June 18, 2013, 10:48:05 PM

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 ... 7
1
Big question - other than the focus being perhaps a hair off, how fast and, most importantly, how accurate do you feel the focus is?
Focus is fast. Not quite as fast as the Canon 400 f2.8 II. But its pretty fast. Fast enough for sports.  As to the accuracy, not ready to put a stamp on it yet due to the back focus. I had some misses.  Not an exceptional number of misses for a softball game. Some that surprised me were the longer shots. For instance shooting an outfielder with center focus, I caught the fence more often than I thought I would. 

Update: I just spent some time tweaking the focus with the doc. I reset the 1Dx micro back to 0. I eventually worked my way up to a -15 setting on over 100'+. At that setting it is sharp!  I then started working on the 120, 150 and 200 mm settings. I did not have time to put on the 5DIII and test it with the updates.   I'll do a full review soon.

Suggestion, if you buy this lens, get the dock. Not sure if my situation is typical, but without it, I'd be calling Sigma or considering returning it.
-Mike
    You mean you can adjust the AF accuracy using the dock? I'm using 60D which do not have the AFMA, so if can adjust the lens AF without using AFMA, it will be very tempting.

   Just wonder how well does this lens take 2x TC?? I'm currently using EF 400mm F5.6L for birding... so really tempted to "upgrade" to this lens if IQ and AF perform reasonably well with TC.

   Have a nice day.

2
Hi,
   May be it's the high temperature that cause the issue?? I once going for birding under a very hot afternoon and most of my shots come out either soft or out of focus, so when I use live view to try to focus, I realize that it's the heat wave that cause the problem... can clearly see that the image in and out of focus in quick succession... like shooting through a wave of water.

    Have a nice day.

3
Lenses / Re: What exactly is a 100% crop?
« on: April 27, 2013, 11:26:13 PM »
Hi,
    Basically, 100% crop mean not resizing or 1:1. Lightroom will always export 100% crop image as long as you don't set the "Image Sizing" (Resize to Fit) during export. Also, to view 100% crop, you need to set 100% or 1:1 for your viewer software.

    By the way, some website will resize the image automatically if it exceed a certain resolution when you post them, so make sure you know the maximum resolution that they allow and limit your photo resolution to that.

   Have a nice day.

   

4
EOS Bodies - For Stills / Re: 5dmk3 shoot burst w/10 second delay?
« on: April 26, 2013, 08:36:43 AM »
Hi,
    Any remote controller with intervalometer function will do:
1) Set your DSLR drive mode to high speed continue shooting and AF mode to AI SERVO or manual focus mode if you want to pre-focus.
2) Set your remote controller intervalometer as:
     a) Initial delay: 10s
     b) Interval: 0s
     c)  Long exposure: 2s (for 6fps)
     d) Shot: 1

   Have a nice day.

5
EOS Bodies - For Stills / Re: Any astrophotographers out there?
« on: April 10, 2013, 08:20:21 AM »
I was hoping I could get some advice regarding using a camera for astrophotography. Any advice is greatly appreciated!! I am not looking for exceptional pictures of nebulas, but something that can take pictures of some of the larger planets and the moon.

Unfortunately, my budget is rather limited. As much as I would love a star tracking telescope system, I am hoping to settle for a dobsonian reflector.

What I am looking at is as follows:
Orion SkyQuest XT8 - F/5.9 @ 1200mm (build a scope version)
Orion 2" low profile focuser
Canon T-mount adapter and Orion 2" Zero-Profile Prime Focus Camera Adapter
And a kit of 2" eyepieces for when I want to do viewing rather than imaging

I read that refractors are considerably better for astrophotography, but ouch are they expensive. I am always open to suggestions though!

I am hoping to get into astrophography, but fear spending money on a system that isnt compatible or wont give good results at all (I have heard focusing issues is a common problem).

Thanks! Feel free to post pictures you have taken or of the setup you use to photograph the night sky!
Hi,
    Orion SkyQuest XT8 is a visual scope and not for Astrophotography. If you want to go into Astrophotography, you need a good equatorial mount and a good mount is very important... If you are starting into Astrophotography, I suggest you get a good equatorial mount first and use your existing camera lens to shoot first. Get a feel of it and learn the image processing software.

    Have a nice day.

   

6
EOS Bodies / Re: Canon Announcements on April 23, 2013? [CR2]
« on: April 07, 2013, 12:37:09 PM »
Pay close attention to the new sensor in the Canon EOS SL1 as far as performance goes. We’re told this sensor will appear in the EOS 70D, but not the EOS 7D Mark II.

Ok, Canon has just mutilated the potential of the 70D to sell well.


LOL.. if canon has proved one thing over and over again it is that they can sell even old bread well.

what people on this forum think has absolutely no influence on the mass market.
actually it´s sad because i too would like to see canon make more progess on image quality.

not that canon cameras make bad quality images.. just that IQ has not much improved over the last years.

Correction: Canon's IQ hasn't changed or improved over the last years for anything besides those moving from the 1D series to the 1DX. Nikon, Sony, Pentax, are all delivering new sensors with better performance.

What is Canon doing?

Nothing. What a joke of a company.

