March 05, 2015, 11:42:04 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 - weixing

Pages: [1] 2 3 ... 28
1
Third Party Manufacturers / Re: Upcoming Sigma "trifocal" lens?
« on: March 04, 2015, 07:18:33 AM »
Hi,
Sigma had already mastered the bifocus: Lenses that nails the focus in 2 places -
1) Focus in front of the subject
2) Focus behind the subject

</Snarky-comment>
    This is a good one... ha ha ha  ;D ;D ;D

     Have a nice day.


2
Hi,
    May be the weasel get the idea after seeing avatar?? Weasel: "I believe I can fly... I believe I can touch the sky..."  ;D

    Have a nice day.


     


3
EOS Bodies / Re: 7D Mark II Firmware update??
« on: March 03, 2015, 01:02:07 PM »
Hi,
Anybody know if there are any plans for a firmware update to address the focusing issues for the 7D Mark II? I recently upgraded and my images are just ok. Far from tack sharp. It seems Canon has sacrificed some image quality for speed :-\  I am trying to figure out if I want to sell and get the 5D Mark III or hold out for a firmware update.  Kinda Bummed out as I waited so long for this camera.

Thanks!
    Have you compare the sharpness of Live View AF and normal viewfinder AF by shooting same object? May be you can post some images, so that some of us can help you take a look.

   Have a nice day.

4
Lenses / Re: True reach of 100-400 L II
« on: February 27, 2015, 11:02:34 PM »
Hi,
    IMHO, 6m is a bit too short to test the 400mm focal length... may be you can compare the FoV of the 400mm F5.6L with it at longer distance?

    Have a nice day.

5
Lenses / Re: Canon EF 11-24mm f/4L Shipping This Week in United States
« on: February 26, 2015, 08:49:40 PM »
Hi,
    Found some images shoot by this lens: https://www.flickr.com/photos/29823753@N02/sets/72157648710973594/

    Have a nice day.

6
Lenses / Re: Canon EF 11-24mm f/4L Shipping This Week in United States
« on: February 23, 2015, 01:12:18 PM »
Hi,
I get needing a 16-35mm F/2.8, but I really can't see any tangible use for a 11-24mm F/2.8 except astrophotography. If you're shooting action at 11mm, your subject is either going to be really, really close, or really really small in the photo. And if your subject is that small, you're going to have focus problems tracking the fast action happening in a small part of the frame.

If shooting events/dances/etc, I've never been bothered by F/4, simply because a close-up subject that can fill 16mm can be lit by color-corrected speedlights, and that gives you a subject-background separation by lighting your subject and thus bringing them out of the background. In that way, I've always found that dances/etc can be easily done with an F/4, because naturally lighting them would be improbable anyway.

I know at the end of the day, photography is creative and about breaking the rules, but if you need a wide, fast lens, there's the 14mm f/2.8, and the 16-35mm F/2.8, and if you're shooting action, I really think there's no need to be wider than 14mm anyway.

Just my opinion and way I shoot, I've loved using my 16-35mm F/4 IS and 70-200mm F/2.8 IS II for news and events, even in abysmal lighting situations;  when I used a 17-55mm F/2.8, I still ended up using a color corrected flash, so it's not a big deal to me.
    Don't be so confidence of yourself... may be later you'll find yourself wanting this lens... ha ha ha ;D

    Anyway, birder and wildlife photographer will be envy of you guys... you "only" need to spend US$3K to get the world widest FF lens... they had to spend double the price just to get the "entry level" F4 super telephoto lens... ha ha ha  ;D

    Have a nice day.

7
EOS Bodies - For Stills / Re: Coincidence or?? MP/SEC
« on: February 17, 2015, 02:05:50 AM »
Output data at 14fps would be JPEG, but the input data from the sensor would still be 14-bit. I don't believe Canon does any kind of downgrading on the bit depth of the ADC units (I've never found any information indicating as much anyway), so I don't believe there is a 12-bit 14fps read mode. The output data rate for JPEG (when writing to the memory card) would certainly be lower, but the input rate into the DIGIC processor would still be 14-bit.

It's difficult for anyone outside of the development team to do any more than speculate, but I'd argue that if the camera can really handle 14 bit readout at 14 FPS, then why force JPEG only on users? The buffer is still there, and if the readout and JPEG engine can keep up with 14 bits, the buffer should be able to too - so instead of forcing JPEGs on the user, why not give them a choice of a smaller buffer depth and raw? Card speeds only become relevant once the buffer fills up, and the target audience of the 1D X should in Canon's eyes be capable of deciding which trade off to choose.

I'm under the impression (falsely or not) that it's JPEG only as the readout doesn't support 14 bit CR2 files at 14 FPS.


The readout is simply transferring charge and converting it to digital numbers. JPEG doesn't come into play until that native signal information has already entered the DIGIC chip, since it is DIGIC that is actually performing the conversion to JPEG. The sensor isn't going to natively spit out 8-bit JPEG data, as that requires processing, like color space conversion, compression and encoding, etc.


Why does Canon limit 14fps to JPEG? I don't know the answer to that. I am just quite certain that neither the sensor nor the off-die ADC units are spitting out JPEG data natively. It could be possible that the ADC units are switching to 12-bit mode at 14fps. Samsung certainly doe it at 15fps. Why Canon even bothers with a 14-bit ADC in the first place when their data barely supports more than 11 bits worth of information because of system noise levels is beyond me. If a 12-bit ADC would allow them to process 17.5fps, without any loss in DR, I don't know why they don't. That said, I've never encountered any information anywhere, including in patents, that indicates Canon switches to 12-bit data output from their ADC units. There could very well be a different reason they had to limit 14fps to JPEG.
Hi,
    Because Canon RAW files include the bias information. And bias information is useful in perform calibration of image.

    By the way, 7D2 is dual pixel meaning that they actually had 40.4MP. Now if the dual-pixel operation is perform in analogue form (before the ADC), that mean the data rate will still at 20.2MP level, but if the dual-pixel AF is perform after the ADC, then the data rate will be at 40.4MP level. Just wondering??

   Have a nice day.

8
Lenses / Re: Why does 7D II seem COMPARATIVELY soft with certain lenses?
« on: February 16, 2015, 11:52:23 AM »
Hi,
    Here is my experience: when use my 7D2 with my Tamron 150-600mm, my keeper rate is not high and AF seem not consistent. When use my 7D2 with my EF 400mm F5.6L, my keeper rate is way higher and AF is fast and consistent. So my conclusion is that my Tamron 150-600mm had some issue with my 7D2.

    By the way, my Tamron 150-600mm had a live view AF issue with my 7D2 (no such issue when I use with 60D and 6D), but not sure does this issue affect the normal AF operation, but will going to do a 1 to 1 exchange tomorrow... after that I'll sell the Tamron and join the EF 100-400mm II club...

    Have a nice day.

9
Lenses / Re: Canon EF 11-24mm f/4L Already Shipping in Asia
« on: February 16, 2015, 10:59:46 AM »
Hi,
    Just wonder is the Sony A7 mount is strong enough to support the lens when the camera is mounted on tripod... hmm... Look like they might need to come out an adapter with a tripod collar so that can support this heavy lens on the smaller mirrorless camera.

   Have a nice day.

10
EOS Bodies / Re: Patent: Optional Image Stabilization Unit
« on: February 16, 2015, 10:54:55 AM »
Hi,
    The EF 400mm 5.6L rear element is very deep inside the lens rear, so may be this will extend the product life cycle of EF 400mm F5.6L.... EF 400mm F5.6L IS  ;D

    Have a nice day.

11
Lenses / Re: 11-24 is here, with images of it compared to Nikon 14-24
« on: February 13, 2015, 03:25:45 AM »
Hi,
    May be next time they should design a ultra wide angle lens with a drop in filter (like those use in the Super-Telephoto lens). Hmm... Or may be someone could design a EF adapter with a drop-in filter for mirrorless camera... Sony mirrorless landscape photographer who want to use this lens will be very happy.

   Have a nice day.

12
Lenses / Re: New Unique Macro Coming? [CR1]
« on: February 09, 2015, 11:57:35 AM »
Hi,
    With dual speed focusing ring?? One for fast focusing and one for very fine focusing??

   Have a nice day.

13
Pricewatch Deals / Re: Official: Preorder the Canon EF 11-24mm f/4L
« on: February 06, 2015, 09:35:03 AM »
Hi,
    So with the new 11-24mm F4L, Canon just need 3 L lens to cover from ultra wide to super telephoto: 11-24mm, 24-105mm and 100-400mm II... :)

    Have a nice day.

14
Lenses / Re: 11-24 is here, with images of it compared to Nikon 14-24
« on: February 06, 2015, 07:19:55 AM »
Hi,
   All description never mention about fluorite elements, but the product page in Canon USA website on this lens indicate that this lens had 2 fluorite elements (fluorite elements icon "CaF2" with a 2 below)... someone cut and paste from another product, but forget to remove the fluorite icon?? Ha ha ha
http://www.usa.canon.com/cusa/professional/products/lenses/ef_lens_lineup/lens_uw_pro/ef_11_24mm_f_4l_usm

     Have a nice day.

15
Lenses / Re: 11-24 is here, with images of it compared to Nikon 14-24
« on: February 06, 2015, 06:51:13 AM »
Hi,
   Found some high resolution sample here (click the "High Res" button):
   http://www.ephotozine.com/article/canon-ef-11-24mm-f-4l-usm-lens-sample-photos-26926

   Have a nice day.

Pages: [1] 2 3 ... 28