Andrew Macpherson

Tag: Gizmos

Using a Tilt Shift Lens, let’s re-design for photographers not the convenience of lens makers

by on Oct.22, 2013, under Equipment, Off the wall

In the beginning cameras with lenses (vs pinholes) were built round a laboratory optical bench, where the various elements could be relatively easily adjusted. This led to the “Stand” and “Field” plate cameras where he lens and the plate (sensor) could be moved relative to each other.

This arrangement had lots of freedom, but the basic arrangements were relatively easily split into what we now call Shift or Perspective Control, and Tilt where we take control of the “plane” of focus. I put “plane” in quotation marks because in the general case, where very clever lens designers have not been at work, that plane is actually the round inside of a ball, and we rely on depth of field and the effective radius of that ball to compensate.

Perspective adjustment (shift) works by setting the back of the camera flat on to whatever we want to look straight, and then moving the lens up, down and sideways relative to the back of the camera until the image appears in then right place on the sensor. Shift lets you take photos of mirrors apparently in the centre of your frame without showing the reflection of the camera, of a tall building with its sides vertical without having to hire a helicopter to get to that position half way up and so on. The usual issue with these shots is the vignetting of the further parts of the image — in effect only half the image will suffer, and in digital post production one stage will be to add temporary blank pixels (or a layer with the 180°opposite shift for symmetry) to the “near” side of the image so that the vignetting circle is around the midpoint, allowing standard lens correction tools to be used to cancel it out in post. With a Canon TS lens on a tripod one can simply rotate the lens to get the perfect 180° reverse shift to make sure the generated composite is the correct size.

Tilt is much harder to use. What tilt lets you do is play with your plane of focus, either reducing it to a narrow line across your frame, or bringing a large receding plane into focus, from foreground right to the furthest distance. This is where the mechanical design of he lens can make all the difference to how easy the lens is to use for the photographer.

The ideal Tilt lens will have a tripod mount ring, and the tilt’s axis or point of rotation will be across the sensor of the camera. This lets the photographer compose their shot, and use the most sensitive central focal sensor on their camera to get a sharp focus, then switch to using a peripheral focal sensor and rotate the camera body (remember we’ve clamped the lens to the tripod, leaving the camera body mobile) until that point too is in focus. The central point will have remained in focus because that’s at the centre of rotation. The composition too will remain almost unaltered.

My Canon TS lenses completely fail on the usability front. They rotate about the front of the camera body rather than the sensor, with no regard to the photographer who will have to try to use it, each movement of the tilt mechanism changes the composition and the focus. This fault is also there in Lensbabys, Samyang and all sorts of other lenses with tilt capability. The “Why?” Is fairly obvious: by having a short radius the lens designer gives themselves twice the angle for a given movement, and reduces the consequential vignetting but at a massive cost in ease of use.

I’m still searching for a lens manufacturer with the guts to trade “spec” figures for usability

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Tethering (Continued)

by on Apr.26, 2012, under Equipment, Off the wall, On Site

This article is intended to build on Scot Baston’s excellent Tip Squirrel article, not to rehearse ground already covered there. I want to cover a few alternatives, and touch on why they might be useful, and look in detail at a slightly less obvious application of tethering.

The first thing to point out about tethering in general is that it does not necessarily involve a cable, with the new Nikon D4 operating on a WIFI tether through its built-in web server and full control at the one extreme, and at the other the wireless capture possible through the Canon battery Grp or the Eye-Fi memory card. For most purposes however the wired tether remains the only really practicable option, and is usually significantly faster than any WiFi options

A regenerating USB cable is required for mobility

So the first thing one needs is a USB cable, swiftly followed by a USB regenerating extension cable, such as the one shown which I bought from eBay 3 years ago. One needs the regenerating extender because without that the maximum length one can use is 15′ (5m). Next useful and slightly non-standard bit of kit in the low profile USB cable one wants to fit in under one’s ‘L’ bracket it’s described as “USB A male to up angled mini B male” (or vice versa) the up angled mini B takes the cable in at right angles through the gap in my bracket rather than interfering with the portrait mounting ‘L’ plate.  Quick Tip: fold your long cable rather than coiling it up.  That way you avoid introducing a twist to it and will not have to unkink it.  Hook and lop cable ties are very useful for keeping things tidy.

Velcro Cable ties the cheaper alternative

Many people will have seen Frank Doorhof or Scott Kelby demonstrating the wonderful “Tether Tools” kit for holding the laptop and the cable snags to stop the USB plug being wrenched from & damaging one’s camera, and some discussion on preventing the USB cable coming apart. I think that one would be wise leaving the cable to be pulled apart, as that avoids trips and things being pulled over. It is desirable to have cable snags at computer and camera to protect those vulnerable ports, but have a relatively loose couple in the middle, that will pull apart when someone falls over it. This will have the disadvantage that you will have to set up the communications again, but that is a small price for not pulling over your tripod and camera, and dragging the laptop off it’s work surface.

