Ad
Ad
Ad
Pages: « 1 [2] 3 »   Bottom of Page
Print
Author Topic: A7r on A/S M-Line Two?  (Read 6934 times)
vjbelle
Full Member
***
Offline Offline

Posts: 203


« Reply #20 on: January 28, 2014, 01:55:21 PM »
ReplyReply

I just got confirmation on A7r capability.  You will be able to use Rodenstock 23mm or longer with the A7r.  In Schneider 35mm XL and longer will also work fine.
So this body opens up more possibilities for wide angles, than Canon or Nikon,  given the Sony's shorter lens mount distance from the sensor.
The Arca-Swiss Sony Bellows should be available in February.
Hope this helps.
Rod

Very exciting...... Please keep us posted as to the exact dates and pricing.

Victor
Logged
ffilk
Newbie
*
Offline Offline

Posts: 1


« Reply #21 on: January 28, 2014, 09:30:49 PM »
ReplyReply

Hi gentlemans,

I'm so interested in the performance of the a7/a7r with large format (film/digital)lenses.

 Grin Grin Grin

Logged
EricWHiss
Sr. Member
****
Offline Offline

Posts: 2372



WWW
« Reply #22 on: January 29, 2014, 01:39:43 AM »
ReplyReply

Dunno about the M-line Two, but…I've been looking at this for some customers who want to use the A7R with an X-Act2 technical camera.  I think the way to go is to fit the bellows directly to the camera lens mount - maybe screw a thin disk onto an adapter plate - sandwiching the bellows leather in between adapter and disk.  The camera could be fit to the inside of the rear standard via a bar that attaches to the tripod mount.  Still going really wide probably means using one of the very expensive retrofocal Rodenstock lenses.    The advantage of using a tech camera over say a Canon TSE 17 is that you would have more movement for stitching, etc.   
Logged

Authorized Rolleiflex Dealer:
Find product information, download user manuals, or purchase online - Rolleiflex USA
torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #23 on: January 29, 2014, 01:45:22 AM »
ReplyReply

That the A7r can do Digaron-S 23mm sounds very interesting indeed. This indicates that IQ250 would be able to do the same as it has similar sensor technology.

I would have expected color cast and angular vignetting issues even with these retrofocal lenses, but it's great to hear that it works. But maybe it only works dead in center and shifting cause severe DR loss due to casts/vignetting?

It's looking like the A7r could really work as a poor man's digital back, which is exciting.
« Last Edit: January 29, 2014, 01:51:03 AM by torger » Logged
bradleygibson
Sr. Member
****
Offline Offline

Posts: 829


WWW
« Reply #24 on: February 09, 2014, 11:57:39 PM »
ReplyReply

Thank you for the follow-up, Rod.  I'll give you a call this coming week.

All the best,
Logged

GregShapps
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #25 on: February 27, 2014, 11:42:45 AM »
ReplyReply

Just wanted to inform that I have my A7R up and running on my Cambo Ultima.    It took some rigging and figuring but its working out great.  Connected to the Ultima 35 bellows and not the rear standard board - need to test how wide I can get with it now.
Logged

torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #26 on: February 28, 2014, 03:41:41 AM »
ReplyReply

I've seen that the IQ250 is quite sensitive to crosstalk on wide angles when shifted, the A7r is likely to have the same issue as it's the same sensor technology. This will be seen as residual effect after color-cast correction (LCC) in the form of desaturation of colors in shifted areas, or if more severe as a residual color cast.

The A7r has micro lens offset on the sides to handle wide angles better, this however assumes that the lens is not shifted. This means that if you move the lens center towards an edge of the sensor (or even worse -- move the center of the lens outside the sensor) you can get a sudden uneven increase in crosstalk issues.

Without movements the A7r can probably handle quite short focal lengths though.

Anyway, be sure to check color rendition before assuming a certain technical wide is a good combination with the A7r. This post over at getdpi explains a trick how to check if the lens+sensor combination suffers from crosstalk: http://www.getdpi.com/forum/570913-post78.html
« Last Edit: February 28, 2014, 03:43:44 AM by torger » Logged
Rich_Gale
Newbie
*
Offline Offline

Posts: 2


« Reply #27 on: February 28, 2014, 05:57:34 PM »
ReplyReply

I use the Sony A7R on a Rollei X-Act2. http://www.flickr.com/photos/melting_bloke/sets/72157641407451984/with/12709044765/

infinity capable on 6000 series lenses and with good movement capability due to the 60mm image circle of the medium format lenses on the smaller sensor.  Planned on the IQ250..  but the A7R does everything required and more on this setup.

