p.10 #1 · Sony A7r some full resolution test shots
sebboh wrote:
i checked the corners on the files dakw23 provided. they all show the same result. that just means things are centered though, they could still be tilting when the helicoid is extended, which would also throw all 4 corners out of alignment.
Which way would it tilt to throw all 4 out of alignment with the same degree? I'm just curious. I just checked the full res and it seems that the FLE (I assume without extension) center is softer than the Macro center. So backward FC (toward the lens) around the corners could be the reason as well. I apologize for nitpicking but I just want to make sure the comparison is valid. This is quite illuminating if it is.
p.10 #2 · Sony A7r some full resolution test shots
hiepphotog wrote:
Which way would it tilt to throw all 4 out of alignment with the same degree? I'm just curious. I just checked the full res and it seems that the FLE (I assume without extension) center is softer than the Macro center. So backward FC (toward the lens) around the corners could be the reason as well. I apologize for nitpicking but I just want to make sure the comparison is valid. This is quite illuminating if it is.
i noticed that too, but i think that is due to focus variation since i assume dakw23 focused at the center point after positioning the adapter helicoid.
gravity would pull the front of the lens down making the top corners front focused and the bottom corners back focused. you would have to measure the point spread to determine if they are all the misfocused by the same amount in the same direction.
p.10 #3 · Sony A7r some full resolution test shots
sebboh wrote:
i noticed that too, but i think that is due to focus variation since i assume dakw23 focused at the center point after positioning the adapter helicoid.
gravity would pull the front of the lens down making the top corners front focused and the bottom corners back focused. you would have to measure the point spread to determine if they are all the misfocused by the same amount in the same direction.
That is definitely a focus variation, and it is my point. If he focused a bit behind the center, that would bring the backward FC corners a bit more into the zone of focus. Then in the next picture, by focusing spot on at the center, the corners would be thrown away from zone even further.
As for the tilting, the way you explained (top front, bottom back) would mean that there will be a portion of the picture along the edge matches the sharpness of the non-tilted one. I don't see that.
p.10 #4 · Sony A7r some full resolution test shots
hiepphotog wrote:
That is definitely a focus variation, and it is my point. If he focused a bit behind the center, that would bring the backward FC corners a bit more into the zone of focus. Then in the next picture, by focusing spot on at the center, the corners would be thrown away from zone even further.
As for the tilting, the way you explained (top front, bottom back) would mean that there will be a portion of the picture along the edge matches the sharpness of the non-tilted one. I don't see that.
Ah that's why I love FM. We are debating the validity of competing criticisms of a test to focus one sub-type of adapted lens two different ways.
p.10 #5 · Sony A7r some full resolution test shots
hiepphotog wrote:
That is definitely a focus variation, and it is my point. If he focused a bit behind the center, that would bring the backward FC corners a bit more into the zone of focus. Then in the next picture, by focusing spot on at the center, the corners would be thrown away from zone even further.
As for the tilting, the way you explained (top front, bottom back) would mean that there will be a portion of the picture along the edge matches the sharpness of the non-tilted one. I don't see that.
your first statement assumes a curved field and your second statement assumes a flat field. other than that i won't disagree.
p.10 #6 · Sony A7r some full resolution test shots
hiepphotog wrote:
Thank you for the test. Just want to make sure, did you check the other corners as well? Extended adapter might cause a slight tilt, so this might be an asymmetry issue.
There's an interesting technique for aligning the camera with the subject plane when using focus peaking. When the camera is not quite perpendicular to the plane, you'll see the a wave of peaking colours move across the screen as you cross the focus point. That wave might move top/bottom or left/right, and by adjusting the tripod head carefully you can remove any directionality to the wave, at which point everything is perfectly aligned.
This is a lot easier than messing around with rulers and spirit levels and worrying about the adaptor's alignment, so that's what I did when taking those pictures.
I'll post the A7r results on a new thread when I have them, as we've wandered some way off the original topic!
p.10 #7 · Sony A7r some full resolution test shots
ebrandon wrote:
Ah that's why I love FM. We are debating the validity of competing criticisms of a test to focus one sub-type of adapted lens two different ways.
Attention ebrandon:
The International Committee Of Posts Of The Year (TICOPOTY) hereby notifies you that your latest, quoted above, was entered in competition with 2.7 million other highly imaginative and thought provoking forum posts.
Please allow us the great honour to inform you that your entry has been chosen to receive the 2013 Post Of The Year Golden Pen Award. In addition to a golden pen, a cash award of $3,000,000 (THREE MILLION U.S. DOLLARS) in your name has been made.
