Iphoto won't let me burn 3.1Gb of photos on a DVD with 5.0GB available. Why not?

Question

I'm trying to clean up my iphoto library and I finally got the pictures ready to burn and make some room, but I get  a message that there is not enough room on the DVD for the pictures. Accoreding to the info on the selected photos they are 3.1 GB and there is 5.0GB available on the DVD, which shows it is full. Why is 5.0 GB not enough room for 3.1GB to burn?

Answer 1

Yes, most people dont have a clue about such professional media,...pro photographers and data archivers use it extensively for obvious reasons.   100 pack is usually aroud $40
As for HD, theyre all fragile, and without redundancy, anyone is in serious trouble of losing data. Its ALL about redundancy in case of ext. HD.
Here they are,
http://www.amazon.com/Taiyo-Yuden-JVC-Thermal-DVD/dp/B000NE9BE4/ref=sr_1_cc_3?s= aps&ie=UTF8&qid=1389293161&sr=1-3-catcorr&keywords=taiyo+Yuden+DVD%2BR
They can also be found in Ebay.... stick with DVD+R not -R since +R has several design advantages over -R
True longevity, long-term professional data protection. The Gold and Platinum standard
When it comes to long-term data protection, there is optical and there is NOTHING else, period. While modern notebooks and macbooks have forgone, for the most part internal optical DVD/CD readers/writers, this is most entirely due to the fact that commercial videos and movies have gone to online rentals and Itunes purchases, additionally nearly all software now is online purchase and download. However external USB DVD burners and readers are going nowhere anytime in the foreseeable future,... and until a new optical technology emerges for data preservation, DVD writers aren’t going anywhere.
Online media and software however has no bearing or impact on the fact that the fragile nature of ferromagnetic storage has not gotten any better now than it was 20 years ago aside from improved production specifications in physical hard drive builds. There are many that would point out in incorrect conjecture that “optical is a dying or dead medium”, such people don’t know what they're talking about and are directing their comments at optical based movies and software, not data archiving and protection which in fact is growing in scope, not declining.
While low grade consumer DVD blank media has a life between 8-15 years best case, professional DVD blank media has both a different standard of manufacture and chemically a different read/write layer that has serious professional longevity with 19 years real world testing and age-stress progression testing proving that at the very minimum, 60 years viable protection if stored correctly and in some patented mfg. standards, 100+ years data retention and preservation. While "gold" disks have been superceeded by even better technology manufacted disks, this is still a term of reference as implying professional DVD blank media.
In fact a new breed of disks that use a higher powered write-laser are commercially available and have a rated life of 1000 years and are referred to as M-DISK. Governments, military, and professional businesses have much time and money invested in high-importance data storage on optical media out of necessity given the extremely fragile nature of ferromagnetic storage.  Such new optical technology creates permanent pits in the disk surface, which are not affected by light like consumer DVD media which uses a organic dye layer to write and read from of the data.
While DVD media are only 4.7GB single layer in scope, and cannot store massive amounts of data, not even by the 100-pack, most vitally important priority data people own are picture collections, texts, audio, and other small scale media. In such an evaluation, high priority data is necessitated out of prudence, to be written to professional archival grade DVD media, not low-grade consumer DVD blanks. Such professional DVD blank media is only roughly 30% more expensive than low grade consumer DVD blank media.
As for HD:
Hard Drive Warning (all makes and models)
Ironically but logical, new hard drives are far more fragile than one that has been working for several months or a couple years. So beware in your thinking that a new hard drive translates into “extremely reliable”!
Hard drives suffer from high rates of what has been termed "infant mortality". Essentially this means new drives have their highest likelihood of failing in the first few months of usage. This is because of very minor manufacturing defects or HD platter balancing, or head and armature geometry being less than perfect; and this is not immediately obvious and can quickly manifest itself once the drive is put to work.
Hard drives that survive the first few months of use without failing are likely to remain healthy for a number of years.
Generally HD are highly prone to death or corruption for a few months, then work fine for a few years, then spike in mortality starting at 3-4 years and certainly should be considered end-of-life at 5-7+ years even if still working well. Drives written to once and stored away have the highest risk of data corruption due to not being read/written to on a regular basis. Rotate older working HD into low-risk use.
The implication of this is that you should not trust a new hard drive completely (really never completely!) until it has been working perfectly for several months.
Given the second law of thermodynamics, any and all current mfg. HD will, under perfect storage conditions tend themselves to depolarization and a point will be reached, even if the HD mechanism is perfect, that the ferromagnetic read/write surface of the platter inside the HD will entropy to the point of no viable return for data extraction. HD life varies, but barring mechanical failure, 3-8 years typically.
Hard drive failure and handling
The air cushion of air between the platter surface and the head is microscopic, as small as 3 nanometers, meaning bumps, jarring while in operation can cause head crash, scraping off magnetic particles causing internal havoc to the write surface and throwing particles thru the hard drive.
Hard drives are fragile in general, regardless, ... in specific while running hard drives are extremely fragile.
PDF: Bare hard drive handling generic instructions
hard drive moving parts
Some of the common reasons for hard drives to fail:
Infant mortality (due to mfg. defect / build tolerances)
Bad parking   (head impact)
Sudden impact   (hard drive jarred during operation, heads can bounce)
Electrical surge   (fries the controller board, possibly also causing heads to write the wrong data)
Bearing / Motor failure   (spindle bearings or motors wear during any and all use, eventually leading to HD failure)
Board failure   (controller board failure on bottom of HD)
Bad Sectors   (magnetic areas of the platter may become faulty)
General hard drive failure