Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: meurten on December 14, 2007, 07:21:50 pm
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Hai
Has anyone experienced, or does anyone know what causes this green part on the right hand side of the photo?
It was shot with an Alpa- schneider digitar 35, with an Aptus 22 back on 30 seconds.
There are three examples all shot in night conditions, no shift. and I have seen it happen more times in same kind of conditions.
Uptill now not in a daylight shootings?
Maarten
[attachment=4254:attachment][attachment=4255:attachment][attachment=4256:attachm
ent]
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Hai
Has anyone experienced, or does anyone know what causes this green part on the right hand side of the photo?
It was shot with an Alpa- schneider digitar 35, with an Aptus 22 back on 30 seconds.
There are three examples all shot in night conditions, no shift. and I have seen it happen more times in same kind of conditions.
Uptill now not in a daylight shootings?
Maarten
[attachment=4254:attachment][attachment=4255:attachment][attachment=4256:attachm
ent]
[a href=\"index.php?act=findpost&pid=160745\"][{POST_SNAPBACK}][/a]
Some magenta cast and some green cast can be corrected using the Leaf gain adjuster software as I'm sure you know. However I don't think it should happen with Schneider Apo-Digitar 5.6/35 mm XL . It does happen to me with Schneider Apo-Digitar 5.6/24 mm XL and Rodenstock Apo-Sironar digital HR 4.5/28 mm using my P45+, also the Aptus75s I borrowed from a friend had a little cast showing but to my surprise less than Phase, but as I said nothing that cannot be fixed with the Leaf gain adjuster software or C1 for Phase.
If you can or if it is not too late to test few more examples of your Schneider Apo-Digitar 5.6/35 mm XL would be a good idea if not the Leaf gain adjuster software should do it.
Did you already processe these files because they also show vignetting, perhaps if to your desire than it is perfectly fine.
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It looks like the long-exposure blooming on the original Canon 1D, which was caused by the amplifiers next to the sensor chip heating the edge and causing a purple aura on one side of the frame. I wonder if something similar isn't happening to your back during long exposures.
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Hai
Has anyone experienced, or does anyone know what causes this green part on the right hand side of the photo?
It was shot with an Alpa- schneider digitar 35, with an Aptus 22 back on 30 seconds.
There are three examples all shot in night conditions, no shift. and I have seen it happen more times in same kind of conditions.
Uptill now not in a daylight shootings?
Maarten
[attachment=4254:attachment][attachment=4255:attachment][attachment=4256:attachm
ent]
[a href=\"index.php?act=findpost&pid=160745\"][{POST_SNAPBACK}][/a]
Did you check out the Gain Adjuster? Leaf released a PDF also regarding problems with color casts with certain lenses..
good luck. it's irritating when you bump into sensor issues.
on the bright side your long exposures seem to be much more pleasant than mine!
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it could eventually has to do with oversensitivity of the dalsa22 sensor to different tungsten light sources, especially to (some) fluorescent lights.
in this respect the dalsa75 behaves much better than the prior chip.
no real cure.
white shading can help but not under all conditions.
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it could eventually has to do with oversensitivity of the dalsa22 sensor to different tungsten light sources, especially to (some) fluorescent lights.
in this respect the dalsa75 behaves much better than the prior chip.
no real cure.
white shading can help but not under all conditions.
[a href=\"index.php?act=findpost&pid=160795\"][{POST_SNAPBACK}][/a]
I know it's a strange suggestion, but I would check the cover glass of the sensor in this special case.
Edmund
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I experienced exactly the same thing sometimes with my A17. Not sure what caused it. It seemed to be some sort of weird fluke that came up now & than. One shot had green on one site and the next one I took did not.
It just happened every now and than.
Sorry not much help, no explanation for it.
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I know it's a strange suggestion, but I would check the cover glass of the sensor in this special case.
