Glaringly obvious problems exist with the Sony A7. Reading reviews from when the camera was released 5 years ago don't mention any of the problems.
After purchasing a used A7, I began to immediately notice problems I was not made aware of.
The star eater problem is the only deal-breaker, and it only applies to astrophotographers. Other issues can be worked around or avoided, as long as you are aware of them.
Used or new, the Sony A7 is the least expensive full-frame mirrorless camera available. Seeing as it was also the first mirrorless full-frame camera, it will likely permanently occupy that position.
Despite the numerous negative things I have to say about the camera, buying a used one isn't a waste of money. I like to adapt vintage manual focus lenses onto my A7. None of the newer full-frame mirrorless cameras are tempting me to spend considerably more on an upgrade.
Lens Mount Problems
The mount is made of plastic, it wobbles, and leaks light.
These problems shouldn't affect a camera with a kit lens used for general photography. Caution should be taken when adapting lenses, using heavier lenses, long exposure, and flash photography.
Fotodiox has manufactured multiple TOUGH E-mount light-tight replacements for the A7 and A7R. You can also replace the mount with an A7S mount, which is all metal.
The Sony A7 Lens Mount is Made from Plastic
The piece that holds a lens onto the camera body is made of plastic. There is a metal face plate over the plastic, but it is still plastic.
Wear to the mount will cause lens alignment issues. Fast or aggressive lens changes could cause wear to the plastic.
Heavy lenses can also cause damage, but that is a concern with any camera.
Special care needs to be taken when adapting lenses. Cheap adapters are often not machined very well.
A sharp edge or poor tolerances can result in wear to the mount. Make sure to pay attention to the first few times you use a new adapter. Also, take care when mounting and removing adapters.
I purchased the camera specifically to use with adapted lenses. I have 8 different adapters and have not had any problems. There isn't any noticeable wear on my mount.
A plastic mount is going to break more easily than one made of metal. However, the amount of force required to break the plastic mount would cause damage to a camera with a metal mount.
Replacing the piece of plastic is easy because it is held in place by 4 screws. Damaging the mount on a Nikon or Canon will be a more difficult repair.
The Mount Flexes & Wobbles
Almost no force is required to get the mount to wobble back and forth. Lenses do not wobble up and down.
This reflects poorly on the build quality of the camera. I'm not sure if the problem gets worse over time.
In portrait orientation, the weight of a lens will shift the mount. The plane of focus is no longer going to be perpendicular to the camera sensor.
Think of it as using a tilt/shift lens with a degree or two of tilt. As depth of field gets smaller, the effect will be more noticeable.
The Mount Leaks Light
The mount leaks light through the sides where the lens wobbles. Testing for the problem is easily done by shining light at the mount during a long exposure. Setting a high ISO makes the light leaks easy to see.
Light leaks will cause problems for long exposures and small apertures. The stronger the ND filter, the worse the problem is going to be. In order to use a ND 10 filter, the mount is going to have to be covered or replaced.
This camera already isn't an ideal choice for astro photography because of the star eater problem. Night photography and stacking large numbers of images are also going to potentially run into problems.
Roger Cicala's write up on the Lens Rentals blog - https://wordpress.lensrentals.com/blog/2014/03/the-sky-is-falling-the-light-is-leaking-and-the-a7r-anti-massacree/
How to Fix the Sony A7 Mount
Use a Sony A7S Mount
Sony has made 2 changes to the full frame mount. With the release of the A7S, all mounts have been made out of metal.
Two additional screws were used to hold the mount onto the camera with the release of the A7Riii.
The first way to fix the mount is to replace it with one from a A7S. Sony is still manufacturing the A7S so the part can be purchased directly from Sony or possibly found online.
Sony.encompass.com is the website to buy OEM Sony parts. The A7S mount part number is 453653101, and the screws are 4-186-545-0. (Screws from the A7/A7R should be able to be reused.)
It is nice that Sony will sell repair parts directly, unlike Nikon.
Buy a Fotodiox Light Tight Replacement Mount
Fotodiox has released 4 different E-mount replacements. The mounts are designed to help reduce lens wobble and the light leaks. They cost between $40-60, which is less than the $65 a replacement A7S mount costs.
- Signature Edition 2015 TOUGH E-Mount
- TOUGH E-mount Replacement Lens Mount
- TOUGH E-mount Signature Edition LT (Light Tight) [Amazon][eBay]
- Fotodiox Light Tight Replacement Lens Mount
Purchase links above are affiliate links.
There are also generic mounts on eBay for ~$25. I am very wary of these mounts as a poorly made mount will negatively effect image quality.
Based on reviews, the Signature Edition mounts are the only non Sony mounts worth getting.
