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06-29-2010, 03:21 AM   #1
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Star Trails using a Super A

Good Evening All,

I want to try star trails using a Super A with a 400 ASA film. I have an A series f2 50mm, 3.5 35-105 and an f4 70-210 lens to choose from. what are your suggestions regarding settings.

I was advised not to use my K20D as it would possibly burn out the sensor on a long exposure.

Regards,
Gordon.

06-29-2010, 04:03 AM   #2
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Hi Gordon,


Not sure of the K20 burning up, I do suspect noise could be an issue in single long exposures. Most DSLR users stack images for star trails.

As for film, I would stay away from 400 speed films as most have reciprocity issues, not to mention lots of grain. I would suggest a film like Provia 100F, Astia 100F, Kodak E200, Kodak Elite Chrome 200, or for B&W, Fuji Acros 100. Kodak Gold 200 is a good print film for star trails as well. It has superb reciprocity.

I imagine you already know how to use a tripod and cable release for such exposures. As for lens settings, normal or wide angle lenses work best for star trails. Stop down the lens to say, f/4 or f/5,6 for hour long exposure if you have dark skies. Under some moonlight try f/8. Full moonlight stop down to f/11, but you will record few stars in full moonlight. Longer, multi-hour exposures will require stopping down another stop or so.

Get away from manmade light sources, prefereably a country sky free of light pollution.

Frame your shots with interesting landscapes and in directions relatively free of aircraft, unless that's what you like.

Experiment with exposures, the above settings are just a starting point. You will want to adjust depending on your personal taste and unique situation.

Good luck.
06-29-2010, 04:12 PM   #3
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QuoteOriginally posted by nightfly Quote
Hi Gordon,


Not sure of the K20 burning up, I do suspect noise could be an issue in single long exposures. Most DSLR users stack images for star trails.

As for film, I would stay away from 400 speed films as most have reciprocity issues, not to mention lots of grain. I would suggest a film like Provia 100F, Astia 100F, Kodak E200, Kodak Elite Chrome 200, or for B&W, Fuji Acros 100. Kodak Gold 200 is a good print film for star trails as well. It has superb reciprocity.

I imagine you already know how to use a tripod and cable release for such exposures. As for lens settings, normal or wide angle lenses work best for star trails. Stop down the lens to say, f/4 or f/5,6 for hour long exposure if you have dark skies. Under some moonlight try f/8. Full moonlight stop down to f/11, but you will record few stars in full moonlight. Longer, multi-hour exposures will require stopping down another stop or so.

Get away from manmade light sources, prefereably a country sky free of light pollution.

Frame your shots with interesting landscapes and in directions relatively free of aircraft, unless that's what you like.

Experiment with exposures, the above settings are just a starting point. You will want to adjust depending on your personal taste and unique situation.

Good luck.
Hi nightfly,

Thanks for your advice so I will try next week when I get back to work in the Pilbara region in North Western Western Australia.

Regards,
Gordon.
06-29-2010, 07:19 PM   #4
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Be aware that long exposures can be hard on batteries for some cameras with electronic shutters.


Steve

06-30-2010, 03:31 AM   #5
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QuoteOriginally posted by stevebrot Quote
Be aware that long exposures can be hard on batteries for some cameras with electronic shutters.


Steve
Good point. I'm not familiar with the Super A. Might want to get some extra batteries or invest in a mechanical body.
06-30-2010, 04:53 AM   #6
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QuoteOriginally posted by gordon_l34 Quote
Good Evening All,

I want to try star trails using a Super A with a 400 ASA film. I have an A series f2 50mm, 3.5 35-105 and an f4 70-210 lens to choose from. what are your suggestions regarding settings.

I was advised not to use my K20D as it would possibly burn out the sensor on a long exposure.

Regards,
Gordon.
Gordon, there is obviously some urban myth about sensor burn out. That is nonsense, as long as you don't put a 400/2.8 lens on the camera and expose the sun for a minute fully open…

The thing is, that the sensor gets warm, some call it hot, at long exposures, which leads to an annoying level of noise and a very visible noise gradient in the image. The K20 seems to be quite sensible to this. But this will not damage the camera.

