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Messages - Meh

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541
Canon General / Re: Dynamic Range - Digital sensors
« on: November 08, 2011, 12:14:43 PM »
Where does this notion that film has more DR than digital sensors come from?  Ken Rockwell who only shoots jpeg?

Checkout the Zacuto clips on youtube of them comparing the video output of the 1D4/5D2/7D with that of Kodak film. The kodak film has 14.2 & 14.5 stops of DR whereas the 5D has 11.2 but usable is probably closer to 10. Episode 1 of the Great Shootout of 2011 covers DR.

Now I don't know if all film has the same DR as the Kodak film used in that "shootout" but it is a place to start.

http://www.youtube.com/watch?v=k-hqzw5MEa8&feature=channel_video_title

that kodak is motion picture film...not photography film ;)
but still, look at the DR of it.

Right.  My understanding (albeit limited and prone to being wrong!) is that motion picture film is designed differently and optimized for things like DR rather than resolution which is far less important when there's motion... for example in digital video 1080p (2 megapixel) is high-res and 4k (~9 megapixel) is super-high-res.  The transfer functions used in the movie-land are also different.  Consider also that the DSLR video is an h.264 output.

542
EOS Bodies / Re: Final shopping list for tomorrow..
« on: November 08, 2011, 11:13:48 AM »
As you saw from that post, I just recently replaced my Manfrotto QR plates (they use their own designs) with an AS-type system.  In fact, today I sold my set of Manfrotto clamps, RC2 plates, and BlackRapid FastenR-T1's.

Are you still using the Manfrotto ball head (468MG) or will you be swapping that out for a Kirk or RRS?   I think my new system of choosing gear will be to save myself hours of painstaking deliberation and just buy what you buy  ;D

543
Canon General / Re: Dynamic Range - Digital sensors
« on: November 08, 2011, 10:51:18 AM »
Where does this notion that film has more DR than digital sensors come from?  Ken Rockwell who only shoots jpeg?

It might have been true 10 years ago for some mass market sensors but even then it wasn't significantly more.   Digital sensors produced anytime in the past 5 years have more DR than film.   The response curves are different and the fall off into highlights and shadows is different and to some it's less "pleasing" with digital but digital technically has more DR, which is why you hear talk of "useable DR".   

However, if you're looking at jpegs it's a different story because they are only 8-bit files so a transfer function has to be applied to fit 4096 luminance levels (14-bit) into only 256 luminance levels and highlights and shadows are typically where there is more compression applied.   Keep in mind that LCD displays and prints have much less DR than the original RAW files or film.

I'm not an expert in this and not the best at explaining it so if anyone has any corrections or additional details feel free to correct me.

544
Canon General / Re: New APS-C Camera in February?
« on: November 07, 2011, 11:07:19 PM »
If Canon was smart they would outfit the 7Dii with a sensor with the same philosophy as the 1Dx... lower mp count with larger pixels!  ;D

If Canon was smart?  I just checked, they are.  Market cap is $53B, annual revenue $47B, annual income about $8B, $11B in cash, and most important of all... this site has 13,840 members who just can't get enough of Canon cameras!   :P   But seriously, I'm with gmrza, I think they'll stick to 18MP in the APS-C line and work on improving noise and DR just a touch.

545
EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 07, 2011, 10:08:24 PM »
I ran some tests this evening, and in a day or two I'll tabulate and post the results.  But preliminarily, a 90 MB/s cards does result in a slight performance boost on the 5DII compared to 60 MB/s cards (roughly, shaves a second off the write speed following a 3 second burst, and allows a few more frames during 20 s of continuous shooting).

Consistent with my anecdotal observations with my 7D that I mentioned earlier in this thread.  Do you have a 200x card available to measure the jump in performance compared to 400x cards?

546
EOS Bodies / Re: Video Moire/Aliasing!?
« on: November 07, 2011, 01:55:10 PM »
@jasonmillard81... looking back over your posts from the previous threads along with the most recent posts I'm wondering if for your mostly video shooting that upgrading to a higher-end camcorder wouldn't be the better choice over a DSLR or GH-2.  For example, the Sony NEXVG10 has a larger sensor and longer lenses that would give you more control of DoF and might be easier to use than a DSLR form factor.

547
EOS Bodies / Re: Mobius by Vincent Laforet on the EOS C300
« on: November 07, 2011, 12:10:06 PM »
I don't know who Canon is competing with a $20K price range, the Sony F3? It certainly isn't the Scarlet-X. Why pay more for a video system that performs poorly against its cheaper rival? Only an idiot would do that.

Perhaps that's exactly the answer... that Canon sees the C300 competing against the other similarly priced cameras.  Or they believe the overall image quality, build quality, the Canon name, service, support, etc. is somehow superior to Red?  Just posing the question, I don't presume to have that answer.

548
EOS Bodies / Re: Mobius by Vincent Laforet on the EOS C300
« on: November 07, 2011, 12:05:15 PM »
A $20,000 C300 with 1080p vs a $10,000 Scarlet-X with 4K resolution...did someone at Canon forget to do the math? Personally, if the C300 were more reasonably priced at 7-8 grand, then Canon would have something and I'd consider buying it. But with the Scarlet-X and its better resolution and sporting an EF mount, why would you pick the Canon. As it turns out, I will probably purchase the Scarlet-X in the future.

I suppose Canon is, whether right or wrong, claiming by virtue of their design choices and pricing that the C300's 4k sensor that uses pixel binning to produce a final 1080p image will have better image quality than competing cameras.

