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180 Minutes onto the Plejades with 200ASA

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#1 Lucullus

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Posted 10 February 2020 - 06:40 PM

About five or six years ago, I made my last analogue astrophotography attempts -  sadly, I haven't had time since then. I was still more into film than into digital astrophotography blink.png and had (if memory serves me right) an ASA200 film in my camera. I attached a 300mm objective, set it up to about f/4, mounted the camera on my 102/1000 achromat, used as guider with my haircross eyepiece, and intended to capture the Plejades for 60 minutes. No worries, I had the mount track the guide star and applied some regular manual corrections...but it was a real pain! But then I wondered how much more I might see if I go to 120 minutes, at which time I thought "The heck with it!" and extended to 180 minutes. The film was not full and I did some daylight images with the rest over the coming months. But then I forgot to have the film developed and it is still in the camera. I would like to have it developed once I get back home but I am wondering what I can expect from the Plejades image.

 

I only recently learned that once you expose past a certain time limit there are no more benefits and only the background gets brighter and brighter. Moreover, do I have to fear that the years in the camera degraded the film in some way, although it was stored dry and out of heat? Please tell me I will have a good nice photo to look at... one that was worth the efforts.praying.gif


Edited by Lucullus, 10 February 2020 - 07:47 PM.


#2 Alen K

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Posted 10 February 2020 - 07:36 PM

It will likely be grainier than it would have been if you had developed it right away. 

 

Whether you have anything good depends on how much sky glow you experienced at the time, what kind of film (different films had/have different degrees of reciprocity failure), and how well you guided, although guiding a 300mm lens is quite forgiving. 

 

That said, if it were me and I had switched from film to digital (which I did), I probably wouldn't bother developing the roll (unless the rest of the images on it were important). Film is anywhere from ten to thirty times less sensitive than a DSLR, meaning I can do an equivalent image wrt signal-to-noise ratio using a DSLR in something like between six and 18 minutes, and that's without taking reciprocity failure into account. 

 

PS. I used to shoot with ASA/ISO 200 film a lot, specifically Kodak Elite Chrome 200 slide film. Some of my photos are posted to my gallery. No 180-minute exposures, though.


Edited by Alen K, 10 February 2020 - 08:31 PM.

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#3 TxStars

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Posted 10 February 2020 - 11:03 PM

If you were shooting from a dark sky site then you should still be able to see some nebula in the image.



#4 telesonic

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Posted 11 February 2020 - 02:01 AM

From my own experience, albeit... only a year or so into actual film stuff and only a roll or three / four.....old film can get funky color shifts if not developed quickly, or if it was not stored properly and it's a old roll. Grain, fogging. Also - your own sky conditions are a factor. I sure as heck haven't mastered it as well as some here have done.

 

But, I'd definitely get those negatives developed, since you might have some really good daytime shots on there, and you may even have a stellar shot in there. It's also a good point to start to check your camera is working, and if there are light leaks.... etc..... and if want to keep shooting film in the era of DLSR. In my area the only developer I have in town is a   big box store   that sends the film out.... and what you get is on photo CD or prints. I ran a few old rolls, and was surprised. Some tweaks with an image editor fixed 'em..... so YMMV.

 

 

 

Cheers,



#5 Lucullus

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Posted 11 February 2020 - 04:40 AM

Before I had mine developed by a professional photographer I went to a big box store as well. That changed once they lost my 800ASA astro roll during development...I never got pictures nor the negatives!

 

BTW once the negatives are developed the images on them don't degrade anymore?


Edited by Lucullus, 11 February 2020 - 05:16 AM.


#6 Todd N

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Posted 11 February 2020 - 03:57 PM

Before I had mine developed by a professional photographer I went to a big box store as well. That changed once they lost my 800ASA astro roll during development...I never got pictures nor the negatives!

 

BTW once the negatives are developed the images on them don't degrade anymore?

Film properly processed and kept in ideal conditions will last for decades and longer than any of us. B&W has better longevity over color film that fades.


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