Monday, April 18, 2011

Not Bad For a 40-year Old ;-)

Took a little stroll tonight with the D7000 and Nikkor 28mm f/3.5 H Auto (Ai converted). Shot in RAW, a little shadow recovery in NX2 and cropped to 5:4. I can't see much ghosting here, just the sun stars (not unexpected at f/8, could have gone for a wider aperture, but might have struggled for depth of field). I had a UV filter on the lens as well.

Tuesday, April 12, 2011

Just Out of Curiousity...

...I timed the 30s shutter speed on my D3, and the mirror flips back down after 31.6 or 31.7 seconds, which explains the strange behaviour of the intervalometer.

Doesn't explain why 30 seconds isn't 30 seconds though.

Monday, April 11, 2011

Nikon Interval Timer

I find Nikon's intervalometer in their D3 and D7000 cameras to be a bit peculiar. It's pretty obvious that if you set an interval shorter than your intended shutter speed, the intervalometer will fail at the second exposure, since the shutter will still be open when the second frame should be fired. So, you can't for example, set a 1s interval and a 2s exposure. Nothing wrong with that.

But if you wanted to take a 30s exposure, you would think that setting a 31s interval would be fine, yes? No! In fact, even 32s doesn't work. For some bizarre reason, you have to set the interval at 33s, and then it will happily click away. I can't see the reason for this: I don't imagine that the shutter speed is inaccurate (although I haven't timed it), and I can't seeing if being a buffer/card writing issue on a camera like the D3 that shoots 9 frames per second (besides, there isn't a 3s delay between exposures anyway, more like less than 1s), but it works and does the job.

As I see exactly the same behaviour with the D7000 and D3, my assumption is that this is how it was designed to work.

Having finally figured this out, I now know that a D3 used like this with a fully charged EN-EL4a battery will take around 370 30 second exposures before the battery dies completely. Obviously this will vary a bit with temperature, but I guess you are looking at 2 to 3 hours of star trails under most UK conditions, which equates to around 30 to 45 degrees of rotation. It will be interesting to see what the D7000 can do, as I have an idea for a project that using this technique that the lighter D7000 will be better suited to and where external power won't be an option.

For now though I am going to concentrate on the D3, as I have an EH-6 mains power supply (a legacy from D2x days when you had to power that camera from the mains in order to clean the sensor), so there's the prospect of capturing some pretty spectacular star rotation.

Saturday, April 09, 2011

Another One...

Slight Correction

First up, there was an error in the post below, of course the orange glow has nothing to do with moonset, it's just the result of light pollution from the surrounding towns and villages.

Also, as I've tried to go for longer sequences, I've hit the limit of the continuous shooting mode on the D3 i.e. 130 shots (100 on D7000). Given that the maximum shutter speed is 30s, we're limited to 50-65 minutes. It doesn't look like either cameras intervalometer helps either, as whilst at first glance it looks like you can set up to 999 exposures, that's not actually how it works... more on this and a possible solution shortly.

Friday, April 08, 2011

Star Trails - Part Two

Nikon D3, Tokina 11-16mm @ 16mm, 132 exposures at 30s & f/5.6, ISO800

For my next session I switched to a wider lens (note how the DX Tokina has not vignetted, even on a full frame camera). This sequence was started just after moon-set, hence the glow at the horizon. Caught a couple of airplane trails, but still very happy with this image.

I really like using this composite process, it's reminds me a little of the days of film, in that you don't quite know what you're going to get until the files are processed. It's great watching the image form and appear in Startrails.

Thursday, April 07, 2011

My First Ever Star Trails!

Nikon D3, 20mm Ai-S, 30 seconds @ f/5.6, ISO800

This is a composite of about 120 30 second images, stacked using a freeware application, startrails.exe (see below). Initially I was going to use the D3s built-in interval timer, but frankly it was such a faff that I gave up, stuck the camera on continuous drive and locked off the MC-30 cable release. With the shutter set on 30s on manual, it just keeps clicking every 30s until you stop it, or the batteries die! If you have a D7000, I'd advise getting the MC-DC2 wired remote - the intervalometer has a similar menu to the D3, and so it's also a pain to use.

I had to take out a couple of images due to airplane light trails, that's why if you look closely you can see some small gaps in the star trails! This is one advantage with stacking, but there are others: for example, you might even getting away with swapping the battery part-way through the sequence - if you are quick - which might be handy on cold nights. Plus, if your battery does fail you won't have wasted the whole session, which you will if attempting one long exposure.

Lessons learned? I normally shoot Raw, but for this jpegs are definately the way to go - you could be dealing with 100's of images from each session and although I could batch process them, this seems over-the-top for this application.

Also, a ultra-wide angle exaggerates the curvature, so in future I'll be using the Tokina 11-16mm (works on full frame at 15 or 16mm). Focusing in total darkness is impossible, so you'll need to know where infinity focus is on your lens, and set it at that - or the hyperfocal distance if you have objects in the foreground (note: infinity focus is not necessarily where the infinity symbol is, and it may well change at different focal lengths on a zoom).