Allow the cable to come apart if someone trips on it

The USB cable isn’t everything of course, one needs some software to drive the connexion. Canon cameras come with an extensive remote control suite, whereas for Nikon it’s an additional package such as the seriously expensive Capture NX2. Lightroom has a built in remote capability which addresses this to a certain extent but the control available is frankly poor, the trigger function is there, but that’s all, there is no access to even the simple exposure controls beyond displaying what is currently set. Where the Lightroon tethering really wins is for use by a Photographer who is using the camera hands-on, and does not need to make semi-remote adjustments. Like all tethering software the system responds to manual triggering and copies the image back to the laptop from the camera whenever the shutter is pressed.

Where more control is needed I’ve found On One’s Software’s DSLR Camera Remote HD for the iPad to be the most useful complete remote triggering package, as it addresses lots of the issues left open by other packages, and at reasonable cost. There is also a slightly cut down version for the iPhone, mostly what is missing is the video.  It integrates very well with Lightroom’s Watch Folder auto-import feature, but will work equally well just importing to a selected folder, again it responds to manual shutter activation, and all photos get copied to the computer.  The rest of this article will be about using DSLR Camera Remote. (continue reading…)

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GPX Master+ GEO Tagging made easier

by on Feb.04, 2012, under Equipment, Tags and Copyright, Travel, Workflow

I very much like to GeoTag my photos, particularly Landscape and Street photography.  I’ve been a great fan of both GeoTagger and GPS Photolinker on the Mac.  The first links to a Google Earth plugin to find where you have placed location crosshairs, the second works with GPX track logs to work out where you were when you took a photo.  In both cases one has to get Lightroom to re-read the metadata for it to notice the location.

Lightroom 4 Beta has all this functionality built in to the Maps module, which is a big win, but ideally one should still carry a GPS device, such as a Garmin eTrex and download the tracks to synchronise with the photo timestamps.  Of course there is also the track data held inside one’s iPhone, but Apple have gone out of their way to make that difficult to access.

Enter GPX Master+ which uses your Dropbox account to synchronise track files to your computer from your iOS device, ready for import into Lightroom 4 (or GPSPhotoLinker) and just makes life that little bit easier.  Usual caveats about Battery drain apply — you have about 1 hour, but if like me you have a car charger this is unlikely to be an issue.  For all-day use the Garmin E-Trex is still the way to go.

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Planning a Trip?

by on Jan.22, 2012, under Camera Club, Off the wall, Travel

The "Stuck On Earth" iPad App

The Camera Club is heading out in early May (Bank Holiday Weekend) to Bodelwydnn Castle Hotel, North Wales, and there were a couple of spots that are on my “Must See” list for the trip, In particular Pontcysyllte Aqueduct the new World Heritage Site, and Sir Clough William Ellis’ famous Portmeirion Village, background for the cult TV series “The Prisoner,” after that it is simply a case of where the whim takes one… or is it?

Trey Radcliff famous for his HDR style, and “Stuck in Customs” travel photography blog, has had an iPad & Android App built called “Stuck on Earth” which uses Flickr geotagged photos, and various cool aspects of Flickr’s organisation and cataloguing to pick some existing images to find the spots & shots others have shared, and challenge one to do better.  It downloads the photos one picks out as trip markers to the portable device so that the challenge remains with one, even when out of WiFi range, or failing again with mobile data networks.  (BTW go into a trip and the add image interface will let you remove shots)

I haven’t found out how to edit the spelling of a failed search (vs retyping from scratch) but otherwise I’m finding it fairly useful for picking out some potentially interesting spots.

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Seasonal Toys & Games

by on Jan.21, 2012, under Equipment, Learning, Off the wall

It’s very useful having a wish list somewhere that your friends and family can consult before the holidays or your birthday.  Luckily for me some did just that, so now I am the proud owner of Pixel TD-381 external 8 cell battery packs for 2 of my speedlights, that reduce the recycle time down to well under 2 seconds, from the unenhanced 7 seconds, a Wex 5-in-1 diffuser/reflector (which will not need explanation), and a Powerex 8 cell Ni-Mh charger/conditioner

The battery packs each have 2 banks of 4 cells, so you can use 4 or 8 cells in each pack, and when attached to the speedlight, these are what powers the flash high voltage / power section, while the internal batteries only run the logic and control circuitry.  Pixel suggests that they can run your speedlight for over 500 full flashes before needing recharged, (possibly more with the newer 2900 mAh cells) and another big advantage is that being flat they also have better heat loss properties than the bundle inside the speedlight, (and also a thermal cut-out) so reducing your chance of melting that expensive flash unit.

The plug fits both Canon 580, 580 MkII and Nissin Di866 Mk II.  There is a different model number for the Nikon and Sony compatible versions.

As for Games, I’m going to try to keep up with the LensProToGo 52 week challenge on Flickr, come and join in — as the adage goes “It’s not about winning, it’s about taking part” and maybe we’ll all be stretched along the way.

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Free airport camera bag filled with goodies #TTPIAB

by on Dec.07, 2011, under Equipment, Travel

Think Tank Photo who make rather good camera bags, are doing an advent accumulator with their “In a Bag” promotion.

It’s free to enter, so probably worth following this link and filling in the entry form to get a chance to win. I quite fancy the bag itself, but there are already a whole lot of really worthwhile goodies added, and a daily chance at one of their superior shoulder bags

Good luck!

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