Phototest of CombineZM

[sizemore]

Assuming the layout was finished and a Photoshop touch here and there....

Not a bad photo!

The S.

PS. Maybe there should be a Photography Section for tips, tricks and tutorials on Railwire?

[Ed Kapuscinski]

There was a photography thread there, if I remember correctly.

I know I've flogged the article on my site to you before, right?

[sizemore]

There was a photography thread there, if I remember correctly.

I know I've flogged the article on my site to you before, right?

When I goto the General Discussion on Railwire there is nothing for Photography. And I think I may have read it long ago but throw me the link again I could use a refresher!

I wanted a free alternative to HeliconFocus, CombineZM is free and super simple to use, but never put it to use until tonight. The results are totally worth it.

The S.

[Philip H]

There was a photography thread there, if I remember correctly.

I know I've flogged the article on my site to you before, right?

When I goto the General Discussion on Railwire there is nothing for Photography. And I think I may have read it long ago but throw me the link again I could use a refresher!

I wanted a free alternative to HeliconFocus, CombineZM is free and super simple to use, but never put it to use until tonight. The results are totally worth it.

The S.

Then give us the link man!!!!

[John]

Search function !!!   There are 50000+ threads on this forum ..

[sizemore]

http://www.hadleyweb.pwp.blueyonder.co.uk/CZM/combinezm.htm

[AlkemScaleModels]

http://www.hadleyweb.pwp.blueyonder.co.uk/CZM/combinezm.htm

There was a pretty good discussion of focus stacking (mostly with Helicon Focus but the techniques are similar) on the MRH forum last year.

http://model-railroad-hobbyist.com/node/138

[sizemore]

http://www.hadleyweb.pwp.blueyonder.co.uk/CZM/combinezm.htm

There was a pretty good discussion of focus stacking (mostly with Helicon Focus but the techniques are similar) on the MRH forum last year.

http://model-railroad-hobbyist.com/node/138

Thats a good read. I used my Nikon D40 with 18mm - 55mm lens. Set the aperature to 18mm/F-32 with a 5-6 second exposure (IIRC). I then took about 15-20 photographs manually changing the focus point all from the tripod. The lens was about 7 inches away from the loco. I've read that I would need to walk through the F-stops, but I reasoned that if I take more photos, walking the focus I wouldnt need to do the F-stops. I'm going to try again tonight from a lower angle to see what I can get.

The S.

[asciibaron]

i have gotten really good results with a very small aperture and a massive exposure time in a dimly lit room.

this was taken in a mostly dark room... F/32 at 30 seconds.

[Ed Kapuscinski]

Steve's got the right idea. That's exactly what I do (although I also usually place the camera directly on the layout too, eschewing tripods).

[tom mann]

Again guys, and I keep telling Ed this, you lose significant sharpness smaller than F8.  Play with the lens tool on dpreview.com if you don't believe me!  So the reason behind focus stack tools is to combine photos taken at the optimal aperture.

[DKS]

Less light = more CCD noise, problematic white balance, diminished contrast and poor to no shadow detail.
Smaller aperture = greater depth of field BUT also greater blurring due to diffraction.

Ideally, use as much light as you can practically deliver to a scene--the equivalent brightness of natural sunlight is ideal. Use an f-stop that matches the lens to the CCD for the least amount of diffraction. This site is helpful (thanks, Tom): http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

The smallest practical f-stop is barely adequate to deliver a depth of field sufficient for much of anything except side-on shots, like Steve's (notice the far end of the B&O box is already falling out of focus). So-called pinhole apertures (anything greater than around f/45) will greatly increase depth of field but also greatly increase diffraction blurring. If you're shooting down the track, or if the field of view encompasses objects ranging from inches to feet from the lens, image stacking is virtually a must no matter what aperture you use.

In this image, the crossing flasher is about six inches from the lens, the caboose is about a foot and a half away, and the rock face about two feet. Five images shot at f/22 in natural sunlight were combined with Helicon Focus. Even at f/32 (smallest aperture the lens could deliver), there was simply no possible way to keep both the flasher and the caboose in focus. Notice the slight overall softness in the image; sharpness could be improved by shooting with a larger aperture (will be doing this soon as a comparison).



For image stacking, more images is better (they can be all the same f-stop, just different focal points), but there's a point where the ROI for shooting more images drops off. I've found it's possible to guesstimate the number of images needed by observing the image while changing the focus with a wide-open aperture (only works with SLRs) to see how quickly things fall out of focus. Shooting more images in the closer focal range is the most useful.

Setting the white balance manually can prevent white balance shifting between images. Use a cable release or the shutter release timer to avoid camera shake. Also, be mindful of other image stacking pitfalls: small foreground objects (such as telephone poles) set against a distant background can produce halo effects and other bizarre artifacts. Experimentation and careful composition can help prevent these problems.

Personally, I've found CombineZM to be a frustrating app to use. (The company I work for uses CombineZM as a macro for crystallography, and many of the features in the current version exist because of our collaboration with the developer.) I spent a couple of hours fiddling with it and was unable to come up with satisfactory results. Helicon Focus worked perfectly out of the box; the default settings of the demo version produced a perfect image in just a few clicks, and I immediately paid for the full version. Since my hobby time is limited, it was well worth the cost to get immediate results.

[AlkemScaleModels]

Again guys, and I keep telling Ed this, you lose significant sharpness smaller than F8.  Play with the lens tool on dpreview.com if you don't believe me!  So the reason behind focus stack tools is to combine photos taken at the optimal aperture.

I don't think this is as true for a lens designed for macro photography. I have a both Nikon and Canon 50mm Macro lens and both do great work at f32.  I agree that the diffraction from smaller f stops is an issue for other lens though. Not sure how they optimize the macro lens for smaller f stops, but it seems to work.

[DKS]

Again guys, and I keep telling Ed this, you lose significant sharpness smaller than F8.  Play with the lens tool on dpreview.com if you don't believe me!  So the reason behind focus stack tools is to combine photos taken at the optimal aperture.

I don't think is as true from a lens designed for macro photography. I have a both Nikon and Canon 50mm Macro lens and both do great work at f32.  I agree that the diffraction from smaller f stops is an issue for other lens though. Not sure how they optimize the macro lens for smaller f stops, but it seems to work.

The problem with macro lenses is their difficulty focusing on distant objects. They're really suited only for "subject" photographs, as opposed to scenes. Also, the closer the subject, the shorter the DOF, so a macro lens really suffers, and DOF becomes even more critical. The diffraction issue may be complicated by the angle of view a macro lens has--this would take much more study to understand.

[wm3798]

This was shot at f5.6 for 15 seconds in a dimly lit room.  I flashed the building lights and track power to limit overburn.  The trick I like to use to "broaden" the focal area, is to stage two subjects parallel to the lens.  In this case it's the bulkhead flat and the locomotive.  While both are at an angle, the focal plane slices through both subjects, so more of the image appears to be in focus.  The truck and the forklift, as well as the lumber stacks under the canopy, and to some extent the main warehouse are sharpened a bit by the long exposure.

I'm not concerned about the stuff in the far background, although if that could be sharpened up as a third layer with helicon or something, that would improve an otherwise pretty good shot.

Lee