A shot with the system.  :-
http://www.flickr.com/photos/melting_bloke/12450571104/
Logged
ctz
Full Member
***
Offline Offline

Posts: 179


« Reply #28 on: March 01, 2014, 03:04:18 AM »
ReplyReply

Just wanted to inform that I have my A7R up and running on my Cambo Ultima.    It took some rigging and figuring but its working out great.  Connected to the Ultima 35 bellows and not the rear standard board - need to test how wide I can get with it now.

Greg, can you show us a couple of pics of this rig? Sounds terrific.
Logged
Pics2
Full Member
***
Offline Offline

Posts: 158


« Reply #29 on: March 01, 2014, 03:15:42 AM »
ReplyReply

I use the Sony A7R on a Rollei X-Act2. http://www.flickr.com/photos/melting_bloke/sets/72157641407451984/with/12709044765/

infinity capable on 6000 series lenses and with good movement capability due to the 60mm image circle of the medium format lenses on the smaller sensor.  Planned on the IQ250..  but the A7R does everything required and more on this setup.

A shot with the system.  :-
http://www.flickr.com/photos/melting_bloke/12450571104/

I'm interested in Rollei X-Act2. Can you please tell me what's the difference between this cam and, let's say, Linhof 679cs? Arca Swiss M line 2 looks good, too, but I just can't figure out why Arca didn't include all rear standard movements on this cam.
Logged
torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #30 on: March 01, 2014, 04:10:31 AM »
ReplyReply

I'm interested in Rollei X-Act2. Can you please tell me what's the difference between this cam and, let's say, Linhof 679cs? Arca Swiss M line 2 looks good, too, but I just can't figure out why Arca didn't include all rear standard movements on this cam.

Removing rear standard movements has also been made on the Linhof Techno. The reason for doing so is to increase the parallelism precision which is important when you focus close to infinity (or otherwise have a large depth of field) as any tine parallelism error can show up as blurry sides of the image. It also makes the camera lighter, which is good for field use. In the field the need of rear tilt/swing is less critical than in the studio too.

In a studio when you shoot at closer distance and have relatively short depth of field the parallelism precision is less critical (you won't notice if the depth of field has a tiny residual tilt/swing), and the extra weight is not harmful. I do not think that the Rollei X-Act2 would be a great landscape or architecture camera compared to my Techno, but certainly a much better product photography camera thanks to the extra movements.
« Last Edit: March 01, 2014, 04:14:03 AM by torger » Logged
Pics2
Full Member
***
Offline Offline

Posts: 158


« Reply #31 on: March 01, 2014, 05:28:03 AM »
ReplyReply

Removing rear standard movements has also been made on the Linhof Techno. The reason for doing so is to increase the parallelism precision which is important when you focus close to infinity (or otherwise have a large depth of field) as any tine parallelism error can show up as blurry sides of the image. It also makes the camera lighter, which is good for field use. In the field the need of rear tilt/swing is less critical than in the studio too.

In a studio when you shoot at closer distance and have relatively short depth of field the parallelism precision is less critical (you won't notice if the depth of field has a tiny residual tilt/swing), and the extra weight is not harmful. I do not think that the Rollei X-Act2 would be a great landscape or architecture camera compared to my Techno, but certainly a much better product photography camera thanks to the extra movements.

Thanks for the great info! Yes, I need the camera for studio work, so I'm not well informed about a landscape photographer needs. So, M2 is not for me. Too bad, it looks like a great camera otherwise.
Logged
Rich_Gale
Newbie
*
Offline Offline

Posts: 2


« Reply #32 on: March 01, 2014, 08:39:13 AM »
ReplyReply

indeed, I find the rear standard movements are often used when doing tabletop work.  Though the additional adjustment could be seen as a possible weak link and a hindrance in shooting landscale/archi work I think having live view with capability to punch in in any point of the frame by 14x allows the user the ability to check for issues on longer distance shots that need more critical alignments.  I'd certainly not see the X-Act2 being too cumbersome for paid archi work.  it's a lump of metal that deters me from taking it out for personal work but if I was given a brief to get 10 or so immaculate archi shots at different angles I'd certainly not feel the X-Act would slow the process down at all.  and the smaller sensor of the a7r compared to a 36x48 sensor is going to be less susceptible to the type of misalignments being discussed here.     
Logged
torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #33 on: April 09, 2014, 07:54:34 AM »
ReplyReply