Nevertheless for long star trails a film camera is the better option, at least for starters. Use the widest lens you have and expsore for at least 20 minutes. This gives a good length to the single star trail, short trails just look as whether you had camera shake. If you live near city lights, stop down the aperture to f/8 or smaller with your 400ASA film. Out under really dark skies, you can open up to f/5.6 or so.

One important thing about star trails: look for a place with a nice foreground (tree silhouttes or a mountain range or whatever), because including some foreground detail makes the image much more interesting.

Ben
06-30-2010, 07:52 AM   #7
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Sensor won't burn out, but you'll get very noisy pictures.


I've tried K100D - totally useless. Terrible noise at ISO 200 even for 2 minutes exposure.

K10D is much better. I've tried upto 8 minutes sky exposure. The problems are 3 heat glow areas on the sensor (due to nearby warm hardware) and green-magenta gradient. This one is iso 800 and 2 mins with EV+ in editor.
Name:  S_BOA_e20580_lzn.jpg
Views: 1439
Size:  158.4 KB

Also some guy on penta-club.ru tried K20D for 89 minutes at iso 400
The result was really funny.
Name:  IMGP7895_copy_89 минут исо 400 к20д_.jpg
Views: 1276
Size:  109.1 KB
06-30-2010, 09:23 AM   #8
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QuoteOriginally posted by Zebooka Quote
Sensor won't burn out, but you'll get very noisy pictures.

Also some guy on penta-club.ru tried K20D for 89 minutes at iso 400
The result was really funny.
Attachment 65311
That's a great image. Probably far off the intention of the photog, but nevertheless great.

Ben

06-30-2010, 10:50 AM   #9
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Here's one I did with my K20 last year - exposure was 40 mins at 200 ISO.



As I remember, the biggest concern I had with going longer was battery life.

re-tom
06-30-2010, 12:14 PM   #10
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QuoteOriginally posted by tpeace Quote
Here's one I did with my K20 last year - exposure was 40 mins at 200 ISO.



As I remember, the biggest concern I had with going longer was battery life.

re-tom
This is a beautiful image, that show the star trails nicely within the context of a great foreground feature. Just wonderful. Good work!

Ben

P.S.: and its a good example of the long exposure time capabilities of the K20, by the way
06-30-2010, 03:44 PM   #11
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QuoteOriginally posted by Ben_Edict Quote
Gordon, there is obviously some urban myth about sensor burn out. That is nonsense, as long as you don't put a 400/2.8 lens on the camera and expose the sun for a minute fully open…

The thing is, that the sensor gets warm, some call it hot, at long exposures, which leads to an annoying level of noise and a very visible noise gradient in the image. The K20 seems to be quite sensible to this. But this will not damage the camera.

Nevertheless for long star trails a film camera is the better option, at least for starters. Use the widest lens you have and expsore for at least 20 minutes. This gives a good length to the single star trail, short trails just look as whether you had camera shake. If you live near city lights, stop down the aperture to f/8 or smaller with your 400ASA film. Out under really dark skies, you can open up to f/5.6 or so.

One important thing about star trails: look for a place with a nice foreground (tree silhouttes or a mountain range or whatever), because including some foreground detail makes the image much more interesting.

Ben
Good Morning All,

I spoke to a technician at CR Kennedy's yesterday, the Australian importers, who said that the only way I could damage the sensor was if I photographed the sun for an extended period.

Thanks for all the advice, but I have already reactivated the Super A. I think it is called the Super Program in the USA. It was the top of the range when I bought it in 1985 in Pentax's 35mm cameras.

Regards,
Gordon.
06-30-2010, 04:17 PM   #12
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Star trails are the simplest form of astrophotography and can be of the greatest satifaction for a photographer.

I still prefer film. No noise when properly exposed. No practical limit to exposures or batteries to wear out. And did I mention it was easy?

The films I mentioned earlier have little or no color shift, that's another concern besides reciprocity failure.

Last edited by nightfly; 10-26-2011 at 06:26 PM.
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