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Messages - Jackson_Bill

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31
EOS Bodies / Re: A Rundown of Canon at Photokina
« on: September 03, 2014, 12:13:53 PM »
Quote
EF 400mm f/4 DO IS II

...
The 7D II sounds good too, and if its sensor is a true breakthrough, I'll probably go through five of them just like I did with the first version!

...
I'm curious - You went through a 7D body per year? How many photos were you taking and how did they fail?

32
Animal Kingdom / Re: BIRD IN FLIGHT ONLY -- share your BIF photos here
« on: August 30, 2014, 11:42:46 PM »
An interaction between an osprey and an eagle at Oxbow Bend in Grand Teton Natl Park
The osprey caught a fish and the eagle hassled him until he dropped it
The eagle took the fish
and the osprey tried to get it back, but no luck

best I could do hand holding the 500

33
EOS Bodies - For Stills / Re: 7DMk II or the 1DMk IV
« on: August 30, 2014, 10:43:01 PM »
I have the 5dMkIII with TC 1.4Mk III and 100-400mm, 4.5-5.6L

Thinking of getting the 7DMk II

or

the IDMkIV with 2x TCIII with 400 f5.6/USM

Objective: Best IQ at distance handheld for BIF.

Saw the discussion on the 300mm with TCs and was quite impressed with that combination.  Any comments or opinions would be appreciated. Now if handheld is a bad idea, then I can go with a monopod, or gimble or whatever. Hands on experience is a plus.

I suggest you save up for a 400 f2.8, either new or used. Either one will provide better resolution.

34
Here is a way of calculating the effective extra reach or resolving power of a crop body versus FF, which will amuse the geeks among us.

Measure the MTF of a lens on the crop (= MTFcrop) and the same lens on the FF (= MTFff). The ratio of the MTFs, MTFcrop/MTFff, gives the relative resolving power of the bodies with that lens. However, the crop body can be placed 1.6x further away to give the same field of view. Therefore, the true effective relative resolving power, R, is given by:

R = 1.6x MTFcrop/MTFff.

Photozone lists measured MTFs for a set of lenses on the 5DII and 50D. I calculated their ratios for the Canon 200mm f/2.8 II, 85mm f/1.2 II and 35mm f/2 at wide apertures below the DLA. MTFcrop/MTFff is very close to 0.726 in all cases.

This gives R for 50D/5DII = 1.16.

So the effective extra reach is 16%.  (Based on the ratio of their pixel sizes, a value of 36% is expected.

The dpreview widget gives values for the 5DIII and 7D only for a few lenses. I did the same calculations with the Tamron 150-600mm (between 150-400mm), the Canon 200-400mm and the Sigma 50mm f/1.4 A at wider apertures below the DLA. In all cases, MTFcrop/MTFff is close to 0.742.

This gives R for 7D/5DIII = 1.19.

So, the effective extra reach is 19%. (Based on the ratio of their pixel sizes, a value of 45% is expected).

There are always arguments about using MTFs quantitatively, but I think in this particular calculation it is reasonably valid to use them. It fits in reasonably well with experience - Jon has shown there is better resolving power in photos of the moon with the 7D, but it doesn't look 45% better. And my own experience is that the 7D and 70D aren't much better than the 5DIII, certainly not 1.6x.

I assume you mean you're dividing the line widths per picture height (LW/PH) at the center when you say you're dividing the MTFs. If so, how do you figure that you can divide the APS-C by FF LW/PH values when the max LW/PH stated in the charts are different for the two sensors?

35
Landscape / Re: Yellowstone and Grand Tetons
« on: August 28, 2014, 09:21:32 AM »
Yes it is beautiful country indeed!
Thank God for Teddy Roosevelt and John D Rockefeller, Roosevelt especially.

36
EOS Bodies / Re: Are you planning to purchase a 7D2
« on: August 27, 2014, 07:20:53 PM »
...

I'm not really impressed with 6,000 focus points with multi quad-sensors. Give me a strong center point focus that brings the goods most of the time, and then we'll go from there. My 7D couldn't even do that with telephotos.

A little off topic but I've got to disagree with just a center focus. Put the center focus on the moose's head and his rear is out of the picture (having made this mistake many times).

37
EOS Bodies / Re: Are you planning to purchase a 7D2
« on: August 27, 2014, 07:15:48 PM »
Also see a lot of folks discussing focusing issues with 7D. I can't say I've noticed any more or less problems there myself. Granted it doesn't have the nuclear powered laser guided focus of a 1DX, but nothing else does. What is the general problem with it?  Is it tracking action in Servo? Stills? Portraiture? I've shot college football games with that and the 70-200 IS MkII and the 2.0 Extender MkII. It's not perfect but it's far from what I'd consider problematic.