Is there any news about Sony A7r on Arca-Swiss MF-two? Anyone tried it yet?
Logged
bradleygibson
Sr. Member
****
Offline Offline

Posts: 829


WWW
« Reply #34 on: April 13, 2014, 08:52:39 AM »
ReplyReply

I spoke to Rod about the A7R on ML2 back in February; it will be a direct attachment to bellows affair, and was expected in March.  Other commitments have kept me from exploring further, but the first stock should have arrived by now.  Cost with all required bits (I do not currently have the DSLR setup on mine) was approx. $1k.
Logged

RobertJ
Sr. Member
****
Offline Offline

Posts: 586


« Reply #35 on: April 14, 2014, 05:25:21 AM »
ReplyReply

Can someone tell me what flange-to-sensor distance really means?

For infinity focus:  If the lens is in a Copal shutter, is this the distance you must achieve from the front of the lensboard to the sensor, or the front of the shutter to the sensor? 
Logged
torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #36 on: April 15, 2014, 02:26:39 AM »
ReplyReply

For infinity focus:  If the lens is in a Copal shutter, is this the distance you must achieve from the front of the lensboard to the sensor, or the front of the shutter to the sensor? 

If you look at the Rodenstock diagrams flange focal distance is to the front of the lensboard, not sure how to interpret the numbers though... they have different number for their helical focus mounts.
Logged
klane
Sr. Member
****
Offline Offline

Posts: 785

I live in a c-stand fort.


« Reply #37 on: April 18, 2014, 07:30:27 PM »
ReplyReply

Any updates from arca? Any testing with retro wide angles yet?
Logged
Frederic_H
Newbie
*
Offline Offline

Posts: 31


« Reply #38 on: April 25, 2014, 08:37:50 AM »
ReplyReply

You should contact your dealer, I was at Arca this morning and Martin told me it's available.
Logged
torger
Sr. Member
****
Offline Offline

Posts: 1376


« Reply #39 on: April 25, 2014, 09:25:14 AM »
ReplyReply

From the IQ250 testing I've seen which has the same type of sensor technology but a slightly larger pixel pitch (5.3um vs 4.9 on the A7r) I would not be too optimistic about technical wide angles, even the retrofocus Rodenstock ones (which still are much less retrofocus than a typical wide for a mirrorless camera). It will probably perform slightly worse than the IQ250 due to the smaller pixel pitch (unless it's matched with a shallower pixel depth, but I doubt that).

It will sort of work, the huge dynamic range will take care of color casts in a good way, but you'll have quite severe issues with crosstalk meaning desaturated/shifted colors and difficulty to demosaic well for most raw converters due to the crosstalk messed up green channel.

Like the IQ250, the A7r sensor has microlens offset towards the sides, which is designed to better handle wide angles -- but only when they are not shifted. For large shifts the microlens offset will have the opposite effect and cause a sudden drastic loss of performance. You'll also see a large variation in behavior if you have the camera in portrait or landscape orientation, as due to the wiring on the sensor the crosstalk is different horizontally vs vertically.

So I'd say that like with the IQ250 you probably would see surprisingly nice initial results at first, but when you really analyze the results you see a sensor pushed past its limitations, and personally I much rather would use a fuzzier standard retrofocus wide angle lens (like the Canon TS-Es), than put on a tech wide angle and run with these issues.

Still I'm very curious to see what it can do. My guess is that you need to get up to as much as 50mm focal length of the tech cam lenses before the sensor starts to behave well.

A sensor is designed with a specific "critical crosstalk angle", and a lens is designed to not deliver light over a specific angle, if those are compatible it will work well. Unfortunately these numbers are not easy to get from either sensors or lenses, otherwise we could see directly on paper what would work flawless and not. In practical tech cam photography one usually exceed the critical angle a bit though, as the image quality degradation is generally not too drastic for mild crosstalk. You get some crosstalk on a IQ260 with a shifted Rodenstock 40mm too... so it will be a bit subjective what works and not.
« Last Edit: April 25, 2014, 09:34:01 AM by torger » Logged
Pages: « 1 [2] 3 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad