf, cleaning up with One, Two, Four and Six!

Good stuff. Congrats.