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Author Topic: How do you stitch shift with a tech cam?  (Read 3801 times)

Rob Whitehead

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How do you stitch shift with a tech cam?
« on: September 05, 2013, 08:53:12 am »

Hi all,

Well, I've now got 30 minutes of experience as a tech camera shooter! Heading off tomorrow on a little expedition and am going to try and get some panorama shots.

I've shot a couple of shift panoramas this evening, raises a couple of questions. I normally shoot rotational panoramas with a RRS pano head.

1. How much do you shift? I'm using a Rodenstock 45mm with a P65. I shot at 10mm and 20mm shift. Looking at the files, I'm not impressed with the edges of the 10mm. I'm guessing about 8mm of shift is what I could use. Obviously this is lens dependent, but are many people getting 10mm plus of usuable shift?

2. Does the camera have to be level? It's generally considered best to do so for rotational shifting as it means less image modification required. Most of the test panos I just shot were with the camera horizontal. Is this best practice for shift stitching or does it not matter because the lens is not moving? Or should I just keep it horizontal and use rise/fall instead of pointing my camera up and down?

3. LCC's. Not as scary as I thought. Used Capture One for the first time tonight after using a tech camera for the first time and...only took two minutes to work out how to do an LCC correction (so for anyone else out there who thinks it sounds difficult, no it's pretty easy once you've got the gear). My question is - is it fine to just shoot this at the same exposure as the actual shot? Or do you need to overexpose (as per M.R.'s article here on LuLa.) I ask because it sounds like an uncertain topic and I found that changing my exposure between shots wasn't great for speed of shooting and introduced the potential for errors when shooting panos.

4. Overall, are shift panos of sufficiently better quality to justify using this method over rotaional panos? Looking at the blurry, smeared edges of my 10mm shift panorama I did wonder if I'd be better off just sticking to rotational panos arund the nodal point. Or what about combining a bit of rotation with a bit of shift?

5. Which program to stitch? I usually use PTGui but tried photomerge in CC tonight - unlike for rotational panos, it actually worked pretty well. Any advantage in using PtGui etc?

Thanks for any advice - would like to get my first 'real' shots right tomorow!

Cheers,

Rob

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Doug Peterson

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Re: How do you stitch shift with a tech cam?
« Reply #1 on: September 05, 2013, 09:26:08 am »

1. How much do you shift? I'm using a Rodenstock 45mm with a P65. I shot at 10mm and 20mm shift. Looking at the files, I'm not impressed with the edges of the 10mm. I'm guessing about 8mm of shift is what I could use. Obviously this is lens dependent, but are many people getting 10mm plus of usuable shift?

That 45 is not the best lens for stitching and is the primary reason why you're seeing softness at 10mm.

Other lenses like the Schneider 60XL Super Digitar or Rodenstock 90HR-SW or the Schneider 120mm ASPH have MUCH more room to shift before you see dropoff in image quality.

You can see a tech camera lens visualizer on our website which will give you a rough idea of image circle size and relative allowed movement. Bear in mind that the visualizer is based off the manufacturer spec so if possible work with a dealer that actually knows the characteristics of each lens (e.g. Schneiders in general fall off in sharpness before their stated image circle while Rodenstock's numbers are more conservative).

2. Does the camera have to be level? It's generally considered best to do so for rotational shifting as it means less image modification required. Most of the test panos I just shot were with the camera horizontal. Is this best practice for shift stitching or does it not matter because the lens is not moving? Or should I just keep it horizontal and use rise/fall instead of pointing my camera up and down?

If it's not level, and you want the final image to be level, then you'll have to crop; the further you stitch the more impact that crop will have. Note the 65+ has a virtual horizon, which can be very useful for getting to a quick level position.

3. LCC's. Not as scary as I thought. Used Capture One for the first time tonight after using a tech camera for the first time and...only took two minutes to work out how to do an LCC correction (so for anyone else out there who thinks it sounds difficult, no it's pretty easy once you've got the gear). My question is - is it fine to just shoot this at the same exposure as the actual shot? Or do you need to overexpose (as per M.R.'s article here on LuLa.) I ask because it sounds like an uncertain topic and I found that changing my exposure between shots wasn't great for speed of shooting and introduced the potential for errors when shooting panos.