Edmund
[a href=\"index.php?act=findpost&pid=160811\"][{POST_SNAPBACK}][/a]
Hi edmund could you tell me why you would chech the glass, or what could be wrong with it?
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Hi edmund could you tell me why you would chech the glass, or what could be wrong with it?
[a href=\"index.php?act=findpost&pid=161061\"][{POST_SNAPBACK}][/a]
It's just an intuition, I think I have seen similar effects with glass slide mounts when I was much younger.
Edmund
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Thanks for the reply's
What is strange to me is that it doens't happen in daylight in combination with a long exposure, and that it only appears on the right hand side.
If it would be the lens I guess it should see in tho other dide as well?
I will try some test shots at night with the back and the alpa 35mm see if I can make it appear again & then with the back on a hassy to see if anything changes.
Any other suggestions for a test?
maarten
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light sources.
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Some magenta cast and some green cast can be corrected using the Leaf gain adjuster software as I'm sure you know. However I don't think it should happen with Schneider Apo-Digitar 5.6/35 mm XL . It does happen to me with Schneider Apo-Digitar 5.6/24 mm XL and Rodenstock Apo-Sironar digital HR 4.5/28 mm using my P45+, also the Aptus75s I borrowed from a friend had a little cast showing but to my surprise less than Phase, but as I said nothing that cannot be fixed with the Leaf gain adjuster software or C1 for Phase.
If you can or if it is not too late to test few more examples of your Schneider Apo-Digitar 5.6/35 mm XL would be a good idea if not the Leaf gain adjuster software should do it.
Did you already processe these files because they also show vignetting, perhaps if to your desire than it is perfectly fine.
[a href=\"index.php?act=findpost&pid=160764\"][{POST_SNAPBACK}][/a]
I haven't really done anything to them yet, only processed them for this forum.
The problem with the gain files under these conditions is the shutter time 30 seconds is the max so it's hard to make a good gain file thats +2 exposed.
maybe there's another way Im not familiar with?
Maarten
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I haven't really done anything to them yet, only processed them for this forum.
The problem with the gain files under these conditions is the shutter time 30 seconds is the max so it's hard to make a good gain file thats +2 exposed.
maybe there's another way Im not familiar with?
Maarten
[a href=\"index.php?act=findpost&pid=161071\"][{POST_SNAPBACK}][/a]
Long exposure was the only reason I went with Phase. As soon as my friend comes back I will use his Aptus again and try to simulate your problem to see if it happens but I tell you now I didn't have any cast showing with 35mm on Aptus 75s no vignetting also.
Did you take a reference shot prior to the ones you made? because I would like to see them.
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I would try a bunch of shots in quick succession. That would eliminate heat as the cause. I'd also double check that your lens and 'film' plane match up evenly. It seems as if the green section has a curve to it which would suggest to me that it is a camera/lens issue. Perhaps then do a bunch of shots with 4 different swings and 4 different shifts (ie up down left right). Maybe try rotating the lens in the lens board as well.
BTW - very nice work - especially your interiors. Are those night shots all done with the Leaf? I'm really interested in the Aptus backs but long exposures has me holding back.
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Now I remember! I had these now & then with my flexbody & A17. It only occured sometimes, so when I noticed I simply took another shot. It never really bothered me until I started using the Flexbody with the Hasselblad CF39. With the CF all my shots ended up weird. It turned out to be a sync problem between the shutter and the back. A lube (CLA) job for the flexbody was all it needed to fix it.
Maybe you have a similar problem?
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You can read a few Idea's I posted before If you do a search on on LL for Leaf Aptus 75.
Its an easy fix, just use a small strobe pointed at the white disc mounted on the camera. I use a small morris type strobes but you can use any cheap strobe.
I haven't really done anything to them yet, only processed them for this forum.
The problem with the gain files under these conditions is the shutter time 30 seconds is the max so it's hard to make a good gain file thats +2 exposed.
maybe there's another way Im not familiar with?
