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Fun with the RX-1

barjohn

New member
Sorry John, I was reading it another way thinking it could not AF/MF at wider apertures than f/4.

But did Lloyd actually show that AF at the shooting aperture is less accurate? I have seen no evidence of it, although in low light the AF slows down at smaller apertures, but I am unsure if that is just because of illumination or DoF. I think the comparison of Phase detection in a DSLR to CD in a mirrorless is not a great comparison.
Try and MF the camera at f5.6 or f8. Even with magnified view and focus peaking you will see it indicating focus over quite a large range compared to f2. Purely speculation on my part, but my miss focuses with the camera have all occurred at f4 and above so maybe that is the reason.

The Sony function is simply for MF, hence the name MF Assist. They clearly state that. Don't fault an MF function because it works exactly like it should and does not AF. My E-P1 works just like my RX1, so it is not universal. Lloyd might like to have that, but that is not a fault. I am not even sure it is really very useful--what is so hard to use AF and then fine tune with MF Assist. It seems unnecessary to have a magnified AF. And why not praise for the RX1 way of setting up zone focus--put AF on the C button so in manual focus you can get a focus point with AF and then quickly confirm it with MF Assist and then just shoot away.
It's a feature the X100 had and a lot of people liked. Maybe because the MF was so bad. I certainly don't intend to defend Lloyd, it is his opinion.

Sorry, but there comes a time when nitpicking simply becomes annoying. Ken is just making stupid comments and now Lloyd is just picking at things that are not even worth mentioning and certainly not showing that it is actually significant to the operation.

I agree. Overall the camera has been a really good camera. :thumbs:

Below is an example shot at f4 with the focus box on her face.
 

Shashin

Well-known member
I am not sure anyone will find this impressive, but getting natural images of a burning fire is actually quite difficult. It is a really contrasty subject with lots of subtly in the shadows and highlights. Color temperature is tricky as well. This is right out of the camera with some simply tweaking with the highlight and shadow sliders in ACR.
 

pophoto

New member
Do all owners here have the EVF, I'm having trouble finding one here in San Francisco!
Actually I've been searching most of the world via the web, but mostly well known stores!
 
Thanks Pophoto.

Thanks Brian. Yes I do miss the eye level viewfinder. Thinking about picking one up. We'll see.

Ashwin, I am still evaluating how responsive the Rx1 is for street photography. As you know, street photography is anticipating the moment and then taking the shot. As long as your anticipation is better than average, I believe any camera can be used for street photography - you just have to learn a camera's strengths and weaknesses and adjust accordingly to get that shot.

I once used a Hassleblad for street photography in Hong Kong. Worked surprisingly well - just a bit too heavy and obvious for prolonged use. My Nikon DSLRs, Fuji X100, Fuji Xpro1 and Sony Rx100 have all been successful street cameras for me.

Regarding the Rx1, the first thing for me is getting comfortable with the focusing capabilities. So far, I can't autofocus fast enough for many of my shots. Don't know if it is me or the camera. But, that's OK, because only my Nikon DSLRs and to some extent the Rx100 have been capable of sufficiently fast focusing. I may end up using zone focusing which is what I did with x100.

The next important thing is exposure and the Rx1 seems plenty responsive. So far I like adjusting aperture and shutter speed manually and setting iso to auto. No problem with the shutter speed dial not on top of the camera. And I'm always adjusting the compensation dial. Kind of gives me the feel of control even if I'm only making adjustments of 1/3 of a stop.

Another learning curve is how to hold the camera for street photography. I use a number of techniques but each camera is different. Waiting for a gordy strap to see how it affects my holding technique.

So far I really like the Rx1. Why? Because the Sony Rx1 is a true pocket hercules of a camera - carries a full frame, great low light, great dynamic range powerful punch in an incredibly small, unobtrusive package. Nothing quite like it.
 

barjohn

New member
I haven't had time to get out and shoot much so a few from around the house.


Beach Balls at Christmas


A Star is Born


The Christmas Sea
 

barjohn

New member
Lloyd Chambers has just added additional coverage on the RX1 including the color shift issue. Of greater significance to me was his section stating that the color bit depth was only 8 bits for the RX1. I have sent him the following inquiry and will post his answer when I receive it:


I just read your section on files sizes and bit depth on the RX1 where you state that the RX1 only uses 8 bits per byte; however, the Sony web site specification states:

"A whole new world of high-quality images are realized through the 24.3 MP effective 35 mm full-frame sensor, a normal sensor range of ISO 100 – 25600, and a sophisticated balance of high resolving power, gradation and low noise. The BIONZ® image processor enables up to 5 fps high-speed continuous shooting and 14-bit RAW image data recording."