They make nearly a $1 billion in operating profit.   Hardly call that a joke.   Keep in mind that most purchasers of the low end cameras want very basic functions (I doubt many even shoot in raw) so current technology is good enough for them
Hi,
   Totally agree... many people are happy with the image taken from their mobile, so image from any Canon entry level DSLR will be wow to them. IMHO, the selling point of Canon DSLR is easy to use and that will make a big different when choosing their first DSLR.

   Have a nice day.

7
EOS Bodies / Re: 6D Autofocus not impressive
« on: March 26, 2013, 09:24:32 PM »
Hi,
   When 6D is launch, Canon already mention that 6D AF system is design to be low-light AF priority rather than AF speed and they cannot put in more cross point due to the larger AF element require for good low-light AF performance.

http://www.imaging-resource.com/news/2012/09/20/qa-with-canons-mike-owen-behind-the-scenes-in-developing-the-6D-and-whats

   Have a nice day.

8
EOS Bodies / Re: EOS 70D, DIGIC 6 & 18mp Sensors
« on: March 21, 2013, 03:18:46 AM »
Ah the EF 200-400 f/4L IS... The worst kept secret and will be the most un-exciting announcement ever.

No no... he's not talking about the 200-400.... he's talking about the 00-400 lens.... obviousl some new super-ultra-mega wide angle lens...

It's so wide it takes a detailed scan of the brain of the person behind the camera and delivers a picture of what they're thinking.
Ha ha ha... What You Think Is What You Get...  ;D

Have a nice day.

9
EOS Bodies / Re: Canon EOS-b Images Leak & a New Kit Lens
« on: March 19, 2013, 10:45:52 AM »
Hi,
    EOS-b (baby??)...  May be Canon want to test the market... which one can sell more.... a mirrorless camera or a DSLR as small as a mirrorless camera.

   Have a nice day.

10
Third Party Manufacturers / Re: DxOMark trashes the Leica M9 sensor
« on: March 13, 2013, 06:18:38 AM »
Hi,
   IMHO, if DxOMark use the RAW file produce by the camera to perform the calculation, the result is only valid for camera of the same brand.

   Have a nice day.
 

   

11
Lenses / Re: Bridge not sharp - why?
« on: March 12, 2013, 01:05:10 AM »
did you confirm that Mirror Lock was on? didnt see that in any of your replies. anyone else having issues like this in the future should understand that this is a likely cuplrit for camera shake at slow shutterspeeds on a tripod.

you also have to be careful of your own movement when making exposures like this. even if you are not physically touching the camera or tripod, walking around the camera position can cause vibration in the ground (depending on the surface you are on) and that can be transferred through the tripod and show up in exposures. this is not as likely outdoors but i have seen it happen on several occasions indoors when i or someone else walked by my rig during a long exposure.

Didn't use mirror lock. It might be helpful in some situations, but it wouldn't have caused this kind of motion blur.
   Err... Mirror lock-up is use to prevent this kind of blur... not create it. You should use mirror lock-up or live view when shooting at slow shutter speed.

   Have a nice day.

12
Lenses / Re: Bridge not sharp - why?
« on: March 11, 2013, 08:29:37 AM »
Hi,
   How heavy is your tripod? Make sure your tripod is steady and your setup is heavy enough... if you are using those carbon tripod, your setup might not be heavy enough to prevent the slight shake that cause by wind, people walking nearby & etc. You didn't see your camera shake, doesn't mean the camera didn't shake... at 1/20s, a slight shake during the exposure can cause your image to be blur. You can use the hook (a lot of modern tripod had that) below the tripod to hang something heavy to increase the weight of the setup.

   Best is to increase your ISO to get a higher shutter speed. If not, I recommend you to use live view to focus at the object using 10x, make sure everything is lock down and make sure you see that the image is perfectly still before you trigger the shot... also, try to be as still as possible when trigger the remote cable... don't laugh... during some macro shot, I can see the image shake a bit in live view when I move my feet a bit.

   Also, the blur might be cause by air turbulence which is very possible by looking at your image... the temperature different between the heated stone bridge and the cooler environment in the shadow might create some air turbulence which blur the image.

   Just my $0.02.

   Have a nice day.

13
EOS Bodies / Re: Will the 70d have a new sensor?
« on: March 09, 2013, 02:36:35 AM »
Hi,
   IMHO, 700D, 70D and 7DII will all using the same new sensor... build quality, focusing speed, frame rate and features available will differential the models. Release sequence will be 70D, 700D and 7DII.

   Have a nice day.

14
EOS Bodies / Re: Canon EOS 6D Firmware by June? [CR1]
« on: March 07, 2013, 09:37:50 AM »
Hi,
   I was expecting the 6D to have F8 AF at center AF point since the center AF point is the most sensitive AF point in all Canon DSLR, but it didn't when launch.... so 6D was out on my next camera list. If they include the F8 AF in the next firmware update, I might be interested now.

   Have a nice day.

15
EOS Bodies / Re: How do I set button to use only center AF point?
« on: March 03, 2013, 08:44:54 PM »
Hi,
   For setting <AF-ON> button, look for it under [C.Fn III: Operation/Others]->[5. Custom Controls]
   For selection of center point as AF, press the <SET> button... you can only change AF-point if you are using Creative Zone mode (Av, Tv, B & etc).

   For details, look up in the manual.

   Have a nice day.

Pages: [1] 2 3 ... 7