Maarten
[a href=\"index.php?act=findpost&pid=161071\"][{POST_SNAPBACK}][/a]
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Maarten this is an issue related to the sync between the shutter and the back.
If it does it at 30 seconds, try a slightly shorter exposure
You can try another sync cable and if that still fails I would suggest sending your lens for a service.
Yair
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Hello Yair.
I will try nad make pictures with different speeds close to 30 seconds, but do you know if it happends under colder conditions, or could it have anything to do with the humidity?
The lens is a brand new Alpa / schneider lens, so it should be ok, but then again so is the aptus.
thanks,
Maarten
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This looks like something that I have experienced the odd time .. first with a hasselblad V as in this thread...
http://luminous-landscape.com/forum/index....71&#entry144671 (http://luminous-landscape.com/forum/index.php?showtopic=20145&st=0&p=144671&#entry144671)
But then I noticed it later with my rodenstock 35mm (On gottschalt) ... I think it is either a sync problem .. which accounts for most of the mess ups I encounter .. but also maybe me taking the shot again just at the point of the aptus finishing processing a shot ... the problem then persists until I turn the unit off and on again.
Ros
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The green is far to strong on the side to lens cast. Sync errors are generally magenta and often streaky.
These files show pretty well what happens when you hit the exposure limit of the camera, try pushing the exposure even longer and you will begin to see a bunch of hot pixels as well. Try a P45 or any of Phase's +series and you wont see the green error. With the Aptus it will need to be rather cold outside for the CCD to sustain the full 30seconds
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The green is far to strong on the side to lens cast. Sync errors are generally magenta and often streaky.
These files show pretty well what happens when you hit the exposure limit of the camera, try pushing the exposure even longer and you will begin to see a bunch of hot pixels as well. Try a P45 or any of Phase's +series and you wont see the green error. With the Aptus it will need to be rather cold outside for the CCD to sustain the full 30seconds
[a href=\"index.php?act=findpost&pid=161284\"][{POST_SNAPBACK}][/a]
JDG, on the Aptus when you "hit the exposure limit of the camera" it won't save the picture and will produce an error message.
All backs from all makes can suffer from sync errors at various shutter speeds with mechanical cameras and the results can be anything from Magenta/ Green streaks to totally corrupt files.
To "sustain the full 30 seconds" all the Aptus needs is to have the OFF signal happen 30 seconds after the ON signal, regardless of the temperature.
Hot pixels, should they appear, are dealt by LC11
We are all trying to help a photographer here not to sell him a different product....
Thanks, yair
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Yair,
My apologies, I mean no offense!!! I only meant it as a suggestion should he have a shoot requiring longer exposures.
I do not dispute that all backs suffer from sync errors, as they are caused by the lens. I should clarify what I mean by "sustain the full 30 seconds." I am not saying produce an image, but rather an image that is produced optimally. When a CCD is "on" or capturing, heat is produced... as heat increases (as it does on long exposures) the signal to noise ratio becomes worse, producing less than optimal images. (hence the reason for the 30 second limit) Therefore the colder the air temperature, the better the performance of the CCD.
When you say that it wont save the picture and displays an error, is this automatic at a certain time or dependent on image signal to noise?
JDG, on the Aptus when you "hit the exposure limit of the camera" it won't save the picture and will produce an error message.
All backs from all makes can suffer from sync errors at various shutter speeds with mechanical cameras and the results can be anything from Magenta/ Green streaks to totally corrupt files.
To "sustain the full 30 seconds" all the Aptus needs is to have the OFF signal happen 30 seconds after the ON signal, regardless of the temperature.
Hot pixels, should they appear, are dealt by LC11
We are all trying to help a photographer here not to sell him a different product....
Thanks, yair
[a href=\"index.php?act=findpost&pid=161291\"][{POST_SNAPBACK}][/a]
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When you say that it wont save the picture and displays an error, is this automatic at a certain time or dependent on image signal to noise?
