Monday, April 29, 2013

Using an Old Router as a Wireless Access Point

These days, many of have a collection of 'free' wireless DSL or cable routers, as these tend to be given away when we change to a new provider, and usually these end up unused in a drawer or cupboard (as I type this I can think of at least 2 we have lying about).

This happened to me recently, and I really wanted to keep using the old router (BT Home Hub 3), as it had a natty power save feature (it switches off WiFi) that I could use to prevent the children accessing the Internet from any of their devices outside of the hours we had agreed. Having the WiFi just switch off automatically and on again at preset times seems much easier than trying to setup firewalls and VLANs to try and limit their access.

Also, with the BT Home Hub 3 it's very easy to bypass the power save feature and extend their access time, so the kids can watch movies, for example, at weekends and sleep overs. So, the challenge was to re-use the BT Hub as a dedicated access point (AP) for the kids PCs, phones and iPods.

A quick bit of 'research' (aka google) revealed that this should be relatively simple, but I thought it worth documenting the simple steps required. Below is what I did (the order is important!). I've assumed that you haven't re-configured the old router too much, but you could always factory-reset it before starting (which I would recommend if you customised it's setup a lot):
  1. Firstly, disconnect your computer from any networks (wireless and wired).
  2. Attach the old router to your computer using an ethernet patch cable.
  3. Login by browsing to the old router's address (usually 192.168.0.1 or 192.168.1.1, but often printed on a label underneath).
  4. The username and password are usually on the label to, but you should change these to something more secure.
  5. Go to the WiFi settings page and configure the access point's SSID as you want it (I took the option here to restrict this network to the slower b/g standards as a way of throttling the bandwidth being 'hogged' for Skype etc.!).
  6. Next, change your old routers IP address to something that is in the range used by your new router, you'll probably find this setting on the 'LAN' settings page. In my case, the new router was 192.168.1.1, so I chose to set the old router to 192.168.1.2. Just make sure you're not selecting an address already in use - you'll need to login to your new router to check, or download fing.
  7. Next, again usually in 'LAN' settings, disable DHCP (this is the service that issues out IP addresses, and you only want one device on your network doing this, and your new router is doing this and will continue to do so).
  8. Disconnect your old router from your computer, and instead connect it to a spare ethernet port on the back of your new router.
  9. Now, logon to your new router and in the LAN settings, look for a setting called 'reserve addresses' or similar, and reserve the address you selected in step 6. This ensures that the address will not be dynamically allocated to another device, for example if the old router (which is now just an AP) is switched off.
Finally, logon to the new SSID and check that it connects to the Internet. That's it, and for no extra cost I have a separate access point for the kids, time-limited and restricted to the theoretical 54Mbps of wireless 'g', while the adults and the Apple TV get to connect to the new router by wireless 'n', which theoretically offers 6 times the bandwidth (300Mbps). In practice, real throughputs will be a lot lower so this is a crude way of carving up the 25Mbps or so we have from our fibre broadband.

Wednesday, April 17, 2013

Print Size vs Resolution

I should probably inject some clarity into my comments below about D7000/D7100 choice, and why you might actually need more resolution.

The accepted rule of thumb for printing for display is 300 points-per-inch, so to determine the 'native' print size from your camera, simply divide it's horizontal and vertical resolution by 300 to give your print size in inches.

Thus the D7100 should be easily good enough for 18"x12" prints. But here's the rub: you can get to this size from a D7000 file by only slightly reducing the resolution to around 250ppi.

Such a reduction will be practically unnoticeable at normal viewing distances - chances are a carefully shot and post-processed D7000 RAW file will compare very well to a D7100 jpeg.

So, if you never print beyond A3, and if you're not already routinely shooting RAW, with good shot discipline and are completely competent in your RAW conversion and processing, then the D7100 is probably more camera than you need.

Friday, April 12, 2013

Dxomark Nikon D7100 Review

See here, image quality doesn't appear much different to D7000, which is either:

1. A very good thing if you like the D7000's IQ but really need the extra resolution.

2. A really good thing if you don't - because it means you can stick with your D7000, if you have one, or if you don't, save yourself about £500 over the D7100 and buy a D7000 instead (but be quick!).

But there are a couple of reasons that might be compelling reasons to buy a D7100 for sports or wildlife, the expansive AF system that covers much of the frame, and the 1.3x crop mode (2x the lens focal length).

Samsung Phablets News

Following on from my post on Helicon Focus, I just saw Samsung have announced even more 'phablets', with even bigger screens than the 5.5" Note II I used, see here for details.

Focus Stacking for Macro

A great article with some excellent examples of focus-stacking in macro photography on dpreview.

Tuesday, April 09, 2013

Helicon Focus mini review

I got the opportunity to try Helicon Focus recently, which is a software package that automates taking a sequence of images at different focus points, and then 'stacks' these to produce an image with massive depth of field. Applications are macro work, product photography and landscapes, the latter being my particular interest.

For landscapes you ideally need an Android or Apple iOS tablet, as carting a laptop around is not really practical. I chose the former as iOS support seems a bit clunky, and I was able to get hold of a Samsung Galaxy Note II Android 'phablet' which with it's 5.5" AMOLED display makes it viewable in daylight and it is also extremely portable at under 200g.

With the Helicon Focus Android app downloaded and installed, the Note was connected to my Nikon D3x camera via a USB Host Adapter (I used a genuine Samsung item, about £8 from Amazon) and a standard mini USB cable. The app worked flawlessly with the D3x and 50mm 1.8G AF-S lens.

You simply select the near and far points you want in focus using the liveview image shown on the Notes' touchscreen, and the app works out the number of images required and then takes them in sequence. The resulting images (jpeg only in trial version, full version supports RAW) are then imported into the desktop application on your PC and stacked to form single image with vastly increased depth of field compared to a single image.

For landscapes this means you can get the depth of field you want without degrading quality by stopping your lens down beyond it's diffraction limit, or resorting to fiddly and expensive tilt/shift lenses. Instead you can shoot with a relatively modest lens at it's optimum aperture, like f/5.6 or f/8.

Given that a single Canon or Nikon tilt/shift lens retails for around £1400, the cost is competitive - even the Note II retails for around £500 SIM free and the Helicon Focus lifetime license is about £180 i.e. about half the cost of a single tilt/shift lens. A Galaxy Tab 2 7" halves the price down to a total of £350, but it is heavier and I haven't used one so I cannot vouch for the screens viewability in daylight.

I'm still evaluating this setup for landscape use and will post an update when I have reached a conclusion. At the moment it all still seems a bit cumbersome but I sense some real possibilities.

Wednesday, April 03, 2013

Nikon DSLR Firmware Updates

Nikon launched a gaggle of Firmware updates for their DSLRs yesterday.

The main feature for older models is EXIF data for the new 800mm f/5.6 lens, so, if you sprung £15K on one, you might want to check this out ;-)

Some more interesting stuff for current DSLRs though! Nikon Support Centre (Europe) is here and a some detail of the updates are here from Thom Hogan (bear in mind Thom rolls these articles off his home page every few weeks, so if you're looking at this post mid-April 2013 and don't see it there, you'll need to search his site).