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Thread: Newbie: advantages of really long exposure times (>30s)?

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    Newbie: advantages of really long exposure times (>30s)?

    I am trying to decide which digital back I want to save for, and at the moment I am considering the Kodak DCS Pro, the Phase One P21, and similar backs, and finally, after the recent price drops, the Sinar 54LV.

    One difference which I have repeatedly heard about is the Phase One backs' ability to do long exposures. When is this relevant? The Sinar backs are able to do about 30s, which to me seems quite long already. What is a use case for really long times?

    Thanks in advance!
    Carsten - Website

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    Sr. Administrator Jack's Avatar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Hi Carsten -- it can be relevant if shooting in the early pre-dawn or post sunset light, or in dark environs like slot canyons or unlit building interiors. In these situations it is not uncommon for me to have exposures run several minutes. OTOH, if you don't find yourself doing that type of shooting with your present equipment, then it's probably not a concern for you.
    Jack
    home: www.getdpi.com

    "Perfection is not attainable. But if we chase perfection, we can catch excellence."

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    carbonmetrictree
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Hey Carsten, Jack is right on the ball about sunset shots or dark environments. The longest exposure I've ever ran was around 10mins at f/16 ISO50 in a really dark and unlit street at night with a plus series Phase back. Most of my personal work heavily relies on Phase's long exposure capabilities, it would be tough to walk away from an amazing location if I couldn't capture it at the exact ISO and f stop I would like to photograph it at. Though, I've noticed that most of my paid work does not require more than 30 seconds at ISO100 for interior and exterior architecture shots. If it does require more time, then I'm not lighting enough!

    Either way, you'll be happy. A quick way to figure out if you need a Phase back would be to look at your entire portfolio and see how many images are committed to long exposures.

    Good luck!

    Andrew

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    Re: Newbie: advantages of really long exposure times (>30s)?

    I see. Well... I don't have any. On the other hand, I am not getting into this to do the same thing I always did, so I will have to consider it a bit. On the one hand, I am sure my use of the camera in really dark places will be minimal. On the other hand, it would be nice to be able to, and to try. Hmm. Is there some other solution, if, say, I had a Sinar E54LV, capable of going to around 30s?
    Carsten - Website

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    Senior Member Graham Mitchell's Avatar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Only very specialized situations will require more than 30 seconds. That dusk shot which I posted for you was shot at 2.5 seconds at ISO 50 and f8, to give you an idea.

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    thsinar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    hi Carsten

    I second Graham's experience with some other images taken during night. Go here and look at Rainer's work, especially "Suvarnabhumi Bangkok Airport": all the night shots were taken with eMotion 22 (the previous model of the 54), at maximum 20" and f8 or f11 and ISO 25.

    Here:

    http://www.tangential.de/tangential-...humi/index.htm

    Best regards,
    Thierry

    Quote Originally Posted by foto-z View Post
    Only very specialized situations will require more than 30 seconds. That dusk shot which I posted for you was shot at 2.5 seconds at ISO 50 and f8, to give you an idea.

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Definitely specialized and rare to need over 30".

    An hour long exposure may be rare, but on the other hand an hour long exposure is rare! And its easy to be one of the best when almost no one else is doing it!

    Doug Peterson, Head of Technical Services
    Capture Integration, Phase One Dealer
    Personal Portfolio

    P.S. My senior thesis back in college was involved star trails and exposures in this field can last hours.

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    thsinar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    hi Doug,

    Nice!

    Do you mind to share a bit more, technically speaking, about your thesis? Such as camera/capture medium used, technical aspects and issues to take care of, etc ...?

    Would be interested to know, found it always an amazingly interesting subject, shooting stars.

    Thanks and best regards,
    Thierry

    Quote Originally Posted by dougpetersonci View Post
    Definitely specialized and rare to need over 30".

    P.S. My senior thesis back in college was involved star trails and exposures in this field can last hours.

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Quote Originally Posted by thsinar View Post
    hi Doug,
    Do you mind to share a bit more, technically speaking, about your thesis? Such as camera/capture medium used, technical aspects and issues to take care of, etc ...?
    Thanks and best regards,
    Thierry
    It was a year+ long project, and I am a sadomasochist so there were many many technical issues. I'll say a bit about the star trails just to avoid completely hijacking the thread.

    First I shot a single long frame (5min+) for each frame of the output video. But this meant the star trail moved too fast relative to its length for my taste (I wanted to establish a relaxed and aloof sense of time, not a rushed feel). Also, background light became a technical problem at anything past a minute. The ambient light would build up a noise floor that overwhelmed all but the brightest stars.

    So second I reduced the shutter speed for each input frame to 30 seconds and then I combined them into an output frame in the following manner. Each output frame consisted of 30 frames. Each sequential output frame added one input frame and dropped the oldest input frame (i.e. a First-In-First-Out stack). All the frames were set to "brighten" meaning that if any input frame contained a star then the output frame contained a star. This was awesome because it allowed me to adjust the length of the star trail (the number of frames in the stack) as well as the apparent movement speed across the sky (the number of frames added per cycle). However it required an enormous amount of processing time and the process introduced strange artifacts and noise which clashed with the clean white snow shot i wanted to pair it with.

    So finally I used the above technique to create a single frame of a simulated 20 minute exposure and then used a series of photoshop actions to rotate the star field a fraction of a degree around the north star and save as a new image. Repeat this several hundred times and then mask the stars over a standard time lapse of the below horizon content.

    Of course the frame that I used was heavily enhanced. I started off by clipping the histogram at the noise floor and then stretching the histogram to brighten dim stars. Then I switched to LAB and stretched the alpha and beta channels so that the range of colors in the stars was expanded to cover the whole color circle.

    Doug Peterson, Head of Technical Services
    Capture Integration, Phase One Dealer
    Personal Portfolio

    *by the way I made up the exact numbers because I couldn't remember if it was 30 or 35 frames, 5 minutes or 6 minutes etc

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Man viewing it now I wish I had another year and a quarter million to do it again and do it right. It's okay, but the original vision was more powerful then what we were able to produce.

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Quote Originally Posted by foto-z View Post
    Only very specialized situations will require more than 30 seconds. That dusk shot which I posted for you was shot at 2.5 seconds at ISO 50 and f8, to give you an idea.
    Nice shot, btw, Graham. Do you have a perspective control lens for the 6008, or is it software?
    Carsten - Website

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    thsinar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Thanks Doug, much appreciated!

    Thierry

    Quote Originally Posted by dougpetersonci View Post
    It was a year+ long project, and I am a sadomasochist so there were many many technical issues. I'll say a bit about the star trails just to avoid completely hijacking the thread.

    Doug Peterson[/SIZE]

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    Senior Member Graham Mitchell's Avatar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Quote Originally Posted by carstenw View Post
    Nice shot, btw, Graham. Do you have a perspective control lens for the 6008, or is it software?
    That was a stitched pano. No perspective control necessary for stitched panos.

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    Re: Newbie: advantages of really long exposure times (>30s)?

    One nice thing I have noticed shooting the Phase backs which I find really a great feature but the back actually counts time elapsed so you can read it as you are shooting on the back, no need to count when on bulb. Nice thing is you can repeat a shot accurately which is really handy when doing Pano's and such. Not sure the other backs on the market do this but avery useful tool. Sounds trivial but when in the field and in the dark very very handy because you can see the back count.
    Photography is all about experimentation and without it you will never learn art.

    www.guymancusophotography.com

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Funny you mention this, Guy. I felt pretty silly when I finally noticed it after taking a couple of frames and carefully counting because I couldn't see the second hand on my watch. On about the third or so frame I noticed the feature and kind of felt like discretely looking around to see if anyone was laughing at me. (I was in a river canyon and no one was around, but I still sort of had the feeling.) Made me laugh.

    Great feature.

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Truth be told , i did not notice it either for awhile . i was doing the one one thousand, two one thousand and I looked at the back and felt pretty stupid but happy it was there. LOL
    Photography is all about experimentation and without it you will never learn art.

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    carbonmetrictree
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Hey Guy, have you ever noticed if your back counts faster than an actual second? I have to use a stop watch because my back seems to count faster than it should. If I do a 10 second exposure, the back will be around 18-20 seconds.

    Any ideas?

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    Senior Member yaya's Avatar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    Maybe it is counting One, Two, Three instead of One One Thousand, Two One Thousand...
    Yair Shahar | Product Manager | Phase One | Mamiya Leaf
    e: [email protected] | m: +44(0)77 8992 8199 | yaya's blog

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    Administrator, Instructor Guy Mancuso's Avatar
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    Re: Newbie: advantages of really long exposure times (>30s)?

    LOL

    I have not noticed it but will check.
    Photography is all about experimentation and without it you will never learn art.

    www.guymancusophotography.com

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    Re: Newbie: advantages of really long exposure times (>30s)?

    Andrew,

    Maybe your back is set to New York minutes. Perhaps you can check under "settings".


  21. #21
    carbonmetrictree
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    Re: Newbie: advantages of really long exposure times (>30s)?

    lol thanks guys, but I've compared the Phase timer with another digital timer and it is still off. The thing is, when it counts down back to zero for the dark slide shot, the timer counts normally.

    Weird. It has to be a high strung Los Angeles thing..

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