Nah, not scary. Mildly annoying sometimes. But not difficult.

Ideally an LCC should be exposed around middle gray erring on the side of bright than dark and at no time clipping any highlight data.

With most lens/back/exposure combinations you can fall well short of this "ideal" exposure for the LCC and still get excellent results. When the results start to fall off the first thing to go is dust-removal, the second thing to go is color correction, the last thing to go is light falloff. When shooting stitch panos it's perfectly acceptable to shoot the LCCs as a group before or after the group of actual captures, especially if you're using a system like the Cambo tech cameras which have detents every 5mm (allowing you to quickly/accurately return to the same position) or you're using the end-range of a cameras movement (e.g. on an Arca RM3Di you are shifting 15mm to the right and 15mm to the left). You can also capture preset selections of movements and create a library. A lot of my tech camera work is done with a left/right stitch with the back in a vertical position with either 0, 5, or 10mm of rise. When I'm shooting that stitch-pattern I don't need to do fresh LCCs as I already have them in the library. If for some reason I wanted to do e.g. 7mm of rise (not 5 or 10mm and crop slightly) then I would need to shoot fresh LCCs as I do not have 7mm rise left-right stitch in my LCC library.

4. Overall, are shift panos of sufficiently better quality to justify using this method over rotaional panos? Looking at the blurry, smeared edges of my 10mm shift panorama I did wonder if I'd be better off just sticking to rotational panos arund the nodal point. Or what about combining a bit of rotation with a bit of shift?

Very different methods each with advantages and disadvantages.

Rotational allows you to use the center of the lens and allows any AOV (even 360 degrees if desired) given enough shots
Shift stitching allows you to see the final composition in-camera, feels (to me) more traditional/direct/tactile, and requires no deformation/stretching/pinching/geometric-remapping of the images to fit together.
Shift stitching requires LCCs
Rotational stitching (with a tech camera) only requires one LCC for a given lens/back/position combination.

Easiest answer is to do several scenes with both techniques and see what you like. Personally I love shift-stitching and find rotational-stitching to be annoying and a necessary evil. Bernard (on this forum) creates beautiful images with rotational-stitching only and seems to enjoy the process (in addition to his wonderful results). So there is no doubt it's down to personal preference.

5. Which program to stitch? I usually use PTGui but tried photomerge in CC tonight - unlike for rotational panos, it actually worked pretty well. Any advantage in using PtGui etc?
[/quote]

For shift stitch no need to be fancy. Drop the files into photomerge and push go.

Paul2660

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Re: How do you stitch shift with a tech cam?
« Reply #2 on: September 05, 2013, 09:51:41 am »

Doug said it all very well, but here are a few more thoughts.

I always shift, either 3 verticals to get a single horizontal, or three horizontals to get a more true panorama.  However even 20mm of shift will not get a real pano. 

With your P65+, you can consider the following amounts of shift (camera in the horizontal position)

Schneider 35mm Super Digitar 8mm to 10mm (much past will have magenta shift, loss of color/sat (non recoverable) and detail smearing (non recoverable))
Schneider 43mm Super Digitar 12mm to 18mm.  (much past 15mm most times will have image detail smearing and loss of color that is non recoverable)
Schneider 60mm Super Digitar 15mm to 20mm even 25mm (overall IMO one of the best shifting lenses on the market).  However it suffers from shallow DOF just like any medium format lens in
                                         focal range.  Tilt helps a great deal here. 

Rodenstock 40mm HW easily 15mm, (would go further if there was not a hard disk inside the lens that causes a non-recoverable vignetting much past 15mm).  You might get 16mm to 18mm
                                          but would have to crop the overall image.  NOTE this is an amazing lens overall.  No color loss, sat loss or detail smearing @ 15mm of shift
Rodenstock 32mm HW  Never shot it but it should be very similar to the 40mm in results
Rodenstock 28mm HR   Amazing sharp lens, but pretty much worthless on shifting much past 5mm as again you hit the disk and the image circle is only 70mm.  On center it's the sharpest wide
                               I have ever shot.  Not filter friendly but there are ways to use them. 
Rodenstock 55mm Not sure of the series here but it's an older lens.  This lens has a huge image circle and is very sharp to the edge. 

