Rethinking the trade-offs in sensor size with modern digital cameras

If you follow my YouTube channel or The Image Doctors Podcast, you probably saw that I recently purchased a OM Digital Solutions (formerly Olympus) OM-1 body and an assortment of lenses. This is something I’d been contemplating for quite some time, given that the majority of my photography involves travel and wildlife. The OM-1 is not a perfect camera, but it has some features that make it extremely compelling for photographers who want professional quality in a vastly smaller package. It’s also far less expensive ($2199 USD) than a comparable 35mm format body (think Sony Alpha A1, Nikon Z8/Z9, Canon R5).

Each of these cameras is outstanding. They offer subject-detection based AF systems (including bird and vehicle detection), excellent in-body stabilization (IBIS), and high speed shooting of 20fps or greater for raw images using an electronic shutter and stacked sensor technology. The biggest difference then? Size. The OM-1 is a fairly small (1.3 lb) camera, but the lenses it uses are in some cases downright tiny. That one factor alone is what made me consider the OM System gear for my work.

For travelers, smaller is often better

For travel photography, size and weight is critical. With an OM-1 kit, I can use anywhere from 1-3 Olympus lenses and get coverage equivalent to 16-300mm on 35mm format. For example, I can pair the OM-1 with the 8-25mm f/4 (16-50mm equivalent) and the 40-150mm f/4 lenses, and walk around with a total kit weighing just over 1500g (3.3 lbs). In contrast, my Nikon Z9 kit would have to include the 14-30mm f/4, 24-70mm f/4, and either the Nikon 70-300mm f/4.5-5.6 VR P (F-mount + FTZ adapter), or the Tamron 70-300mm in Z-mount (which is lighter but lacks image stabilization). The Nikon-based kit weighs in at 3065g (5.9 lbs). Sure, I could obviously save some weight by selecting the Nikon Z6 or Z7, but neither of those bodies offer the autofocus system of the Z9 with advanced subject detection features.

For an incredibly lightweight configuration, I could pair the OM-1 with the Olympus 12-45mm f/4 lens, which weighs in at a mere 285g (0.63 lbs.) and provides angle of view coverage equivalent to 24-90mm on 35mm format. It’s also very sharp across the frame, even when used wide-open. Keep in mind that the effective depth of field with a Micro 4/3 mount sensor is 2x what you’d get with a 35mm camera. Effective depth of field wide-open at f/4 is roughly the same DoF as f/8 on my Nikon Z cameras (but obviously with more light-gathering capacity).

Ridiculous IBIS for hand-held shots

If you’re in an indoor setting and aren’t allowed to use a tripod, what’s the slowest shutter speed you can get away with while hand-holding your camera?

In-body image stabilization is a great feature in most mirrorless cameras. Just how much you can get, however, depends a lot on the size of the sensor, and how big the lens mount is. Manufacturers make all kinds of claims about how many stops of stabilization their cameras offer, but at the end of the day, the question comes down to this: If you’re in an indoor setting and aren’t allowed to use a tripod, what’s the slowest shutter speed you can get away with while hand-holding your camera?

While focal length definitely plays a factor in getting sharp shots (wider is better), I’ve found that with my wide-angle (14-30mm f/4) Nikon lens, I can get consistently good hand-held shots at 1/10s (sometimes a little slower if I’m at the extreme wide-end). With the OM-1, I tried using the 12-45mm f/4 lens at 12mm (24mm equivalent) and wide-open to capture a SHARP shot hand-held at 4s. Yes, FOUR SECONDS. That’s simply incredible, and opens up a ton of possibilities for travel photography where using a tripod just isn’t permitted. Moreover, the longer exposures mean I can use lower ISO settings for better dynamic range.

A kitchen table experiment for indoor shooting

The combination of IBIS plus greater apparent DOF gives the OM-1 a potentially huge advantage for indoor shooting without a tripod.