If you would kindly remit TWO THOUSAND TWO HUNDRED NINETY NINE U.S. DOLLARS as a processing and handling fee to our offices in Reno, Nevada, the director of TICOPOTY will release your awards for full and final payment.
Sincerely,
Benjamin Noseworthy
TICOPOTY
[1] All awards final.
[2] Any similarity between the processing and handling fee and the retail cost of a Sony A7r are purely coincidental. Offer void where prohibited by law or common sense.
p.10 #8 · Sony A7r some full resolution test shots
sebboh wrote:
your first statement assumes a curved field and your second statement assumes a flat field. other than that i won't disagree.
, i did make two different assumptions there. In the end, it might be more complex than just simply curving backward toward edges and corners. Definitely want to see similar test on a FF though.
p.10 #9 · Sony A7r some full resolution test shots
michaelwatkins wrote:
Attention ebrandon:
The International Committee Of Posts Of The Year (TICOPOTY) hereby notifies you that your latest, quoted above, was entered in competition with 2.7 million other highly imaginative and thought provoking forum posts.
Please allow us the great honour to inform you that your entry has been chosen to receive the 2013 Post Of The Year Golden Pen Award. In addition to a golden pen, a cash award of $3,000,000 (THREE MILLION U.S. DOLLARS) in your name has been made.
If you would kindly remit TWO THOUSAND TWO HUNDRED NINETY NINE U.S. DOLLARS as a processing and handling fee to our offices in Reno, Nevada, the director of TICOPOTY will release your awards for full and final payment.
Sincerely,
Benjamin Noseworthy
TICOPOTY
[1] All awards final.
[2] Any similarity between the processing and handling fee and the retail cost of a Sony A7r are purely coincidental. Offer void where prohibited by law or common sense....Show more →
p.10 #10 · Sony A7r some full resolution test shots
michaelwatkins wrote:
Attention ebrandon:
The International Committee Of Posts Of The Year (TICOPOTY) hereby notifies you that your latest, quoted above, was entered in competition with 2.7 million other highly imaginative and thought provoking forum posts.
Please allow us the great honour to inform you that your entry has been chosen to receive the 2013 Post Of The Year Golden Pen Award. In addition to a golden pen, a cash award of $3,000,000 (THREE MILLION U.S. DOLLARS) in your name has been made.
If you would kindly remit TWO THOUSAND TWO HUNDRED NINETY NINE U.S. DOLLARS as a processing and handling fee to our offices in Reno, Nevada, the director of TICOPOTY will release your awards for full and final payment.
Sincerely,
Benjamin Noseworthy
TICOPOTY
[1] All awards final.
[2] Any similarity between the processing and handling fee and the retail cost of a Sony A7r are purely coincidental. Offer void where prohibited by law or common sense....Show more →
Wow! I'm so excited. I don't usually win anything.
To show my gratitude I'm willing to let you have my 1DX, 24-70mm f2.8, and 70-200mm f2.8 IS for $300. I have no idea what they're really worth as they were a gift from my granny and they're taking up way too much space here in my bunk at US Army Base Bravo in Afghanistan.
Please send the funds via Western Union to my brother in Spain, and I'll ship the cameras out to you no later than yesterday.
p.10 #11 · Sony A7r some full resolution test shots
That offer sounds great Mr. eBrandon, but I'm travelling through Morocco at the moment and am not sure where I will land next.
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p.10 #12 · Sony A7r some full resolution test shots
hiepphotog wrote: , i did make two different assumptions there. In the end, it might be more complex than just simply curving backward toward edges and corners. Definitely want to see similar test on a FF though.
that test was on a FF sony camera, the vg900 has the same sensor as the a99, but without the mirror. for those of you who are keeping score at home, i'll go ahead and say it: the 75 cron will perform very well on the a7.
p.10 #13 · Sony A7r some full resolution test shots
sebboh wrote:
(...)
gravity would pull the front of the lens down making the top corners front focused and the bottom corners back focused. you would have to measure the point spread to determine if they are all the misfocused by the same amount in the same direction.
I have used the words back- and frontfocus in the opposite way. If the lens points downwards (instead of perpendicular to the the wall, or map I would say the top of the image is back focused and the bottom front focused. I would like to become synchronized with the forum on this one. Which way is it?
p.10 #14 · Sony A7r some full resolution test shots
sebboh wrote:
(...)
gravity would pull the front of the lens down making the top corners front focused and the bottom corners back focused. you would have to measure the point spread to determine if they are all the misfocused by the same amount in the same direction.
Jonas B wrote:
I have used the words back- and frontfocus in the opposite way. If the lens points downwards (instead of perpendicular to the the wall, or map I would say the top of the image is back focused and the bottom front focused. I would like to become synchronized with the forum on this one. Which way is it?
