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Layout and model photography - In-camera focus stacking.


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I can see why you want such a feature on a camera. I'm going to the Stafford Railway Circle show tomorrow at Stafford Showground (plug) and I'll take a few dozen pictures of the layouts, most of which will be of such narrow focus that they'll be rubbish.

Use a high aperture f number that will give you much more depth of field.

I personally dislike this rage for stacked photos. They look false, nothing like how your eyes and brain actually see a scene.

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Use a high aperture f number that will give you much more depth of field.

I personally dislike this rage for stacked photos. They look false, nothing like how your eyes and brain actually see a scene.

The human eye captures depth of field better than any camera, and the brain further enhances that impression. That's why most photos taken from relatively close viewpoints don't have enough of the subject as sharp as we want/expect, even with the lens well stopped down. The natural hyperfocal distance that offers greatest d.o.f  is almost always too far away to be useful in model photography.

 

The idea of focus stacking for model railway pictures is to bring what the camera "sees"  closer to what we would observe in person.

 

However, as with any other kind of manipulation, e.g. image sharpening, it is possible to overdo things and produce an unconvincing result.

 

The more conventional way round it, using a camera with a very high megapixel sensor then drastically cropping the image to isolate the sharp midfield whilst retaining sufficient resolution for the desired size of reproduction is an expensive solution.

 

John

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Use a high aperture f number that will give you much more depth of field.

I personally dislike this rage for stacked photos. They look false, nothing like how your eyes and brain actually see a scene.

 

The problem there is that a high f number can reduce image quality.

 

https://en.wikipedia.org/wiki/Diffraction-limited_system

 

Pin hole cameras aren't known for their high quality images.

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It's funny, I'm writing this on my phone which is in focus. I can see everything around, but it's out of focus.

As with a camera, the closer we focus our eyes, the shallower the depth of field becomes. I'm looking at my laptop screen from about a foot away and my coffee mug, in view but about twice as far distant and off to one side looks fuzzy. However, just by turning my eyes, it snaps into focus instantly, far quicker than any of my cameras would manage. 

 

Focus stacking was originally devised as a method of overcoming the in-focus/out-of-focus "cliff-edge" effect in macro photography, where it's an even greater problem than it is for model railway layout scenes taken from two or three feet away.

 

The physically small sensors and short focal length lenses of most phones compared with my cameras (a DX format SLR and a Four-thirds sensor compact) should make them an easier route to the sort of pictures we want to achieve, but few phones incorporate the level of control required to fully realise their photographic potential.

 

John

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Yes I know this, but when you look even at distant or semi distant items not everything is clear. But when you look a a stacked photo every thing is clear which to me makes it most unrealistic.

If you take a portrait picture of someone and the background is as clear as the person it looks most odd. That's how stacked layout photos make me feel. Along with the colouring always looks a bit off to me.

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Yes I know this, but when you look even at distant or semi distant items not everything is clear. But when you look a a stacked photo every thing is clear which to me makes it most unrealistic.

If you take a portrait picture of someone and the background is as clear as the person it looks most odd. That's how stacked layout photos make me feel. Along with the colouring always looks a bit off to me.

That's caused by overdoing the process. The effect that's wanted is (for instance) to picture a train, (say a loco and four coaches), within a modelled landscape, with as much of it in-focus as there would be in a prototype shot taken at f/8 on a 50mm lens (or whatever) from a comparable distance.

 

Therefore, the rearmost (model) shot used in the stack should be the one that gets the last coach in focus, with the d.o.f. allowed to drop off naturally behind it unless there are other features that would draw attention to the drop-off being steeper than it would be in a prototype shot.

 

Also, of course, a photo of a steam-era model should ideally look like a photo of a steam-era prototype, i.e. as if it was taken on film, so sharpening, contrast adjustment and tweaking of colour balance and saturation should also be undertaken with great caution. 

 

Once you start down the road of photo-manipulation, there is an ever-present danger that George Mallory's reason for wanting to climb Everest kicks in and one can be tempted to use all the tools because they are there.

