Panasonic Lumix GH1

Now available at a greatly reduced price, Panasonic's video‑capable still camera is well worth a look for low‑cost HD video production.

Photo: Bradley Steenkamp

It might surprise you to see a review of the Panasonic Lumix GH1 appearing quite a while after its release, and at a time that coincides with the release of the Panasonic's latest offering, the Lumix GH2. Despite its age, the GH1 is still a very relevant camera and incredibly good value for money. It can now be purchased as a body only for around half the listed kit price, making it the least expensive interchangable‑lens camera with full HD video capabilities.

Panasonic's hybrid still and video camera is more convenient for video production than those of any other brands and, while it might not hold up against Canon's EOS DSLRs in all areas, there are some areas in which it clearly betters them. Panasonic are a leading brand in both the broadcast and consumer video market, and much of their technology has filtered down to their micro four‑thirds range of cameras, of which the GH1 is a prime example.

Micro Four Thirds

The micro four-thirds system is a mirrorless, interchangeable-lens camera design developed by Panasonic and Olympus, which first featured in the Panasonic G1 and Olympus PEN EP1 models. Both the cameras and lenses are smaller and lighter than traditional DSLR models, due to the lack of a mirror and a shorter flange distance (between the lens‑mount and the sensor).

DSLR stands for 'Digital Single Lens Reflex'. Such designs place a mirror in front of the sensor, which reflects light up into a viewfinder that allows the user to see directly through the lens. In order to record continuous image such as video, the mirror must be raised, blocking the viewfinder. Having no mirror, the micro four‑thirds system uses an electronic viewfinder.

The micro four‑thirds sensor is smaller than that found in DSLRs, which results in an increased lens-crop factor of 2x. This means that a 20mm lens on a micro four‑thirds camera looks as 'zoomed in' as a 40mm lens would on a 'full frame' camera, like the Canon EOS 5D MKii. This has obvious advantages and disadvantages! It's not as easy to shoot wide-angle or 'fisheye' footage, as even a 14mm ultra‑wide lens will appear to be only slightly wider than normal on the GH1.

The same doubling is true at the telephoto end, where a 200mm lens performs as a 400mm lens would on a full‑frame camera. This is great if you like to film sports, action or wildlife video, as you can get extra reach without having to spend several thousands of pounds on longer telephoto lenses. The smaller sensor size also means that a deeper depth of field will be seen for the equivalent focal length and aperture than would be seen with a larger sensor. A shallow depth of field (where the background is thrown out of focus) is generally seen as a desirable aesthetic, since it is associated with shooting on film, but the benefit of a deeper depth of field is that keeping things in focus is easier.

Specifications

The GH1 has a 14MP sensor that offers an effective area of 12.1MP, at a selection of different aspect ratios: 4:3, 3:2 and 16:9. This isn't too important if your primary use for the camera is video, as it shoots using the 16:9 area. Moving images are recorded either at 1080/50i, or 720/50p in PAL regions such as the UK, while NTSC users have 1080/60i and 720/60p options. All of these modes record in the AVCHD format at 17Mbps. An MJPEG codec is also offered, with a resolution of 1280 x 720 at 30fps. Why two codec choices? Well, AVCHD can be a bit of a pain to deal with, as some editing software can't edit it natively and it must be transcoded to a different format, plus it's heavy on CPU resources. Motion JPEG is a format that is very easy for editing software to deal with, but it's not as efficient as AVCHD in terms of compression, so won't look as good at the same data rate.

Images are recorded onto SD cards, which are now very affordable and include a useful write-protection tab. I recently purchased a Class 10 (high speed) 16GB Transcend SDHC card for £20$30, and prices seem to be falling all the time. You should be able to fit about two hours of footage on a card of this size, and while movie recording time seems limited at 29m 29s per clip, that does beat the Canon EOS clip-limit of 12m. The longer clip limit is down to the heavily compressed AVCHD codec, and we will look at how this compares with the Canon H264 codec later.

