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Author Topic: Alpa TC21 and Phase MF back?  (Read 12200 times)
narikin
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« on: October 07, 2006, 10:37:22 AM »
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anyone using this combo and can give their advice?
I apprecaite that the Alpa works slightly better with Leaf backs (no wake up issues)
is that a real problem? does the Kapture Group cable release solve it?

need some user advice to help me decide. thanks.
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markowich
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« Reply #1 on: October 07, 2006, 11:16:23 AM »
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the wake-up issue with phaseone backs is an annoyance, but in my view much preferable to the
centerfold problem of leaf. other than that, alpa pairs wonderfully with digibacks and with the schneider digitars.
peter
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narikin
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« Reply #2 on: October 07, 2006, 11:34:18 AM »
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thanks, so is there a handgrip that integrates the KG/Phase cable release into it, like the Linhof anatomical does?  
the tiny finger grips on the TC21 look good, but I cant see how you effectively hold the cable release at the same time.

also are self cocking/ electronic shutters available so you dont need to remember that?
« Last Edit: October 07, 2006, 11:34:36 AM by narikin » Logged
markowich
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« Reply #3 on: October 07, 2006, 11:45:14 AM »
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i  always used the normal (tiny ) handgrip and mechanical shutters. not tooooooooo comfortable but perfectly doable. i hear from alpa/phase that they are developing a new wake up cable though.
peter
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ericstaud
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« Reply #4 on: October 07, 2006, 04:13:36 PM »
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The Alpa system is really a wide angle system.  This is not entirelly clear looking at the camera.  The viewfinder is fisheye (very wide view with curved lines) with masks to crop the image for each particular lens.  The 24mm mask shows most of the  area of the viewfinder.  My 60mm mask looks very small through the viewfinder.  Also, the nature of a range finder on which you estimate focus lends itself more to wide ange lenses with greater depth of field.  

I have used the Phase one on a Cambo wide, which is exactly the same principle as an Alpa ( just a whole lot uglier   ).  You simply press the cable release half way.  Wait for a fraction of a second while the lights on the back will begin blinking. Then you press the shutter the rest of the way.  You will use the cable release all the time with the Phase back.  You will need to anticipate pictures futher in advance to have time to wake up the back.

With the leaf you can use any cable release attached to the lens, or you can press the shutter directly with the nifty release Alpa provides.  If you want to do street, or handheld photography the Leaf is definitely the way to go.  The only special connection is a small sync cable from the back to the flash sync on the lens (don't leave home without that cable).

The centerfold issue on Leaf is no different than the LCC issue with the Phase One backs.  Leaf provides a usefull solution to remove the centerfold just like Phase One has a way to remove LCC.  Both companies have you shooting a white plastic card between shots.  Leaf has promised to provide me with an Aptus 75 which does not suffer from these issues.  When that arrives  I will not be shooting the white plastic card.  I will also not be waiting for the back to "wake up" before captures.  The centerfold effect comes from using non-retrofocus lenses which sit very close to the sensor, and as such, mostly effects architectural or landscape photographers.

It may be possible with the 12TC to shoot a few calibration images and keep them at home for either Phase One or Leaf.  Because you will not be using shifts on the TC you may only need a few images for each lens at different F-Stops.

The Leaf Custom Gain Adjuster which fixes the centerfold issue also can remove Lens falloff the same way you would use a centerfilter.  You dial in the ammount as a percentage from 0% - 100%.  Phase one does not do this.

The Custom Gain adjuster also creates a new MOS file with the falloff and centerfold fixed.  This allows you to take the corrected RAW file to ACR or Lightroom or RAW Developer....

If you have LCC issues with Phase One I believe (don't quote me) that you would be forced to use the C1 Pro software to process the RAW file.

-Eric
« Last Edit: October 07, 2006, 04:16:12 PM by ericstaud » Logged
markowich
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« Reply #5 on: October 07, 2006, 05:39:59 PM »
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The centerfold effect comes from using non-retrofocus lenses which sit very close to the sensor, and as such, mostly effects architectural or landscape photographers.

