Neptune Photo Newsletter
June 2017 Volume 66
by Steve Zimic
Mirrorless Versus DSLR Cameras
It's no big news that over the last several years camera sales have been steadily declining, mostly in favor of the smart phone. The good news is that the latest sales figures show the volume of interchangeable lens cameras as a whole are holding steady over last year. The bad news for the DSLR is that sales are still declining, while mirrorless cameras are on the rise. That said I thought this would be a good time to show some of the reasons why folks are starting to prefer the mirrorless variety. Before we get into that, I think it would be useful to visit the history of the Interchangeable Lens Camera (ILC), so bear with me here for just a little bit.
The very first film ILC's were of the range-finder variety, using a separate viewfinder for composition and focusing - a carryover from the very popular fixed lens range-finder - like the Argus 3C, at the risk of revealing my age. These cameras were quite small and light but the disadvantage of a separate viewfinder in these cameras was problematic for a variety of reasons, especially with telephoto lenses. Enter the much larger SLR with its reflex mirror that allowed one to look directly through the lens for more accurate composition, metering and focusing. It was only natural for this reflex mirror design to be carried over when digital photography entered the picture - pun intended. For Canon, Nikon and others, the digital version of the SLRs allowed the use of all the current film lenses and the same auto focusing and metering technology. This was a big cost savings compared to creating a totally new system, but even more importantly, it allowed film users to easily make the switch to digital by just buying a digital camera body, despite the exorbitant cost at the time. Over the next decade or so, the performance of digital imaging sensors advanced at a feverish rate. Besides huge increases in image quality and size, these new sensors could now perform advanced functions such as the ability to focus a lens extremely fast and more accurately than the DSLR. Another significant factor that gave rise to the mirrorless camera was the development of high quality the electronic viewfinder (EFV) which replaces the optical viewfinder. The EVF eliminated the complicated and noisy reflexing mirror along with the prism needed to see through the lens thus allowing camera bodies to be considerably smaller and lighter. So in a way we've come back full circle to the first ILC, at least with regard to size. OK, that's enough background info and thanks for staying with me if you've read this far. So here is my pro and con list of mirrorless cameras in general compared to DSLRs, regardless of image sensor size. I've listed them in order of priority, well at least my priority.
1. The electronic viewfinder (EFV) allows for real time viewing of how your image will look, including any exposure compensation you've used. Most cameras' EFVs will even allow for a live histogram.
2. Most mirrorless cameras have In Body Image Stabilization (IBIS) which precludes the need for IS in the lens. This is often more effective than lens IS, plus it can be used with any after market lens. Lenses without IS are also traditionally less prone to repairs and less expensive.
3. Autofocusing accuracy is done by the image sensor providing more accurate focusing, eliminating the need for focus calibration.
4. The latest pro models can shoot at a higher frame rate with continuous AF+tracking, than the best pro DSLRs.
5. Many mirrorless cameras offer the option to use a totally silent electronic shutter. This is a big plus for weddings or other types of photography where the shutter sound would be a problem. The rolling shutter issue (distortion of fast moving objects) when using electronic shutters has been significantly reduced or in some cases eliminated altogether in the latest models.
6. Depth of field preview via the LCD or EFV is at full brightness.
7. Comparing the overall DSLR field versus mirrorless, you're more likely to get better video performance especially with regard to focusing.
1. Smaller body sizes can be uncomfortable for some users, especially for the full frame mirrorless cameras which have relatively heavier lenses. Optional battery grips will usually solve this issue, although at additional cost.
2. Currently, DSLRs have a larger selection of lenses available from 3rd party manufacturers although that difference is quickly shrinking.
3. Hit rate using CAF+tracking is generally lower than on comparable DLSRs.
4. Optical viewfinders are not an option.
5. If you're a fan of top mounted information LCD panels, you won't see them on mirrorless cameras.
6. Switching from a DSLR to mirrorless often means learning a totally new menu system.
Having switched to a mirrorless system myself, I actually struggled with finding an almost equal number of cons, so maybe I missed a few. Nevertheless, you can hopefully see why these new cameras are becoming more popular. Next month I'll go into more specifics, comparing some of the smaller sensor mirrorless cameras to full frame counterparts.
Tamron 18-400mm VC f3.5-6.3
It's been 7 years since Tamron introduced the 18-270 for cropped sensor (APS-C) cameras and now they've upped the game considerably with this new ultra range zoom lens, a world first. In addition to the crazy 28-600mm equivalent focal length, they've included 2 1/2 stops of vibration control (VC) and weatherproof construction. Like most super zoom lenses, there's a lock to prevent zoom creep when carrying the camera and lens. The minimum focusing distance of approximately 18" should allow for wonderful macro shots at a very discrete distance - great for those skittish creatures. Even though it's not a fast lens, Tamron has managed to deliver some pretty smooth bokeh, no doubt with the help of a rounded 7 bladed aperture. I think it's pretty amazing that they've been able to do this and have the lens weigh in at only 25 ounces. I've yet to see any test results but the MTF charts on the linked page below look very promising, especially at the 400mm setting. Aperture control is now electronic for the Nikon mount so check your camera model to see if it's compatible. You should see it become available sometime this month for $649. More details with some sample images can be found on the Tamron Website.
Canon 6D gets a major upgrade with the MKII
After 5 years of success with the 6D Canon has brought some significant upgrades with this new MK II model. The articulated LCD is the only real change to the camera physically with all the other upgrades under the hood so to speak. The image sensor goes from 20 to 26 MP with a base ISO range of 100-40,000, expandable to 50-102,400. The focusing module now has 45 points compared to 11 in the 6D, although they're still tightly centered. In live view though you'll get dual pixel AF across 80% of the frame, all accessible via the touch screen. In optical view the frame rate with continuous AF almost doubles over its predecessor to 6.5FPS. Video resolution remains at 1080P although you'll now get up to 60P. Connectivity is via Wifi, Bluetooth or NFC for both iOS and Android devices and GPS is built in. As an entry level full frame camera I'd say this model is aimed primarily at the still photographer. Nevertheless, there's lots to like here and its introductory price of $1999 is $100 less than its predecessor. You should see it available by the end of this month. In the meantime you can check out more details on Canon's website.
Sony - a7RII and a7SII, A7II, a6500, a6300 - Several bug fixes and additions but mainly adds support for the upcoming 100-400 f4.5.6 GM OSS lens.
Sony - a9 - Fixes the problem of the overheat warning being displayed earlier than necessary.
Sigma 100-400mm F5-6.3 DG OS HSM - version 1.01 - improves the AF performance when used with the Sigma MC-11 teleconverter. Sigma USB dock needs to be running the latest Optimization Pro software before upgrading the lens firmware.
Canon - 5DS and 5DS R - version 1.1.1 - Bug fixes related to error 70, level operation and power up delays.
Nikon D5600 and D3400 - Fixes connectivity issues between the camera and the Snapbridge app on Android phones.