April 19, 2014, 06:50:41 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - neuroanatomist

Pages: 1 ... 418 419 [420] 421 422 ... 843
6286
Animal Kingdom / Re: Bird ID - Help Please!!!
« on: November 26, 2012, 11:31:56 AM »
He looks like the guy below, who is definitely a Semipalmated Sandpiper (I snapped this on an outing with a guide from Mass Audubon, so I'm not relying on my own ID  ;) ).   Apologies for the bad IQ, this is a 100% crop from too far away, and it was raining at the time.

6287
EOS Bodies - For Video / Re: Quick help needed: Polarization filter
« on: November 26, 2012, 11:26:54 AM »
Yes, you rotate it until you get the effect you desire.  The angle of the sun matters, and best resutls are at 90° to the sun.  If you're moving the camera around for the shot, and you change the angle relative to the sunlight, you'll change the polarization, too - probably with undesirable results (exposure changes, etc.).

6288
EOS Bodies - For Video / Re: Quick help needed: Manual White Balance
« on: November 26, 2012, 11:24:50 AM »
See p.138 in your manual.  Take the pic, assign it to custom WB in Shooting Menu 2, then select Custom WB, symbol is:

6289
Lenses / Re: whats up with my focus?
« on: November 26, 2012, 11:19:53 AM »
Have you done autofocus microadjustment for those lenses?

What are all those little boxes in the second image, with things like Tmax and Ektar on them?   :P

6290
Animal Kingdom / Re: Bird ID - Help Please!!!
« on: November 26, 2012, 11:16:47 AM »
Looks like a Semipalmated Sandpiper, but I'm no expert.

One challenge is that many of the pictures you'll see as species examples online are breeding plumage, but at this time of year they have non-breeding plumage and can look different. 

6291
Software & Accessories / Re: What's your favorite Lightstand?
« on: November 26, 2012, 10:57:22 AM »
I've got several of the Manfrotto air-cushioned (10xxBAC) stands (two 7', two 8', and one 12'), all are excellent.  The 8' ones have a 2' diamater base, which is nice for small rooms.  Any of them will hold a PCB Einstein 640 monolight, although I generally use the 8' or 12' if using a large modifier (a 48"/120cm octabox, for example) because the 3' diameter base provides better balance.

6292
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 26, 2012, 10:47:03 AM »
Take the period out of the url and fire again.
http://toothwalker.org/optics/dof.html


Apologies.  You can thank my iPhone's automatic punctuation...

6293
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 06:57:36 PM »
I meant the same framing, of course.
My opinion was determined by looking on my photos, thus your simplified theories are not able to reverse my mind.
Obviously. Misinformed opinion trumps fact every day of the week, in one's own mind if not in the real world.

Through the filter of our own misconceptions, everyone else's statements are part of the blurry background.
Well said Sir.

Why, thank you!  You were, of course, quite correct.  Don Quixote notwithstanding, the windmill will remain in this case. I'm out.

6294
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 06:14:28 PM »
Another example: shooting straight en face with 50/2.8 both eyes are sharp pretty the same, but shot with 300/2.8 = it is easy to say which eye was focused on.
Sure it is, if you are shooting at the same distance - in that case, if the face fills the 300mm frame, it's only a small portion of the 50mm shot, and if it fills the 50mm frame then your 300mm shot is only showing the eyes (or would be, if you weren't closer than the MFD of the lens). But if you're 6 times further away at 300mm compared to 50mm, so the framing is the same, then the DoF is the same

It always has and always will be difficult to convince people that what they think they see is not in fact true (even with explanations and examples).
Through the filter of our own misconceptions, everyone else's statements are part of the blurry background.

6295
Lenses / Re: PROBLEM: AF Does not work!!
« on: November 25, 2012, 05:42:54 PM »
Much thanks to all of your replies!

I bought an Kenko PRO 300 AF DGX 1.4X teleconverter for my Canon 100-400L to use with my 60D. But the AF does only work manually! No automatic AF. I tried it on my 70-200, 100mm, and so on. but the AF does not work.
Even not on my wifes 7D.

Should I give it back? Or do I make something wrong?

With an f/2.8 or f/4 lens, it will be f/4 or f/5.6 with the TC, and that combo should AF on any body.

I bought it, because I heard that this converter let the AF work on the 100-400L (aperture of 8 ).
My origrinal 1.4x  Canon converter does only work on my Eos 1V and 3.  You know the problem-

Yes, I understand. My point is that if the Kenko TC you just bought doesn't allow AF with an f/2.8 or f/4 lens, it's defective.

6296
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 05:40:36 PM »
Exactly.  Your eyes are being fooled. The blur is the same. That it doesn't look that way is an illusion. But...it's a good illusion.

I think that we need to define "background blur" now, because it does not look like the same COC at 200mm and 400mm.
And what about my extreme examples in the previous post? Do you still call it: "my eyes are fooled"?

If you crop just the tower from both images, and view them at the same size on the screen, they will look identical.  That means the blur is identical. 

Examples from http://toothwalker.org/optics/dof.html.

100mm f/4:


28mm f/4:


The car to the right of the subject has more blur with the 100mm lens than with the 28mm lens, right? 

 

Wrong. Same blur. That's the case even in your extreme example.

I'm not saying it looks the same, the tower and car do look more blurred with the longer focal lengths. Like I said, it's good illusion.

6297
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 04:15:02 PM »
No, look again, the actual blur of the tower is the same, BUT the tower is much bigger with the 400, you are looking at the effects of perspective in those shots NOT depth of field.
Yes - the tower is bigger and blurred part is bigger too - thus better blur in my eyes.

Exactly.  Your eyes are being fooled. The blur is the same. That it doesn't look that way is an illusion. But...it's a good illusion.

6298
Software & Accessories / Re: Help: choosing Canon EOS 1000D tripod
« on: November 25, 2012, 02:27:18 PM »
Shooting fast-moving subjects usually means a fast shutter speed, and that means a tripod/monopod is of less importance, unless you're shooting with a very long lens (>500mm).  If your main interest was landscapes, I'd get the tripod first, but for action shooting I think a fast lens would be better. Agree that the 200/2.8L is an excellent value, or for closer subjects, the 100/2 or 85/1.8.

6299
Lenses / Re: Red Ring Broke Off on 24-105 lens
« on: November 25, 2012, 02:21:46 PM »
There is an L-series red ring repair kit.  Actually, it's the same as the non-L to L-lens conversion kit.   ;)



I'd say DIY with glue or call Canon...

6300
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 02:16:08 PM »
Now that the test parameters are fixed, whats the maximum working distance with a 85f/1.2 maintaining mackground blur?


That one is going to depend on the physical separation between subject and background.

If you run Windows, you might try Bob Atkins background blur calculator:

http://www.bobatkins.com/photography/technical/bokeh_background_blur.html

Pages: 1 ... 418 419 [420] 421 422 ... 843