549
Australia / Re: ND filters
« on: November 06, 2011, 08:51:43 PM »
I have a couple of step-up rings (67mm and 72mm up to 77mm).  No issues with vignetting.  One problem is that, with rare exceptions, a step-up ring and larger filter precludes use of the lens hood, meaning less contrast, more flare, and less protection.  They also tend to get stuck, so have a set of filter wrenches.

Baffles can help here, as can an extra hand by itself or holding a card/hat/etc to keep out stray light.

The hood isn't the only way to block out incident light. Just look at the baffles used in hollywood.

Can you point me to any alternate "hoods" that would screw into an 82mm filter thread?  I have a Mamiya rubber lens hood that screws into a 77mm filter thread but that one is for longer lenses.  I use it for shooting hockey with my 70-200mm and 7D... I especially like it if I'm ever shooting through the glass... I can put it right up the glass and if the players hit the boards or someone bumps me it has some give so I won't get a black eye!

550
Australia / Re: ND filters
« on: November 06, 2011, 08:38:33 PM »
I have a couple of step-up rings (67mm and 72mm up to 77mm).  No issues with vignetting.  One problem is that, with rare exceptions, a step-up ring and larger filter precludes use of the lens hood, meaning less contrast, more flare, and less protection.  They also tend to get stuck, so have a set of filter wrenches.

Thanks, good to know.

551
Australia / Re: ND filters
« on: November 06, 2011, 12:31:42 PM »
Does anyone have experience buying one set of larger filters such as 82mm (I have a 16-35mm f/2.8 II) and some step-up rings to fit lenses with smaller diameters?  Any problems such as excessive vignetting?

Also, how much better is the image quality from a single ND filter versus stacking one or more filters to get the desired density?

552
EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 06, 2011, 09:16:09 AM »
I did have but on this occasion I don't know where it is! Shooting RAW takes longer to process because of the amount of data, much of the data from a jpeg is dumped in processing.

Please look, because that statement makes no sense to me. You seem to be saying jpg processing is faster because data are discarded during processing, but that would mean bits are tossed without being processed, e.g. take every other pixel and just ignore it. It can't work that way - the data have to be analyzed during processing, before elimination. Write would be faster, with less data to write. Processing would be the same. It's write speed and quantity of data that determine overall throughput - I don't think the processor is a significant bottleneck. That's why frame rate and buffer capacity take a bit hit going from JPG to RAW, and another small hit from RAW to RAW+JPG. There's no difference in the processing required for those three modes - all involve processing the full sensor RAW image to a JPG, including applying the in-camera settings (Picture Style, ALO, PIC, etc.), the only difference is the amount of data that need to be written to the card.

I agree with neuro... RAW files have to be processed first then converted to jpg (which is done even if you shoot in RAW only because a small jpg is needed to display the image on the LCD).   If you shoot in jpg only then after processing only the jpg is written back to the buffer saving a lot of space and reducing the write time to the memory card.

Edit:  Actually, even in jpg only mode, the processed RAW file also may be written back to the buffer first and then deleted if the user selected JPG only.   Discarding the RAW file is not likely built in to the processor as that would be an unnecessary function since it can be done after the fact.

553
EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 06, 2011, 09:10:23 AM »
Unfortunately not and it's a common missconception, there might be a slight advantantage, but it is slight.  This is because the bottleneck in the system is not the memory card, or the buffer, it's the image processor.  The data from the sensor is written to the buffer, processed, written back to the buffer and then to the memory card, when the buffer fills up it isn't full of data waiting to be written to the memory card, it's full of data waiting for the image processor to catch up.  A faster memory card can't make the image processor work any faster, all it can do is empty a single image from the buffer a little bit quicker, and if you still have the shutter pressed another shot can be taken.

That is the correct order of the processing but I'm not sure the image processor is the bottleneck as you suggest at least not with current generation processors and files sizes.    The following quote from a Canon website http://cpn.canon-europe.com/content/education/infobank/capturing_the_image/digic_processing.do confirms the order of processing but implies the image processor is not the bottleneck.

"To overcome limitations with processor speed and capacity, manufacturers can install large and expensive buffers as a temporary store for unprocessed data, or compromise image quality by ‘dumbing down’ image processing, or both.  DIGIC II is designed to avoid these compromises. The processor is so fast it can read, process, compress and write JPEG image data back to the buffer between exposures."

554
EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 06, 2011, 08:51:16 AM »
If that's the case, why does shooting RAW give significantly lower frame rates than JPG? I'm skeptical of your claim, do you have a reference?

By "frame rates" do you mean frames per second or total number of frames before the buffer fills?  I don't believe the frames per second drops shooting JPG, RAW, or RAW+JPG at least not on my 7D but could be different for other bodies (7D has dual DIGIC4 processors).

Shooting jpg only many more shots can be taken before the buffer fills because once processed they take up less space in the buffer before being written to the memory card.

555
EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 06, 2011, 08:46:39 AM »
interesting.
i didnt realise 3.9fps only ment for 2 seconds. oh well saves me buying a faster card. thanks

2 seconds is fairly a long time I think... I'm not saying that say 3 seconds or maybe 4 might be useful in some situations but in most high-speed action sequences wouldn't the action be just about done in that amount of time or less?  I'm not an expert sports shooter so I honestly don't know how many seconds would be optimal for a sequence and I hope I'm not starting a theoretical debate that ends up in someone pointing out that "if you could just hold down the shutter button for an hour you'd never miss anything" ;p

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