Site Sponsors
Results 1 to 9 of 9

Thread: lens not waking up digital back

  1. #1
    Workshop Member Wayne Fox's Avatar
    Join Date
    Nov 2009
    Location
    Draper, Utah
    Posts
    871
    Post Thanks / Like
    Images
    134

    lens not waking up digital back

    I have one lens which for some reason doesn't seem to be working correctly on my arca setup. I'm not exactly sure how the Kapture Group cable works (and why it plugs into the lens), but I'm assuming something is wrong in the lens so the cable/back doesn't detect the shutter tripping. I always assumed the wakeup cable just triggered the back slightly ahead of the camera, seems the sync from the lens would always be slightly after shutter is fully open so using it as the trigger would mean the shutter speeds were slight shorter than set. Maybe that delay is insignificant ...


    I thought zero latency was a mode on the back which made the wakeup cable unnecessary (basically leaving the chip active, with the caveat of short battery life and possibly extra noise), and while I can make a capture this way, the resulting files look really strange ... not sure if that's normal and can be fixed in post or what is going on there.

    So is it the lens? If so, any suggestions/workarounds until later in the year when I can be without it long enough to get repaired greatly appreciated. (fortunately it's my 150 and my least used lens).
    wayne
    My gallery

  2. #2
    Workshop Member
    Join Date
    May 2008
    Location
    NYC
    Posts
    3,275
    Post Thanks / Like
    Images
    7

    Re: lens not waking up digital back

    If a particular lens firing, when connected to the back, does not result in any activity (no error, no capture, no blinking lights) then the issue is likely lens based. Make sure the back is otherwise ready to fire (CF card inserted and formatted, battery not nearly empty) or check to make sure another lens is working.

    Check to make sure the lens that is problematic is 100% closed before firing it. The Copal open/close mechanism is annoying in that it can be 100% open and 100% closed, but it can also be in a precarious middle ground in which the lens will still fire, but the flash sync port is not properly engaged.

    The back normally requires two signals. With a KG 1-shot cable one signal is sent from the cable as you start to push the cable through the micro-switch in the middle, and another is sent by the lens (if the lens is working) upon start of the capture. If you change the back to zero latency it's only expecting one signal rather than two. If you then use it with a KG 1-shot cable you'll be giving it two signals and the second signal messes it up and leaves the colors oddly inverted/funky or creates large streaks in the image. If using zero latency mode you'd want to use a standard lens-to-back cable and trigger the lens with a standard cable release (or the back of your finger).

    I'll be in Provo, UT in a few weeks. Shoot me an email if you'd like to meet up.
    Doug Peterson , Digital Transitions | Email
    Dealer for: Phase One, Mamiya Leaf, Arca-Swiss, Cambo, Eizo, Profoto
    Office: 877.367.8537. Cell: 740.707.2183
    Likes 1 Member(s) liked this post

  3. #3
    Senior Member dchew's Avatar
    Join Date
    Feb 2011
    Location
    Northeast Ohio
    Posts
    971
    Post Thanks / Like

    Re: lens not waking up digital back

    Wayne,
    You might try just connecting the back to the lens PC socket without any wake up device, i.e. use the std Phase cable that came with the back. Fire the shutter once then cock and fire it again within 4 seconds. The first should wake up the back, the second takes the photo. If nothing happens at all then it is probably the lens.

    Dave
    How glorious a greeting the sun gives the mountains! - John Muir

    davechewphotography.com
    Likes 1 Member(s) liked this post

  4. #4
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,803
    Post Thanks / Like
    Images
    564

    Re: lens not waking up digital back

    I have a similar problem with the sync port on a brand new lens/shutter at the moment. The Alpa or KG release will fire the back but there is never a closing pulse at the end of the exposure. The back will time out with a warning and may capture an image with a purple color cast or just nothing.

    As Dave said, try just the regular sync cable against the back in either zero latency or normal. If you get a pulse then the back will at least flash the LED and either capture an image or time out depending upon whether normal or zero. If the sync isn't working you can easily check it in zero latency mode with another lens. That'll prove the back/cable at least are working.

    With the KG, I used to get false releases when triggering in normal mode. It is very sensitive to the timing and smooth pressing of the release otherwise you can get what appears like "bounce" and mis-trigger the back.

