Canon 1d3 long exp.

[chrisjb]

Hi, I did a search and may have missed. When taking long exposures with Dslrs

to avoid noise a series of ahorter exp layered together in PS works well. But

when using `dark subtraction` process we end up with gaps in star trails.

 

The 1d3 has 2 digit3 processors, so, after taking a 2min exposure does one proc

control the dark subtraction and leave the camera free to continue on to the

next 2 min exp,etc therefore virtually elliminating the gap? or am I thinking

too far in advance

 

TIA

[colinsouthern]

Hi Chris,

 

Yes, the 1D3 will allow you to eliminate gaps in star trails. I just did some quick tests for you on mine and can confirm that it can take further shots whilst it's still working on the noise reduction of previous shots. To be honest, I'm not sure just how they've implimented it - it appears as though you can stack up many images "in the que", so it appears to be more than just load-sharing across the 2 Dijic IIIs.

 

I did an interesting experiment with my 20D some time ago - I took 32 images on ISO 3200 (all indoors - static scene) and then blended them in photoshop (base layer opacity 100%, next layer 50%, then 33%, then 25% etc) - the flattened end result was at least as good as ISO 200 - it was quite impressive actually.

 

Personally, I'd be surprised if you needed to stack images for noise reasons when doing astrophotography the way you suggest - the technique you talk of is mostly for cameras attached to tracking devices, as a way to "amplify" very dim images without amplifying the noise.

 

Hope this helps.

[chrisjb]

Thankyou Colin, this body appears to be so far ahead of others, I doubt when I get hold of one I`d touch another 35mm film. it must be a joy exploring its capabilities, appreciate your time

 

cheers

[colinsouthern]

Your very welcome Chris - I'm very happy with mine, although I've "had" to forward a few firmware enhancement suggestions to Canon which I hope that they'll pick up on :)

 

Truth be known, it's a joy on one hand, but can be a bit daunting on the other - quite a few settings on one area filter through to affect settings in others - thankfully you can save 3 different configurations for "instant setup" (eg Landscape, Sports, Portrait).

 

Cheers,

 

Colin