Upon thinking about it, I find yesterday’s corner color cast results with the M-mount lenses on the a7R pretty depressing. We’ve already seen that lenses long enough to require a lens collar – or even, I suspect, mounting to the tripod via a plate on the adapter — have a problem on the a7R because of shutter shake. Now we see that M-mount lenses as long as 50mm suffer from quite noticeable corner color casts on the camera.
What does that leave us with?
- The 75, 90, and 135mm Leica lenses, plus Zeiss equivalents
- F-mount and Canon lenses of 180mm or shorter, and not real heavy ones at that. Forget the Zeiss 135mm f/2, and the Zeiss 100mm f/2, since they both need you to use the tripod plate on the adapter to avoid putting too much strain on the a7R lens mount.
- The Sony/Zeiss E-mount lenses
That’s a slim slice of Leica glass. [Addition: As is pointed out in a comment below, I’ve reached my conclusions about the 50mm and 35mm focal lengths based on the lenses available to me for testing. Others have reported good performance at 50mm and 35mm using different Leica lenses.]
I’d just as soon use F-mount lenses on the D800E. The a7R offers better live view and the EVF, but using those lenses on the D800E allows mirror lockup, autofocus, and auto-diaphragm. I find auto diaphragm especially hard to give up in many situations; the last preset lenses I owned were a Komura 200mm and a Spiratone (remember them?) 25mm in the sixties, and I’m not anxious to return to those not-so-halcyon days, although I’d consider it a good trade if I could have my 20-something body back.
Then there are the E-Mount lenses. The full-frame E-mount line is barely getting off the ground, so there’s not a lot to choose from. The 35mm? I’d rather use an RX-1. The 55mm, when it finally starts shipping? Not my favorite focal length. And besides, I’m not ready to buy into a new set of lenses based on what I’ve seen in the a7R. Sure, it’s small, and I grant that the very nice built-in EVF is the wave of the future. But the haptics of the controls? Yuk. And the menus? Double yuk.
So that leaves me looking for some way to make 50mm and shorter M-mount lenses work, and I have a promising direction. The beta, as-is, don’t call us if you have any problems, Adobe Labs corner cast correction plug-in for Lightroom has a mode that may make the correction workflow tolerably easy, and eliminate the need for field record-keeping.
If you tell it to, the plug-in will scan a group of images looking for interleaved correction images, and will automatically use the correction images on adjacent (forward? backward? TBD) real images. My guess is that it does the detection based on average spatial frequencies in the images.
So, you’d find a scene, and make some exposures. Then, without changing the f-stop or distance, you’d slap a diffuser over the lens and make a correcting image. Then you’d move on and do it again. Sounds like it might work. I’ve ordered a couple of diffusers to try.
In the meanwhile, there’s comer color smearing to worry about. I’d had to go to a lot of trouble to fix the color casts and be left with unusable images because of the smearing. I’ll start testing that next.
This is not an easy camera to like.
Jim, it seems that you’ve concluded that all range finder 50mm lenses will be problematic by extrapolating your results with one lens – your 50 Lux. From looking at the test images done by many posters on the Fred Miranda alternative lens forum, it seems clear that the 50 Lux does have some problems as does the ZM 35/2, but many other 50 mm RF lenses and some 35 mm RF lenses have no problems. I have tested my 50 Cron and ZM 50/2 on my A7r and have seen no corner color cast or smearing that would in any way be visible on a print. As far as 35’s, the CV 35/1.2 seems perform very well on the A7r also.
Would that make the A7 a better all-around camera in your mind? It plays better with shorter M-mount lenses and has electronic first curtain for help with longer lenses. Add in a faster burst rate, OSPDAF and maybe it’s the one to get.
Or is the resolution and better overall sensor worth the downsides?
Jeff,
You’re right. I’ve been hasty. My only excuse is that I have no other 50mm or 35mm RF lens available to me other than the two I tested. If I had a different lens inventory, I could easily have come to different conclusions. I’ll insert a comment to that effect in the post.
Jim
Since you have the 5o Lux and ZM 35, the A7r isn’t a great solution for you to use RF lenses on a non Leica camea unless you want to buy some different lenses. Since my most used RF lenses are the CV 35/1.2, 50 Cron and 90 Cron, the camera is working really well for me.
Another difference is that I’m using Capture One instead of Lightroom/ACR and setting up a lens correction profile in C1 is very easy, so my 28 Cron isn’t that difficult to deal with. It’s also easy to track, because I do a different lens correction profile shot every time I use the 28 Cron for the light and aperture at that set of shots. So, for example, if I’ve taken 4 shots with my 28 Cron at f5.6, the shot of my Expodisk (or Pringles cap) that immediately precedes those shots is the one that I use for the LC profile for those 4 shots.
Jeff,
More Leica lenses: thanks, but no thanks. I’m thinking I’ve already gone too far there. Capture 1 workflow. I hear you. See the next post.
Jim
Jon,
The plain a7 might, as you suggest, be better for my intended use, although, for many things, it’s not as good as the similar-resolution M240. The EVF is better, and it’s smaller and lighter, and it has less noise and no green shadows, but there’s no RF, the controls and menus are inferior (although I don’t love either on the M240), and it has the AA filter. I was hoping to get D800E resolution and IQ with Leica lenses, and the A7R doesn’t do that across the board.
Jim
Wow… Jim, Jon and Jeff. Our simple names are starting to get confusing! Jim, just to clarify, I wasn’t suggesting that the A7 would be better for you in particular, it was more me struggling with my own decision. I’m a fairly basic hobbyist who likes to take family photos of my young kids generally, but the hiccup is that I’m a golf writer and the A7r would be incredible on the course.
Jon, if your golf images are intended for normal magazine-quality publication, the a7 resolution should be just fine. If your printer wants 300 ppi images, the a7 will go to 20 inches in the long direction. If they want 450 ppi, that’s still 13 inches in the long direction.
For golf, wouldn’t you want a camera with a quieter shutter? The RX-1 shutter is marvelously quiet, if a fixed 35mm lens will work for you.
Jim
You write, “Forget the Zeiss 135mm f/2, and the Zeiss 100mm f/2, since they both need you to use the tripod plate on the adapter to avoid putting too much strain on the a7R lens mount.” How do you know this?
I contacted Sony, and they said that the lens mount can handle 2.5 pounds, including a Canon 17mm TS-E with a Metabones III adapter. I’m interested to hear your take on this, Jim
I was just guessing, based on the amount of material and how much flex there is. Nice to have a number from Sony. Thanks for the information.
What puts the strain on the lens mount is the torque exerted by the lens, which depends not only on the weight of the lens but also on its length, or more precisely, its center of mass.
OBTW, the Zeiss 135mm f/2 and the Metabones adapter together weigh half an ounce over Sony’s limit.
Jim
You’re welcome, and thanks for your answer.
Yes, both f/2 Zeiss telephotos you mentioned are longer than any TS-E lens. The longest and heaviest TS-E, the 17mm, is 3.5 ounces lighter and 21mm shorter than the Zeiss 135mm f/2. Funny thing is that the center of mass of the 17mm TS-E might be about as far forward as the Zeiss 135, agreed?