If you want a true 3:1 pano, you still will need to rotate around the nodal point of said lens.  This does require you to be level.  No way around that.  It also requires a bit more hardware.  A nodal slider and panning head.  I use RRS for this both their nodal slider and the 360 degee panning adapter they make that fits into their arca mount heads.

The beauty of working with the tech camera solution is you don't have to be level, you can point the camera down and depending on the lens can get up to 20mm of shift.  This is enough to get what I call a short pan or to go vertical and get a huge MP single image made from 3 shifts.  Not to mention that the tech camera wides are the best/sharpest lenses made for medium format currently.

If you are seeing blur at 10mm, I would consider looking towards the 43mm Schneider or 40mm Rod or 55mm Rod.  You will get easily past 10mm of shift with any of these with the P65+.

You can use PTGui, but most times CS6 gets the job done for me.  There was  posting showing softening of the combined edges on pano combos using CS6, I don't notice this but do tend to add a bit more sharpening (photokit creative).  Ptgui works well also and has more features.  Works better if you did a 9 stitch pano, say up 15mm out 15mm 3 across 1 row, center just 15mm 2nd row, and down 15mm across 15mm bottom.  Total is 9 images.  Here CS6 is not as adept at getting the job down, PTgui is a better solution.

The much much bigger issue I run into is color shifting and Capture One's non ability to totally correct it (much worse a problem when blue sky is involved)

Exmaple:

3 shifts, with the 40mm.  Back vertical.  3 separate LCC's processed out.  Capture One still has a bit of a problem color correct the shifted files especially towards the 15mm shifted edges.  I almost always have to go back and do some color tweaking on the files.  However Capture One's color tools do make this very easy.  Hopefully Phase One will tweak this a future release.  There has been a lot written about it especially on the getdpi.com medium format forums.

Personally I love it and no matter where I got I always try to get in a pano as I never know when I will be back there and if the conditions allow it I will shoot for a pano with the tech camera.   

Paul Caldwell
 
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Ken R

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Re: How do you stitch shift with a tech cam?
« Reply #3 on: September 05, 2013, 10:05:09 am »

I have the Rodenstock 40mm HR and I shift up to the 15mm limit of my Arca with my IQ160 back. Awesome quality. When doing panoramas I only need 2 images for a full stitch of the whole angle of view of the lens so I just shift 15mm right, take a shot, shift 15mm left, take a shot, take a LCC shot, shift 15mm, take LCC shot. Thats it. I like to have the least amount of time between shots to avoid any big changes on the scene. With the 70mm Rodenstock HR lens I do the same but do not reach the limit of the lens.
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Paul2660

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Re: How do you stitch shift with a tech cam?
« Reply #4 on: September 05, 2013, 10:43:42 am »

Ken,

That is what I am doing now also as like you pointed out it saves a ton of time especially in harsh light conditions.  The 40mm works great here since it holds all the way to the edge of the frame.  I have taken the 40mm to 18mm of shift by rotating my camera 90 degrees (rm3di).  You hit the hard vignette of the internal disk or whatever it is, but you many times can crop the top/ bottom off and still use the rest.  This of course works closer to a true 3:1 pano after the cropping.

Paul Caldwell
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Rob Whitehead

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Re: How do you stitch shift with a tech cam?
« Reply #5 on: September 05, 2013, 12:06:49 pm »

Great info - gold! Thanks guys.

I've been rotational shifting for a while now with Canons, tried it for the first time with the DF yesterday. As mentioned, use the RRS pano head, also use a nodal slider from RRS. Shooting with the Phase 45mm, doing a lens correction in lightroom (only been using Capture One since this afternoon), and stitching with ptGUI worked well enough.

I'm hoping that shift-stitching will give me some advantage - mainly better quality through less manipulation of the photos being required to make them fit each other. Only had the Cambo since late this afternoon so it was a bit of a rush to work out what a tech cam was (haven't actually seen one before except on the 'Show us your tech camera' thread on GetDPI!), bolt it all together and get out to a half decent spot before sunset! Got about 30 mins of light before having to call it a day.