 

In all cases, it is useful to question whether one should exploit the limits of the available technology or only take it as far as is necessary to produce the effect you actually seek. 

 

However, that tension between doing what's possible, and doing what's appropriate to the subject has been present in photography since the beginning

 

John

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The price of the LUMIX G9 + Leica 12-60 lens has come down sufficiently to make me jump on it. The camera takes a short MP4 movie sequence whilst simultaneously adjusting focus. It then combines the sharp bits of the resulting files to produce a single jpeg. The processing takes the camera about 90 sec. but doesn't have to be done immediately.

 

Sample shot, taken at on the excellent Sandford and Banwell at Southampton show last month. Hand-held (the instructions recommend using a tripod) with the layout lighting only. Taken using "Intelligent Auto" mode and the effective settings are ISO 1600, 1/200sec at f/3.8.

 

Uploaded just as it came out of the camera but for re-sizing to keep the file size within the limit. 

 

John

PPG90038_web edit.jpg

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58 minutes ago, Dunsignalling said:

the effective settings are ISO 1600, 1/200sec at f/3.8.

 

 

Those, for me, are the all important numbers; the ISO being the weakpoint. I understand the methodology of course of the 4K file but what is the longest exposure possible? Will it reach 1/25th as a maximum?

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36 minutes ago, AY Mod said:

 

Those, for me, are the all important numbers; the ISO being the weakpoint. I understand the methodology of course of the 4K file but what is the longest exposure possible? Will it reach 1/25th as a maximum?

With the limited amount I've played with it so far, it looks like 1/30th. The posted shot was taken using 6k but the camera will do 4k. I haven't yet tried that but it may offer a little more "give" in the shutter speed/ISO, as might using aperture priority with the ISO set manually. Interpolating what the camera did with the sample shot, I'd think ISO 400 should be achievable with decent layout lighting. The combined body/lens "Power OIS" seems ferociously capable, but I think a monopod will be a good idea!

 

From reading the book, the camera will also do "conventional" focus stacking using RAW files, but isn't capable of processing that in the camera.  Panasonic refer to that as "Focus Bracketing". It can be programmed to take up to 999 shots, which is probably (!) excessive. That will have to wait until I get some suitable processing software.  

 

I'll run off some A4 prints to bring to the SWAG do to give an idea of the quality obtainable using the "easy" method.

 

John

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Tilt-shift lenses are used tilted, seemingly commonly (and thus often badly), to make real landscapes look like miniature models by deliberately foreshorting the focal length of the shot.  Diorama effect, I think it is named, amongst other things.

 

Less well known is their use by landscape photographers to do the reverse, to get wideangle shots with all of the landscape in focus.  I'm not going explain how the tilt function works here, you'll have to do a bit of Googling if you're interested.

 

That said, the shift function is also interesting, it can let you do very odd things, like take a photograph of yourself in a mirror with no camera in sight.  Effectively, it automatically does what @Dunsignalling suggested a few posts ago - it drastically crops the image.  The difference here is that it's selecting the area of the lens which is being directed onto the sensor - so you don't lose resolution.  The fact it can do this at all is why T/S lenses are horrendiusly expensive there's some big pieces of very high quality glass in there.

 

I believe a combination of tilting and focal stacking could get you even closer to that 'real' photo of a model, and the use of the shift might allow you to place the point-of-view lower, giving the illusion of putting the camera at a scale 5ft high even in the practically 'too high' locations we are forced to shoot from.

 

This option is only open to DSLR users, and even then, to follow-up on this myself, I think I'd rent 2 lenses (say a 24mm and a 90mm) and run through a series of experiments to confirm the theory and see what really worked.

 

Just some more discussion ideas for now, unfortunately for me.

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I've gradually been working out the plusses and minuses of the in-camera focus stacking system in my G9.

 

Selecting the facility seems to override whatever the mode dial is set to and puts the camera into Program, with a shutter speed of either 1/60th or 1/30th, an aperture close to wide open (this on the standard 12-60 Leica f/2.8 - f/4 zoom), and with auto ISO taking care of the rest.

