Any experiences with the Sinar Xact back?

[Theodoros]

From what I am told the Sinarback 86, which is the same sensor as xact but just 4 shot,
produces very comparable results to the 54H in 16 shots.

So the Xact in 16 shots should be the xtreme?

From what I hear, there are people that although they have a successful process when they do 16X with their 22mp backs, the result is softer than what they get when they do 4x with the same backs… Clearly they are doing something wrong and although there is no vibration detection from software, they do have vibration "within the error limits" of the software… 16X result should be unbelievable… With a 6micron back, I expect the 16x process (as Steven confirms) to be even more demanding…

PS: If 86H produces very comparable results for some when compared with 54H shot at 16x… I believe they are doing something wrong with their 54H… with 54h shot at 16x, you have much larger pixels and much more resolution, it easy to conclude that the result (if the process is done correctly) should be clearly better.

[torger]

"6um"?  

6 micrometer technology. Dalsa made 9um, 7.2um and then 6um. They exist in various sizes but if sensor share the same pixel size they have the same properties, but digital back surrounding electronics has meaning too in the performance of course.

The P40+, P65+, IQ160, IQ140, Credo 60, Credo 40, Aptus-II 8, Aptus-II 10 and these Sinar backs etc all share the Dalsa 6um technology.

[Theodoros]

6 micrometer technology. Dalsa made 9um, 7.2um and then 6um. They exist in various sizes but if sensor share the same pixel size they have the same properties, but digital back surrounding electronics has meaning too in the performance of course.

The P40+, P65+, IQ160, IQ140, Credo 60, Credo 40, Aptus-II 8, Aptus-II 10 and these Sinar backs etc all share the Dalsa 6um technology.

Don't think on "single-shot" terms… there is no interpolated colour processing with MS, so "colour processing" is not depended on software or processor advance as it does with single-shot.

[torger]

Actually the sensor is the same as the P65+/IQ160/260, only cropped down to 36x48mm and 48mp.

IQ260 is slightly different as far as I understand, but yes otherwise the same. It's the 48x36mm crop size I'm missing in a normal non-tethered back. I think 48x36/48 megapixel is a very good tradeoff for field work with a tech cam, a full-frame 60 megapixel is more expensive and I think it's a less good tradeoff concerning movements. Only the CFV-50 with the Kodak 49x37 50 megapixel sensor has this desirable tradeoff in a standalone back.

[Theodoros]

Steve,
Maybe you know - do these Sinar Xact backs come in either the Rollei 6008 or Hy6 mounts? 


I've compared quite carefully my Leaf AFi-ii 12 (80mp) vs the CF 528 (22mp) in 16 shot mode on some art reproduction work of priceless paintings (which I can't share) using the same exact lens the Rollei Schneider 90mm APO Macro and the results are quite close - so close the processing makes the difference - but you have to use detail recovery software on the Leaf to have it match the CF 528.  Interestingly, when you apply the same recovery software on the 528 files you can't pull up the same gains, probably because it was so much better to start with.   The 528 has more DR than the Leaf in multishot mode and probably better color detail, but its possible that more accurate larger color could be coming from the Leaf.  The multishot just picks up subtle details the single shots can not.  Even with the 22mp m/s back, the only contest the 80mp comes out clearly ahead is in workflow and ease of use.

I regularly use my CF 528 as a 'scanner' for negatives and for this work, the 4 shot or 16 shot modes are ideal.  Compared to scanning the 16 shot mode isn't all that bad and I prefer the results to my 80mp back in this application as well. Occasionally the film grain messes up the multishot math in a few spots, so this is way more tedious than a single shot, but I do it because well I think this is an area where you see the difference.

I would expect the 48mp multishot back to produce some stunning files when used in the right application.

 

Eric, I know you are quite experienced with MS which is a "routine" process in your work, but I think that if you find resolution (just) comparable with am 80mp back, you may have something further to improve in the set up… It's not enough to have "no error detected" (i.e. a successful process with "flexcolor") to get the maximum out of 16x, there is some performance latitude too, which the software cannot detect.

[henrikfoto]

90% (unless the distance to subject is limited by factors that one cannot overcome, I use the Zeiss 120macro APO at f11 or f8 on Contax 645…

Interesting. I have a Contax and the 120 apo, but have never tested it with the 54H.
Except for the right adapter for the back, what else do I need?
Just a sync-cable from the lens to the back?

[Theodoros]

Interesting. I have a Contax and the 120 apo, but have never tested it with the 54H.
Except for the right adapter for the back, what else do I need?
Just a sync-cable from the lens to the back?

I have never used 54H with the Contax either… the back that I use is the same as Eric - the Imacon 528c - which I assume it is equal to 54H, since they are using the same sensor, both do 4x and 16x captures and they address to the same use (other than that the 528c is also able for untethered single shots like other single shot backs at the time (P25, Aptus 22, …etc)). But… I do have the 54H adapter for use with the Contax (I am planning to add a back up for my Imacon) and having the Imacon, I can tell you how it works with the Contax… So…, you obviously need a FW cable to connect the back with a computer (obviously I can only advise on the FW version of the back) and you need an extra cable (it's included with the adapter plate) so that the back fires the camera's focal plane shutter (it is plagued in the remote release prong socket of the Contax) for multishot, since Contax doesn't have this communication provision included among the CPU contacts with the back… that's all you need (nothing but the FW connection if you find a complete adapter kit as it was produced from Sinar). It is also the same with my Fuji GX680, you need a dedicated cable which plagues in the Fuji's multi-pin remote release socket, so that the back can direct the (this time leaf) shutter to perform the 4x or the 16x sequence.

[EricWHiss]

From what I hear, there are people that although they have a successful process when they do 16X with their 22mp backs, the result is softer than what they get when they do 4x with the same backs… C

I've never heard that and it isn't my experience.  I more reliably get 4 shot captures than 16 shot, but when it's working the 16 shot has twice the linear pixels (4 times the resolution) so its no way going to be softer.

I've got the CF version of the 528 so it can store directly to the CF card.  What I've never understood is why  I couldn't do a multishot untethered and have it do the processing later.  This would be on my wish list for MS backs.

[Steve Hendrix]

From what I hear, there are people that although they have a successful process when they do 16X with their 22mp backs, the result is softer than what they get when they do 4x with the same backs… Clearly they are doing something wrong and although there is no vibration detection from software, they do have vibration "within the error limits" of the software… 16X result should be unbelievable… With a 6micron back, I expect the 16x process (as Steven confirms) to be even more demanding…

PS: If 86H produces very comparable results for some when compared with 54H shot at 16x… I believe they are doing something wrong with their 54H… with 54h shot at 16x, you have much larger pixels and much more resolution, it easy to conclude that the result (if the process is done correctly) should be clearly better.

I've never heard that and it isn't my experience.  I more reliably get 4 shot captures than 16 shot, but when it's working the 16 shot has twice the linear pixels (4 times the resolution) so its no way going to be softer.

I've got the CF version of the 528 so it can store directly to the CF card.  What I've never understood is why  I couldn't do a multishot untethered and have it do the processing later.  This would be on my wish list for MS backs.

I believe part of this perception comes from (at least my impression) that there is more algorithmic sharpening applied (whether it shows in the sharpening tool or not) on the Hasselblad 16 shot capture vs the Sinar 16 shot capture).

The multi-shot capture cannot be produced without tethering to the computer because the digital back lacks the processing capability - the infrastructure of the digital back would need a significant boost to perform this in camera.


Steve Hendrix
Capture Integration

[Theodoros]

With painting reproduction, I only do 16x no matter the size of the painting… I have 100% success with all my shots, no matter if it is the Contax or the Fuji-GX680 the camera I use… for me, multishot is nothing more than what a long (longish) exposure would be, With the Fuji, I get pink cast at speeds lower than 1/2 a second, so that is the lower I use, with the Contax, I can use shutter as low as 8" (all the way) for all continuous shots… but it took a lot of head scratching to achieve all that… I have to say once more that many people think that they are doing successful 16X because they see an impressive result... but what they don't realise, is that there is some "error tolerance" which makes the outcome (although impressive) much softer than what it would be if it was perfect... Comparing 16X with an 80mp back (only for sharpness - there is no comparison for colour) is a good way to find out how successfully the process was performed… if the result is comparable, the process can be improved further… when a 16x shot is perfect, there should be a clear difference from any single shot back of 80mp count, a difference that would be as obvious as it can be… Perfect 16x with a 22mp back, can beat a Cruse scanner for a painting of more than a square meter size….

[henrikfoto]

Can you give a few hints what you work with in your setup to keep it all steady?

Mirror up
Heavy tripod
Steady floor (is it possible on a wooden floor you think?)

And what else? Do you use a gyro or other things to keep it all steady?

[Theodoros]

Can you give a few hints what you work with in your setup to keep it all steady?

