SD14 Bulb & telescope adapter

[OyvindS]

SD14 usertips

Hi Savourylie

If you need to know more about the SD14, I have compiled some info:
http://www.foto.nordjylland.biz/SD14/SD-usertips.htm

Hi Bob,

Thank you so much for the information! I bought SD14 because I really loved it's film-like tones and I also knew about it's 30 seconds limit before I bought it. But now I'm really glad to know that I can still use it to shoot star trails! It's a bonus!

Calvin

 

[OyvindS]

SD14 - astrophotography?

Hello Steaphany

Interesting information. Very interesting.
But a few things hit my mind.

First, this is actually multiexposure, right? Meaning that each image is underexposed?
This is bad news for the SD14, which excels at good light, with proper exposure.

A series of exposures with the SD14 will be limited to one shot every 5-6 seconds, would that pose a problem?
I also wonder how/if the dark frame capture of the SD14 will interfere with timed multiple exposures. One has to calculate with twice the exposure time in single shot, and 7x exposure time in a series of 6 images in continous.
Maybe a problem, but maybe not. I suspect the SD14 only do a dark frame capture below certain (to me, unknown) speed.

Also, does the below suggested technique require that the noise is equal from frame to frame?

Another thing to consider is the lock error; occationally lock when shooting before the buffer has cleared - supposeedly (but not completely, at least not for everyone) fixed with v1.08. Required remedy of the lock error is to pull the battery, loosing all unwritten images.
It has been suggested that turning off preview helps, but this is not verified.

Whether you've upgraded your SD14's firmware to support 120 Second exposures or not, the short exposure time, 30 or 120 seconds is not a problem.

Many astro-photographers, from amateur to professional have turned to a technique of combining multiple images as a means to reduce noise and increase image quality. Referred to as image stacking, the idea is to align and combine multiple images so that the random thermal noise cancels out. I have also seen examples of large astronomical observatories aiming their cameras onto a uniformly pure grey region of the dome's interior to measure a base line of each pixel element in the imager chip. This base line is then used to compensate for hot pixels and to enhance weak pixels.

Here is also a free software package, RegiStax, to align and stack images:

http://www.astronomie.be/registax/index.html

Here is an example of what enhancements can be achieved from the RegiStax web site:

http://www.astronomie.be/registax/html/multipoint_alignment2.html

Another example of a image stacking program is Startrails:

http://www.startrails.de/html/software.html

Here is something that I found, by searching on google, to add to this post to demonstrate what imaging stacking can do. The link:

http://forums.dpreview.com/forums/read.asp?forum=1019&message=29727985

Shows the results of stacking 35 images taken with a EOS 50D with a Canon 100-400mm set to 400mm, each exposure being just 1 Second. The page does show the results of the 35 frames stacked and an example of a single frame to show how the image was captured.

I personally have not yet gotten around to my own astrophotography with my SD14, mainly because I have yet to either find or design my own interval timer to automatically shoot a series of images. I will be posting my results when I have them.

Finally, here is a link for a multitude of astrophotography resources which may help:

http://www.eaas.co.uk/news/astrophotography_resources.html

I've noted that there is little to no mention of the SD14 in astrophotography applications, so fellow amateur astronomers here should speak up about their efforts.

kind regards
Øyuvind Strøm

 

[Niabhim]

Please remove my account

Thank you for your message.

Having been seriously ill for several months and unable to contribute I have decided to leave the forum.

Having made something of a recovery I have decided to join a local Photographic Society and gain in competency.

Maybe next year when I might better be able to add to the Sigma forum I will join up again.

Meanwhile, please remove my account.

Regards

Norman C. Richards

 

[DSG]

Does anyone have an idea how to get the SD14 to take longer exposures than 30 seconds on bulb.

Yes, switch to extended mode. Extended mode gives you ISO50 capabilty and extends the shutter open time to 120 seconds.
I have FW1.07 installed and I have extended mode so you dont necessarily have to upgrade the FW to 1.08.

If this cannot be done it severely limits the usefulness of the camera for astrophotography. With it's removable NIR/dust protector, this camera should be a natural for this application to augment its' great flexibility. If it hasn't already been contempleted Sigma might think about another firmware upgrade to fix this problem, ie., greater than 30 second bulb.

Also, where can I find a T mount adapter for my telescope so I can marry the camera to my Meade telescope.

Simple, get a T2-PK (Pentax K) adapter. There is no T2-SA adapter but the PK one fits on no problem. An T2-M42 adapter is the other option but you will need an M42-SA adapter.
There are cheap Chinese M42-SA adapters available but I would avoid them as they dont have an AA pin compression flange built in. Without the flange many M42 lenses wont be able to stop down as there is nothing to keep the AA pin pressed in.
There are two recommended types on M42-SA adapter available, the Japanese JTAT adapter (which is the best quality version) and the cheaper but adequate Polish-made PMBAA (Polish Made Black Anodised Aluminium version.

The T mounts avasilable do not fit the SD14 which is another significant issue for astrophotographers that might want to use the excellent SD14/F3 sensor for this application.

I dont know which T-mounts you've tried but as I mentioned before, the T2-PK and T2-M42 adapters fit fine.