Jump to content

Recommended Posts

I am using the Sony a7iii and it appears that uncompressed RAW for stills is 14-bit. However, the specs show that the uncompressed raw for 16:9 resolution is 14-bit but doesn't mention bit depth in the 3:2 which I will use. Should I assume that the 3:2 ratio is also 14-bit? If so, then my main question is this...

If the RAW file is 14-bit depth at 24 megapixels, then is the correct calculation:

  • 24,240,576 pixels X 14 bits = 339,368,064 bits

  • 339,368,064 bits / 8 = 42,421,008 bytes

The file sizes I am getting in the .arw are about 49,668,000 bytes so I was curious what is the overhead in this RAW file? Why is it 7,000,000 bytes more than this calculation?

Link to post
Share on other sites

It is 14-bit @ 3:2. As for the rest, no idea. Not sure why it matters? What is it you're trying to determine?

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Link to post
Share on other sites

Good to know it's 14-bit. The page I found only shows 14-bit for the 16:9 ratio and not 3:2 which was the only reason it was a question. https://www.sony.com/electronics/support/e-mount-body-ilce-7-series/ilce-7m3/specifications

As for the other stuff, the reason I ask is because I'd like a decent understanding of what I'm working with. I know it doesn't matter to most people but I have a personal curiosity about it. I am trying to understand more about what a RAW file actually is, how it got there (because of the amount of pixels on the sensor and each pixel's bit depth) and then from that RAW file, understanding that a piece of software would have to triple this size when it interpolates the RAW bytes. 

I've been reading all week and I think I have my answer but just wanted it clarified here.

Link to post
Share on other sites

First off, uncompressed 14 bit data is not stored packed together - each 14 bit sample is stored in 2 bytes (16 bits).

Also, bear in mind that a RAW data file has more samples than there are pixels in the finished image - you need samples beyond the edges to be able to interpolate full colour information for the pixels on the edges. 

And yes, it's 14 bit data for the full 3:2 image.

The ARW file holds more than the RAW data, too - it holds metadata about the image, and it holds a JPEG that can be used to show a thumbnail.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Posts

    • From my records, Minolta made about 8500 85mm F 1.7 lenses bearing the MD badge. The MC-X version was slightly double that. So these are not that rare. I just saw an ad for a Limited Rare MD 45mm F2 lens ( Minolta made over a million of these) so the word rare is often used in a bizarre way. Seeing that the OP has a MD ROKKOR-X version and that he appears to have bought it from Europe is kind of unusual since the ROKKOR-X versions were to be sold exclusively in America. So in Europe, this lens naming was rare.  I think the confusion about a reworked version may come from the fact that during the MC-X era (1972-76), Minolta made numerous changes to their lens line-up. First they changed the lens Mount Index dot which was initially painted like their previous series of lenses but after about 1 year, they replaced this with a slightly larger diameter plastic bead. This change happened around the introduction of the X-1, XM, XK bodies. Then they removed the small Stop Down Levers that were on most lenses up to now around 1975 since their SR T and XK/XE bodies were now boasting a Stop down mechanism. Then a little later Minolta even removed the lens formula (in this case PG) designation from the lens markings. This may have caused people to believe there was some kind of modification to the lens when it was only a marking  change. Also around 1973-74 they decided to provide a different marking for lenses sold in America ( at least USA and Canada) to identify lenses sold on the grey market that was often cause for confusion with consumers buying a great deal they could not get repaired under warranty. Same applies to Bodies starting in the same era where  X-1 was for Asian market, XK for American market and X-M for rest of the world, then SR T 102 in America, SR T Super in Asia and SR T 303 in rest of the world. So you could find all of the following with their respective front markings: - MC-II: MC ROKKOR-PG 1:1.7 f=85mm ( with SDL) This type has the hills and valleys metal focusing ring -MC-X: MC ROKKOR-PG 1:1.7 f=85mm ( with SDL and Painted Lens mount index changed around 1973-74) -MC-X: MC ROKKOR-PG 1:1.7 f=85mm ( with SDL and Plastic Bead Lens mount index changed around 1973-74) -MC-X: MC ROKKOR-PG 1:1.7 f=85mm ( with No SDL and Plastic Bead Lens mount index ) -MC-X: MC ROKKOR 1:1.7 f=85mm ( with No SDL and Plastic Bead Lens mount index and no more PG lens formula index) -MC-X: MC ROKKOR-X PG 1:1.7 f=85mm ( with SDL and Plastic Bead Lens mount index, Orange colored ROKKOR-X marking for the American market) -MC-X: MC ROKKOR-X PG 1:1.7 f=85mm ( with No SDL and Plastic Bead Lens mount index, Orange colored ROKKOR-X ) -MC-X: MC ROKKOR 1:1.7 f=85mm ( with No SDL and Plastic Bead Lens mount index and no more PG lens formula index, Orange colored ROKKOR-X) -MD-II: MD ROKKOR 85mm 1:1.7 ø55mm -MD-II: MD ROKKOR-X 85mm 1:1.7 ø55mm (Orange colored ROKKOR-X again for the American market) -MD-II: MD ROKKOR-X 85mm 1:1.7 ø55mm (White colored ROKKOR-X ( iguess orange paint was getting too expensive) ) It was then replaced with the MD-II MD ROKKOR (X) 85mm F 2 There was no MD-I version of this lens and the same with a few lenses with large apertures ( 35mm F 1.8, 58mm F 1.2, 300mm F 4.5) since they had issues with the speed of the aperture mechanisms closing down for what was  a last minute check on XD/XD-7 and XD-11 bodies requiring stopping the lens down just prior to the shutter opening to ensure accurate exposure. Some late MC-X lenses may have had the modified aperture mechanism causing the confusion that there was an updated version but the optical formula seems to indicate there was no change.

      Welcome, dear visitor! As registered member you'd see an image here…

      Simply register for free here – We are always happy to welcome new members!

    • It could probably be used directly on the A7R ( or any other body using the Sony MIS shoe) in manual mode provided it can be positioned properly in spite of the zillion contacts Sony placed on these bodies at the front of the shoe which may prevent the shoe from making proper contact at the center. If proper central contact is not achieved, using a ADP-MAA adapter topped by a Minolta FS-1100 will do the trick. Tried it with older flashes like 360PX and a few others and it works. The issue with using it in Manual Mode is that due to the very short distances involved, calculating the proper aperture for correct exposure is a challenge. Add to this that the assist lights will not operate the way they were designed if at all.
    • I've found some great lenses that way too -- like a Tokina 24-200mm AF zoom on a Maxxum 5 for $20.  I sold the camera for $40 and kept the lens.
  • Topics

×
×
  • Create New...