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Messages - privatebydesign

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Lenses / Re: Canon EF 100-400 f/4.5-5.6L IS II [CR1]
« on: July 15, 2014, 09:26:14 PM »
Understanding resolution is not a simple topic. The Rayleigh Criterion in the reference I gave above is the "textbook" example. I got this in a class I took in microscopy decades ago. In this next reference (link at end of this statement) the authors argue that this is not good enough for digital. It is very long but if one scrolls down and looks at the tables (the resolution numbers in the columns go up (apertures decrease in size as one goes down) in each table but the values vary according to criterion - going across in the table (for a given aperture)) it is obvious that the maximum theoretical resolution (i.e., diffraction limited) at f/2.8 is greater than f/5.6
link: http://www.luminous-landscape.com/tutorials/resolution.shtml

Theoretically that is obvious, from a practical standpoint aberrations and mp limits cut in way before that when wide open for us camera users and the lenses we actually have available. Your assumption earlier was "assuming similar correction for lens aberrations", it is more than four times more difficult, many would say sixteen times, to manufacture a 400 f2.8 than a 400 f5.6 with the same optical aberrations.

Theory ends when "limited" purchasing options are all we have.

Lenses / Re: Canon EF 100-400 f/4.5-5.6L IS II [CR1]
« on: July 15, 2014, 07:18:44 PM »
Sorry Don, I'll slink off back to my hole  :)

Lenses / Re: Canon EF 100-400 f/4.5-5.6L IS II [CR1]
« on: July 15, 2014, 06:45:02 PM »
My bet is that Canon could design and build a 400 5.6L IS that could produce images every bit as good as the 400 2.8L IS (stopped to 5.6), of course much lighter and cheaper. Light and cheap means you're more likely to have it with you.



EOS Bodies - For Stills / Re: 1DX dust behind superimposed screen
« on: July 15, 2014, 12:26:23 AM »
My hardest worked 1Ds MkIII has more S___ in the viewfinder than the African savannah after the wildebeest migration. I wouldn't dream of cleaning it, it works. Next time something on it breaks it can go to Canon and if they clean it, great.

I understand the "collectors" mentality for bespoke items like limited edition Leica's, but to try to do that to simple workers tools seems a bit strange to me; these things are not built in dust proof clean rooms, they are not collectables, in fact they are nothing special at all in and of themselves, they are tools that enable us to take amazing images.

Worry about the colour of your output images, worry about lighting, worry about AF, exposure, or any number of important things, don't worry about a spec of dust in the camera, a scratch on the paint, a broken catch or seal, it is nothing more than a tool to take your great images.

Lenses / Re: Canon EF 100-400 f/4.5-5.6L IS II [CR1]
« on: July 15, 2014, 12:09:04 AM »
There is no reason why the 400F5.6, in an updated version, can't have the same IQ as the 400F2.8. It's that full stop faster that you pay so much for.

For example, the 24-70 F4 and the F2.8 are similar in IQ, but twice as much for a half stop.....
The 70-200 F4IS and F2.8IS are similar in IQ, but twice as much for a half stop....

Not to sound too pedantic, but the difference between f/5.6 and f/2.8 is two stops, not one. (Which only further reinforces your point.)

There is a full stop between f4 and f2.8 too.

EOS Bodies / Re: DSLR ? - thinking out loud ....
« on: July 14, 2014, 11:22:57 PM »
Since we're speculating...

7 years down the road your pro/semi-pro camera will not only be mirrorless, but will have no built-in display and limited controls.  Instead, it will have a dock for your smartphone, which will serve as the control panel and view screen.(*)

(*) Not an actual prediction, for entertainment purposes only.
actually..... I would love it if I could use the Wi-Fi on the camera to connect to a smartphone or tablet and have the device act identically to the screen on the camera, or in the case of a tablet, have all the controls at your fingertips...

Im sure you can already do that...
Check 6D plus EOS app on your smart phone...
Of course it isn't perfect but it can do what you want...

You have been able to access Live View on a phone or tablet since the 1D MkIV and the 5D MkII, 2009-2008 via a Canon WFT. You have been able to control the camera and view and download the images since at least 2002 with the 1Ds and the WFT. Not to mention various third party work arounds.

Pricewatch Deals / Re: Searching for a lightroom 5 deal...
« on: July 13, 2014, 11:35:50 PM »
I wasn't answering the OP's question in that comment, I was correcting your incorrect statement.

Pricewatch Deals / Re: Searching for a lightroom 5 deal...
« on: July 13, 2014, 11:12:42 PM »
I was content with using lightroom 5... and then my desktop computer decides to commit suicide... thought it might have been auto erotic asphyxiation considering the materials on the hard drive... but I digress. 

If yall come across any decent deals with LR6 as an add-on or on just the software alone... I'd be very interested. 

I'm sure this goes without saying for most people, but I'm not interested in the Creative Cloud.

Also, when you buy the software... you can get a multi-use registration code... because I would want one for my laptop and for my desktop's successor.

There is no Lightroom 6, yet.

Their website does not seem to offer the option of downloading a "standalone" version anymore

On the other hand......   https://www.adobe.com/products/catalog/software._sl_id-contentfilter_sl_catalog_sl_software_sl_mostpopular.html?promoid=KLXMI

Site Information / Re: Post Precessing Section
« on: July 13, 2014, 10:43:34 PM »
I agree, I have posted a couple of post processing videos and would happily do more. I am no guru but I do know a decent amount with LR and PS.

Lighting / Re: Anything Strobist
« on: July 12, 2014, 07:24:37 PM »
So anything shot with artificial lights and, or not, ambient? Isn't that a bit broad?

Like RL I have always considered "Strobists" as small hotshoe mountable flashes users, though normally not on the hotshoe.

EOS Bodies / Re: Unknown lenses with Canon Explorers
« on: July 12, 2014, 11:53:08 AM »
I think they are typos too. But there are a lot of them, the photo info details also list the lenses incorrectly, Quentin is shooting the EF 24-70/2.8 L IS USM on his 5D MkII (a lot of the Ambassadors/Explorers are still shooting 5D MkII's) and Andrey Golovanov and Sergey Kivrin would have no use for an EF-S lens as they, apparently, use 1DX's and 1D MkIV's. Wish they had a good proof reader!

Lenses / Re: Canon 400 f/2.8 II .. times 8!
« on: July 11, 2014, 09:01:42 PM »
I posted about this in the Astro thread the other day. I have seen several wide field astro cameras with 200 f1.8 arrays. Indeed one of them had the worlds largest supply of FD manual focus 200 f1.8's, it was a long time ago but, I recall it had four of them.

This comes up regularly.

Cutting round sensors out of a bigger round sensor is way more wasteful than squares or rectangles that can be cut edge to edge.

You can't use a bigger than 24mm on the short side sensor for our lenses image circle, the image below has the image circle our lenses make, the pink rectangle is our FF sensor, the big square is what people think they could get, the small square is what you can actually cover.

The 24mm short side is dictated by the image circle and flange distance needed to clear the mirror (don't start on mirrorless!). The guys that designed this stuff did actually think about it first.

well yes lenses have to be designed.
and it´s expensive.

but i would be interested in a affordable fixed zoom lens medium format camera. :)

like a sony RX1 on steroids.

You and about 12 other people, which would put it at about 100x affordable!

EOS Bodies / Re: which model is this?
« on: July 11, 2014, 01:23:12 PM »

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