Mirror up
Heavy tripod
Steady floor (is it possible on a wooden floor you think?)

And what else? Do you use a gyro or other things to keep it all steady?

Mirror-up is not possible with either the Contax or the Fuji… with the Contax, one may use tape to lock it up after he has set things up… with the Fuji, I've applied some rubber damping behind the mirror frame for the mirror return position and on the corners of the mirror for the mirror up position, the most important part though is the tripod… (for accurate focusing one must learn to use the awful "live video" function).
One has to understand that sturdy tripod is not enough for correct multishot… you see, the problem is not the same as in long exposure with single shot… What one needs for "multi", is a tripod (not a stand) that has as fast mechanical earthing design as possible, in other words, a tripod that "sucks" mechanical energy from the camera and earths it at light speed and additionally, it prevents (blocks) energy from the environment to enter the system... I use a 45 years old tripod made for professional cinema capture… (the maker is Fatif of Italy). If you think about it, with cinema there is the same problem (even more demanding) since what you have there, is continuous shots at a fast frame rate of a constant scene… Both my Manfrottos (the top models and heaviest duty head) are great for long single shot, but completely useless for multishot, same thing with other modern great tripods that are great for long single shots.

[EricWHiss]

Normally I have no trouble doing 16shots with my profoto strobes, however once I used some big flat daylight fluorescent light panels which messed it up and only four shot was possible.   Vibration is usually not an issue, but once in a gallery the owner kept walking right up to the base of the tripod on the old wooden floor boards and that caused it to hiccup.

[Theodoros]

Normally I have no trouble doing 16shots with my profoto strobes, however once I used some big flat daylight fluorescent light panels which messed it up and only four shot was possible.   Vibration is usually not an issue, but once in a gallery the owner kept walking right up to the base of the tripod on the old wooden floor boards and that caused it to hiccup.

What we were discussing Eric, is not how to have the capture done (that's not difficult to achieve), but rather how one can maximise the result… May I suggest a test? May you borrow a 4-5000 USD professional cinema (Holywood level) tripod and try it against a good quality 500 USD tripod? ….see if anything is improved with the cinema standard one? I bet you my hat, you'll be surprised! The difference can be a world apart… yet in both cases one will not get a "movement detected - image quality may be affected" signal from Flexcolor….

[henrikfoto]

So the tripod you are using is something like Sachtler with a fluid video-head?
In carbone fiber?

[henrikfoto]

Normally I have no trouble doing 16shots with my profoto strobes, however once I used some big flat daylight fluorescent light panels which messed it up and only four shot was possible.   Vibration is usually not an issue, but once in a gallery the owner kept walking right up to the base of the tripod on the old wooden floor boards and that caused it to hiccup.

Hi Eric!

So the light panels did not work for 16 shots?
Maybe the flash is better because it freezes the object better? Or shouldn't
that be important in stills?
I ask because the last days I have been testing a setup with 16 shots, Sinar and a light panel.
I am not happy by the results, but I thought that might be my wooden floor.
So maybe it's just the wrong light...

[Chris Gahran]

Put a glass tumbler nearly filled with water on your floor and see if the surface of the water is calm or shows movement. This simple test can be an eye opener.

I am not sure 16-shot is possible on wooden floors. My 16-shot images have always been on cement floors using a big studio stand or a Gitzo Studex Giant with a sandbag around each leg.

[Theodoros]

So the tripod you are using is something like Sachtler with a fluid video-head?
In carbone fiber?

My point doesn't have to do with the tripod maker or the materials used, but rather to the fact that the additional equipment (the tripod for example) that is needed to maximise the result, has been designed having other uses in mind... With MS one has energy production repeatedly in the system, as long as the process lasts, while in a long exposure single shot capture, you only have energy produced once… So, since there is no dedicated tripod designed for MS, one has to test as many different solutions as possible and find out which maximises the result. In other words, it's the  system as a whole that has to be perfect to maximise the result, which of course means that having the appropriate MFDB and a great lens, it isn't enough.

Now, going back on to the O/P requirement of e-Xact performance, I suspect (I haven't tried it) that if one manages to have a perfect process with it, the result should be jaw dropping, but if one is already using a 54H (for example) and hasn't maximised the performance of his system, by just replacing his 54H with the much more demanding e-Xact, he may multiply the errors that he already has and end up with inferior results than if he would stay with his 54H… just my two cents.

[henrikfoto]

Would it be possible to see a pic of the tripod you use?

[Theodoros]

Would it be possible to see a pic of the tripod you use?

Sure…  what are friends for?