I decided to do a quick test between my Nikon Z9 and OM System OM-1 for indoor shooting in poor lighting. This wasn’t a test intended for scientific publication, just for my own enlightenment. I used both cameras indoors, hand-held, and set them up for the same framing and apparent depth of field. For the OM-1, that meant using the 12-24mm lens wide-open at f/4, and for my Nikon Z9, using my 14-30mm f/4 lens set at f/8 (remember, you get 2 stops of apparent DoF with the smaller sensor). I set the focal length to 12mm on the Olympus to match 24mm with the Nikon. In both cases, I got sharp, usable shots of my messy kitchen counter. But the differences were apparent in the EXIF:

• Nikon Z9: 1/10s f/8 ISO 2200
• OM-1: 1/2.5s f/4 ISO 200

The OM-1’s outstanding IBIS, combined with the 2-stops greater apparent DoF, allowed me to use a much slower shutter speed than what I needed from the Z9. That meant I could use ISO 200 in the OM-1 instead of 2200 in the Z9. At those settings, the OM-1 has roughly 2EV greater dynamic range than my Z9 simply due to the difference in ISO. The combination of IBIS plus greater apparent DOF gives the OM-1 a potentially huge advantage for indoor shooting without a tripod, which is becoming quite common these days.

Wildlife Photography with the OM-1

I made some test shots with the OM-1 paired with the Olympus 100-400mm f/5.0-6.3 zoom lens. The OM-1’s bird-detection AF system worked easily as well as what I’d seen from my Nikon Z9. The biggest difference? On the OM-1, that 100-400mm lens acts like a 200-800mm lens on 35mm format, but it weighs in at 1200g (2.6 lbs.) when you remove the tripod collar. Total kit: 1792g (3.95 lbs). Honestly, I didn’t really even notice the weight when I walked around my local lake looking for birds.

By comparison, I was able to get the equivalent of 840mm using my Nikon Z9 on my recent trip to Panama. This required me to pair the 100-400mm Z Nikkor with the Z teleconverter 1.4x and use DX crop mode. Guess what? That combo weighs 3819g (8.4 lbs), and I was producing 19.3 megapixel images. Remember, the OM-1 produces a 20.1 megapixel image, and at ISO 200 and up, its dynamic range essentially matches that of the Nikon Z9 in DX-crop mode.

Enter the Nikon Z8

I’m glad you asked! The newly announced Nikon Z8 is exactly the camera I wanted from Nikon. I hesitated to purchase the Nikon Z9 when it was announced due to its massive size, but its autofocus system is downright amazing, and it has some features that I really like (built in GPS, 4-axis tilt LCD, bird and animal detection). I’ve absolutely been happy using my Z9, but it is certainly heavy, especially for international travel. I saw some of my clients struggle to handle the Z9, especially when paired with a telephoto lens like the brilliant 100-400mm f/4.5-5.6 Z Nikkor.

Where 35mm format (don’t call them “full frame”) cameras shine is with their outstanding resolution and dynamic range, and the ability to shoot 8k video. When you shoot a Z7, Z8, or Z9 camera below ISO 200, their dynamic range easily exceeds that of the smaller format systems. That advantage isn’t as noticeable at higher ISOs, though. It’s also true that the Olympus cameras currently max out at 20.2 megapixels, which is actually plenty for most of us, but you can get 45-60 megapixels from a 35mm digital camera. So for pure resolution, bigger sensors deliver the goods.

35mm digital is the new medium format

These differences put the two systems into a different perspective for me. The Nikon/Canon/Sony 35mm systems are more like modern-day medium format cameras in terms of sheer resolution and dynamic range. They use substantially larger lenses (it’s physics) than small-sensor cameras, making the entire system heavier and bulkier to pack and carry. That doesn’t make them bad, it just makes them fit into a different role (at least for me) than what we were used to before. Is bigger better? That depends on your needs. Believe me, I still really enjoy the feeling of zooming in on a 45+ megapixel image and seeing the level of detail that’s there. But I’m usually the only one who sees it, because those details are lost in anything except the largest prints.

So yes, I have pre-ordered the Nikon Z8, and I’m excited to add it to my kit. I absolutely love my Nikon gear, and that’s not changing anytime soon. However, I expect the Nikon Z8’s role in my kit to be more specialized; I’ll use it for landscape and portrait photography, or anytime I want the benefit of 45 megapixels and one of the best AF systems available. Nevertheless, the Nikon Z8 still weighs 2/3 of a pound more (305g) than the OM-1, and requires bigger, heavier glass to maximize its benefits. I’ll play to the strengths of each system for my work.