What Will I Compromise On If I Move From A DSLR to Olympus OM-D?
This is a fair question.
As photographers we spend a lot of time researching lenses, camera bodies and other accessories so that we can get the best possible results. In my opinion the only way to find out the truth about how something performs is to try it out yourself. I can’t begin to tell you how many times I have bought a lens or a camera based on the recommendations of others only to find that I hated it. The opposite is true too, where I have bought lenses that other reviewers have pasted but I ended up loving them. OK, so not everyone can afford to drop a few thousand Dollars on every new camera or lens that comes out in the hope that it meets expectations (especially not me), but if you’re going to use a review site to form an opinion, at least make sure you check with one that delivers actual results in the form of images you can relate to. Stuff that you're going to make yourself.
I have never and I will never look at scientific charts to make a decision on whether a lens or camera is going to cut it for me. I will look at photos of real subject matter and wherever possible I will go out and make photos of subjects I like to shoot, assess them and decide for myself if the gear meets my expectation. If I need the camera/lens for action photography I will look for sites where the authors show actual action shots using the equipment, or I'll borrow the lens/camera and go and do some of my own work. If I want the camera/lens to do portraiture I will look for a site that shows actual portraits taken for real world use or go and do it myself. You get the picture? If the reviewer is not showing photos like the ones you want to take, how can they make a decision on how it performs in that situation? Conjecture? Well, personally I don't go for that. Show me the shots I will probably want to take. Don't show me charts and make inferences from them.
So when I first got interested in m43 I didn’t get my information from the likes of dpreview, DXO or any of those scientific sites. I went to Flickr and some other image hosting sites where there were actual photos I could look at taken with the kit I was interested in. What I found on Flickr when looking at shots taken with the OM-D system kind of floored me. Surely it couldn’t be that good? Why aren’t more people using it? I had to know more, so I got involved and what I discovered is that the so-called disadvantages of smaller sensors that are constantly being debated online didn't affect my photography at all.
In my opinion the micro four thirds image quality has advanced to the place where under normal viewing conditions you would be hard pressed to tell the difference between photos taken with the big expensive DSLRs and those taken with something like the Olympus E-M1. So what was I losing out on? These are the main compromises you'll read about online.
Compromise #1: Depth Of Field Is Increased
(often interpreted as "you can't get shallow depth of field from a small sensor")
As the camera’s sensor gets bigger while aperture stays wide open, the depth of field decreases. According to scientific calculations the m43 system is about 2 stops different in terms of d.o.f. when compared to the same photograph taken at the same focal length and perspective of the 135 system. This is explained very nicely on this page, so I won't go into it here, but If you’ve ever had a look at the effects of this on a very fast lens you’ll see that 2 stops doesn’t make an enormous difference to the out of focus areas of your frame at all. However, something to consider very seriously is that when you are shooting a very fast lens on a large sensor at wide aperture, you have to absolutely nail the focus otherwise your image is going to look soft all over. You're going to be stopping down anyway, so why not enjoy more depth of field with wider apertures and the resulting faster shutter speed in the first place?
This is just the nature of the fast lens on a bigger sensor. How often do you actually find yourself shooting them wide open and nailing the focus? In my experience the phase detection autofocus systems used in these big DSLR’s are just not always accurate enough for this and unless you spend a lot of time calibrating your autofocus you’re going to run into this problem over and over again with ultra-fast lenses shot wide open - almost everything looks soft. It takes a lot of practise and technique to get it right.
So, very short depth of field is not as short on m43 but this is to a large degree dependent on the shooting situation, distance to the subject and distance from the background. I have seen some amazing images shot on m43 that have very short depth of field - just go and visit Robin Wong’s blog to see what I mean. I’m totally fine with the depth of field of my fast glass on m43 - I'd rather have more depth of field at wider apertures than less.
Click on the images to enlarge them.
