October 25, 2014, 10:56:09 AM

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Messages - teedidy

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Third Party Manufacturers / Re: Woe and Pathos in the Sigma 50 Art?
« on: October 06, 2014, 01:54:59 PM »
I just finished renting this lens and the usb dock for the past 2 weeks. Everything that is said about this lens is true. It is wonderfully sharp, and without the usb dock it has severe focusing issues. AFMA does not help except for the exact distance you set the AFMA for. Using the usb dock and software you set the focus for 4 different distances. each of the distances had different calibrations. After some meticulous calibrations (roughly 60 minutes tethered and zooming in at 100%), this lens worked great! Testing for constancy I was able to find the following miss rates:

Canon 50 f1.8 @1.8             = 3/60 miss rate
Canon 24-70 @ f2.8/50mm  = 1/60 miss rate
Sigma 50 art @ 1.4             = 3/60 miss rate  (closer to 2.5 as one was usable, but not tack sharp so I included it)

In summary, unless someone spends the same required attention to detail I refuse to consider their input on the quality and consistency of this lens' focusing ability. This is an awesome lens, but only with the addition of usb dock.

If requested I can upload some of my testing shots and discus my methodology.


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Reviews / Re: Consumer Reports: Canon G1X MK2 Best Ever
« on: September 02, 2014, 12:59:55 PM »
i have the G1X mkII and i love it. if you ignore every persons comment on price, all you ever see is glowing reviews. if you compare noise at a pixel level, there are only a few cameras that beat it.  http://www.dpreview.com/reviews/canon-powershot-g1-x-mark-ii/10 check out the comparison to the sony rx100 raw at 3200 iso, its pretty clear how much better the canon g1x is. if you flip through other cameras, only half of the full frame cameras clearly beat this little G1X.

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EOS Bodies / Re: How do reds come out in your 5d3 ?
« on: August 13, 2014, 10:59:31 AM »
LightRoom tip: While holding down the alt key you can adjust the Whites the screen will turn completely white unless a channel is at 100%. If you see any black, that indicates pure white. If you see any other color, it indicates that channel is 100%. In your case with the Red flowers you will see large patches of red indicating that the red channel is at 100%. Back down the white slider until the last bit of red disappears and there is only one or two pixels that are at 100%. This will allow your flowers to have detail in the red.

notes while holding down alt key and adjusting whites:
Yellow = Red 100%, Green 100%
Purple = Red 100%, Blue 100%
Cyan = Blue 100%, Green 100%
Red = Red 100%
Green = 100%
Blue = 100%
Black = Red 100%, Green 100%, Blue 100%

Adjusting the Blacks works in a similar manor.

-T

4
Really right stuff made a plate for the mark 1 version. I called them about the mark 2 version. They said they wanted to gauge the market before making a plate. If everyone can request it from them they are likely to produce it.

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PowerShot Cameras / Re: Anything Shot with a G1X Mark II
« on: May 31, 2014, 03:31:47 PM »
Last weekend near Pebble Beach CA.

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EOS Bodies / Re: Debating on selling my 5D II and 35L/135L for a...
« on: May 26, 2014, 11:54:27 PM »
Canon G1X mark ii has been a great little camera. when you read any of the reviews they are all glowing if you omit anything about price, while high, its a canon.  Great low light performance, great af performance ( with a few quirks ), great image quality for a camera its size.

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Lenses / Re: Video Review: Canon PowerShot G1 X II
« on: April 27, 2014, 03:44:17 PM »
I picked one up for my wife as a combo birthday present from her family and me (to offset the cost to me). Very early I will say I am very pleased with the camera. The photos in RAW are great, ISO 6400 is comparable (similar, but not as good) to my 5Dmk III at the same ISO, very usable for my wife. She might even be fine with ISO 128,000 however I would not be. It does feel small to me, I am hoping the RRS plate will give it slightly more height and feel better in my hands. All in all we are both very happy with the camera, it fits in much smaller bag then my 5DIII so it has been going more places with us. Since the best camera in the world is the one in your hands, I am happy with it. Autofocus is really nice, I wish the M could have done this well on its initial release. Few quarks, but nothing I would return it for.

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Lenses / Re: Bad Copy of 24-70 f/2.8 II?
« on: October 06, 2013, 10:44:38 PM »
I had the exact same thing with my first copy of this lens. I did return mine and got a better copy the 2nd time.

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Software & Accessories / Re: And another MagicLantern cool feature
« on: July 16, 2013, 05:41:53 PM »

Interesting, I didn't read far enough for that. I guess it sets the chips to different sensitivities, and then is basically line-skipping and doing the interpolation between them all. Ouch. I think I just hurt my brain trying to think of the math that's needed for some of this.

