Hi Matt,

With digital is now much more common to take a series of short exposures and use software to stack them on top of each other. This avoids both the increased noise in high ISOs and the problems DSLRs have with very long exposures.

There's software called RegiStax which seems the most popular free option: link.

An example of this is here (87x 20.sec exposures): link

John.

Hi All,

I've been interested in photographing cruising airliners since somebody showed me this site link where it looks like they're using astronomical telescopes.

I wanted to see how well I could do with the photo gear I have, which is a K-5, a Tamron 500mm f/8 mirror lens, a couple of teleconvertors (Teleplus 7 element KA 2x & Vivitar K 3x) and a Uni-Loc 1700 system tripod. All of the photos below are full APS-C frames for comparison, I've boosted the contrast on most of them and sharpnd them all.

First a straight handheld shot with the 500mm f/8, 1/350, ISO 160:



Secondly a handheld shot with a Teleplus 2x, 1/250th, ISO 400:



At this point I was a little disappointed, zooming the images in camera and computer to 'full size' and seeing all sorts of artifacts. It looked like camera shake or that the mirrors had been knocked out of alignment. After some thinking I thought it might help if the image was larger, I wouldn't have to zoom quite so much. I bought the Vivitar 3x teleconvertor with the aim of taking the lenses out and using as an extension tube, but the thought of getting a usable image out of it seemed remote.

With the Vivitar 3x I got the following: 1/2000th ISO 6400:



and 1/1500th ISO 6400:



Along way from the photos in the link at the top, but gives some idea of the focal lengths required (I suspect they're using eyepiece projection on the scopes their focal lengths are unlikely to be over 1000mm and it looks like they're using much longer than my 1500mm f/22.

My technique for the shots with the 3x was to use the tripod to take the weight off, unlocking the ball head and framing by hand. The head wouldn't hold the weight at the angles of elevation required and the subject is moving very quickly. Framing & focussing were the biggest problems.

As a further experiment (and I expected this to fail), was stacking the TCs (Vivitar 3x closest to the camera). Obviously this pushes my aperture out to 'tiny'. I didn't get a chance to try this on an airliner, but found a ladybird, tripod mounted about 3m away, 1/750th ISO 12800:



I haven't looked at trying to change/apply noise redution on this yet, but still far better than I expected.

I hope this is of some interest to somebody.

John.

At first glance I wasn't sure my S1a matched any of your photos, after much squinting, it looks like the third (definitely not the second or fourth). I really think the plate is the same as the first and the mechanism the same as the third (although it may be some shadows that are confusing me).

40mm is an excellent focal length (for film), but as an equivelent 60mm on APS-C I'm not sure? I have the M 40mm pancake and it was perfect for my Super-A, but would I want a 60mm equivelent?

The 21mm would be my choice (unless you fancy the 15)!

I know how you feel, it started with dials, then buttons, then it all went 'retro' and back to dials. The MZ-M, the last manual focus SLR (unless the K1000 outlived them all!) went back to a dial.

Almost sounds like the camera was engraved in the shop after the buyer decided which lens he wanted

Sounds more likely that for a period between the S2 & S3 production, random bits ended up in random cameras (I had a Land-Rover like that)

Hi Michael,

How old was your Sigma 70-300? I have a 70-300 APO Super from around the time when they were started to be also marked as Samsung mounts. I've been disappointed by it's performance at 300mm and had been considering reverting back to my Tamron AD2 60-300 SP.

Digging into my copy of:

Asahi Pentax and Pentax SLR 35mm Cameras 1952-1989
Danilo Cecchi
Hove Foto Books
ISBN 0-906447-62-3

This has several sections to describe the S2, S1a, Sv etc, although trying to understand the variations isn't straight forward. I have attempted to pick out relevent info below:

Page 49: "Production of the S3 was sporadic and inconsistent. Cameras with even quite considerable differences had the designation S3."

Pages 50/51: A photo of an S3 with top speed of 1/500th (number 426160), the caption states that some examples labeled S3 had a top speed of only 1/500th.

Page 56: A photo reportedly of an S2 Super (engraved S2) with serial number 755920 and a caption stating it had an automatic counter like the SV. This photo shows the camera to have the 'windowed' type of frame counter unlike yours.

Page 56: The following paragraph about the S2 Super:
"Alongside the cheap Asahi Pentax S1a, a number of cameras were built which were identical to the S1a but were marked with the 1/1000th sec. shutter speed. The S1a with the 1/1000th sec. was mainly sold in Japan with the designation S2, idenical to that characterizing the initial 1959 production. These cameras gave up their position to the S1a and came out of production. In order to distinguish them from the first generation S2's, they were commonly known as the Asahi Pentax S2 Super, even if the word "Super" was not engraved on any part of the camera body."

Make of that what you will (I'm confused)!

Hi HG,

What problems are you having with the buttons?

To change the exposure mode you hold the 'Mode' button down and press the Up/Down buttons to cycle through them, the options are:

Aperture not on 'A': Auto (Aperture priority), Manual, x-sync (1/100th) and Bulb.

Aperture on 'A': Program action, Program depth.

In manual press the Up/Dn buttons to change the speed (pressing 'Mode' in manual locks the current speed 'L' appears - press 'Mode' again to unlock).

To set exposure compensation, hold the 'EF' button down and use the Up/Dn buttons to set the required value.

The 'ML' button around the lens is the meter lock. Depth of field preview is above the lens release (but stops the lens down to minimum aperture when the ring is set to 'A').

The self timer is set by holding down the front part of the On/Off switch and sliding the lower part past 'ON' to 'S.T'.

And that's it, film speed is read from the DX coding on the cassette.

Hope this helps, John.

I shoot in RAW+ 16MP DNG and a 2MP ** JPEG and the camera suggests about 500 shots on a 16Gb card. The 2MP JPEGs are handy as quick 'web friendly' files without having to spend time cutting them down later.