I purchased my GH1 as body only (it's usually sold with the 14‑140mm kit lens, but some stores split the kits) and the included battery will give you 150 to 160 minutes of video recording. If you'd rather power the camera from the mains, this is possible using the included adaptor. Unfortunately, this adaptor uses the battery compartment to connect, which means that if it should become disconnected, there is no battery backup to keep your camera going. Perhaps it's a bit too risky if you are shooting a live gig where someone might trip over the power cord, resulting in loss off footage and potential destruction of the camera!

Control Layout

The mode selection dial has plenty of semi‑automatic settings, and you can record video in most of them. Note the Film Mode button, for choosing different colour styles.Photo: Bradley Steenkamp

The GH1's controls are fairly similar to those found on DSLRs, with a few additions. On the top right you will find a mode dial with an extensive range of options. These are broken down into three categories: Basic, Advanced and Advanced Scene modes. The basic modes are the Intelligent Auto and Program modes, while the advanced modes include Aperture Priority, Shutter Priority, Creative Motion Picture Mode and several others. The Advanced Scene modes include Sports mode, Portrait mode and several others, and each of these has several internal options to choose from!

It's all quite involved, as this is something of a hybrid camera. Put simply, each of the modes will prioritise capturing a certain type of picture or footage, either allowing you to adjust one parameter (aperture, for example) while balancing the others for correct exposure, or switching to automatic control with a certain subject in mind. The Creative Motion Picture Mode is the one intended for video shooting, but you can actually film in most other modes too, if you wish.

Situated around the mode dial are the power switch and the drive-mode lever, the latter of which lets you select between single shot, burst, auto bracket and self-timer still modes. To the right of the dial, you will find the Quick Menu button, which allows you to make changes to various settings in 'live view' mode (viewing the image on the rear screen), and below that is the 'Film Mode' button. You can use this to select various colour presets (similar to the popular Picture Profiles in Canon EOS DSLRs), such as standard, dynamic, black-and-white and custom profiles.

On the top of the camera is a hot‑shoe for a flash or accessories such as the Rycote Camera Kit or an LED light. At the front is a stereo microphone, which is a huge step up from that found on Canon and Nikon DSLRs. Although it also has an annoying automatic gain-control system (a form of compression) it's actually quite subtle, and much of the audio recorded by the mic is surprisingly usable. It's more than adequate for home movies, but you might still prefer a separate audio recorder for serious work.

On the top left of the camera is a small dial that can be used to select between auto-focus modes and manual focus, while on the top right is the shutter‑release button Press halfway to focus and all the way to take a picture. When in movie mode, pressing the shutter button will start and stop the recording: still image shooting in movie mode is not possible. On the front of the camera, close to the shutter button, is a control wheel that can be used to adjust shutter speed, aperture and exposure compensation. Though it might seem odd to have three controls on one wheel, pressing it in movie mode changes between shutter and aperture, while pressing it in aperture priority mode, for example, will switch between aperture control and exposure compensation. It's actually very intuitive and easy to use once you get used to it.

To the right of the display there is a cluster of cursor buttons that also double up for ISO, autofocus mode (selectable between face detection, AF tracking, 23-point area and one-area focusing) and white balance, plus an assignable function button. In the centre of this cluster, there is a menu button allowing access to various menu and setup items, while to the top left of the screen there is a switchable live viewfinder/LCD button. You can use this button to manually switch between the Live View display and the viewfinder display, or you can allow the camera to do it for you, using a sensor around the viewfinder to detect when your eye is nearby.

Various outputs are also provided, including USB 2 and HDMI, which will allow you to watch your video footage on a compatible display. There is also a 2.5mm microphone input socket, so you'll need an adaptor to use a mic with a standard 3.5mm connector.

Viewfinding

The articulating LCD screen is great for shooting in awkward spaces. One advantage over DSLRs is the electronic viewfinder, which is active during video recording.Photo: Bradley Steenkamp

On the rear of the camera, you'll find a three‑inch, 460,000‑dot LCD screen with full articulation. This is fantastic for filming at tricky angles, such as on the ground or above your head. It's not a particularly high‑resolution screen (the Canon EOS 550D Rebel T2 ihas a 1,040,000‑dot screen) but it's clear and easy to use, and I didn't find the resolution to be a problem. The screen can also be folded away facing the camera, to keep it protected when the camera is stored in a case or bag.