I shoot almost exclusively in AI servo and I've taken to shooting high speed continuous so I get one keeper. Say I take three shots in succession - often one (not necessairly the first) will be sharper than the others. Another issue is that in certain situations (grass or flat water behind the subject) even in spot focus it will back focus. And I've checked the AFMA so its not that.

38
EOS Bodies / Re: Are you planning to purchase a 7D2
« on: August 27, 2014, 07:07:16 PM »
yes, assuming I can use ISO 1600 at least, which I can't on my 7D. If not, it'll be time to take a hard look at a 5Diii and 1.4x for my 500 f4 vs jumping ship for Nikon.

What are you shooting though mostly?  A 7DX and 6D will likely be more comparable pricing, and if High ISO performance is a key for you then no crop will ever beat out a Full Frame.  If you're not taking tons of sports or fast action then look at the 6D perhaps?

Over 90% wildlife so the reach of the crop is important. If I went FF I'd need an 800mm to get the same image as my 500m on the APS-C or, as I mentioned, use the 1.4 (700mm vs 800mm) but I haven't been happy with the results with my 500 f4 and the 1.4x II.


39
EOS Bodies / Re: Are you planning to purchase a 7D2
« on: August 27, 2014, 03:22:58 PM »
yes, assuming I can use ISO 1600 at least, which I can't on my 7D. If not, it'll be time to take a hard look at a 5Diii and 1.4x for my 500 f4 vs jumping ship for Nikon.

40
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 12:51:59 PM »

Me too! Would be a replacement for the 40D in my case - if IQ is much better.

To Jackson_Bill : I think the specs look really impressive ... for sports and other action related photographers! For me, remote operability with wifi is missing to make that camera perfect including that I think that there will no high DR sensor / readout available.

So it might be possible that I skip this model again and go for a 6D or ... let's see.

IMO, it all comes down to the high ISO performance and I'll have to wait for the data. If its good at 1600 or higher (which the 7D is not),  I'm all for it. If the high ISO performance is similar to the 7D, none of the other features would make me buy another one.
Where do you use the wifi? I can't see an application for wifi in what I do.
 

41
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 11:33:53 AM »
Very disappointing specs after so long a wait. IMO, minor evolutionary improvements.
There's no reason to think that this sensor can do any better at high iso than the 7D and that was the most important thing I wanted to see.

I'll wait and see. In a previous CR2 rumor (http://www.canonrumors.com/2014/06/new-sensor-tech-in-eos-7d-mark-ii-cr2/):

"We’re told to definitely expect new sensor technology to be introduced in the Canon EOS 7D Mark II. This tech will be used in all forthcoming Canon DSLRs."

If the above CR2 rumor is true, then the technology is probably something major. Hopefully, it's not some improved dual pixel AF with servo capability. DPAF without touch screen is useless to me.


I sincerely hope there is some high ISO improvement.

I have very little use for DPAF at all, if it only works in live view. I use live view less than 10% of the time and from what i've seen, most wildlife shooters don't use live view routinely.

42
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 09:45:42 AM »
Very disappointing specs after so long a wait. IMO, minor evolutionary improvements.
There's no reason to think that this sensor can do any better at high iso than the 7D and that was the most important thing I wanted to see.
The second most important was the AF performance (as others have also noted, a lot of misses with the 7D) so if the additional AF points implies that the AF performance of the 7Dii will be better that's nice but being limited to 800 ISO is still a major drawback.
The rest of the features really don't add anything for me.

43
Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: August 14, 2014, 01:05:10 PM »
Based on the RAW files that he posted, we know that he did the AF Servo test on the Canon using Spot AF...

Interesting.  Presumably, he doesn't know that Canon recommends against using Spot AF with moving subjects.

Off on a tangent but...
That's only because the spot AF is harder to hold on the moving target, not because of any inherent problem with the AF, isn't it?

44
Animal Kingdom / Re: Your best animal shots!
« on: August 03, 2014, 12:58:47 AM »
back to the deer theme for a moment - another species - the mule deer.

45
Animal Kingdom / Re: Show your Bird Portraits
« on: August 03, 2014, 12:39:35 AM »
I'll bet the  fish weren't happy to see this bunch show up!
Note the two in the lower right - they swim along with their eyes below the surface.

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