notocactus

Mike B in OKlahoma · Post by **Mike B in OKlahoma** » Wed Feb 14, 2007 12:13 am

welcome back, Sue!

Nice photos, the first one especially almost looks like digital art, jazzed up in PS somehow.

I haven't a clue about cactus IDs. I can tell a saguaro, two times out of three, and that's pretty much it!

By the way, are you using the light meter any?

cactuspic · Post by **cactuspic** » Wed Feb 14, 2007 12:58 am

I think it is probably a Noto ubelmannianus but I would also google the herteri and the roseoluteus. Hope that helps. Dave may even have a site for Notos and Parodias.

Hope that helps.

Irwin

salden · Post by **salden** » Wed Feb 14, 2007 5:10 am

Mike B in OKlahoma wrote:welcome back, Sue!

Nice photos, the first one especially almost looks like digital art, jazzed up in PS somehow.

I haven't a clue about cactus IDs. I can tell a saguaro, two times out of three, and that's pretty much it!

By the way, are you using the light meter any?

Thanks Mike.

Yes, I had to use it during my lightening classes. It was so so and I actually got better results with my in camera meter. Maybe I am not doing it right, but according to how you do it, you have to put the thing right up to the subject's face at both the highlighted and shadowed areas and meter average the two. Try doing that to a bear...

DaveW · Post by **DaveW** » Wed Feb 14, 2007 1:23 pm

Sorry I missed this one and only stumbled on it today. As Irwin says it is one of the "Gymnocalycioide" Notocacti, N. uebelmannianus, but they changed the name to Parodia werneri on the transfer to Parodia because there already was a Parodia uebelmannianus.

http://www.desert-tropicals.com/Plants/ ... ianus.html

They have also lumped Notocactus arachnites with it. When N. uebelmannianus was first discovered by the Horst-Uebelmann expedition, the purple flowered form was named Notocactus uebelmannianus and the yellow flowered form N. uebelmannianus v. flaviflorus. But it is now known that both flower colours exist in the same population with a certain percentage yellow and a certain percentage purple. I cannot remember what the percentages are I am afraid, but I believe that the yellow flowered form is the most numerous.

DaveW

Mike B in OKlahoma · Post by **Mike B in OKlahoma** » Wed Feb 14, 2007 5:12 pm

salden wrote:
Yes, I had to use it during my lightening classes. It was so so and I actually got better results with my in camera meter. Maybe I am not doing it right, but according to how you do it, you have to put the thing right up to the subject's face at both the highlighted and shadowed areas and meter average the two. Try doing that to a bear...

Have you tried using it as an incident light meter? You have to be in the same light as your subject for that to work, but that always seemed to me to be the most interesting way potentially to use a light meter.

I'm interested in this, 'cause it has always intrigued me, but the people who used light meters usually seemed to me to be large format mentality--Oriented towards intense setup and preparation with enormous care. And I'm not that sort of photographer (Unfortunately--I wish I was, it appears to me to produce better photos in many circumstances). So I'm curious how someone with a more 35mm mindset can use the meters effectively, even though they sound good in theory.

salden · Post by **salden** » Wed Feb 14, 2007 6:00 pm

Mike B in OKlahoma wrote:
salden wrote:
Yes, I had to use it during my lightening classes. It was so so and I actually got better results with my in camera meter. Maybe I am not doing it right, but according to how you do it, you have to put the thing right up to the subject's face at both the highlighted and shadowed areas and meter average the two. Try doing that to a bear...
Have you tried using it as an incident light meter? You have to be in the same light as your subject for that to work, but that always seemed to me to be the most interesting way potentially to use a light meter.

I'm interested in this, 'cause it has always intrigued me, but the people who used light meters usually seemed to me to be large format mentality--Oriented towards intense setup and preparation with enormous care. And I'm not that sort of photographer (Unfortunately--I wish I was, it appears to me to produce better photos in many circumstances). So I'm curious how someone with a more 35mm mindset can use the meters effectively, even though they sound good in theory.

Good questions. I have the meter only because it is required for many of my classes. I really do not care for it.

DaveW · Post by **DaveW** » Thu Feb 15, 2007 12:09 am

Incident metering is by far the most accurate form of photographic light metering, beating all modern complex in camera metering because it records the light falling on the subject so is not influenced by the subjects tones. That means it is not fooled by over light or dark coloured subjects.

The reason it has fallen out of favour is it does not lend itself to incorporation in modern automatic "point and shoot" cameras, even professional ones. These require reflected light for their meters to work. With incident metering you have to approach the subject to take a reading if your camera is in different light to the subject, or take a reading in similar light to the subject.

In portraiture, given even modern fancy camera metering, an incident reading is still more accurate, failing that a close up reading of the face lit by the main light using the camera or reflected light meter and giving + stop for Caucasian skin, the actual reading for Asian skin and - 1 stop for Black African Skin. This is because the meters will try and integrate any sobject before them to an 18% grey (an average scene) that they are calibrated for.

A decade or two ago many of us used incident metering for 35mm work. It was because it could not be incorporated into self-metered cameras very well (though they did have a few tries) that it fell from favour except with professional photographers of the time.

DaveW