Compromise #2: The Resolution Is Lower
The resolution of the current generation of m43 cameras tops out at 16MP, which is significantly less than something like the Nikon D800 and slightly less than the 22MP Canon 5DMk3.
How important is this? Some photographers have genuine needs for the extremely high image resolution, like making large, highly detailed prints, whereas many others need it mainly for having the ability to zoom into a small part of an image and marvel at whatever detail they might find there. Yes, it’s cool to be able to do that, but in reality it’s not a good reason for buying camera X or lens Y. Not in my opinion anyway. Besides, if you’re shooting something like a landscape you can quite easily obtain a high resolution file by stitching several images together.
I have made a conscious decision to assess images I take as an entire thing as they would be seen by a non-photographer (ie, client) and not to nit pick about micro contrast, chromatic aberrations or or how much tonality exists at a 100% crop of any given image. The only reason I zoom into an image at 100% is to check that I have got the parts I want to be in focus nice and sharp. Other than that I make my decision on image quality by looking at the whole image. If it looks great when you’re looking at the whole thing do I really care what it looks like when I am looking at a tiny part of it? No. I don’t care at all.
Not everyone agrees with this approach and I dare say that if the resolution aspect is that important to you, then perhaps the micro four thirds system is not the thing that will satisfy you right now. For me 16MP is plenty. I can make good prints out of them and I can still crop away significant parts of an image with decent results.
Compromise #3: High ISO Is Not As Good As DSLR
I’ve seen some photos shot on cameras like the Nikon D3S and the new Nikon D4S and Df. They’re undisputed kings of the high ISO world and you can comfortably shoot them at ridiculously high ISO values over 25600 and get perfectly acceptable image quality by any standards. However, I have to say that the Olympus E-M1 is producing very acceptable images for me at ISO 12800 too. I am actually quite often startled at just how well this particular camera deals with noise at such high ISO values. This is something we couldn’t do with the E-M5, where 3200 was about as high as I liked to go. Anything higher resulted in banding and a general loss of image aesthetic.
I don’t think you can really call the E-M1 high ISO images noisy so much as you can call them grainy. And in my book grain is good. It adds atmosphere to images. The grain on the E-M1 at ISO 12800 is not anything like the kind of pain I often felt from looking at images shot on certain lesser DSLR cameras at significantly lower ISO values in the past. There’s no luminance noise that shouts at me and while the graininess becomes quite visible the higher up the scale you go, it’s not affecting the sharpness of the images as much as you’d expect it to. I run a slight noise reduction preset over my images in Lightroom, just enough to drop the grain a bit without affecting fine details and I’m very happy with what I see. Convert it to black and white and you might be forgiven for thinking you’re shooting with old Kodak Tri-X pushed a few stops. Tri-X was the staple film stock used by generations of photojournalists in the 20th century and its ISO rating is 400. Imagine the shots the journos of the day might have been able to get if they could have shot at 12800, had the fast glass and a built-in image stabiliser on their film?
So is it possible to use an E-M1 at high ISO values? Oh yes, it certainly is. But you shouldn’t expect results quite as good as those found on cameras that are known to excel at high ISO, such as the likes of the Nikon D4, etc. I’d put the high ISO aesthetic performance of the E-M1 about a stop above that of the Nikon D700 (which I used for 5 years in many a low light situation), so if you’re using that camera as a benchmark you’ll be pleasantly surprised with what the E-M1 does. It’s a whole lot better than the E-M5 too. I use the word aesthetic because while the D700 might have less noise at the same ISO values, the grain of the E-M1 just looks better to my eyes. I would never shoot the D700 at 6400 on purpose, yet I am quite happy to shoot the E-M1 at 12800 - it just looks better. Your mileage may vary depending on your tastes.
Compromise #4: Auto Focus Tracking is Inferior to DSLR’s
The E-M1 has made huge strides in the auto focus tracking department compared to its forerunner the E-M5. This is because they added phase detection auto focus sensors on the imager. It makes a big difference because it is now possible to get decent auto focus using the older 4/3rds lenses.