One of my favourite features of the GH1 is the electronic viewfinder (EVF). This could easily have been a major disadvantage, as EVF systems on many cameras have very poor display quality. Fortunately, this isn't the case on the GH1. The resolution is wonderfully high (1,400,000 dots) and it offers 100 percent coverage of the lens view.

The beauty of the system is that it's active during movie recording, so you can keep the camera up against your eye for an additional point of stabilising contact. It also means you don't have to buy a pricey 'aftermarket' viewfinder! I absolutely love this. It means you can carry around less equipment and shoot very nice handheld footage with just an inexpensive Joby Gorillapod as a makeshift shoulder mount (see my article 'Going Steady' in SOS Video Media October 2010).

The viewfinder can magnify an area before filming begins, to help you check focus at a critical point. This is a very useful feature, especially when using manual, prime lenses with wide aperture, which exhibit very shallow depth of field.

In Use

It's clear that this camera is packed with some advanced technology — much of it not seen in traditional DSLRs — but what's it actually like to use? Well, it's easier than it sounds! As I've already mentioned, you can capture video in virtually all modes, but if you want full creative control, it's best to film in the Manual Movie mode, which will allow you to choose your shutter speed, aperture, white balance and ISO to suit your needs. If filming at 25fps (50i full HD mode) it's best to select 1/50th-second shutter speed to comply with the 180 degree shutter rule (see 'Making Movies' part two in SOS Video Media June 2010 for an explanation of film‑like shutter speeds), and if you choose 720/50fps mode, select 1/100th-second shutter speed.

To judge the exposure, you can either use the exposure compensation display, which will indicate the current number of 'stops' above or below the correct exposure, or use the live histogram. Yes, that's correct, the GH1 features a live histogram, something missing from the Canon EOS cameras, and an incredibly useful tool. To be fair on the other brands, it's not strictly necessary, but it does make it just that little bit easier to keep exposure under control, by showing the intensity of light at different colour frequencies. Now that I've got used to this, I don't know how I ever managed without it!

Another GH1 feature I find very useful is the ability to use autofocus during video recording. Once again, this isn't available on the current line-up of Canon DSLRs, but has been added to the latest breed of Nikon cameras. Autofocus during video recording only works with compatible lenses (see 'Four-thirds Lens Options' box) and it's not something you're likely to use for shooting a scripted film. For live events, sports, live music and home movies, however, it's very useful, and has allowed me to capture some interesting shots that I would have missed if I'd been fumbling with manual focus! Autofocus is, on the whole, fast, accurate and very quiet, although this is somewhat dependent on the lens you're using.

The electronic viewfinder is a dream feature, and the option to magnify a portion really helps if you do decide to use manual focus. I do wish the viewfinder image was a bit bigger, with a higher level of magnification, as this would make it even easier to focus during movie recording, but even as it is, it's an excellent tool. The articulating LCD screen is incredibly useful, and filming at tricky angles is a breeze. The only problem I could find is that I was nervous about snapping it off! It isn't poorly made, but I wouldn't want to stress the connection too much, just in case!

Compared To Canon

This crop from full‑size video shows an example of compression 'mud', where the fine detail of the water's surface has been turned into blocks by the AVCHD compression.

For those looking to purchase a combined still and video camera, the GH1 is something of a direct competitor to Canon's EOS 550DRebel T2i, their lowest priced HD video‑capable DSLR with identical video features to the 7D and 60D (reviewed in SOS Video Media July 2010). Since they are so close but so different in many ways, a direct comparison is necessary. In basic terms, the 550DRebel T2i is primarily a stills camera with nice HD movie recording added as a very useful extra. The Panasonic GH1 is more of a hybrid camera, with features weighted slightly towards the video side.