[a href=\"index.php?act=findpost&pid=79471\"][{POST_SNAPBACK}][/a]

this is not true. the centerfold effect is a consequence of sensor design/readout, it is certainly much more visible with wide angle non-retrofocus lenses. i shall be very happy to receive an aptus 75 without the centerfold effect on alpa/shneider digitar 24mm but i doubt that this will happen without a serious sensor redesign by dalsa (so my chip cowboys tell me).
peter
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vgogolak
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« Reply #6 on: October 07, 2006, 06:34:05 PM »
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The centerfold issue on Leaf is no different than the LCC issue with the Phase One backs.  Leaf provides a usefull solution to remove the centerfold just like Phase One has a way to remove LCC.  Both companies have you shooting a white plastic card between shots.  Leaf has promised to provide me with an Aptus 75 which does not suffer from these issues.  When that arrives  I will not be shooting the white plastic card.  I will also not be waiting for the back to "wake up" before captures.  The centerfold effect comes from using non-retrofocus lenses which sit very close to the sensor, and as such, mostly effects architectural or landscape photographers.


I recently tried the P45 with my contax 645 35mm (pretty wide, against pale sky and had no color cast issues at all)
maybe a Schneider 24 is a different story but 35mm is quite wide on MF

Victor
« Last Edit: October 07, 2006, 06:34:41 PM by vgogolak » Logged
ericstaud
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« Reply #7 on: October 07, 2006, 10:08:01 PM »
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"I recently tried the P45 with my contax 645 35mm (pretty wide, against pale sky and had no color cast issues at all)
maybe a Schneider 24 is a different story but 35mm is quite wide on MF

Victor"

Hi Victor,

It is important to understand that all the people on the forum having trouble with the centerfold effect are people using Non-retrofocus lenses like the schneider digitars on cameras like the Alpa 12SWA, Cambo Wide DS, or Horseman SW-D.  This is not an issue for the retrofocus crowd.  The 35mm lens on your Contax is an entireley diffferent lens design than the 35mm digitar.  The rear element on my 35 digitar sits about 25mm from the sensor.

-Eric
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ericstaud
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« Reply #8 on: October 07, 2006, 10:15:19 PM »
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"this is not true. the centerfold effect is a consequence of sensor design/readout, it is certainly much more visible with wide angle non-retrofocus lenses. i shall be very happy to receive an aptus 75 without the centerfold effect on alpa/shneider digitar 24mm but i doubt that this will happen without a serious sensor redesign by dalsa (so my chip cowboys tell me).
peter"

I don't get the point of disagreeing with me Peter.  "it is certainly much more visible with wide angle non-retrofocus lenses".  Are you implying that there are people with Retrofocus lenses having this issue?  Can you point me to the threads?  As I understand it, this is strictly limited to the non-retrofocus lenses.

As for your second point... I hope it is not true that the redesign will have to occur.  But this is no different than it is with Phase One files.  The rainbow colors of a Phase One image on my Alpa are no more usable uncorrected than the Leaf images with a centerfold line.

-Eric
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zzzone
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« Reply #9 on: October 08, 2006, 02:43:42 AM »
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Can anyone advise whether the centrefold or alternatively the lens cast issue are problems with the Aptus 22 or the P25 backs i.e. those backs with the large sensor sites?

I am in the process of purchasing a MFDB probably to go on a Cambo WDS with the 24 and 35 schneider lens.  So far I have come to the conclusion that the price differential between the A22 and A75 or the P25 and P45 is insufficient to persuade me to go for the lower resolution back.  I had concluded that I would just bite the bullet and go for it, the A75 or P45 being more futureproof for me.

But to buy into these problems described on this excellent forum I would be very disappointed.  The truth of the matter is that my clients would be more than happy with the output from the lower res solution and should either the A22 or P25 not have their respective problem then I would be much happier too!!  The purchase would actually be their respective replacments the A54s or alternatively the P25+

Steve
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marcwilson
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« Reply #10 on: October 08, 2006, 04:07:43 AM »
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Can anyone advise whether the centrefold or alternatively the lens cast issue are problems with the Aptus 22 or the P25 backs i.e. those backs with the large sensor sites?


Steve
[a href=\"index.php?act=findpost&pid=79513\"][{POST_SNAPBACK}][/a]


also do these issues affect aptus 17 backs.
It would be interesting to know..not because that would turn me away from leaf..phasse have their own isues also..but just to be prepared.