    Doug: is there any magic trick with a new shutter to fix perhaps the intermediate state you described? That's eactly how my shutter appears to be at the moment with no sync. I had flicked the preview lever up/down several times but to no avail. The lens is off to the dealer in the morning but if there is something I can try that alleviates what appears to be something like this "stuck" state I'm keen to try it first.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  5. #5
    Workshop Member Wayne Fox's Avatar
    Join Date
    Nov 2009
    Location
    Draper, Utah
    Posts
    871
    Post Thanks / Like
    Images
    134

    Re: lens not waking up digital back

    Thanks for the ideas. I don't believe I have the cable your are referring too I may try a few things to see if I can work around this.

    So am I wrong in that zero latency is intended to be used when there is no wake up cable? I'm thinking my problem with that may have been leaving the KaptureGroup cable plugged into the back, which the back mistook as an end of capture or something. I thought I had used zero latency before when I was shooting the alpa because I forgot the wake up cable and it worked OK.
    wayne
    My gallery

  6. #6
    Senior Member stephengilbert's Avatar
    Join Date
    Nov 2007
    Location
    Santa Monica, CA
    Posts
    2,275
    Post Thanks / Like
    Images
    2

    Re: lens not waking up digital back

    In zero latency, you need the "sync cable:" the straight connection between lens and back, with no wake up button.

    See https://captureintegration.com/produ...digital-backs/

  7. #7
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,803
    Post Thanks / Like
    Images
    564

    Re: lens not waking up digital back

    Wayne,

    If you disconnect the main trigger from the cable release mount on the lens but leave the sync cable in place you should be able to trigger the back just by manually pressing the cable release on the shutter. That'll work in both single release in zero latency and a double release in normal mode. The cable is actually passive and the copal shutter just makes/breaks a sync connection to the back like a switch. I can't vouch for the KG cable but I can say for certain that the Alpa cable release will work this way - you won't use the trigger end at all, just the sync cable part and you use the cable release on the shutter body, not the fancy cable release/block.

    Quote Originally Posted by stephengilbert View Post
    In zero latency, you need the "sync cable:" the straight connection between lens and back, with no wake up button.

    See https://captureintegration.com/produ...digital-backs/
    That's the correct sync cable for normal use (I have several), but in a pinch you can also do what I mentioned above to test things. I don't think that the KG release is any different to the Alpa one. I've had to do this in the field on occasion when the performance unreliability of the KG/Alpa assembly has driven me to distraction and so I've resorted to zero latency but didn't have the simple cable with me (or typically just buried in the bag).
    Last edited by GrahamWelland; 22nd September 2014 at 23:05.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  8. #8
    Workshop Member Wayne Fox's Avatar
    Join Date
    Nov 2009
    Location
    Draper, Utah
    Posts
    871
    Post Thanks / Like
    Images
    134

    Re: lens not waking up digital back

    so somehow in my travails something seemed to have “fixed” my problem. Trying Grahams suggestion of using a separate cable for the actual release worked fine. I w as puzzled as that seems to imply the back was still getting a trigger form the lens sync. So using a flash I tried to determine if the lens sync was at least occurring while the lens was fully open. I had trouble getting the flash cables pc connection into the lens, kept falling out, as though I couldn’t insert it far enough. On the third try felt like something sort of “gave way”, and the connection became much more like I would expect. Flash sync appeared normal. And suddenly the lens is working perfectly.

    So apparently something was askew in that connector, which seems to have “fixed” itself. Hopefully I didn’t damage something else by forcing the connection. At least I can use the lens for now.

    Don’t like the lens much anyway, have been contemplating getting a better quality lens between 150-180mm. I hear the schneider 150 is pretty sweet. I’ll have to search the forums, I think I remember this being discussed a few times.
    wayne
    My gallery

  9. #9
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: lens not waking up digital back

    Sounds like something was in the sync socket and got pushed through. Could have been sand or dirt but I'm guessing now that is floating around inside the shutter. Probably needs service to be sure.

    I use both the old and new Schneider 150 on my Cambo. The digital version is a better lens but both work very well. The older version is a little sensitive to flare so it needs good shading on long exposures.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •