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Archive 2007 · interesting focal length/DOF sample
  
 
pere marti
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p.2 #1 · interesting focal length/DOF sample


DrPablo,

No need to be rude. You haven't understood me. About aperture and scaling both f-number and focal lenth to achieve comparable DOF, see here:
http://www.luminous-landscape.com/essays/Equivalent-Lenses.shtml
For sure Mr Charles Sidney explains better than me.

His images were not necessarily slanted inward...

Not necessarily, but they were (at least for the description he made and for the interesting "wrapping" effect of the blurring).

Jun 13, 2007 at 08:06 PM
Daniel Buck
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p.2 #2 · interesting focal length/DOF sample


hm... maybe we should lighten this discussion a bit, I didn't intend it to be so heated :-) Interesting read though, just don't want it to get personal with anyone!


DrPablo wrote:
His images were not necessarily slanted inward. If you use a shift lens, or if you use a bracket that allows parallel shifting, there is no rotation about a central nodal point. Thus, the plane of focus can remain unchanged depending on technique.


The camera was fixed on the ball head, no correction for parallax or shifting around of the camera (and obviously, no lens shifting!), just simple rotation (horizontal and vertical) of the camera on the ball head. However, the camera was angled downward for just about all of the shots (as much as probably 60 degrees!) but for the top row of images I'd say the camera was probably parallel with the horizon. (see the image of the tripod, notice how much higher the tripod is than the hood of the car) This creates kind of the 'sphere of focus', which is why none of the ground is in focus, because the focus area is so curved (due to the camera rotating all around?) the in-focus ground area is actually right at the base of the tripod, (maybe a few feet farther out).

The next one I do, I'll make sure to keep the in-focus ground area visible in the photograph.

Jun 13, 2007 at 09:01 PM
Daniel Buck
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p.2 #3 · interesting focal length/DOF sample


Finally got out to shoot some 'woods' (not the type of woods I was hoping for, but the test worked just fine, no problems stitching!)

Since I was with a group of people, I didn't want to hold them up from hiking, so I only shot about 4 images per stitch. The DOF will get thinner next time, and a wider field of view!

I was wondering how the forest areas would stitch (alot of messy details for the stitching software to possibly get confused with?) but I had absolutely no problems!

Another problem with this setting, the path I was shooting is actually much wider than it looks, it's wide enough for two people to walk side by side. First stitch was taken standing up, 2nd was taken crouched down, but focused much farther away.

Next time I hope to shoot a forest area with large thick trees that give more a sense of scale (which will make for a more confusing/odd image!)



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Jun 17, 2007 at 04:09 AM
nikt
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p.2 #4 · interesting focal length/DOF sample


I must admit that is very cool. Interesting idea, don't know if I've seen it done like that before.

Jun 17, 2007 at 06:23 AM
Daniel Buck
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p.2 #5 · interesting focal length/DOF sample


nikt wrote:
I must admit that is very cool. Interesting idea, don't know if I've seenit done like that before.

I have been wondering this myself? I doubt this could have been done in the film days, so it would have to be done sometime in the past 5 years or so. I have done a bit of searching around, but haven't found anything particularly like this. Only a mention that when stitching things (for the purpose of more resolution) apertures need to be closed smaller to keep the same DOF.

Jun 17, 2007 at 06:28 AM
Graham Mitchell
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p.2 #6 · interesting focal length/DOF sample


Daniel, this is one of the most inspirational threads I've seen in a long time. Great stuff and I can't wait to try it out as well.

Jun 17, 2007 at 08:35 AM
carstenw
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p.2 #7 · interesting focal length/DOF sample


Very cool technique. I have been wanting to do something similar for a long time, but never got around to it. Now you've set my arse on fire What stitching program do you use?

By the way, the version which is getting printed looks a little green. Is that on purpose?



Jun 17, 2007 at 10:00 AM
pere marti
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p.2 #8 · interesting focal length/DOF sample


Really interesting and worth exploring. Nice tunneling effect, specially the 2nd one, although I don't like the colors/lighting (I understand they are test shots). There are countless possibilities playing with the field of view and degree of overlapping.

Jun 17, 2007 at 12:19 PM
DrPablo
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p.2 #9 · interesting focal length/DOF sample


Daniel Buck wrote:
I have been wondering this myself? I doubt this could have been done in the film days, so it would have to be done sometime in the past 5 years or so. I have done a bit of searching around, but haven't found anything particularly like this. Only a mention that when stitching things (for the purpose of more resolution) apertures need to be closed smaller to keep the same DOF.


Really really cool stuff.

It's perhaps a little different, but this can be done with film. With LF even wide angle lenses have a very shallow DOF -- like a 150mm lens is a super-wide on 8x10 (comparable to around 20mm on full frame 35mm or 12.5 on APS-C). So you can indeed get a razor thin DOF with a wide angle.

You can also do it using extreme camera or lens movements if you have a tilt-shift lens or a view camera with movements. Like this one of mine that I captured on 4x5.



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Jun 17, 2007 at 01:18 PM
Daniel Buck
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p.2 #10 · interesting focal length/DOF sample


DrPablo wrote:It's perhaps a little different, but this can be done with film. With LF even wide angle lenses have a very shallow DOF -- like a 150mm lens is a super-wide on 8x10 (comparable to around 20mm on full frame 35mm or 12.5 on APS-C). So you can indeed get a razor thin DOF with a wide angle.

You can also do it using extreme camera or lens movements if you have a tilt-shift lens or a view camera with movements. Like this one of mine that I captured on 4x5.

I have seen thin DOF stuff with large format, but not very often. I was referring to the stitching aspect (when I said can't really be done with film). I have seen the tilt-shift type 'DOF' as well, but that gives a different look.


carstenw wrote:
Very cool technique. I have been wanting to do something similar for a long time, but never got around to it. Now you've set my arse on fire What stitching program do you use?

By the way, the version which is getting printed looks a little green. Is that on purpose?

I use Autopano (autopano.net) and at work we use both autopano, stitcher, and ptgui

Yes, I played with the colors a bit before I sent it to print, put a bit of green in there



foto-z wrote:
Daniel, this is one of the most inspirational threads I've seen in a long time. Great stuff and I can't wait to try it out as well.

I look forward to seeing your results



I wonder, what should I refer to this technique as? "Thin DOF stitching" ?

Jun 17, 2007 at 03:41 PM
carstenw
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p.2 #11 · interesting focal length/DOF sample


Stitching for DOF?

It occurs to me that one can get the DOF effects of large format on any format for which there is at least one lens which gives the thin DOF desired, such as 35mm. Very cool.

I am happy to hear that you use Autopano. I have been playing with this program myself and was almost ready to buy. Now I certainly will. I just need to find the money I have made two large panoramas today with little DOF. I will try to stitch them and see how it goes.

Jun 17, 2007 at 03:57 PM
Daniel Buck
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p.2 #12 · interesting focal length/DOF sample


carstenw wrote:
Stitching for DOF?

It occurs to me that one can get the DOF effects of large format on any format for which there is at least one lens which gives the thin DOF desired, such as 35mm. Very cool.

I am happy to hear that you use Autopano. I have been playing with this program myself and was almost ready to buy. Now I certainly will. I just need to find the money I have made two large panoramas today with little DOF. I will try to stitch them and see how it goes.


Autopano is great! It's handled everything I've thrown at it! And Alexandre is very nice as well, has made the updates that I have requested, and many others as well in a very timely fashion! As soon as the demo version handled a stitch that no other program would (in 2 minutes, no less!) they had my money. That was before stitcher had it's 'auto stitch', I haven't done a comparison since then, however.

Look forward to seeing your results as well

I have done alot of stitching in the past back when I was shooting with a 1D (4mp!!) so I would always stitch for resolution. Alot of times I would use my 135mm and do a 4x4 grid, or 6x6 grid of images. I'll have to try shooting the 135 at f2.0 and see how that one works as well! It won't give quite a wide angle look though.

Jun 17, 2007 at 04:03 PM
Andi Dietrich
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p.2 #13 · interesting focal length/DOF sample


Daniel, like it a lot, made me remember a photographer from Switzerland I met once

http://www.gerardpetremand.ch/index.html



Jun 17, 2007 at 05:39 PM
 



carstenw
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p.2 #14 · interesting focal length/DOF sample


Here is my first attempt. I had a lot of trouble controlling Autopano. It seems to be missing some manual control options, and anyway, I just bought it today, so I am not so used to its tools. That's 36 shots with an M8 and a 50 Summilux Asph, at f/1.4, at about 1.5m.



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Jun 18, 2007 at 12:29 AM
DrPablo
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p.2 #15 · interesting focal length/DOF sample


Daniel Buck wrote:I was referring to the stitching aspect (when I said can't really be done with film).

People have been doing it with film since the 19th century. Not for DOF per se, but for juxtaposing different captures to create panoramas.

Now with Photoshop there are all kinds of possibilities for scanned film. I mean, rather than buying a $6000 Fotoman panoramic 6x17 camera, I could just take three lateral captures with my 6x6 and stitch them after scanning. I could also do that with my 8x10 to produce huge stitched images -- imagine taking a 3x3 set of 8x10 frames and stitching them to produce a 24x30 image that is 24x30 inches at capture size (and with the tiny DOF of the format -- my wide angle on 8x10 is a 300mm lens).

At any rate, that's not to argue for equivalence. I mean there are all kinds of possibilities for stitching with DSLRs and even point and shoot digitals that are worlds more convenient than on film. And you've certainly discovered a very distinctive technique that holds great creative promise!

Jun 18, 2007 at 12:53 AM
Daniel Buck
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p.2 #16 · interesting focal length/DOF sample


carstenw wrote:
Here is my first attempt. I had a lot of trouble controlling Autopano. It seems to be missing some manual control options, and anyway, I just bought it today, so I am not so used to its tools. That's 36 shots with an M8 and a 50 Summilux Asph, at f/1.4, at about 1.5m.


Yes, I'm finding that autopano doesn't take to friendly to photos that are completely out of focus. However, every other stitching program I have tried (I tried stitcher and ptgui tonight) does even worse on defocused images!

Yes, autopano does have manual control point editing. That's not the strong selling point of the software though, from what I gather. Ptgui is probably better for this? I donno, I haven't done to much control point editing in autopano. I suspect I will be in the very near future though! The only bit of editing I have done so far, is select two images (either two already 'stitched' or one stitched and one that wasn't able to stitch) select the areas of both images that overlap, then hit "add control points" so far every time I have done that it has come up with a perfect match, even on defocused points. I've never had to add individual points one point at a time like ptgui. All in all, autopano seems to be exactly like the name suggests, very automated! Even the control point editing. you just kind of hint at what it needs to do, and it does it!

Jun 18, 2007 at 05:21 AM
kgelner
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p.2 #17 · interesting focal length/DOF sample


I'm late to the party I see, but I just wanted to add I find the effect really interesting and I'll be trying it out myself on something or other...


Jun 18, 2007 at 05:40 AM
rico
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p.2 #18 · interesting focal length/DOF sample


I don't know what I'm looking at, but it has Super-Cool written all over it! Thank you, Daniel.

I like Carsten's image very much, too.

Jun 18, 2007 at 06:46 AM
Daniel Buck
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p.2 #19 · interesting focal length/DOF sample


here is one from tonight. I have more images surrounding the car, particularly to the left of the car, and the ground below the car that is in-focus, but I just need to spend some more time stitching them. Compositionally, the in-focus ground probably wouldn't work for this image, being that the car itself would be so high in-frame, however I'm going to try and stitch it all anyway just to see what it looks like. It's quite hard to judge composition when you are shooting cropped images for a big stitch! I guess a good rule of thumb for this would be to shoot wider than you think you need, then crop in after the stitch!

I'm finding that autopano needs to be guided with these extreme stitches. This is the first one that it's really had alot of trouble with outside the car area, almost all of the images outside of the car I had to help autopano along by selecting the areas it needs to place control points in each image link for each image. I think another few hours and I'll have the remain portions of the image finished.




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Jun 18, 2007 at 07:04 AM
carstenw
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p.2 #20 · interesting focal length/DOF sample


Daniel, Autopano does not have manual control point addition. The only thing is this select two areas and hit go workflow. This works well as long as there is some detail somewhere, but when there isn't it can completely fail. I have sent two pairs of images which clearly fit with each, but are out of focus, to the developer, so that he can take a look. I still worry about the totally out of focus stuff, but perhaps simply being able to add manual points and letting the blend take care of the rest would suffice.

Jun 18, 2007 at 02:11 PM
carstenw
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p.2 #21 · interesting focal length/DOF sample


Here is the rose I have been having trouble with. Even this stage was hours of work, and you can see how many connections are still missing. I can't get some of these added, and there are still clear flaws in the image. I hope that the Autopano developers add manual control point addition.

For now, whenever working with areas of little fine detail, make sure that the overlap is rather larger. Autopano will not work with details in the 20 pixels nearest the edges, for example.



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Jun 18, 2007 at 03:10 PM
DrPablo
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p.2 #22 · interesting focal length/DOF sample


This may prove difficult with such shallow DOF, in the absence of small details and sharp edges that the program can easily identify and compare.

Jun 18, 2007 at 03:30 PM
Daniel Buck
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p.2 #23 · interesting focal length/DOF sample


Alexandre said that manual control point (actually clicking where you want the control points to be!) will probably be in the next version

Jun 18, 2007 at 03:57 PM
carstenw
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p.2 #24 · interesting focal length/DOF sample


It *is* proving *very* difficult But it does seem to work, given enough pictures to work with. Lots of overlap is the rule here, as well as lots of images around the periphery. In the rose image here, I am finding that I don't have enough around the edges for a nice crop, for example. I will have to reshoot it.

Daniel, I saw that comment on the forum too. "probably"? It *must* be.

Jun 18, 2007 at 04:07 PM
Daniel Buck
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p.2 #25 · interesting focal length/DOF sample


I didn't say it was easy It's addicting though, I think! Once you get your first one done and it looks awesome, it makes you want to do another one!

I do alot of stitching though (currently, and in the past), so maybe I'm used to it a bit more that most folks. Autopano is a bit new to me, so I think once I fully understand how it works (and get completely manual control points!) it will be awesome. It's worked amazing on everything up until these defocused images (understandably!)

Jun 18, 2007 at 04:09 PM




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