Marc
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yaya
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« Reply #11 on: October 08, 2006, 04:25:02 AM »
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also do these issues affect aptus 17 backs.
It would be interesting to know..not because that would turn me away from leaf..phasse have their own isues also..but just to be prepared.

Marc
[a href=\"index.php?act=findpost&pid=79516\"][{POST_SNAPBACK}][/a]

The A17 and A22, using larger pixels and a slightly different sensor design, do not appear to have any centerfold issues and will very rarely show any colour casts with wide-angle, non-retrofocus lenses.

Yair
« Last Edit: October 08, 2006, 04:25:39 AM by yaya » Logged
zzzone
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« Reply #12 on: October 08, 2006, 04:38:17 AM »
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The A17 and A22, using larger pixels and a slightly different sensor design, do not appear to have any centerfold issues and will very rarely show any colour casts with wide-angle, non-retrofocus lenses.

Yair
[a href=\"index.php?act=findpost&pid=79518\"][{POST_SNAPBACK}][/a]


Hi Yair

Presumably I am correct in assuming that this will be the case with the forthcoming A54s back as well?

Steve
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markowich
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« Reply #13 on: October 08, 2006, 04:54:46 AM »
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"this is not true. the centerfold effect is a consequence of sensor design/readout, it is certainly much more visible with wide angle non-retrofocus lenses. i shall be very happy to receive an aptus 75 without the centerfold effect on alpa/shneider digitar 24mm but i doubt that this will happen without a serious sensor redesign by dalsa (so my chip cowboys tell me).
peter"

I don't get the point of disagreeing with me Peter.  "it is certainly much more visible with wide angle non-retrofocus lenses".  Are you implying that there are people with Retrofocus lenses having this issue?  Can you point me to the threads?  As I understand it, this is strictly limited to the non-retrofocus lenses.

As for your second point... I hope it is not true that the redesign will have to occur.  But this is no different than it is with Phase One files.  The rainbow colors of a Phase One image on my Alpa are no more usable uncorrected than the Leaf images with a centerfold line.

-Eric
[a href=\"index.php?act=findpost&pid=79505\"][{POST_SNAPBACK}][/a]

hi eric,
sorry for the confusion, but it was merely a 'philosophical-scientific' issue, i wanted to make the point that the current chip design is at fault. actually, i am not sure whether the centerline effect may also-conceptually- occur in retrofocus lenses, wider than, say 35mm (which to my knowledge are not on the market yet). in any case, my contacts in the chip design community are pretty firm on the necessity for redesigning the salsa chip. unless, of course, a software fix is acceptable. yair just sent me the leaf custom gain adjuster, i shall try it out.
p
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marcwilson
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« Reply #14 on: October 08, 2006, 05:02:24 AM »
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The A17 and A22, using larger pixels and a slightly different sensor design, do not appear to have any centerfold issues and will very rarely show any colour casts with wide-angle, non-retrofocus lenses.

Yair
[a href=\"index.php?act=findpost&pid=79518\"][{POST_SNAPBACK}][/a]


Thanks yair,
That is what I assumed but good to make sure. It is the lack of colour shift etc that is making me lean towards the leaf backs over the phase ones.

Marc
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narikin
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« Reply #15 on: October 08, 2006, 09:40:45 AM »
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i  always used the normal (tiny ) handgrip and mechanical shutters. not tooooooooo comfortable but perfectly doable. i hear from alpa/phase that they are developing a new wake up cable though.
peter
[a href=\"index.php?act=findpost&pid=79441\"][{POST_SNAPBACK}][/a]
thanks for the info (and for staying on topic).
any more info on that cable??

I appreciate that the TC21 is designed really as a wide angle camera, but am surprised they dont make a 'normal' finder available for when you are using a 60-90mm lens, or thereabouts. It's a sweet small package otherwise, and I covet it for that.

