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Messages - Meh

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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.

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!

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.

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?

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.

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 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."

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.

EOS Bodies / Re: Max CF Card size that can be used in the 5D2?
« on: November 06, 2011, 08:46:39 AM »
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

EOS Bodies / Re: Final shopping list for tomorrow..
« on: November 04, 2011, 09:56:41 PM »
I love 'em.

Me, too.  Especially yellow ones. Obviously.

Except for the im2500, I don't really use them for travel. But in a house with two toddlers, the protection during storage gives me some piece of mind (especially since they changed their former gaurantee statement to be proper and boring - the old one specifically excluded damage caused by shark bite, bear attack, and children under five - and no, I'm not kidding, it was on their website!).

That's great advice... my daughter is 4 and wants to play with Daddy's camera whenever she can get her hands on it!   Nice advice on putting the backpack into the pelican for travel... I will definitely be following your lead on that one, thanks.  I have a number of bags and most are Kata... very good quality although I don't think anyone else mentioned them.

EOS Bodies / Re: *UPDATE 2* The Red Dot EOS DSLR
« on: November 04, 2011, 09:36:49 PM »
Like Foveon technology the output of the sensor does not need demosaicing and instead of interpolating colour then de-bayering, the sensor has a separate red, green and blue photo site for each pixel – hence the 8MP count and the 1080p output.
That is, by definition, not Bayer interpolation, just like I wrote.

Right, but that is for the C300 sensor... they are binning an RGGB set and not using bayer interpolation.  But your assumption for the "red dot DSLR video camera" was that they were also going to use the same binning as the C300 which is why you then came up with the 50MP sensor (unless I misunderstood).  My point is that they won't use binning, rather they would capture a 4k image from the centre section of a ~17-18MP sensor (i.e. the 1DX sensor) and use the usual bayer interpolation to derive colour and luminance for each pixel.  This would differentiate the two cameras... the C 300 would only be a 2k output (from an 8MP sensor) but much better colour (they talked about getting better skin tones) and less noise than the 4k output of the new DSLR camera (from an 18MP FF sensor).

Anyway we're all just guessing here, who knows what they'll come up with.

EOS Bodies / Re: *UPDATE 2* The Red Dot EOS DSLR
« on: November 04, 2011, 09:13:48 AM »
The question is which 4K or is it actually QFHD instead?

This could be a 50MP camera, Assuming 4:1 binning, Full Aperture 4K X 4 is 50.1MP, Academy 4K X 4 is 39.0MP, QFHD X4 is a mere 33.2MP and QFHD horizontal resolution X 2 with a 1.5:1 aspect ratio is 39.32MP.

My guess is the last value, but I still want to see if/how Canon handles viewfinder masking. I'm also a little puzzled why they would invent this new cinema body then stick their highest resolution sensor into a DSLR body instead.

Why do you assume binning?  That could be a difference between this new video-DSLR (capable of 4k but still Bayer interpolated) and the C 300 that only outputs 1080p but uses binning to increase image quality.

Assuming no line skipping and no binning, a 4k capture from an approximately APS-H sized crop mode (the press release noted "approximately 80% of the vertical and horizontal) would suggest the sensor is just under 17MP.  Given that they said "approximately" it could be the 17.9MP 1DX sensor.

EOS Bodies / Re: Concept Cinema DSLR Official
« on: November 04, 2011, 09:04:21 AM »
Again, if you are going to claim this is f/2.8-3.5 you need to back it up because you're stating something that seems physically impossible - the lens having a smaller aperture than its T-stop rating permits.
Is that not how T-stop ratings work, T>f? ie DXOmark gives the EF 24 f/1.4 Lii a Tstop rating of 1.6, and the 17-55 f/2.8 has a T-stop of 3.4. At T2.95-3.7, I just guessed the new lens would have f/2.8-3.5, could be a lot wider aperture.
An "ideal" lens would have T=f, impossible is T<f? Or maybe i'm backwards, it's late.

I believe that's correct.  A T-stop can be measured for any lens, it is common for cine-lens where very precise control and consistency of the exposure is required.  For any lens, the T-stop is the equivalent f-stop if the lens had zero transmission loss.  Therefore the T-stop is always higher (larger number) than the f-stop of the lens.

EOS Bodies / Re: Concept Cinema DSLR Official
« on: November 04, 2011, 12:01:49 AM »
At only 8.3MP for the FF sensor, if they've used all of their most recent tech with this sensor, then it should have very good DR.

Why do you think this concept DSLR video camera has an 8.3MP FF sensor.  The 8.3MP is the resolution of the Super35 size sensor in the C 300.

The layout of the sensor is 1920x1080x4 (RGBG)

Not quite.  The red and blue pixels are 1920x1080.  The green pixels are 1920x2160.   But ok, you could look at like 1920x1080x4.

EOS Bodies / Re: Rumors roundup by Jarred Abrams concerning Nov 3rd
« on: November 03, 2011, 10:10:36 PM »
Bornshooter was wrong about a 5D3 but they did announce the development of a new video DSLR... does he get even a little credit for that?   Nah, I guess not.

Since there was no 5D3 announcement I can now open the box to the 5D2 I bought last week  ;D  I probably would have either way.

EOS Bodies / Re: Concept Cinema DSLR Official
« on: November 03, 2011, 09:53:35 PM »
I don't understand why the sensor would only record the size of an APS-H for video in 4k though.

Probably because the centre of the sensor (an area approximately APS-H size) is the exact number of pixels for 4K video recording without doing any line skipping or pixel binning.   They said approx. 80% so 4000/0.8=5000 and using 3:2 ratio that gives a 16.7MP FF sensor.  They said "approximately" so that could mean it's the 1DX sensor (18MP).

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