 

This results in a high ISO setting under most layout lighting, with consequent noise/grain becoming evident. The answer will presumably be to up the lighting level if one wishes to control that sufficiently for publication etc. I've got hold of some cheap LED video lights to play around with for closer shots, though something more meaty will probably prove desirable for more general views. 

 

Specimen attached. Layout lighting only. The stacking process is based on a MP4 movie burst which translates (I think) to the equivalent of 8mp in the final still output. Settings recorded as 1/60 sec, f/3.3, ISO 1250. Focal length 22mm (equal to 44mm on full frame). Camera resting on platform, electric cable release. Shot has been cropped and lightened a bit in the laptop, otherwise untouched from what came out of the camera.

 

34044 'Woolacombe' is pictured running in after visiting my workbench (aka Eastleigh) for new gears.

 

I've begun to find the bulk of the zoom lens to be a hindrance for some shots and have ordered a 15mm f/1.7 which is around a third its size.

 

John

 

 

 

 

P1050055e2.jpg

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This one taken on a better lit area of the layout, with the camera selecting ISO 640. Camera on tripod, cable release.

 

Cropped and with the top edge of the backscene retouched out, otherwise unaltered.

 

John

P1050034e2.jpg

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On 24/02/2020 at 10:48, FoxUnpopuli said:

Tilt-shift lenses are used tilted, seemingly commonly (and thus often badly), to make real landscapes look like miniature models by deliberately foreshorting the focal This option is only open to DSLR users, and even then, to follow-up on this myself, I think I'd rent 2 lenses (say a 24mm and a 90mm) and run through a series of experiments to confirm the theory and see what really worked.

 

I have the Canon 90mm TS-E and I've used it quite a bit for model photography. It works very well.

 

Guy

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20 hours ago, Dunsignalling said:

 

Saturday afternoon, I've just knocked out 7x5 and A4 prints of this picture; as cropped, it's 6.25mp. The Hornby WC is reproduced over life size in the larger print, which displays only very slight noise in the shadows when viewed without a magnifier. I intend to repeat the shot with a bit of fill-in to lighten the shadows and strong enough to get the Auto ISO down around 800, which I'd expect to deal with that.

 

At 7x5 all looks sharp, at A4, the focus just begins to drift off gently behind the tender; very much as I would expect a prototype photo taken on 35mm to look. That's the effect I'm aiming for rather than wall-to-wall razor sharpness which (to me) looks unnatural.

 

Cautiously delighted! A similar photo taken with my first digital camera (2006, a Lumix Fz30 bridge) at ISO 400 would have looked pebble-dashed by comparison with this at ISO 1250 and half of it would have been out of focus.  

 

Quote

 

 

P1050055e2.jpg

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@Dunsignalling Is  the photo with the trolleybuses part of your layout? If so, how did you do the overhead, and does it work? It looks very impressive! I have some Original Omnibus ones to convert with working poles and I'd be interested to know.

 

Cheers,

 

Philip

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59 minutes ago, Philou said:

@Dunsignalling Is  the photo with the trolleybuses part of your layout? If so, how did you do the overhead, and does it work? It looks very impressive! I have some Original Omnibus ones to convert with working poles and I'd be interested to know.

 

Cheers,

 

Philip

Not my layout, Bournemouth Central belongs to a friend and I'm just one of a quartet that works on it and forms the core of the operating crew (or will do when we can safely get the minimum of 6 people it requires in the room again). 

 

The overhead is purely cosmetic but, as can be seen, the streetlights and traffic lights do work. There's not enough continuous highway on the layout to make working road vehicles practical.

 

John 

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Think I'm beginning to get the hang of this, and a little extra light makes a big difference.

 

Layout lighting plus fill in from 2 small LED video lights, 1x 36 LED and 1x 64 LED got the exposure to f/4.5 on ISO 800 which was my aim. As before Leica 12-60 lens, this time at focal length of 28mm (=56 on 35mm). Untouched but for cropping from 4:3 to 7x5 for printing to A4 and resizing to post on here.

 

"35002 Union Castle on shed at 71B"

 

John

P1050091cr.jpg

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