IMO, back focus means the image is focused behind the subject, i.e. the point of focus is in back of the subject. I think that's consistent with your statement. Maybe Derek (sebboh) had a brain fart.
p.10 #15 · Sony A7r some full resolution test shots
jcolwell wrote:
IMO, back focus means the image is focused behind the subject, i.e. the point of focus is in back of the subject. I think that's consistent with your statement. Maybe Derek (sebboh) had a brain fart.
A brain fart is OK, it happens, and Derek is usually clear as water.
I just wanted to know I hadn't got this backwards. Thank you.
p.10 #16 · Sony A7r some full resolution test shots
jcolwell wrote:
IMO, back focus means the image is focused behind the subject, i.e. the point of focus is in back of the subject. I think that's consistent with your statement. Maybe Derek (sebboh) had a brain fart.
p.10 #18 · Sony A7r some full resolution test shots
Very interesting comments here and may I add my thanks to Philip and Ron for their excellent work.
The NEX and MFT lines, as we know, have been instrumental in kindling interest in a whole raft of MF lenses, from LM, ZM an LR through to legacy lenses such as MC/D, OM and FD. The advent of the A7(R) is creating enormous interest in the prospect of using these lenses at their original focal length, rather than at 1.5x or 2x. This is very exciting. However, they were, in most instances, designed for use in film cameras and, up to now, have often produced IQ rather less good than hoped on CLC cameras. The experience on DSLRs using converted Leica Rs and Olympus OMs had been much better, not least because they can be used at native focal length without any evidence of colour shift or smearing. With the A7(R) there is the prospect of reverting to the 60s and 70s film SLR experience with small cameras and small lenses. The joy is in the form factor and the handling. Yet the expectation is that these lenses will be up to modern digital resolution but maybe they wont. It is easy to forget that the resolution constraints of film meant that however theoretically good your camera / lens combination might have been the end result was always defined by the weakest link - film. I would suggest that, flawed as they might be, these results are still by and large better than they would have been with 35mm film even if they have some issues.
There is another consideration here. The advent of the FE mount, even if physically the same size as the E mount, dies not mean full lens compatibility with NEX lenses. There will be vignetting. Now we know that the NEX line is history what forward life can be envusaged for native NEX lenses? They are surely redundant. What value will they have, Zeiss or otherwise? And who is to say tbat the FE mount will be a long-term runner if sales are below expectation? It might be that buyers of new FE native lenses may end up facing the same predicament as thise who have laid out for native E mount lenses. This all suggests to me that the use of adapted lenses will be a safer, and quite adequate, arrangement even if not optiml.
p.10 #19 · Sony A7r some full resolution test shots
waterden, I used to believe that adapted rangefinder lenses were a good hedge against vendor lock in, but I stopped believing that more than a year ago and started selling off my Zeiss RF lenses. I'm not unhappy with those lenses, far from it, but I feared that I was locking myself in by owning glass that was less likely to perform to my expectations on future full frame compact cameras. That future is here, now.
You touch on the reason - many of the RF lenses we've been adapting were designed in the film era. Adapting them to non-native digital bodies is a hit or miss prospect; we can generalize which lenses may *not* work well on a crop or full frame sensor, but in the end we need to test to figure out which benefit from the happy-accident principle of compatibility and which do not. Some lenses will be updated over time to fit into the new digital reality but that's a slow process.
I might have shared your concern about E mount longevity a couple of years ago but no longer. E mount has a growing collection of lenses not just from Sony or Zeiss but from other makers. Sony has a decently large chunk of the compact mirrorless interchangeable camera market. In Japan I believe their share is approaching 30%. APS-C E mount cameras are not going away.
The new FE class lenses, built on top of E mount, do not put E mount in danger, quite the opposite. By adopting E mount you have Sony telling NEX owners they have an upgrade path, and A7 owners can use their FE lenses on APS-C crop cameras. An A7 owner with a NEX-5x in their bag as a backup is not an absurd proposition at all. A7r owners with existing APS-C E mount lenses can use those lenses and get a high resolution APS-C crop image. Even the A7 will deliver useful cropped images.
Sony could maybe have made their designers' lives easier by picking an entirely new mount for the full frame cameras and new line up of lenses, but instead they opted for compatibility and stability of the mount. That should reassure buyers not frighten them.
As far as resale value, Leica RF lenses may hold value more than all of the rest. My expectation is that a used Zeiss M mount lens will not hold its value much more than a high quality used Zeiss FE class E mount lens going forward.
Life is short. Buy the lenses you really like that allow you to achieve what you want to achieve. Buy native glass or adapted lenses for their qualities not for investments or because of fear of vendor lock in.