As an aside I have to say there is a lot of nonsense written about Phase and LCC issues, it really is only in some extreme lens-camera cases that you see this, apparently. I say 'apparently' as I've not seen it once in 8 months of P45 ownership. (I dont do ultrawide architecture photos, but just about everything else, macro to portrait to landscape). It seems there is some rather petty minded Phase-bashing going on by Leaf owners here, that is not worthy of a pro forum discussion.  The P45 is a great product, a mature and stable workhorse delivering excellent results, and about to get even better with the + version. Mine is on order already.
« Last Edit: October 08, 2006, 09:43:47 AM by narikin » Logged
ericstaud
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« Reply #16 on: October 08, 2006, 11:35:08 AM »
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Hi Narikin,

"As an aside I have to say there is a lot of nonsense written about Phase and LCC issues, it really is only in some extreme lens-camera cases that you see this, apparently."

I have used the P25 and H25 extensively with the 24, 35, and 60mm digitars.  These are not extreme lenses.  I use them every day, as does most every other architectural photographer who shoots medium format digital.  I see heavy LC on EVERY picture.  My experience is about 3 years of Phase One use several times a month.  I have used the Leaf extensively for the past year in addition to the Phase One.  What experience do you have with these backs and the non-retrofocus lenses that lead you to post the above statement?  My experience with these products has been very different than yours.

Regards,

Eric

I also don't see how a discussion of lens cast and centerfold is off the topic of:  "Alpa TC21 and Phase MF back?"  Often people don't ask the pertinent questions about a product they are considering.  The LCC and Centerfold topic will consume much more of your time with an Alpa and MFDB combo than the cable release issues.
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pixpop
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« Reply #17 on: October 08, 2006, 03:57:02 PM »
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thanks for the info (and for staying on topic).
any more info on that cable??

I appreciate that the TC21 is designed really as a wide angle camera, but am surprised they dont make a 'normal' finder available for when you are using a 60-90mm lens, or thereabouts. It's a sweet small package otherwise, and I covet it for that.

As an aside I have to say there is a lot of nonsense written about Phase and LCC issues, it really is only in some extreme lens-camera cases that you see this, apparently. I say 'apparently' as I've not seen it once in 8 months of P45 ownership. (I dont do ultrawide architecture photos, but just about everything else, macro to portrait to landscape). It seems there is some rather petty minded Phase-bashing going on by Leaf owners here, that is not worthy of a pro forum discussion.  The P45 is a great product, a mature and stable workhorse delivering excellent results, and about to get even better with the + version. Mine is on order already.
[a href=\"index.php?act=findpost&pid=79542\"][{POST_SNAPBACK}][/a]

my 2 cents: I use alpa and phase one backs with a few of alpa's wide angle lenses in addition to using a hassy system h2 with their wide-angle lens and other hassy lenses and Never had a LCC issue. I couldn't agree more, the phase backs are workhorses. they're very stable, reliable products. . .in all weather and environmental conditions. coupled with their great software product, C1 pro, IMHO, it's the digital back of choice. i also like the fact that phase are upgrading and improving (significantly) their already existing "p" product line to the +. . . .this is a great move by phase. mine are on order too!

BTW: alpa now has a wakeup/handgrip to take the place of the kapture group cable.

pp
« Last Edit: October 08, 2006, 04:10:22 PM by pixpop » Logged
ericstaud
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« Reply #18 on: October 08, 2006, 04:29:43 PM »
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I was told this is normal performance for the Phase One backs regarding LCC with the super wide lenses....  the 2nd one is corrected (obviously)

[attachment=1021:attachment]

[attachment=1022:attachment]
« Last Edit: October 08, 2006, 04:30:36 PM by ericstaud » Logged
pixpop
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« Reply #19 on: October 08, 2006, 05:26:18 PM »
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I was told this is normal performance for the Phase One backs regarding LCC with the super wide lenses....  the 2nd one is corrected (obviously)

[a href=\"index.php?act=findpost&pid=79580\"][{POST_SNAPBACK}][/a]

the important phrase in your statement is "normal performance". i can tell you that this is NOT normal performance for me. and it seems as though it's not normal performance for many of us phase people. i see that you have corrected it beautifully (i will assume in c1 pro). (with tongue firmly planted in cheek): can you correct the leaf centerfold problem as easily?

pp
« Last Edit: October 08, 2006, 05:26:40 PM by pixpop » Logged
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