Since it's ARW files are essentially the same as the ones produced by the A99 (just changing the EXIF descriptor allowed us to process the RX1 RAW files in LR as A99 files before RX1 support was released) it would appear both RAW files use the same compression scheme. Whether that scheme is losss-less or not really depends on the schema used. However, to capture and process 14 bit data, the internal pipeline must support 14 bits (probably 16 bits since that is easier to manufacture and work with in a binary world). Therefore, I don't know where you are deriving the 8 bit per byte data unless you are assuming that based on the file size. I don't think Sony would claim 14 bit raw files if it was only producing 8 bit raw files. Can you please explain where your information came from?

A check on the A99 on the sony web site states:

"Model Features: 24.3MP 35mm full-frame sensor, 14-bit RAW output, uncompressed Full 1080 HDMI® output in 60p/60i, up to 25600 ISO, Dual AF, continuous AF in all modes, up to 10 fps in Tele-zoom mode, 3" tiltable LCD"

We know from earlier experience that we could process the RX1 files as A99 files so they most likely use the same data storage method. Sony further claims to produce uncompressed files. Of course, this raises the question of how do you get 6,000 x 4000 x14 divided by 8 into a 24.3MB file without some type of compression. That should be a 42MB file uncompressed. There are lossless compression techniques that might do it.

I have now received a response back from Lloyd:

"Fact: the file size is always 8 bits per pixel.
Fact: the file size does not vary.
Fact: by the above, the camera thus stores 8-bit per pixel files.
Fact: to guarantee 8 bits per pixel, lossy compression must be employed.
Fact: I stated clearly that internal processing is certainly at a higher bit depth (apparently 14, but this does not work out properly according to RawDigger, which shows 12 bits when delinearized).

How can this be? Only by a scheme that limits storage to 8 bits per pixel by lossy compression. In Sony’s case, by a tone curve with a “sag” in the middle to high key area that effectively compresses the 14 bits down to 8 bits."

Followed by another email:

"This Sony claim is a fraudulent claim ("14 bit data recording"), just as Sony posts fraudulent MTF charts that are not possible by physics.

The files are by simple math, 8 bits per pixel. RawDigger developer confirms that they are 8 bits. This is a fact and not open to argument.

The files record a range wider than 8 bits by a tone curve that maps those 8 bits to a wider range. This is re-linearizing the data.

For example, 8 bits could record a range of 32 bits also. The question is how big the steps are within that range."


I'm not sure what to believe. It doesn't make sense to me that Sony would go to the expense to have a 14 bit processing pipeline only to throw it all away when recording the output. I experimented with converting to DNG and Tif, the ARW files. The DNG files varied in size from 26mb to 29.5mb and the tif files were huge at 144MB. Can anyone more knowledgable about this please provide some insight?
 

barjohn

New member
One last response from Lloyd:
"LLoyd,

By implication the A99 must be using the same lossy compression method.
Assuredly yes, but I have not used the A99, so I cannot personally confirm.


Has this issue been raised on the A99 too?
Dunno, I have never seen/used one.

If so that is disturbing. Why bother with a 14 bit processing pipeline if you are going to throw it away later?

- there is value in of 14-bit pipeline which outputs to a lower bit depth, call this simply "avoiding rounding errors".

- 14 bit dynamic range is possible and this is preserved in 8 bit files (range vs step size).

- it guarantees a smaller file size

- in most real world images one would be hard pressed to find any quality issue.

- the camera can apply smarts to making its 8-bit-per-pixel data of very high quality.

- noise “rounds off”. Generally 2-3 bits are junk (noise). I suspect this is why ETTR seems less effective with Sony; all results round off the noisy low order bits."


His answer seems to make sense.
 

jonoslack

Active member
I have nothing to add to this discussion except that whenever someone says:

Fact: xxxyyy

I'm suspicious - it's so aggressive, and so much smacks of insecurity. Of course, it doesn't mean he isn't right
 

douglasf13

New member
I'm pretty sure that Lloyd is correct about this, although how it affects actual images is up for discussion. It seems to me that the biggest penalty comes if you have to adjust exposure quite a bit in the raw converter.

It's very likely that the A99, RX-1 and NEX-7 all use what used to be called "cRAW" in Sony cameras, or compressed raw. My guess is that they got rid of uncompressed raw option altogether in order to improve advertised frame rates, but who knows?

My A900's raw files are in the neighborhood of 38MB-ish. My NEX-7's raw files are in the neighborhood of 24MB-ish, and there is no option to make larger, uncompressed raws with my NEX-7.

Here is a link about this, in terms of the NEX-7, started by Iliah Borg, one of the developers of the RPP raw conversion software. I'm not sure if the RX-1 and A99 are similar to the NEX-7 in this regard, but it sounds like they might be:
Compressed raw files and exposure strategy:
 

barjohn

New member
I asked him if it was a similar scheme to the one used by Leica on the M8 and he stated that it was similar. I sent an inquiry to Sony CS and their response was to send me their marketing brochure stating it was 14 bit. I asked them to send me a white paper if they have one explaining how they get 42mb file down to 24 mb without compression.
 
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