Rear LCD Screen Can't Be Seen in Sunlight
Forget direct sunlight, even a partially overcast day will render the screen useless outdoors. The screen is not bright enough to use in most outdoor conditions.
Screen articulation is limited to flipping up and down. Without a way to see the screen from the front of the camera, framing video of yourself will be difficult.
Not having enough light also causes problems. Low light will cause the refresh rate on the screen and EVF to drop. Depending on how little light there is this could mean a frame rate drop that could cause motion sickness, or render the screen basically useless due to motion blur.
In terms of specs there are 921,000 dots or 307,200 pixels that cover a 3 inch (76mm) screen. 3 dots makeup one pixel for a resolution of 640x480. The Nikon D750, which was released at close to the same time as the A7 has a screen with 1,229,000 dots and 307,250 pixels. That's 4 dots per pixels which makes it a higher quality screen.
Two generations later and the A7III still has the same 921,000 dots. Both the Nikon Z6 and Canon EOS R have screens with 2,100,000 dots.
Aside from the technical specs, the screens from Nikon, Canon, and Fuji look better than what Sony offers.
The EVF Has a Low Frame Rate in Low Light
A slow refresh rate, poor contrast, and a 1024x768 resolution combine to make the lackluster EVF on the A7. Details are hard to see and colors look washed out.
The EVF screen is a 0.5" XGA color OLED with 100% coverage, 0.7x magnification, 2.4 million dots, and 786,432 pixels.
With plenty of light, the highest refresh rates on the EVF are 30 or maybe 60 frames per second. I was unable to find the exact specs, but it doesn't matter.
Low light will cause the screen refresh rate to drop. With low enough light levels, the refresh rate will be slow enough to where motion blur will render the EVF unusable.
The Sony A7 Has No Weather Sealing
There is no weather sealing. The camera is a terrible choice to take into bad weather. Don't listen to anecdotal evidence by Sony fanboys.
The lens mount leaks light, which means water will also be able to get through. There are no gaskets on the doors for the usb, HDMI, audio jacks, memory card slot, or battery.
The Lens Rentals teardown of the A7R shows the complete lack of weather sealing in the camera. If you're going to take the camera out into nature, make sure you have a water proof bag in case it rains.
Cheap Build Quality
All of the other manufactures have better build quality. Even the Sony A-mount DSLRs are built better. Other than the top of the camera, the body is made of cheap thin plastic.
There are small cracks on the bottom of my A7. The build quality is no where near what a camera that originally cost $1,700 should be.
For example my Nikon D750 also has plastic body panels, but they are made of fiber reinforced plastic and thicker. I have never questioned the durability of the D750.
Bad Battery Life
Battery life is terrible with power saving features enabled, and only gets worse if any of those settings are turned off.
Walking around with the camera on will require multiple spare batteries to be brought along. Turning the camera off and on does not work well because of how long it takes the camera to power on and be ready to shoot.
The Power Save Start Time setting will put the camera to sleep after a certain amount of time. About 1 second is required to wake up from sleep, which is a similar amount of time it takes other cameras to be powered on and ready to shoot.
The two shortest time settings before the camera goes to sleep are 10 seconds and 1 minute. Using 10 seconds, the camera would go to sleep when I was framing and focusing with adapted manual lenses.
30 seconds would be the perfect amount of time for me, but I've had to settle for 1 minute. That extra 30 seconds makes a difference when I expect to get 90-120 minutes of life out of a single battery.
External power sources can be used to power the camera. A power brick will make it possible to do to timelapses without worrying about swapping batteries out.
Sony OEM batteries cost around $50. Compared to the price of the camera and the fact you'll need several, they are expensive. Plenty of cheap third party replacement batteries exist.
Quality is always an issue with replacement batteries because the capacity labeled in mAh will rarely be accurate. Expect most replacement batteries to have much less than their stated capacity.
Testing the capacity of batteries is the only way to know their actual capacity. As batteries go through charge and discharge cycles, the capacity will decrease. For that reason, avoid buying used OEM batteries. To do testing, I purchased a TEC-06. Shipping from China to the US took almost a month. I have done testing of replacement batteries to find which brand is the best.
Slow to Power On
Several seconds are required after powering the camera on before it can be used. The time it takes is noticeably longer than with other cameras.
This is not a camera that can be quickly pulled out to capture an image. Combined with poor battery life and powering the camera on and off becomes a viable option instead of waiting on the camera's power save mode.
Lossy RAW Files
Sony used a lossy RAW file compression in the A7, A7R, A7II, and A7RII. Firmware updates were made to allow the A7II and A7RII to shoot uncompressed RAW files.
Lossy compression results in smaller files, but also loss of details. Most images will not noticeably suffer, but there can be artifacting present in some images.
Lossless compression, like what all other manufactures use, is preferred by everyone that cares about maximizing quality. For better explanations of the problems, and a site that can fix the problems, check the links below.
Menu System is Hard to Navigate
The menu system is difficult to navigate and settings are poorly named. There are 24 pages of settings without a quick way to navigate through them. This problem could be solved if a custom menu could be created.
With use, the location of settings can be memorized. If a setting isn't frequently used, good luck finding it when you want to change it. This is made worse if the setting is poorly named, making it even harder to find. You can find all the settings that are important for using the A7 with adapted lenses here.
Lack of Custom Settings
Custom settings are rendered useless because menu settings are not saved. Live View Preview, Peaking, Display Quality, and other settings do not get saved.
It is not possible to setup custom settings for flash, natural light, or video. You will have to spend time in the menu manually changing settings.
Features Were Removed to Sell in a now Defunct App Store
App stores and microtransactions are terrible for consumers. Sony included the app store as a blatant cash grab. Features that should have been in the A7 were kept out so Sony could charge for them later. The only notable app was one that would allow you to program timelapses into the camera.
The store was not as profitable as Sony would have liked, so it was killed off after the A7RII. That would be fine if those features were rolled into the next generation of cameras, but they were not.
A blatant money grab. Instead of including features, Sony decided to charge extra for them. The most notable app was for doing timelapses.
The store obviously didn't do well because Sony dropped support for it after the release of the A7Rii. Now there isn't even an option of playing to be able to do timelapses in a A7III, A7RIII, or A9. There is no reason Sony should not include that ability in the firmware for cameras that cost $2,000 or more.
Whomever designed the camera had no interest in photography. Buttons are placed in the most awkward and difficult to reach positions.
There was no thought put into how the camera would actually be used. Pressing the shutter button feels unnatural. The record button for video is impossible to reach while holding the camera.
I find the camera grip to be too small to hold comfortably. I don't have large hands and my pinky does not fit on the grip.
There is no palm swell, so holding onto the camera is difficult. Every digital camera that I have owned has been easier to hold than the A7.
Sensor is Exposed During Lens Changes
The shutter stays open when the camera is off. Every time a lens is switched the sensor is exposed to the elements and dust. Having the shutter stay closed when the camera is off would reduce how often the sensor needs to be cleaned.
What You See is What You Get (WYSIWYG)
Exposure preview through the EVF or screen is touted as a way to always get the correct exposure. Unless you're using flash, in which case, the feature is completely worthless.
Using a Sony flash or trigger will automatically turn the 'Live View Display' setting off. If you're using a third party flash or trigger, you'll have to manually turn the setting off.
Custom settings on the mode dial won't save you a trip into the menu because the 'Live View Display' setting doesn't get saved. You also can't put the option into the function menu.
Lack of Video Frame Rates
There's no 30 frames per second for 1080p. The two options are 24 or 60 frames. It is possible to downsample to 30 from 60 fps, but that increases render time and storage space.
Not being able to shoot at 30 fps limits the usefulness of using the camera as a B camera or to take B-roll with.
Like other issues with the camera, only a small subset of users are going to be impacted. The other cameras I currently own can shoot 24, 30, and 60 fps. (Nikon D750, Panasonic G7, and Panasonic G6). Plus, any used cameras I am looking at buying can all shoot at 30 fps.
Astrophotography Star Eater Problem
A spatial filtering algorithm designed to remove hot pixels will remove stars when using the camera in bulb mode. The spatial filtering algorithm is separate from long exposure noise reduction.
Combined with the mount light leaks, the A7 is a very poor choice for anyone interested in astrophotography.
For a more detailed and knowledgeable explanation of the problem, check out The Sony "Star Eater" by Mark Shelley
Release and Depreciation
The A7 was announced by Sony in October, 2013. Cameras started shipping in December. Pricing was set at $1,700 for a body only, or $2,000 when bundled with a kit lens.
A year later in December, 2014, the A7II was released. Sony continued, to sell the A7, but for a reduced price. Doing this dropped the price of the A7 on the used market. I feel bad for the early adopters who saw the value of their cameras quickly drop.
Sony is still selling the A7, and the price has continually been dropping. The price is currently (December, 2018) $800 for a body, and $1,000 bundled with the kit lens. One the used market the A7 sells for $550 and the kit lens for $140. That's an absolutely brutal amount of depreciation.
The A7II has followed the same trajectory. New bodies are being sold for $900, with used ones selling for $700. None of the other camera manufactures have seen those levels of depreciation over the same time period.