Vega above Lyra / Cygnus wide-field

[blackparticle]

Such a clear night so I thought I'd give the Milky Way a go. 28mm wide-field cropped slightly to remove some lens distortions. 50 x 30s @ ISO 800.

[Peter Reader]

So is your camerea just piggy backing the scope? Great image! I want to try this!

[blackparticle]

Yes. Long exposure imaging via the scope isn't an option at the moment so I'm relying on camera lenses for DS imaging. I have found that "prime" lenses give a much better result than a zoom as they are more likely to have perfect focus at infinity and suffer from less distortions.

I should switch to bulb mode really. Got to make myself a proper toggle switch for the shutter. Finger trigger cramp can be a pain!!

[The Stoat]

Great image. What was the lens f?

[ollypenrice]

It is nice, but with no bulb setting??? Heroic!

Olly

[garethmob]

cracking picture i havent even got one that good and i have a timer i use on bulb mode!!!

[blackparticle]

Cheers guys. Went to Maplins to get some parts for a shutter release but they were out of stock of 2.5mm jack plugs. I'm tempted to build the release into an old broken guitar pedal so I can keep it on the floor near the scope. I'll have to look at getting a DC PSU for the camera too. Bulb mode can really drain the battery quick.

f/stop was set to f/2.8.

[blackparticle]

Here's one of the un-processed subs. As you can see, I was trusting somewhat to the maths of stacking and Photoshop processing.

[fatwoul]

It is nice, but with no bulb setting??? Heroic!

Olly

Indeed. My finger cramps up at the mere thought! The picture is definitely worth a cramped finger, though. Nice one, bp.

bp, if you have continuous shutter release mode, until you make your shutter release, can't you just use an elastic band around the grip, with a bit of sponge or something pressing down on the button? The camera just starts firing as soon as it's switched on, and stops when you switch it off. If you want to do one long exposure, you leave the lens cap on until the exposure is already going, and then just gently take off the cap, and then put it carefully back on again before you take the band off and stop the exposure. It's what I used to do with my D100 back when I didn't have an intervalometer, and it worked OK.

[blackparticle]

I did a search on eBay and have ordered one of these.

TIMER REMOTE CONTROL FOR Pentax K100D K110D K10D *ist D | eBay UK

(Works with a Canon too)

[fatwoul]

That looks exactly like the Nikon MC-36 I use, so it should serve you very well indeed.

If the menus are the same (and it looks like a copy in every detail), it will basically offer you 4 or 5 options to choose, and once set will work nicely:

DELAY - how long it will wait before starting the whole sequence. I usually set this to about 10-20 seconds, just long enough to get myself away from the scope, or out of the dome and the door shut.

LONG - the duration of each long exposure in the sequence. At the moment, my guiding is stopping me from going higher than 2 minutes.

INTVL (interval) - the time between the camera's shutter being opened. This confused me to begin with, as I thought it was the interval from the end of one exposure to the beginning of the next. Because it is from the start of an exposure to the start of the next, you have to include the duration of each exposure. So if I am performing 2 minute subs, I set an interval of 2 minutes and 5 seconds, so there is a 5 second gap in between exposures.

N (number) - how many exposures you want in the sequence. Setting this to "--" means it just runs until the camera is full or the battery is dead.

The sequence is then started/stopped by pressing the TIMER START/STOP button. Very simple and quick to set up.

There is also a big button further down that is a simple shutter release, which can be locked to perform long single exposures. This button can be operated without batteries in the unit, but the rest of the functions require 2 AAA batteries.

Good luck with it.

[blackparticle]

That saves me reading the manual. Sounds highly useful.

How does the interval work in relation to the camera having to process the data and transfer the buffer out to the card?

I find with the Pentax that after the first few of shots on long exposure it takes an equal amount of time to process and clear the buffer ready for the next image.

Should I factor this in do you reckon?

[fatwoul]

That saves me reading the manual. Sounds highly useful.

How does the interval work in relation to the camera having to process the data and transfer the buffer out to the card?

I find with the Pentax that after the first few of shots on long exposure it takes an equal amount of time to process and clear the buffer ready for the next image.

Should I factor this in do you reckon?

If that's been your experience, then I'd say it might have to be accounted for.

I find the 5 seconds I allow is all I need, but I have all post-shooting features (noise reduction, etc) switched off, since that's what all the flats and darks are for. With NR switched on, my camera does indeed need as long in between shots as the shots themselves.

[blackparticle]

I'll try it with the noise reduction off and see what happens. I suspect it will zoom along.

Does this generally give a better result as well as I can imagine that the noise reduction may actually impart noise on stacked images if applied to the flats & darks as it may well be trying to remove perceived noise rather than actual noise.

I've been trying to gauge what level of pre-processing yields the best results. If any?