Messages

181

Canon General / Re: Autofocus Problem / Question

« on: September 20, 2011, 09:28:35 AM »

I guess this opportunity is as good as any to throw out a question for speculation. 

Why can't Canon (or any manufacturer) implement automatic MFA for any camera that has Live View?  The user would:

• Mount the camera on a tripod or other sturdy surface
• Point it at a standard target at some reasonable distance
• Choose the function from the menu
• Step back and let it go.

So how does it do its magic?  Simple: it compares Live View focus to phase detect focus, then automatically adjusts PD focus until they are the same.

Yes, there's still room for misuse by n00bs, but much less than with manual MFA.

Thoughts?

182

Canon General / Re: Autofocus Problem / Question

« on: September 19, 2011, 09:19:44 AM »

What's the normal tolerance on phase-detection AF?  I just bought a refurb 24-105 that I've been trying to test.  It might be slightly off focus -- maybe 2-3 mm at f4.  I'm still trying to improve my test technique, though, so it's possible it's experimental error.

183

Software & Accessories / Re: Command Line Software to shoot photos

« on: September 09, 2011, 08:49:14 PM »

Though I have no personal experience with it, you might look at gphoto2 under CygWin.

http://cygwin-ports.git.sourceforge.net/git/gitweb.cgi?p=cygwin-ports/gphoto2;a=summary

184

EOS Bodies / Re: overnight flight next to Canon engineer...

« on: September 07, 2011, 06:41:17 PM »

Steven63: have you ever used Live View? If so, then you have used video mode, you just haven't recorded your video.  Video Mode is little more than saving the data used for Live View.

I bought a 5dmii in June for the FF and low light abilities.  I've yet to switch it over to video mode.  I couldn't care less about it.

185

Canon General / Re: 16GB CF PANIC!

« on: September 07, 2011, 04:28:55 PM »

Aldvan's story brings up a great point: as part of your backup plan, you should practice restoring from your backups at least a few times a year.  You should practice restoring individual files, small collections and your entire collection. You should perform an additional test restore any time you make a change to your backup procedure.

186

Canon General / Re: 16GB CF PANIC!

« on: September 07, 2011, 11:35:43 AM »

<snip>
Before I went I brought 4 Sandisk 16GB 30MB/s CF cards.

<snip>

Clearly the card has been currupted some how, for some reason.

<snip>

Can the card be sent to Sandisk, or any one else?

Hope some one can give me some advice here.

You paid good money for a SanDisk: call the company and ask them for advice, I bet they know the "best" way to do it.

187

EOS Bodies / Re: Canon Lens Mug - Giveaway

« on: September 02, 2011, 09:34:55 AM »

A sensor that covers the entire image circle, out to the distorted edge.  This allows the photographer to decide what to keep after the fact, and eliminates the need for a vertical grip.

188

EOS Bodies / Re: *UPDATED* Big Megapixel Camera Next Week.

« on: August 28, 2011, 09:17:34 AM »

Nothing sacrificed?  How do you know?  R&D dollars (or yen, in this case) are finite. Engineering (soft- or hard-ware) effort devoted to video capability cannot be used for still capabilities. Granted, many features overlap, but some do not.

Which parts don't overlap?

• Rapid capture of frames from the sensor: already done to a great degree for Live Mode.  The next question is whether it can be sped up/scaled-up for true video, but that's already done (due to marketing necessity) for P&S cameras, so it must be similar for higher-end sensors.  There's no reason to believe this is any harder on a DSLR than a P&S.  R&D needed: routine adaptation to the specs of a new sensor.
• Processing frame capture to video: this is just software and, again, they already do this in P&S cameras using same (or very similar) chips.  It may be the same algorithm verbatim, or a family of algorithms that are adapted based on the specs.  R&D needed: routine adaptation to the specs of the new sensor.
• Sensor heat dissipation: this is a bit trickier to judge, but I don't see how it would be worse on a larger, less-dense sensor than on a small, dense P&S.  DSLR users, particularly pros, would demand longer capture times than P&S users, and it may be easier to cool through a small P&S body than a tank-like DSLR.  Nevertheless, seeing how video appeared to be a near afterthought for the 5D2, I can't imagine that this is a huge barrier either.   Furthermore, it seems entirely plausible that creating a sensor that dissipates heat better would add to IQ of still images, not detract.  R&D needed: make sure the sensor can dissipate heat well.