I took a dark frame (leave the lens cap on) at the end of the sequence at the same shutter speed (30s). This helps to remove any noise from the final composite, so long as you specify which frames are 'dark' when you load the images into startrails.exe. I take the dark frame at the end, when the sensor will presumably be 'warm' and therefore at it's noisiest.

It's important to have your camera's long-exposure noise reduction turned off with this technique, otherwise your camera will take a break equivalent to the length of each exposure between shots, to process the noise reduction, and you'll end up with dotted lines!

Overall, I was quite satisfied with this first attempt, now that I have the technique pretty much sorted, I just need to work on composition (it would be nice to get some foreground interest).

Useful star trails links:

Wednesday, April 06, 2011

£100 of Photographic Value

Recently a friend of mine bought a Nikon D7000 body, but he was unsure of what lenses to get, so I invited him over to try some of my gear. His needs were for a general purpose 'walk-round' zoom plus a 'proper' macro lens. Macro lenses aren't cheap, so we needed to squeeze the budget on the zoom. I had already dissuaded him from the Nikon 18-105mm 'kit' lens, reasoning that he could do better for less money by buying second-hand (the 18-105 is around £150 when bought with the camera).

It was an interesting exercise for me, affording me the opportunity to see all my lenses lined up and then re-assess what I like and don't like, and therefore what I need and don't need. I can see a bit of a lens cull coming up...

Anyway, back to the £100 of value, here's 3 ways to spend £100 on lenses for your Nikon, all of which are terrific value, but all in different ways:

Nikon 50mm f/1.8 AF-D

Humble and often overlooked, the current 50mm f/1.8 AF-D is a cracking little lens. Image quality wise, all you seem to lose here against the more expensive standards (I have a 50mm Ai-S f/1.2 as well) is performance below f/2.8 (at f/5.6-f/8 you'd have to be very picky and doing enormous prints to tell!). Bear in mind though, consumer zooms don't even go to f/2.8, so this lens is going to offer low-light capability that your 'do-it-all' zoom won't!

Admittedly construction is plasticky, the depth of field scale is pathetic as only f/11 and f/22 are shown - practically useless for digital. On the plus side it's very light, compact, focuses fast and works on FX and DX, and new can be bought for less than £100. We even spotted some mint second-hand examples from £60 - testament to how unfashionable these excellent optics are, as most people favour a zoom these days.

If you don't like the plastic, and can forego autofocus, a secondhand 50mm Ai f/1.8 or f/2 does the job for about £10 less, plus you get a proper depth of field scale.

Nikon 18-70mm AF-S G DX ED IF

This lens was offered up as a kit lens around the time of the D70, and in the context of consumer grade standard zooms is quite well regarded (see here and here). You're getting three ED glass elements, AF-S, a metal lens mount (18-105 has plastic) and a reasonable zoom range of 27-105mm. This latter point probably partly explains the better-than-expected optical performance, as there are less compromises to be made than a wider-ranging zoom. No depth-of-field scale at all though, and it is DX only.

Nikon made around 2.2 million of these over a period of about 5 years, and today these can be picked up in mint or excellent condition from dealers or ebay for around £100, and you shouldn't have to pay more than £120 for a boxed example with hood. As I explained to my friend, use it for a year or two, then sell it if you decide to upgrade, you will probably get back 80 to 100% of what you pay for it...

My friend was able to use the £50 saving to put towards a good used 105mm f/2.8 AF-D macro, it will be interesting to see how he feels the two lenses compare!

I was somewhat tempted by the 18-70 myself, but it doesn't really suit my style of shooting...but the next lens does.

Nikkor 28mm f/3.5 H Auto (Ai converted)

This lens dates from the early 1970's, when Nikon only made expensive things, and made them out of metal. This lens has the lovely scalloped focus and aperture rings that not only feel good to use, but are very practical with gloves on. Focussing doesn't have quite the 'damped' feel of later Ai & AiS lenses however. By contrast to the 18-70 above, Nikon only made around 500,000 of these over a 23 year period (if you count all the variants of the f/3.5 lens that is).

(Image courtesy of

Ok, I'll admit this isn't everyone's cup of tea, but as I was looking for a 'standard' lens for my D7000, this one came into mind. Manual focus down to only 60cm, it's quite slow and not 'native' Ai. But, despite all that metal, it is light, compact, has an excellent depth of field scale and apparently it's performance into the light is fantastic - hopefully we'll get a few summer sunsets to try it on!

I quite like a slight wideness for a 'standard' lens (42mm on DX), and of course it will work on FX to (although that's not what I intend to use it for, as if I am lugging around a D3, I might as well lug a PC-E lens as well!).

Despite the age, it's relatively easy to find a good example, I got one in excellent condition that had a factory Ai conversion, for £100. This will complete my 3 lens 'hiking' landscape setup for the D7000: Tokina 11-16mm, Nikon 28mm, and Nikon 50mm (or 55mm macro if I decide to keep it!). The Tokina can be substituted for a 20mm when I want to go really light.