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Author Topic: shift lenses for MF digital  (Read 11545 times)

BJL

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shift lenses for MF digital
« Reply #20 on: January 11, 2007, 04:00:14 pm »

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Once we get high resolution digital view finder's, tilt and shift of the sensor will be the way to go... but don't hold your breath
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The video viewfinder could be provided through an attached PDA (as already used with some DMF backs) or a palm top (or iPhone!), or link to a computer, at least if one is working at a slow, deliberate "larger format" tempo.

One limitation is that current medium format sensors are all Full Frame type CCDs, which can only give preview at the camera's rather low frame rate. But the CMOS, nMOS and interline CCD sensors of smaller SLR formats are probably much closer to having a full speed video-out option for preview in conjunction with remote operation: the Olympus E-330 already has it, so I suppose it cousins the Panasonic DMC-L1 and Leica Digilux 3 do also.
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Nick Rains

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shift lenses for MF digital
« Reply #21 on: January 11, 2007, 06:02:03 pm »

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Kirk,
My TS-E 24 suffers from significant vignetting and poor resolution at the edges and corners. This is not a problem for stitching, however, because the overlap areas are always around the central area of the image circle.

Stitching the 2 or 3 images you get using shift on these lenses is a breeze. The following image was stitched automatically with Panavue's Image Assembler. Nothing could be easier and quicker. I show it here with no modification or crop. This is how it looks, straight from the stitching program.

I have exactly the same rig (and a photo taken from almost the exact same position at Preah Khan!) My solution to the edge falloff is simply not to use the full width of the two frames and crop off the bad bits. I end up with a image 50x24mm which I can live with.

Question about stitching, if it's not OT; how do you use the stitching software to flat stitch? It never works for me, I'm using PT Assembler, and it needs things like roll, yaw and pitch which are not relevant for flat stitches.
« Last Edit: January 11, 2007, 06:04:42 pm by Nick Rains »
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Nick Rains
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Kirk Gittings

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shift lenses for MF digital
« Reply #22 on: January 11, 2007, 07:49:50 pm »

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Question about stitching, if it's not OT; how do you use the stitching software to flat stitch?

Nick,

I am feeling pretty dense today........what is OT?
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Kirk Gittings

BernardLanguillier

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shift lenses for MF digital
« Reply #23 on: January 11, 2007, 07:58:45 pm »

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Question about stitching, if it's not OT; how do you use the stitching software to flat stitch? It never works for me, I'm using PT Assembler, and it needs things like roll, yaw and pitch which are not relevant for flat stitches.
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I have used Realviz Stitcher for flat stitches. This mode is supported, although there used to be an annoying preview bug.

Cheers,
Bernard

BernardLanguillier

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shift lenses for MF digital
« Reply #24 on: January 11, 2007, 08:06:57 pm »

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Hi Bernard
Solution: point camera up or down until shape is correct. Shift sensor to re-compose subject.  (The limited rise and fall of old Linhof field cameras used to require this sort of shenanaghan)

Peter
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Peter,

Yes, you can indeed do this. I use this technique on my Ebony when keeping verticals verticals is key after having used the assymetrical back tilt capability.

Cheers,
Bernard

Ray

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shift lenses for MF digital
« Reply #25 on: January 11, 2007, 10:32:25 pm »

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I have exactly the same rig (and a photo taken from almost the exact same position at Preah Khan!) My solution to the edge falloff is simply not to use the full width of the two frames and crop off the bad bits. I end up with a image 50x24mm which I can live with.

Question about stitching, if it's not OT; how do you use the stitching software to flat stitch? It never works for me, I'm using PT Assembler, and it needs things like roll, yaw and pitch which are not relevant for flat stitches.
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Hi! Nick,
It's a small world, isn't it   . I've got lots of shots of that particular scene, some using the 20D with the TS-E 24 lens, some at 24mm with the Canon 24-105 IS and 5D, and some with the Sigma 15-30 at 15mm. There was a problem with the weather when I was there. The sun kept breaking through the haze and clouds for just a minute or so at a time.

Panavue was the first stitching program I tried, years ago. It seemed one of the best at the time and I've stuck with it. In the meantime, they've improved the program greatly. It now handles huge files in 16 bit whilst also preserving the embedded profile. Having up to 8 pairs of flags at each overlap also helps with difficult images.

I've attached the 'Options' dialog box. Hope this helps.

[attachment=1518:attachment]
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Kirk Gittings

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« Reply #26 on: January 12, 2007, 12:37:32 am »

ray,

 Try the stitch plugin in PS CS3 beta. I think it is superior to anything I have tested.
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Kirk Gittings

Ray

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shift lenses for MF digital
« Reply #27 on: January 12, 2007, 01:26:32 am »

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ray,

 Try the stitch plugin in PS CS3 beta. I think it is superior to anything I have tested.
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Thanks for the tip. I'll try to downlod the program and do a comparison. Unfortunately, Australia's a bit lacking in broadband accessibility. In my situation I'd have to subscribe to a premium priced wireless broadband to get that extra speed. I'm not prepared to pay through the nose for such a service, so I'm limited to a 52kbs connection speed.

But heck!, if it's worth the trouble, I'll download overnight whilst I get my beauty sleep   .
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Nick Rains

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« Reply #28 on: January 12, 2007, 07:28:28 pm »

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But heck!, if it's worth the trouble, I'll download overnight whilst I get my beauty sleep   .
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I'd recommend using a download manager for such a big file. Faster speeds too. I'd agree that the CS3 Photomerge works well - now if there was only some way to 'batch stitch' image pairs, that would be so cool...

Where are you that you cannot get decent broadband? I can get 1.5mbps in Brisbane pretty easily with some suburbs getting 24mbsp.
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Nick Rains
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Ray

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shift lenses for MF digital
« Reply #29 on: January 12, 2007, 07:59:07 pm »

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Where are you that you cannot get decent broadband? I can get 1.5mbps in Brisbane pretty easily with some suburbs getting 24mbsp.
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I alternate between two places; Karana Downs on the river bank and Aratula off the Cunningham highway about 25km before Cunningham's Gap. Two streets away at Karana Downs, broadband over the land line is available. The signal strength at Aratula is pretty good (52kbs on a 56kbs modem seems good to me), but the population density doesn't seem to warrant the cost of modifying the telephone exchange. Wireless broadband is available in both areas, but at a cost greater than I want to pay.

As you can imagine, I feel a bit disgusted with Telstra's broadband performance, especially when, in underdevloped place like Kathmandu and Siem Reap, I sometimes find in an internet cafe I'm getting greater speed than back home in Australia.

The fastest internet connection I've ever experienced was at the new Bangkok airport. Everything seemed almost instantaneous.
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