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Messages - neuroanatomist

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6301
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.

6302
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...

6303
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.

6304
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.

6305
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.

6306
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.

6307
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.

6308
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.

6309
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...

6310
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

6311
Software & Accessories / Re: Help: choosing Canon EOS 1000D tripod
« on: November 25, 2012, 01:21:30 PM »
Well, the budget is whatever it takes to buy an quality tripod 'cause I really don't want to have to buy a new one just after a few months or so. And probably just driving around, maybe a little hiking since I do love the woods and mountains. And at the moment, I only have one lense, the usual Sigma 18-50mm but next year, around summer I am planning on getting a new one, probably Sigma 70-300mm or something similar to that.

Well, there's quality, and then there's Quality;)

I recently bought a Really Right Stuff tripod/gimbal/ballhead combo costing more than a new 5DII.  But that purchase was spurred by a need to support a supertele lens. 

My other tripod (purchased when I was just starting out) is a Manfrotto 190CXPRO4, and I'll be keeping that as it's a good travel tripod.  I started with the 488RC2 head (currently the 498RC2), and it's very good, and can support up to a 70-200/2.8L or 100-400L lens.

6312
EOS Bodies / Re: Canon's roadmap
« on: November 25, 2012, 12:07:27 PM »
Which will ... get repaired faster if a repair is needed?

Probably the Tamron - they promise a 3-day repair turnaround for everyone.  You'd need to be a CPS Platinum member ($500/yr) to get faster service from Canon.

6313
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 12:02:30 PM »
Fair enough.  ;)

My succinct and precise statement is a good general rule, although it relies on a couple of assumptions which break down in some scenarios.

Here's a good read: http://toothwalker.org/optics/dof.html

6314
Pricewatch Deals / Re: Canon EOS 7D Body for $1151 via eBay
« on: November 25, 2012, 11:51:49 AM »
The 7D is a great camera, but at this point it's ancient.
You can buy a D7000...

Sure you can. But the 7D has better AF, faster frame rate, a better VF, and better build, despite being a year older in design.  Plus, for the common use of bird/wildlife shooting, the 7D has affordable 400mm f/5.6 options (prime and zoom) that actually deliver good IQ at 400mm, something not available for the D7000.

6315
Software & Accessories / Re: Help: choosing Canon EOS 1000D tripod
« on: November 25, 2012, 11:28:52 AM »
Need to know budget, whether you'll be hiking/traveling with it (meaning carbon fiber is better), or just driving around.  Also, what lenses do you have/plan to get (heavier gear needs a sturdier tripod).  Besides the tripod, you'll need a ballhead.

IMO, Manfrotto is a good compromise between quality and value. A cheap, flimsy tripod won't help you.

Look for legs that are tall enough so the viewfinder is at eye level (or a little above) without extending the center column (remember to factor in ballhead height).


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