Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Any advantages shooting astrophotgraphy with film over digital?

  • Please log in to reply
114 replies to this topic

#101 Ron359

Ron359

    Apollo

  • *****
  • Posts: 1,487
  • Joined: 21 Apr 2008

Posted 14 January 2019 - 01:15 PM

All I can say is, show me the pictures.  We need comparisons of the same subject photographed with the same lens on film and with a digital sensor.

just came across this thread.  you might want to read this (now old) series of articles and comparisons by Roger Clark:

 

http://www.clarkvisi...dex.html#part_7


  • SandyHouTex likes this

#102 Michael Covington

Michael Covington

    Author

  • *****
  • Posts: 6,824
  • Joined: 13 May 2014
  • Loc: Athens, Georgia, USA

Posted 14 January 2019 - 01:47 PM

just came across this thread.  you might want to read this (now old) series of articles and comparisons by Roger Clark:

 

http://www.clarkvisi...dex.html#part_7

Yes -- a good analysis -- but digital sensors have gotten a lot better since then.



#103 Ron359

Ron359

    Apollo

  • *****
  • Posts: 1,487
  • Joined: 21 Apr 2008

Posted 14 January 2019 - 02:07 PM

Yes -- a good analysis -- but digital sensors have gotten a lot better since then.

yes, i did say they're 'old' now.  But Roger has tons of testing, articles, and images on newer and new Canon cams and lenses.    They've only gotten better, while film has stayed relatively 'the same' (but far less available esp. for astro) if you want to make comparisons.  


  • Michael Covington likes this

#104 khingdheano

khingdheano

    Vostok 1

  • *****
  • Posts: 171
  • Joined: 08 Nov 2007
  • Loc: Dallas, TX

Posted 09 August 2019 - 11:33 PM

Could not be a better depiction of the "Diamond Ring" effect. I'm speechless.

 

 

Hello, everyone,

 

I am no longer into film astrophotography having boxed up my Honeywell Pentax Spotmatic many years ago but I raised an interesting subject over in the DSLR group and someone suggested I post it here.

 

Has anyone ever compared the mechanics of a 35mm film camera lens iris and shutter design to those of a DSLR? Until a few days ago I never considered this until I began comparing some photos I took of the 1970 total eclipse in Virginia where I captured a striking image of the diamond ring effect to what DSLR cameras being used today have tried to do.

 

Looking at everyone's eclipse photos I just realized how bland and flattened the diamond ring affect appears when photographed with modern DSLR cameras. I was so excited in planning to venture 400 miles south to shoot the August 21st eclipse with a whole array of high tech equipment that I rented but last minute problems caused my plans to unravel and I had to stay home. I was very fortunate to witness the 1970 total eclipse in Virginia and photograph it with my trusted Spotmatic 35mm camera with roll film, although with only a 200mm prime telephoto lens. And the striking appearance of the diamond ring effect that I captured must have been because of the design of the shutter and iris in the camera which modern cameras don't have.

 

I am far from being an expert on the subject but I would be interested in reading some comments.

 

Regards,

Nelson



#105 Michael Covington

Michael Covington

    Author

  • *****
  • Posts: 6,824
  • Joined: 13 May 2014
  • Loc: Athens, Georgia, USA

Posted 10 August 2019 - 11:17 AM

The shutter and iris are very little changed since the 1970s.   The diamond ring effect is probably more spectacular on film for the same reason that film does a better job of making the bright stars bigger in a star field -- lateral scattering of light within the film.



#106 MDT

MDT

    Lift Off

  • -----
  • Posts: 7
  • Joined: 22 Jan 2020
  • Loc: Northern Colorado

Posted 28 July 2020 - 07:52 AM

I'll resurrect this thread for a comment. 

 

Checking your notes, for exposure times, checking your equipment, hoping clouds don't roll in, or a plane passing through the shot.  Get your guide star in the cross hairs. Shield your lens, or scope. Flop up the mirror.  Open the shutter. Count to 10. Hold your breath.  Remove your shield. Then patiently keep your guide star in the cross hairs for the next 45 minutes. Then, cover the lens, close the shutter and breathe.  

The the anticipation of the shot is killing you. Do you take another? You're freezing, your neck is killing you.  You got to get this little hunk of plastic to the dark room, or to the film lab.