Pretty happy with the Rodenstock 45mm's sharpness when not shifted, and the stitch gives me a bit more width.

I should clarify, when I talked about having the camera level I meant in the tilt plane. I've usually kept that axis level when rotational shifting. Can't see any reason why I'd have to with a shift stitch, and did take one 4 shot shift sequence with the camera angled down which seems to stitch just fine with photomerge in CC. This is one advantage I see in shift stitching - not as much limitation on composition.

I think I might try a bit of rotation with a bit of shift to see how that works - sure I read about that somewhere a long time back with the Canon tilt-shifts. Anyone tried it? (note: I haven't ever owned a Canon tilt-shift, this is my first time ever with movements.)

Rodie 40mm sounds interesting. It's a HR-series so I wonder if it out-ressolves the 45mm (which is an APO-Sirinar digital, but not specified HR) when not shifted (on a 60 megapixel back)? I was hoping the 45mm would hold up a bit better as it's got a decent sized image circle but 10mm seemed a bit much for it. Will try it tomorrow in some better light and see what I can make it do.

Midnight now so time to pack for the trip tomorrow to Millstream Chichester NP - the P65/Cambo is looking forward to getting into the fray I'm sure. My colleagues I'm heading out with have already told me that the Cambo is 'heinously ugly' and are sorted of freaked out now they've worked out how much a P65+ costs. Particularly as they saw me write off my other camera during our last outdoors trip after it took a somewhat unfortunate and unplanned dip in the waters of the Karijini gorges. Hopefully can keep the Cambo drier :)

Thanks again for the advice. Wasn't expecting to have the tech camera up and running for this trip so it'll be interesting to see if I can get a decent shot out of it.

Cheers,

Rob  


« Last Edit: September 05, 2013, 12:08:50 pm by whitey »
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Paul2660

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Re: How do you stitch shift with a tech cam?
« Reply #6 on: September 05, 2013, 12:36:46 pm »

In my experience the 40mm Rodenstock will out resolve pretty much everything.  Th3 43XL Scbenider is very close by F11.  But the 40mm has a better DOF range wider open. 

You can always rotate bit with a shift.  But again you need to be level. 

What I love about shifting (digital back vs lens) is that it greatly frees up options for composition since I can point the camera down or up and still get 25mm of shift with the 60mm Schneider and close to 18mm with the Rodenstock 40mm

Paul Caldwell
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Rob Whitehead

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Re: How do you stitch shift with a tech cam?
« Reply #7 on: September 09, 2013, 06:00:42 am »

OK, so I got some shift stitch shots in at my sunrise shoot in the Chichester ranges, using the Rodie 45mm on the WRS. The location is 50-100km from the nearest campground via a dirt road (in an area 1600km + from the nearest capital city) - so it doesn't often get shot at sunrise.

Shooting 15mm left +0 EV, 15mm left -2 EV, LCC and repeat all three 15mm to the right.

Main problem as noted above is the detail smearing at the further reaches of shift. The image circle of this lens should be plenty wide enough for this, but it seems that the sharpness at the extremes of shifting isn't great. I still shot at 15mm each way as I figure it doesn't hurt to have the pixels - some images will be OK with lower detail in the sides but most will need it cropped off.

Didn't shoot any 0mm shift shots (just far left and far right). I guess the advantage of shooting a centre image is that you have a single image to use for non-panorama output. Would probably add it if the light wasn't changing fast. Not sure if it makes any difference to photomerge or not (I'm guessing not) to have the third, central image.

I usually use PTGui for rotational stitching but photomerge in CC is working well so far for me.

Based on the results I think I'll probably use the Tech cam/Rodie 45mm again next time (rather than the Phase 45mm), but use rotational stitiching. The main advantage is the detail in the non-stitch shots - it's pretty special. At some stage I'll need to properly test it against the Phase lens, but for today I just put it up against a shot I took when I was last at the same spot, using a 35mm DSLR. Chalk and cheese, makes it clear why all the many inconveniences of tech camera shooting are worth it to some.