When I say “decent” I’m not talking blazing fast like you’d get on a top of the line pro DSLR body with lens to match, but decent in the sense that your lens isn’t going to take forever to acquire focus. Depending on the lens you’ll experience something not unlike what you would get from the older Nikon screwdriver type auto focus lenses. I have the Olympus 7-14mm f/4 and the 50-200mm f/2.8-3.5. The 50-200mm is the lens I’d most likely be using to track objects (sports and wildlife) and it focuses really quickly for me, even in poor light. It’s snappy, but there’s a very brief adjustment (back and forth) when it first locks on. Once it does lock on, it doesn’t let go easily.
Bird in flight photographers would not like this behaviour. I don’t do a lot of bird photography, so for me it’s not a deal breaker. I think it’s good enough for me to use on the types of action photography I am more in tune with, namely surfing, motor sport and land based wildlife.
There are a few things you need to be aware of when it comes to autofocus performance with the E-M1. The E-M1 makes use of a dual AF system, namely phase detection and contrast detection, but it decides on its own when to switch between them based on the type of lens mounted. It’s not a user setting that can be changed. When you’re using a micro four thirds lens it will only deploy CDAF, even when its in AF-Tracking mode. The only time it uses the PDAF mode is when there is a four thirds legacy lens mounted. You will notice when it’s in this mode because the AF point layout in the EVF changes from the wide grid to a diamond type layout typically found in a DSLR.
AF-Tracking performance in the CDAF is a lot better on the E-M1 than it is in the E-M5, but the only m43 telephoto lens I have been able to try this out on is the Olympus 75-300mm, which admittedly I am not all that fond of. I did use it once or twice to do surfing shots with and it worked fine in AF-Tr. I can imagine that once the PRO telephotos for m43 arrive (the 40-150/2.8 and the 300/4.0) the tracking performance will get better.
TTL Flash - Compromise or Embedded Memory Confusion?
I will admit to being a little less than thrilled with the way Olympus do TTL flash. It’s complicated but once you do understand how it all works, it is certainly very capable. It offers everything the Nikon CLS offers, but just in a different way.
My biggest gripe is that the interface on the FL-600R flash units is fiddly. You have to contend with buttons and a dial to adjust things and getting used to it takes some time. With the Nikon CLS it was pretty much “plug and play” whereas with the Olympus flash system it’s “plug and pray that you have the correct settings on the flash AND on the camera”. Yes, you also have settings on the camera that you need to fiddle with in order to get the exposure right. I find this very counter intuitive and its especially problematic when you want to bounce flash in TTL mode during an event. I’ve had to resort to putting the flash into manual mode and adjusting the output by compensation dialling the power. Very old school. I suppose I’ve been spoiled by the new school where thinking about flash settings isn’t hard wired into my brain and Nikon iTTL became a crutch.
On the plus side once you get used to the interface there isn’t much you can’t do with the Olympus flash system. For wireless use indoors it works very much the same way that Nikon CLS does and you can also control up to three groups of flashes from your OM-D using the little clip on flash as a commander. The pop-up flash on my Nikon D700 only allowed me to control 2 groups.
I bought two of the FL-600R flash units and while they are diminutive compared to the likes of a Nikon SB-910, they pack a punch. If I need to produce head shots on a white background it’s an easy setup and using manual output on both the background light and key light, I have been rewarded with pretty good results.
Shot with two FL-600R units, one into an umbrella and the other bounced onto the background
As far as I can tell, what I’ve described here are the only tangible compromises I’ve encountered where a DSLR may have an advantage over the OM-D system. For me none of them were critical enough to prevent a complete switch over to OM-D from my fairly well equipped Nikon eco-system and if I am honest with myself and my readers, there are too many advantages to OM-D that cannot be reproduced on a DSLR for me to consider a DSLR as being a better option. Not for the kind of work I do anyway.