Archive for September, 2010

RAW vs JPEG

Monday, September 27th, 2010

It is with some trepidation that I even title a blog post “RAW vs JPEG” because it seems that this is a topic akin to “sex, politics and religion” that shouldn’t be discussed in polite society.  It certainly seems to start flame wars on some of the photographic web sites.

If someone had asked me about using RAW a year ago, or I had discovered someone with a DSLR that was not using RAW, my reaction was usually to say “… but you must use RAW, it is so much better”.  I would have produced the usual arguments about having the raw data off the camera sensor, unprocessed,  so that one could use the full power of one’s computer to process it, to manipulate it safely in the knowledge that one could always go back to that pristine RAW data.  I would have produced the usual arguments about bit depth and the like and that there were a couple of extra stops of headroom for exposure compensation.  I would have produced all the arguments about the dangers of repeatedly editing JPEGs.

I’m now not at all sure about this.  As far as I know, most of the RAW formats are proprietary and whether any particular converter really reflects the manufacturer’s intent may be difficult to establish.  I think there have even been cases where RAW formats change over time (although with the same file extensions — and so not obvious to the user), but not all software will process all the variations.  Thus, I seriously doubt that RAW is a good format for long term archiving, and to some extent, with that goes the notion that at some point in the future one can reprocess one’s old RAW format images with better software and they will look even better.  The danger is that one can’t reprocess them at all.

The in camera processing that generates JPGs these days seem extremely good to me.  I’ve recently bought a Nikon D90 and a number of lenses (so I’m now committed to Nikon), and have retired an old Canon DSLR for which I only had the original kit lens.   For the last few years I’ve been using the RAW format with the Canon (there was no option on that old model for JPEG plus RAW, as far as I could tell) and although iPhoto seamlessly processes the RAW and produces JPEGs, and there is some limited RAW manipulation in iPhoto, the process is pretty slow.  I’ve used RAW because of the arguments above and because I often found that low light performance was poor and so I was for ever slightly underexposing and having to manipulate images.

With my Nikon, I’m finding that the processed JPEG files are better than I can typically produce via iPhoto (or via Nikon View NX software) and while I could spend a lot of time doing little tweaks, it doesn’t really seem worth it.

On the shooting side the disadvantage is that with shooting RAW (or RAW + JPEG) the number of continuous shots that one can take is severely reduced.  So if one is trying to just catch the right moment in an action shot, I would definitely just shoot JPEG.  On the other hand for landscapes and still life images there is no reason not to shoot RAW + JPEG other than the extra space taken up and potentially the processing time.

One of the things I remember from professionals back in the days of film was that the main difference between amateurs and professionals was that we took one shot and they shot a whole roll of film.   Taking more photographs just stacks the odds so much higher at getting just the right shot.   I recall some amazing statistics about the enormous numbers of photographs taken in order to produce the ten or so for a National Geographic article.

Given all this, my inclination is now to take more photographs, mostly JPEGs.  I shall use the histogram on the camera to check exposure and, if necessary, bracket — but even three JPEGs are typically less than one RAW image.   Yes, if I’m taking a landscape photograph perhaps I’ll shoot RAW + JPEG and perhaps even then bracket (if only for the possible option of making an HDR later), but I’m coming down more and more in favour of letting the camera do the processing and get good quality JPEGs out which require as little processing on the computer as possible.

I guess that I might have a different view if I were to change to using Aperture or Lightroom, although I think the argument for just getting the photo as “right” as possible in the first place is a pretty strong argument.

Mobile data getting more expensive

Sunday, September 19th, 2010

I’ve blogged before about how I chose a 3G iPad and took the O2 carrier option in the UK.  O2 was the only carrier at the time (and perhaps still now) that allows one to set up a connection on the iPad without having to make phone calls to set it up, and also had some quite good deals.  Well as with all of these deals, it hasn’t lasted.   This report sums it up. £2 for 500MB over 24 hours was  good deal.  200MB for the same price doesn’t sound half as good and the reduction from 3GB per month for £15 to 2GB will make it much more expensive.  I often wonder when the data providers claim that ”   the vast majority of iPad customers are using under 2GB per month ….” that this reflects the fact that there many customer who might just use it for a day or two or indeed have left a rolling contract continue when they might as well have cancelled it.

iPhoto apparently messing up geodata

Sunday, September 19th, 2010

Updated 4th October with what I think is the problem and solution

I use a Garmin GPS unit and then use HoudahGeo to geotag the photographs. I normally do this after I’ve imported the photos into iPhoto. HoudahGeo supports this usage.

However, for all of the photographs I’ve imported since the end of August, when I look at the location data either from alt-cmd-I or from looking at the little map reached from from cmd-I, it appears that the geodata has been changed. Typically what seems to happen is that if a set of photographs end up with the same placename (although different lat-long), the lat-long is replaced by the centre of the place. It is really strange because the data shown on alt-cmd-I for a group of photographs is all the same, but if one use “show file” to access the actual photograph and then look at the exit data via Preview, then that data is different (and is the correct data as orginally added to the image). “Rescan for Location” doesn’t solve the problem, indeed it might even be the cause of it.