 

At this point  " Wanting is better than Having ". 

 

Oh well, better luck next time.  Or better yet  " Bulls eye !!! "

 

Kinda' like when we used to have to kick-start a motorcycle, " This next kick for sure" 


  • Eric P and ETXer like this

#107 TxStars

TxStars

    Mercury-Atlas

  • *****
  • Posts: 2,596
  • Joined: 01 Oct 2005
  • Loc: Lost In Space

Posted 28 July 2020 - 11:51 PM

"Kinda' like when we used to have to kick-start a motorcycle, " This next kick for sure""

 

The dreaded vapor lock, or early ignition.. Ouchie..That's gonna leave a mark..

 

I remember guiding and seeing the guide star start to bounce..

"Hey I'm in the middle of an exposure don't walk over here please"..



#108 Helge F.

Helge F.

    Lift Off

  • -----
  • Posts: 2
  • Joined: 02 Dec 2020

Posted 03 December 2020 - 06:20 AM

The lower QE of film is not a fundamental of the basic technology, but a question of ease of manufacture and keep-ability.

One could easily imagine film made with some way to get more uniformly and evenly distributed crystals. And one or more of various kinds of doping and hypering.

Trouble is the film has to be on the shelves for months or even years.
Imagine how much thermal and cosmic noise a sensor would pick up from just a week of continuous readout.

There are various things we can do to approximate such an ideal film as previously mentioned.

Combining H2 hypering, flashing, multiple exposures, compensating development and impeccable scanning to pick up the faintest shadow details in the film, will bring you several stops up in sensitivity.

The QE of common camera sensors is on the other hand over-advertised.
Often you’ll hear numbers from huge specialty scientific monochrome, cryo sensors, as universal truths for all sensors.
Sensors and infrastructure that is well out of reach of even a very rich private person.
The real QE of most camera sensors is a trade secret.
But is obviously empirically observable to be far below the often quoted high numbers ranging from 90% to 40%.

Also, it is worth remembering that film scanning unless you have caught onto the recent trend of macro camera scanning, has been absolutely terrible for decades, held up to what we know (but most have selectively forgotten) that film is capable of WRT resolution and dynamics.

Well lit 135 film will in most regards absolutely kill *any* sensor of the same size.
Scanning and erosion of printing knowledge is the problem.
Not film as medium.

Edited by Helge F., 03 December 2020 - 06:24 AM.


#109 Michael Covington

Michael Covington

    Author

  • *****
  • Posts: 6,824
  • Joined: 13 May 2014
  • Loc: Athens, Georgia, USA

Posted 03 December 2020 - 11:51 AM

Very good point, and toward the tail end of the film era, it was well known.  Film has to keep for years.  That means it has to have a lot of reciprocity failure, so that electron activation from thermal noise (for instance) is forgotten and does not accumulate.  Various hypering techniques basically undo the preservatives in the film, making it have a very short shelf life but much less reciprocity failure, as well as higher sensitivity.



#110 Helge F.

Helge F.

    Lift Off

  • -----
  • Posts: 2
  • Joined: 02 Dec 2020

Posted 03 December 2020 - 04:20 PM

If we could get the sellers and consumers in general to understand the need to keep film refrigerated, then we might have a chance at something like the ISO 24000 film teased by Kodak research in 2006.

Also point of use hypering could probably be done.
E.g. when you were about to use the film you pull a tap, releasing a hypering substance over the film.

#111 TxStars

TxStars

    Mercury-Atlas

  • *****
  • Posts: 2,596
  • Joined: 01 Oct 2005
  • Loc: Lost In Space

Posted 03 December 2020 - 07:07 PM

Never had a problem keeping film refrigerated / frozen in bags with nitrogen.

The issue was keeping hypered film dry long enough to use a roll, which is why I went to plates and cut film.

Doing three or four pieces a night saved a lot of film that would have been thrown out.



