--> Skip to main content

Dealing with large digital files for events and other applications where large file size is not necessary.

Dealing with large digital files for events and other applications where large file size is not necessary.


Ok, admit it. It’s a first world problem. Your yacht, house, digital file is too big. But if you are photographing events with say, a Sony A7rII, this really is an issue. You reasonably won’t want to shoot JPGs, which can be dumbed down in camera settings. But you should shoot raw files that can’t be reduced in camera to a reasonable pixel count, they’re always 42mp on this camera. 


So here’s a strategy to consider. Use the Adobe DNG Converter app to both compress (or further compress) and at the same time reduce the pixel dimensions of your raw files. 


Give this a try (see screen shots):


  • Download Adobe DNG Converter (free)
  • Select folder for files to convert, and destination (maybe try testing this on your memory card with your latest images first)
  • Rename if you like

In the bottom dialog box change preferences to the most recent compatibility, jpg preview to full size (speeds editing), embed fast load data (speeds editing), use lossy compression (reduces file size with compression), limit pixel count to 20mp, don’t embed original (that would make the resulting file much larger than the original)


A quick test with a random Sony A7rII raw file starting life at 42mp using this method to go down to 20mp resulted in a ~8mb DNG file on my HD vs 37mb for the full size (in camera lossy compression) 42mp ARW.


20mp is still plenty of resolution. Here are some sizes at given resolutions to ponder:


  • @400ppi 8.5x13” (high resolution art print)
  • @300ppi 11.5x17” (good quality print)
  • @200ppi 17x26" (decent quality print)
  • @100ppi 35x52" (low quality print, good projection resolution)
  • (all sizes approximate)


For some other lossy DNG observations, check out these other entries: Lossy DNG file size by ISO, The Magic of Lossy DNGs.




Comments

Popular posts from this blog

Linhof Serial Year List - Salomon Says

Recently I've acquired a few Linhof cameras. I got a 5x7 view camera from Oakland Museum's White Elephant Sale. Later I stumbled upon a Color Kardan 90 Jahre Jubalaeum edition on Craigslist. And more recently, I found a "baby Technika" 2x3 (6x9) at Oakland's East Bay Depot for Creative Re-use. Not knowing much about Linhof large format cameras, I tried getting more info online, and came across a strange thread on the Large Format Photography Forum . Basically on this thread various Linhof owners ask a guy named Bob Salomon what year their Linhof was made. And the thread is over 100 pages long! Sifting through that thread is mindnumbing. Why Bob doesn't just publish the list of serial numbers is beyond me. Maybe it's just nice to feel needed. So I started compiling a spreadsheet of the serial numbers and the answer Bob gives. If you don't feel like spending a couple days reading this thread to get a hint as to the age of your Lin

Should I ditch my Sony a6500 for a A7r IV?

Recently, I bought a Sony a7r IV. The main reason was for stock photography. The high resolution along with improved focusing and biggish buffer would allow me to make better people (and other) stock photos for my various stock endeavors.  The Sony system has treated me well. I own two A7r II's for stock and other work, and two a6500's for event photography. The A7r II's aren't ideal for events for a couple reasons. The focus tracking is pretty good, but maybe not enough for fast paced people on stage. Another reason is that silent shooting is only available on single shot mode. And (admittedly a first world problem,) the files are much bigger than needed. Well, the last problem, too big files isn't an issue with the A7rIV if you use it in APS-c mode. The files are effectively the same size as the a6500: 24 mp. Focus with the IV is even faster and more effective than the very capable a6500. And with those smaller files, the IV has no problem with buffer overflow. So

Long Daylight Exposure Chart: Kentmere 100

Ultrafine/Kentmere 100 Reciprocity Test-Camera: Fuji G617, Film Ultrafine (E)Xtreme 100, ND-9+red @ f22 140 seconds If you are interested in long daylight exposures, you may have run in to the same problem I have. Say you have your camera all set up, the clouds are whisping by, and you want to get that long daylight blur thing going. You figure a 30 second exposure (approx.) would be ideal. Well how do I get there? I've got a bunch of filters: a 4 stop ND, a 9 stop ND, as well as a red, yellow, and orange filter. It's mid day and my meter reading says 1/125th @ f16. I start counting with my fingers: -1 stop = 1/60th, -2 stop = 1/30th, and so on. So then I get down to 4 seconds with my darkest ND filter. If I stack both my ND filters, I get down to 30 seconds where I wanted to be. But wait! That's without reciprocity corrections. Great if I had Acros for film. But I don't and it's being retired soon, so I wont have access to it at all. What I ended up makin