The same applies if I tag the images first and then import them. However, all photographs imported before the end of August are fine. They may all have been taken in one town (and have the same place name from the reverse geo lookup but the coordinates are the correct coordinates.

This has had me running around in circles all day.   I’ve posted to the Apple forums so will see what transpires.  Perhaps its time to move on to using Aperture or Lightroom.

Update:

The problem seems to be that I had previously made up my own location for photos that I’d taken before I had a GPS unit. It appears that any properly geotagged photos that fall within the circle for that location end up being stored in the database with that name and with their location given as the centre of that circle. Looking at all of my photographs on the map view in places and sufficiently expanding it, it seem that every photo in the vicinity of a location that I have added has had its place recorded at the place where I’d put the pin and not using the precise information in the photograph. This is not what I want — I want the location so that I can geotag roughly photos taken before I had a GPS, but for subsequent ones I want their location recorded precisely not in this general area. I’m not quite sure how to sort this out.

It seems that locations I’ve created manually in iPhoto with reasonably generous size capture photos which have real geolocation in their Exif data and then display their location as the centre of the manually created location. I think I need to go through all of the manually created locations and shrink them and then the good geodata should show up after a rescan for location. I’ve not had much time to do that so far, but one test seemed to show that that will work.

Fortunately I haven’t created too many locations so should be able to solve this fairly quickly. In future when I go back to manually tag locations for photos without location data I shall either use very small locations or perhaps use an external tool to tag them and avoid creating locations within iPhoto.

Strange behaviour of MacBook

Monday, September 6th, 2010

Last Thursday my MacBook suddenly behaved rather oddly.  It was not dissimilar to the problem I’d posted about with Time Machine a few weeks ago. Again it seemed that Time Machine was stuck.  I’d left the machine running over night to do my weekly SuperDuper backup.  In the morning the back up had completed successfully and I wanted to disconnect the MacBook as later in the day I would be travelling and wasn’t sure that I’d have time when I got back to the apartment to do more than just grab the MacBook and put it in my bag with other essentials.  However, Time Machine was running and  I just could not dismount the Time Machine drive.  Whether I tried from the finder window, or the desktop or manually in the terminal it refused to budge.  In the end I logged out but even that wouldn’t complete and I was left with a blue screen and a pinwheel rotating.  I’ve experienced this sort of delayed log out before and assumed that it might take a while but eventually would log out so just left the laptop to log out in its own time.   When I came back later in the day it was still stuck in the same state with the pinwheel rotating.  Nothing would work and so in the end I just had to press the power button to turn the machine off and go off to catch a plane.

The machine was fine while away, but when I came back I thought I’d better check the drives to make sure nothing was left in an inconsistent state.  When I plugged in, my Time Machine disk didn’t show up.  In Disk Utility it was also absent.  This made me start getting worried that the problem was a faulty Time Machine drive, although the disk is only about a year old and hasn’t been subjected to much physical movement as it has stayed on my desk for that time, just being moved occasionally for dusting.

I tried Disk Warrior and the TIme Machine drive showed up in that although was still absent from Disk Utility.   I thought I’d let Disk Warrior rebuild it and knowing it typically takes a long while, left it to run overnight.  In the morning there was a message from Disk Warrior saying there wasn’t enough memory and to do a run from the Disk Warrior start up disk.  So I started a run from the Disk Warrior DVD and left that running, which also failed with the same message.  This left me seriously concerned about the state of the disk.

I reloaded the system, thinking that I might have to buy a new drive for Time Machine and that I might have lost a year of Time Machine backups (although I’d still have my single SuperDuper back up as well as a number of partial cloud backups) and amazingly the TIme Machine drive showed up on the desktop as if nothing had happened.   During the day I have run a disk utility check on the Time Machine drive and, indeed, all of the drives that were connected (including the system drive) when I’d had to power the machine off last week and all passed OK.  So, fingers crossed, everything is OK for now.  There still seems to be something fishy about this whole situation though.

 

Photographs from new camera

Monday, September 6th, 2010

I’ve recently bought a Nikon D90.  I know this is not exactly a new camera; it is probably due for replacement fairly soon, and my reasons for buying it will probably be the topic of a future blog post.  However, I thought I’d post a photograph which was taken on the first day I had the camera and for which the JPG produced in camera was pretty good.  I’d also shot in raw and processed the raw through Topaz Adjust using more or less the preset “Spicify” setting.  This gave the second version shown here.  I”m not sure what it is about this photograph but I really like it.

So, here is the JPG out of the camera:

Cottage — JPG from camera

Here is the version that was from the RAW and through Topaz adjust:

Cottage with Topaz Adjust — Spicify