#112 giganova

giganova

    Vostok 1

  • *****
  • Posts: 154
  • Joined: 14 Oct 2020
  • Loc: Washington, DC

Posted 30 December 2020 - 07:27 PM

Advantages of film? Stable storage medium: you find a 30-year old slide in your drawer and it still looks the same day it was developed. I doubt I'll find a functioning hard drive in my drawer 30 years from now. grin.gif

 

50780466798_c4cba97094_c.jpgComet_Hale_1_4_FINAL


  • Todd N, AnakChan and telesonic like this

#113 GeorgeLiv

GeorgeLiv

    Your Light Pollution Info

  • *****
  • Vendors
  • Posts: 144
  • Joined: 04 May 2018
  • Loc: Montreal Canada

Posted 08 January 2021 - 04:26 PM

I'm quite surprised, no, shocked really, not to find a single mention of the spectral differences between film and digital sensors in this interesting thread. In my view, there's just no comparison with the poor & crude response of any digital sensor to (some) films of the past. Here's a comparison of my sky-glow some years apart shot with the same spectrographic setup (including lens but different body, obviously):

 

Clear-SkyGlow-2001vs2017.jpg

 

Films, some of them quite glorious, generally had wonderful sensitivity in the violet. Celestial objects radiate in both the nearUV and violet, yet (CCD or CMOS) digital imagers ignore that part of the spectrum. That's one reason why many digital images of the Pleiades nebula are poor in comparison to film. Other examples are ion tails of comets. Here's Hale Bopp shot with SuperG800 neg film in April 1997:

 

Hale-Bopp-April-1997.jpg

 

On the other hand, the rather odd spectral response of digital sensors can easily be compensated for if you know what you're doing, and also have higher sensibilities for H-alpha light.

 

Response-of-CCD&Film.jpg

 

 

 


  • Joe F Gafford likes this

#114 Todd N

Todd N

    Messenger

  • *****
  • Posts: 486
  • Joined: 07 Dec 2007
  • Loc: Southern California

Posted 09 January 2021 - 01:09 AM

I'm quite surprised, no, shocked really, not to find a single mention of the spectral differences between film and digital sensors in this interesting thread. In my view, there's just no comparison with the poor & crude response of any digital sensor to (some) films of the past. Here's a comparison of my sky-glow some years apart shot with the same spectrographic setup (including lens but different body, obviously):


 

Films, some of them quite glorious, generally had wonderful sensitivity in the violet. Celestial objects radiate in both the nearUV and violet, yet (CCD or CMOS) digital imagers ignore that part of the spectrum. That's one reason why many digital images of the Pleiades nebula are poor in comparison to film. Other examples are ion tails of comets. Here's Hale Bopp shot with SuperG800 neg film in April 1997:

 

 

 

On the other hand, the rather odd spectral response of digital sensors can easily be compensated for if you know what you're doing, and also have higher sensibilities for H-alpha light.

 

 

For the most part the near UV part of the spectrum is what astrophotographers didn't want in particular with a lens system otherwise one would get bloated stars from chromatic aberration. Light yellow filters(Wratten #2, Lumicon Minus Violet) were used to block that part of the spectrum. Among B&W films Kodak Tri-X and some Rollei films have sensitivity up to 300nm.



#115 GeorgeLiv

GeorgeLiv

    Your Light Pollution Info

  • *****
  • Vendors
  • Posts: 144
  • Joined: 04 May 2018
  • Loc: Montreal Canada

Posted 09 January 2021 - 04:13 PM

For the most part the near UV part of the spectrum is what astrophotographers didn't want in particular with a lens system otherwise one would get bloated stars from chromatic aberration. Light yellow filters(Wratten #2, Lumicon Minus Violet) were used to block that part of the spectrum. Among B&W films Kodak Tri-X and some Rollei films have sensitivity up to 300nm.

Your observation is true but you should understand why we chose that procedure. Possession of lenses & scopes having chromatic aberration is certainly no crime, but it's not the fault of either film or silicon sensors, nor is it a defect in the celestial bodies which I must emphasize readily radiate in the violet and near UV. To this day, I don't understand why that part of the spectrum is ignored by amateurs (but I do know the reasons why).

 

As a photographer I've come across many superb lenses, some of which I own. Some larger lenses had a focus override; many lenses still do. If the imager is astute, one can correct so that a larger span of the spectrum is in-focus if desired.

 

Emissions-Celestial-Objects.jpg


  • Joe F Gafford and Todd N like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics