You can imagine the excitement I had when i received my Canon 6D. I headed out for a 3 night trip to Cedar Mesa, UT and was planning on take photos of the milky way and stars using my 6D with Rokinon 24mm F/1.4 Aspherical Wide Angle Lens. When I was preparing and focusing the lens while the sun was still up I realized there was a major malfunction, I was deflated. The bottom half of the image is black. I took the lens off and looked through it and played with the aperture, looked and felt completely normal. Put it on a different camera (canon T4i) and that was perfectly fine as well. Put a different lens on the 6D and it was normal. Any ideas as to why the Rokinon 24mm F/1.4 Aspherical Wide Angle Lens is on working with my Canon 6d?
When you get a good sample of this lens, it is an amazing lens. But, the problem is, there are a lot of samples with element centering issues. I read that this issue happens also with some Canon samples... the only solution is to return your lens for replacement, it can't be repaired in a service center.
Vasile, thanks for your response and I am familiar with that issue. But then wouldn't it look the same on any Canon camera it is on? Which isn't the case here.
The APS-C sensor is smaller than the full frame, it needs only the center of the full frame lens... well, a little more than just the center, but you get the idea... On that page is a test for centricity, can you do it? Edit: I saw the lens, is completely mechanical. You said that the aperture works right. Then the only logical explanation is that the center of the projected image shifted, it is not perpendicular on the center of the sensor plane and that can be only because of a glass element.
I have decided to bring the lens to local repair shop. I will see what they can do, hopefully they will be able to fix it so it works on my 6D. If not it looks like I will be buying another...the price has gone up 200 dollars since i purchased it.
Could there be a problem with the 6D shutter or mirror box when used with this lens? Perhaps half the shutter is not opening (it does run vertically)? Or perhaps the mirror isn't clearing the rear of the lens? Do you get the same results using live view? Interested to hear the repair man's explanation.
I used other lens that day and they worked great, and after that, so i do not think it is the shutter getting stuck or the mirror either. It was a very curious thing that's for sure. I called today for as update and it is still in line for servicing, i wad told 2 weeks. Frustrating as I am hoping to go to Yellowstone this Memorial day weekend.
Bummer. That would be a great lens for Yellowstone. Still think something on the back of the lens may have been been interfering with the mirror. I remember Canon people putting Pentax K mount lenses on FF bodies. One of the coupling arms had to be shortened on the lens or it would interfere with the mirror and lock up shutter.
Smooth back doesn't necessarily mean the rear element isn't fouling the mirror assembly. Could only happen at infinity or some other focus setting. If it isn't mechanical, perhaps it is electrical? Canon EOS used to have a fatal flaw in the system. Take a lens with no electrical contacts (say a mirror lens) and attach a teleconverter with electrical contacts, the EOS operating system will not fire. No idea if Canon ever fixed this glitch? Perhaps something has changed in the 6D OS? Will a 6D shoot any lens that doesn't have electrical contacts? Other EOS cameras will. Somehow the camera body is being "notified" it is this lens. There are so many ways this happens. Can think of mechanically, electrically, and optically. Any other ways? Repairman hate these "car doesn't like chocolate ice cream" scenarios. Hard to solve.
Probably that happens when those electrical contacts are shortened ... other systems use only a wire for sending commands to the lens, but here are at least two wires for lens communication. A way to protect the microcontroller is to use some serial resistors, but then there must be changes in the firmware to guess when a manual lens is connected. An easy task today.