Skips lines of 2,

RG RG RG RG  -- ISO 1600
GB GB GB GB  -- ISO 1600
rg rg rg rg      -- ISO 100
gb gb gb gb   -- ISO 100
RG RG RG RG  -- ISO 1600
GB GB GB GB  -- ISO 1600
rg rg rg rg      -- ISO 100
gb gb gb gb   -- ISO 100

to avoid funky banding.

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Software & Accessories / Re: And another MagicLantern cool feature
« on: July 16, 2013, 04:38:14 PM »
Looks like it is only available on the 5DmkIII and 7D due to two separate physical chips to read sensor data with different sensitivity levels. Older cameras only have a single input so this will not be available to all cameras.

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Technical Support / Re: Canon 5D3 at airshow
« on: July 16, 2013, 07:29:17 AM »
Would useing a polarizing filter ( not sure of the trerm rotated / stopped down ) to cut out as much of the bright sky to get the planes closer to the same exposure as the sky provide any value?

12
Lenses / Re: Canon EF 35mm f/1.4L II Mentioned [CR1]
« on: June 24, 2013, 10:08:51 AM »
I have already saved up for this lens twice! Instead I picked up the 24-70 f/2.8 and the 70-200 f/2.8 IS. Hoping 3rd time is the charm.

13
I am using a Zacuto z-Finder 3.0. I have attached the adhesive mount to a "Vello Snap-On LCD Screen Protector for Canon 5D Mark III"
http://www.bhphotovideo.com/bnh/controller/home?O=orderHistory&A=details&Q=&sku=860349&is=REG The Screen Protector snaps on and off very easily when I know I am only going to shoot stills. Most of the time I leave it on (Can cause partial loss of 100% viewfinder unless you really "squeeze" your eyeball in there).
 I further secure it with a single "Zacuto Z-Bands for the Z-Finder"
http://www.bhphotovideo.com/c/product/657226-REG/Zacuto_Z_BNDS_Z_Bands_for_the_Z_Finder.html

I find this solution works great. I always have my RRS plate attached so most of the mounting plates are not an option for me.


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Lenses / Re: Canon 24-70 f/2.8L mkii Focus Shift
« on: March 31, 2013, 06:51:26 PM »
HI All,

I have just received my (2nd copy) Canon 24-70 f/2.8 mk II. Being a faithful CR follower and reading http://www.canonrumors.com/tech-articles/how-to-test-a-lens/ I begain from the top and followed ever step I could as best as I could. I also have Reikan Focal and ran through every testing option there was available. What I have found suprised me to the point I originally thought I had received the dreaded bad copy.

There is a definite focus shift on the 24-70 mk II. I have found that from f4 to f5.6 it starts to back focus severely  -5 afma vs +3 afma for f2.8 to f4 and +3 afma f5.8 on.

I am surprised there is not more information already out there on this.
I Found this on a competing forum  http://www.fredmiranda.com/forum/topic/1177402 very similar findings

I understand through research you can hold the DOF button down to get around this issue? But would that reduce effectiveness of the f2.8 cross focus points?

After a quick search it appears the Tamron 24-70 has a very similar focus shift issue. 
http://www.lenstip.com/340.5-Lens_review-Tamron_SP_24-70_mm_f_2.8_Di_VC_USD_Chromatic_and_spherical_aberration.html

Does anyone have any advice? At this point I don't know what to do?

Thank you for your time.

Either exchange it again, or send the lens to Canon for adjustment.  I'd say exchange it if you can.  It might have a issue at 70mm.
 
Due to residual spherical aberration,  a lens focus will appear to shift towards the rear, but the 24-70 should do it only very slightly.  For the most part, its just the depth of field that increases more towards the rear as you stop down.
You can decrease the aperture on this photozone chart and see it.
http://www.photozone.de/canon_eos_ff/773-canon2470f28mk2ff?start=1
 
http://toothwalker.org/optics/spherical.html

Thank you for your time on this. After spending a few more days with the lens (and since BH is closed for Passover). I have had some more time for testing. I have (am attempting to) uploaded 2 files both taken at f4 about 78 inches away. The live view has achieved perfect focus and has equal ticks before and after the target. The AF photo is back focused and has its first tick in focus behind the target. Before I return for a second time, I want to confirm this is not normal and I should at least see at least one tick in front of the target in focus.

Looking at the photozone review of this lens there is a focus shift, but their copy has 2 ticks in front and 10 behind at f4, (vs mine has no ticks in front).

As a side note, I really do love this lens. The colors are amazing! Everything at f/2.8 is amazing.
As a secondary side note: when I don't use the center focus point and use one of the f/4 or f/5.6 points, the back focus is not as prevalent. I will try to upload some pics of that too.
 

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Sedona AZ. 100 miles north. amazing red rock canons. was just there yesterday. will post photos when i get back home. check out the pink jeep tours.

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