The sensor size of the two is different. The 550DRebel T2i has a 1.6x crop factor while the GH1 has a 2x crop, when compared with a full-frame sensor. As a result, the 550DRebel T2i has a shallower natural depth of field but less reach with long zoom lenses. This can make correct focusing a bit more critical in some situations, but will also mean that wide-angle lenses remain wide! If you happen to like using a particular set of lenses, you'll need to remember that a 24mm wide‑angle lens is actually a 48mm standard lens on the GH1, but a 38.4mm semi‑wide lens on the 550DRebel T2i. This means that for GH1 wide lenses you're pretty much forced to use Panasonic's own models. That's not necessarily a bad thing, but the range is quite limited.

The two cameras use slightly different versions of a similar codec, with the GH1 using AVCHD and the 550DRebel T2i using H264. Both are quite heavily compressed, with the GH1 running at 17Mbps and the 550DRebel T2i at about 44Mbps. The two data rates shouldn't be compared directly, as AVCHD is a very efficient, 'long GOP' codec, while Canon's H264 format is I‑frame (see 'Video Codecs' in SOS Video Media August 2010 for an in‑depth guide to codec types). Many find 24Mbps AVCHD (available on the GH1 only via unofficial firmware trickery) is actually very comparable to the Canon 44Mbps H264, due to compression efficiency.

In my own experience with the two cameras, I've found the 550DRebel T2i footage to look a little cleaner, with fewer compression artifacts. The top half of this image shows a crop from a Canon 7D video, and the bottom half a crop from a GH1 video. The GH1's better downscaling algorithm results in a sharper image.The GH1 can suffer from 'mud' in high-detail areas, where fine detail is smoothed out by compression blocks. This codec discrepancy is somewhat offset however, by the excellent downscaling algorithm featured in the GH1, which is used to make roughly 2MP video from a 12MP sensor. It shows almost no aliasing or moiré patterns (jagged edges and colour patterns created by high-detail, striped patterns). This is one of the reasons why I now own a GH1 as well as a Canon 7D DSLR. As much as I love the Canon EOS video, I find the aliasing very irritating — particularly when filming guitarists — as it causes the strings to become very jagged and 'stepped'. The GH1's better downscaling algorithm also results in a picture with slightly higher detail than that created by the 550DRebel T2i.

While it's easy to shoot lovely, shallow depth-of-field footage with Canon EOS cameras, they tend to fall down with wide‑angle, high-detail shots, due to the softer downscaling: everything becomes a bit 'hazy'. This doesn't happen with the GH1. Rolling shutter (or 'jello' effect) problems are still an issue with the GH1, although they seem slightly more controlled than with the current Canon cameras.

There are a few other features found on the GH1 that aren't available on the equivalent Canon models, such as a stereo mic with smoother automatic gain control, live histogram and autofocus during video recording, and a high‑quality electronic viewfinder. Where the GH1 falls behind — in addition to the lower bit-rate codec — is the smaller selection of lenses and lack of frame‑rate options. Being limited 1080/50i and 720/50p in PAL and 1080/60i and 720/60p in NTSC is a shame, considering the Canon models give you all of the PAL and NTSC frame rates, and have true 24p, 25p and 30p on offer. For many people, that wouldn't be a deal breaker; I shoot almost exclusively at 25fps, so the GH1's 50i can be converted down to 25fps when de‑interlaced, but it'd be nice to have all of the options available. You'll have to think about what you'll be shooting most often when you make a purchasing decision.

Conclusion

The Canon 7D (left) and Panasonic GH1 (right) display very different noise characteristics.

Hopefully, this review will have shown you why I'm a big fan of the Panasonic GH1. It's a camera designed much more with video in mind than its Canon EOS competitors. It's just a pity that Panasonic didn't provide a higher data‑rate for the codec, as that would have taken care of the compression artifacts issue. Higher bit‑rates are available, but only via unofficial firmware updates (see 'Firmware Hacks' box) that are not supported and are likely to void the camera's warranty.

Initial reports relating to the Panasonic GH2 show that the 24p, 24mbps AVCHD mode doesn't suffer from unpleasant compression 'mud', and that noise performance is much improved. Is it best to buy a GH2? Well, it will cost a fair bit more, so if your budget is limited and you're looking for a hybrid still and video camera, you really should test out the Panasonic Lumix GH1.