I'm pretty tempted, though, based on the above comments to acquire a Rodenstock 40mm Digaron HR. 15mm+ is the amount of shift I want for my purposes (landscape panoramas).

Questions:
1. Is this the best choice in the focal length range for this particular purpose?
2. Is it any sharper in non-shifted use than the Rodenstock 45mm I'm using?
3. Worth getting the tilt swing base plate option for it?
4. Anyone using it with the HPF ring?
5. The Rodenstock 45mm performed well shooting straight in to the rising sun (no flare). This is something I do a lot of. Is the Rodenstock 40mm a good performer in this regard?

Thanks!

Rob Whitehead
Pilbara, Western Australia


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Ken Doo

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Re: How do you stitch shift with a tech cam?
« Reply #8 on: September 09, 2013, 08:27:11 am »

Rob,

It sounds like I have had the same experience as Ken R with the HR40 and HR70, except I use the Cambo WRS.  

I think the new HR40 t/s will be a better lens---it has a great reputation/following for a reason.  I do like having the t/s on the HR40 and HR70 and find it worthwhile.  But you won't be able to use HPF rings on the Cambo t/s panels with these lenses, at least not without a little help from someone like John Milich.  (Look up his work over on GetDPI on the Cambo t/s lenses).  The stock t/s panel knobs get in the way of the ring.  But it can be done!  You do need to be mindful of the sun for flare, but as long as you are aware of the characteristics of this great lens, it's not difficult. Using a lens shade or hood is a great help in difficult light situations.  For panos, you can rotate and stitch, or shift the MFDB---what's nice is having options.

ken
« Last Edit: September 09, 2013, 10:42:04 am by kdphotography »
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Rob Whitehead

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Re: How do you stitch shift with a tech cam?
« Reply #9 on: September 13, 2013, 01:10:59 pm »



Rodenstock 40mm HW easily 15mm, (would go further if there was not a hard disk inside the lens that causes a non-recoverable vignetting much past 15mm).  You might get 16mm to 18mm
                                          but would have to crop the overall image.  NOTE this is an amazing lens overall.  No color loss, sat loss or detail smearing @ 15mm of shift
Rodenstock 32mm HW  Never shot it but it should be very similar to the 40mm in results

 

Thanks for the info all.

45mm Rodenstock is nice and sharp but not the best lens for me I think as I'm really enjoying my stitch shifting.

Based on what I'm reading here, I'm tempted to get a Rodenstock 40mm (with the WTS lenspanel so I can tilt).

Dealer suggested that the Schneider 43mm might be better given that I want to shift stitch. This seems to go against what I'm hearing in this thread.

Can anyone confirm that the Rodenstock 40mm will give me very sharp images to 15mm on a Cambo WRS with a 60 megapixel back? Or is it starting to get a bit soft by 15mm? Any votes in favour of the Schneider for shift stitching given that I want about 15mm of shift both ways?

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Paul2660

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Re: How do you stitch shift with a tech cam?
« Reply #10 on: September 13, 2013, 09:54:05 pm »

The rodenstock will actually do about 18mm of shift at  F8 to F11 with very little loss of both details or sat.  At 16mm you start to bit the disk that rodenstock puts inside their lenses to I guess let the user know that they have hit the edge of the image circle.  Thus causes a hard edge vignette and is not recoverable which is too bad since the lens might get to 20mm on a 60mp back. 

Sk43 will go to About 12mm of shift at f11 before you start seeing loss of color sat and detail smearing.  I have shifted mine to 18mm but it can get very hard to recover all the details.  I use the physical center filter on the sk43.

For shifting the 40mm rodenstock is hard to beat.  It's a heavy lens 2x the weight of the sk43. 

I currently have both lenses but am selling my sk43 since I recently picked up a rod 40mm.

I have used both on a IQ160 and 260.  I feel the Sk43 will benifit more from tilt for increased DOF. 

Paul Caldwell






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Rob Whitehead

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Re: How do you stitch shift with a tech cam?
« Reply #11 on: September 17, 2013, 04:38:41 am »

Thanks paul. I'm currently shooting some shift panos at karijini np (just popped into town to refuel, im phone range so i'm checking lula!)

The infoemation is much appreciated.

Now - 90 mins til sunset...
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