The only thing I believe would be different about adapting a DSLR for video (vs. P&S) is the expectation of longer capture times, hence the need for heat dissipation.  For a DSLR that already has live view, adapting it for video may not be a true freebie, but it's damned close.  Furthermore, the heat dissipation R&D is only a bonus for still IQ.  If you want to save significant R&D money on a still camera  you'll need to get rid of Live View: that's where the R&D delta is likely found.

I invite critique of the above.

189

Canon General / Re: Canon Canada Cleaning and Calibration Service

« on: August 05, 2011, 12:08:49 AM »

So what does it cost to have a body and handful of lenses cleaned and calibrated?  Has anyone done this who is not a CPS member?   $300 seems high to me, too.

190

Lenses / Re: new lens and camerabody

« on: June 28, 2011, 05:53:07 PM »

... it's a good think i'm patient and my money gets to compound interest until it's announced/released.

Where do you get interest on your money these days?

191

EOS Bodies / Re: A grateful end to the DSLR video "revolution"

« on: June 16, 2011, 11:36:57 AM »

I much prefer a tool to have a single purpose and be the very best tool I can find for that job. As an example, I like my image post-processing software to stick to just that and not pretend its also a digital image management tool as well.

Sometimes the "best" tool for the job is the one you have with you right now.  Think of all the Youtube videos posted during the democracy demonstrations in the Middle East:  the cell-phone video and audio is crappy compared to that from DSLR's, not to mention dedicated video equipment.  Do you think any protesters would be able to smuggle "real" video equipment into those events?

Yes, dedicated equipment is a invaluable for those who have the time, money and opportunity to buy, transport and use it under controlled (or somewhat controlled) conditions.  For the rest of us, DSLR video is a wonderful bonus, and we're happy for the opportunity to create videos well-above the level of cell-phones, even if it doesn't match the quality of dedicated equipment.

192

EOS Bodies / Re: EOS 7D mrk. II

« on: June 16, 2011, 09:16:48 AM »

Personally I'm hoping for an NTFS-like file system that supports files over 4 GB

Not necessary: they could work around the limitation using a series of smaller files that could be merged externally.  The big problem now is that the sensor overheats shooting video, and must be shut down until it cools off.  Until the cooling problem is completely under control, file size is not the limitation.

193

EOS Bodies / Re: "Buy Now or Wait"

« on: June 11, 2011, 12:10:09 PM »

This question comes up all the time, and the answer is pretty much the same.  It would be great if CR Guy would post a short article addressing the standard considerations, like:

• Is it for paying work or fun?
• Are you planning to use "it" for a specific event that sets your timeline?
• If it's for a specific event, can you rent something now, and buy later?
• Do you already have something to use in the interim?
• Have you thought about buying something used now, and the new model later?
• Even after "it" is officially announced, it could be months before your copy gets to you.

What have I missed here?

194

Software & Accessories / Re: advice on CF brand

« on: June 08, 2011, 10:36:35 AM »

Regardless of what brand you buy you should find a way to test the card thoroughly.  I'm fortunate to have the computer skills to construct my own tests, which I typically run around 30 passes.  Why?  Think about what could be wrong with a new flash card, be it CF or any other package.

• Could be a counterfeit made with inferior flash chips that work fine a few times, then die
• Could have a major manufacturing defect that causes the whole card to fail catastrophically
• Could have minor defects that affect a limited number of cells

If the card survives 30 passes of a decent test then the probability of outright failure is pretty small.  Also, for small defects, the controller in the flash card will "map out" bad cells as it finds them, and 30 passes should be enough to eliminate nearly all bad cells.

No, I have no engineering data to prove that 30 passes is adequate, but it's much better than putting my trust in a fresh, new flash card, regardless of brand.

I tend to buy Transcend, which is a well-regarded budget brand.

195

EOS Bodies / Re: 7D focusing question??

« on: May 08, 2011, 09:15:00 AM »

My personal opinion is that this is a depth of field issue.

Agreed.  You need to perform basic tests for front/back focus to assure yourself that there's nothing wrong.

Can anyone suggest a good testing methodology?  A quick Google search yielded two:

http://www.focustestchart.com/focus21.pdf
http://www.leongoodman.com/d70focusnew.html

They're written for Nikon, but should work fine for your 7D.