[a href=\"index.php?act=findpost&pid=161304\"][{POST_SNAPBACK}][/a]
After 32 seconds if the back does not receive the OFF signal it'll produce an error message with a long warning beep, regardless of temperature or shooting conditions
Yair
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I can confirm this statement from Sinar's side.
Best regards,
Thierry
All backs from all makes can suffer from sync errors at various shutter speeds with mechanical cameras and the results can be anything from Magenta/ Green streaks to totally corrupt files.
We are all trying to help a photographer here not to sell him a different product....
Thanks, yair
[a href=\"index.php?act=findpost&pid=161291\"][{POST_SNAPBACK}][/a]
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This looks like something that I have experienced the odd time .. first with a hasselblad V as in this thread...
http://luminous-landscape.com/forum/index....71&#entry144671 (http://luminous-landscape.com/forum/index.php?showtopic=20145&st=0&p=144671&#entry144671)
But then I noticed it later with my rodenstock 35mm (On gottschalt) ... I think it is either a sync problem .. which accounts for most of the mess ups I encounter .. but also maybe me taking the shot again just at the point of the aptus finishing processing a shot ... the problem then persists until I turn the unit off and on again.
Ros
[a href=\"index.php?act=findpost&pid=161277\"][{POST_SNAPBACK}][/a]
Hai Ros.
I know of that issue, it creates some weird effects :-)
But that's not it, the time between shots was more than enough, as I checked the composition after every shot, but didn't see the green part :-(
Maarten
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Hai Ros.
I know of that issue, it creates some weird effects :-)
But that's not it, the time between shots was more than enough, as I checked the composition after every shot, but didn't see the green part :-(
Maarten
[a href=\"index.php?act=findpost&pid=161388\"][{POST_SNAPBACK}][/a]
Maarten,
We can go on here on LL for a while, but if you would like to take it forward and have this resolved quickly, I suggest that you contact our support team via leaf.support@creo.com. If you have any issues you should be in touch with Mr. Alex Granat who's the regional manager responsible for your country.
BR
Yair
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Calumet has had a look at the back and restored the gain file in the backitself with a guick service.
Hopefully that's the end of it.
Thanks for all the reply's ande help,
Maarten
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Without wanting to prompt any more replies ... I think it's useful to share problems on an open forum like this .. even though the equipment discussed sometimes gets an unfair amount of negative publicity. For what it's worth, I have found Leaf and Calumet to be extremely good in backup service .. even though I am based in Dublin Ireland, and deal with Calumet in London. This sometimes doesn't get reflected in these forums so Meurten... good to have the follow up story!
Ros
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Yair, please correct me if I am wrong here.
If the problem was a sync issue between shutter and back (as some including myself believed it to be), resetting the custom gain file will not make it go away.
Maarten, in any case let us know.
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Yair, please correct me if I am wrong here.
If the problem was a sync issue between shutter and back (as some including myself believed it to be), resetting the custom gain file will not make it go away.
Maarten, in any case let us know.
[a href=\"index.php?act=findpost&pid=161728\"][{POST_SNAPBACK}][/a]
Ray there is so much that I can do remotely without seeing the setup in my own eyes, which is sometimes (I know you think differently) it is usually helpful to have someone on site that can have a deeper look and consult with the factory there and then.
I am sure that if Maarten continues to experience this issue, Wouter at calumet with the support from Israel will be able to resolve it, be it by swapping the back, lens or whatever else is necessary.
Thanks
Yair
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I had a similar instance of Green and magenta over the whole image on my Aptus 75. I was on a shoot and freaking out in my head with a relaxed smile. I was 2 hours away from Los Angeles on location, and the Leaf rep at the time offered to drive to the location and give me a loaner back. After taking 1/2 break and reloading the software and a few other small things It just seemed to disappear? I did not really question out of fear it might come back . I never saw it again and hope it stays away. It scary not to have a backup digital back on location but seeing the prices dropping to $15,000 used maybe in a year or two I will get a backup back.