Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-18-2020, 11:16 PM   #16
New Member
R.udyM's Avatar

Join Date: Feb 2020
Posts: 11
Original Poster
QuoteOriginally posted by BigMackCam Quote
Your problem here is the ISO setting of 51200... It's awfully high, even if you're stacking. The reason you're having to use such a high ISO is because (a) your aperture setting of f/6.3 is quite narrow and (b) your shutter speed of 1/10s is pretty fast. That combination of factors means you're not letting very much light at the sensor for the conditions you're shooting in. I'm no astro-photographer, but I'd say you want to be using a lens with a wide maximum aperture set to something like f/2.8 or f/4 (though you can shoot some astro at narrower apertures, with limitations), and a shutter speed up to several seconds in duration (tripod mounting is essential here, of course). That combination will allow you to bring your required ISO setting way down from ISO 51200 to something like 3200 or 6400, give or take.

Does that make sense?

You might have a read through the following article, which I think will help:

https://photographylife.com/landscapes/best-camera-settings-for-astrophotography
Having read through the article I think I have an idea of what to alter tonight when I try again, the lens I was using has a maximum aperture of 3.6 on a 400mm lens, it's an old lens but I think the glass is in mint condition so I'll give it another go tonight and post my results here, wish me luck 😬😂

02-19-2020, 12:22 AM - 2 Likes   #17
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 16,000
QuoteOriginally posted by R.udyM Quote
Having read through the article I think I have an idea of what to alter tonight when I try again, the lens I was using has a maximum aperture of 3.6 on a 400mm lens, it's an old lens but I think the glass is in mint condition so I'll give it another go tonight and post my results here, wish me luck ����
Looking at the settings you previously tried, you had shutter speed 1/10s, aperture f/6.3 and ISO 51200 in order to achieve an acceptable (if grainy) exposure. Even if you'd kept the aperture at f/6.3 for reasonable performance from your old lens, you could have lengthened the shutter speed to 2s (two full seconds), which is roughly four stops longer, and that would have allowed you to bring ISO sensitivity down by four stops to 3200.

Good luck!

Last edited by BigMackCam; 02-19-2020 at 02:37 AM.
02-19-2020, 02:22 AM   #18
New Member
R.udyM's Avatar

Join Date: Feb 2020
Posts: 11
Original Poster
QuoteOriginally posted by BigMackCam Quote
Looking at the settings you previously tried, you had shutter speed 1/10s, aperture f/6.3 and ISO 51200 in order to achieve an acceptable (if grainy) exposure. Even if you'd kept the aperture at f/6.3 for reasonable performance from your old lens, you could have lengthened the shutter speed longer to 2s (two full seconds), which is roughly four stops longer, and that would have allowed you to bring ISO sensitivity down by four stops to 3200.

Good luck!
Ahhh that's a good point, one question I have is regarding the previous issue of the timing of the shutter speed interference with the duration of each shot in the interval settings, is there a certain setting I should aim for or is it more trial and error?

Also, am I right in assuming that to get a more detailed view of the Orion nebula that the older 400mm (I believe it's from the 70/'s or 80's) would be the better choice over the sigma 300mm to get a better overall picture?
02-19-2020, 08:05 AM - 1 Like   #19
Pentaxian
jack002's Avatar

Join Date: Sep 2014
Location: Missouri
Photos: Albums
Posts: 725
I have taken many sky pics of the moon. Most of what I have learned has been from trial and error. Try something, try something else and repeat. I never knew there were so many variables to consider. As for ISO, for my camera (A K5) I like 3600. Its not too grainy and its as high as I like to go. I hope you have a really sturdy tripod and a cable release. Oh you said you have an intervolometer. Use that, keep trying things. Good luck

02-19-2020, 11:36 AM - 1 Like   #20
New Member
R.udyM's Avatar

Join Date: Feb 2020
Posts: 11
Original Poster
QuoteOriginally posted by jack002 Quote
I have taken many sky pics of the moon. Most of what I have learned has been from trial and error. Try something, try something else and repeat. I never knew there were so many variables to consider. As for ISO, for my camera (A K5) I like 3600. Its not too grainy and its as high as I like to go. I hope you have a really sturdy tripod and a cable release. Oh you said you have an intervolometer. Use that, keep trying things. Good luck
Thanks! will do! out of interest how many pictures would you say you take on an average night shoot?
admittedly being from south wales at the moment isnt giving me the best weather for it so I'm hoping that when it clears up and I'm off work ill have a lot more time to make adjustments on the fly and see what works best!
02-19-2020, 12:48 PM   #21
Pentaxian
jack002's Avatar

Join Date: Sep 2014
Location: Missouri
Photos: Albums
Posts: 725
QuoteOriginally posted by R.udyM Quote
Thanks! will do! out of interest how many pictures would you say you take on an average night shoot?
admittedly being from south wales at the moment isnt giving me the best weather for it so I'm hoping that when it clears up and I'm off work ill have a lot more time to make adjustments on the fly and see what works best!
Maybe 5 or 6? Don't be afraid to take dozens. I have issues with focus and try to do a focus range tests.
02-19-2020, 02:35 PM   #22
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 16,000
QuoteOriginally posted by R.udyM Quote
Ahhh that's a good point, one question I have is regarding the previous issue of the timing of the shutter speed interference with the duration of each shot in the interval settings, is there a certain setting I should aim for or is it more trial and error?
Does your intervalometer allow you to set the gap between each shot? If so, you want to set it to just slightly longer than the shutter speed plus processing time. If not, then you'll have to work out how many of the triggers will occur when the camera is ready to take a shot. Or rely on trial and error

QuoteOriginally posted by R.udyM Quote
Also, am I right in assuming that to get a more detailed view of the Orion nebula that the older 400mm (I believe it's from the 70/'s or 80's) would be the better choice over the sigma 300mm to get a better overall picture?
Without knowing the optical performance of the lenses - and, specifically, your examples of them (since there is some copy variation between instances of the same lens) - it's difficult to say. I would take a very good 300mm lens over an average 400mm lens any day of the week - but, if they're of similar quality optically, then the 400mm will obviously give you a bit more magnification. Which make and model of lenses are they?

Last edited by BigMackCam; 02-20-2020 at 08:19 AM. Reason: Updated thanks to stevebrot's info
02-19-2020, 03:09 PM - 1 Like   #23
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 38,862
QuoteOriginally posted by BigMackCam Quote
Does your intervalometer allow you to set the gap between each shot?
Knowing how the intervalometer does its timing is essential. While in-camera features for some brands support timed wait between shots, a true intervalometer performs an action on interval for a given number of repetitions. That is why it is important to only use exposure modes and other settings where the exposure time + processing time is known.

That figured out, it is possible to have some interesting fun with a wired intervalometer combined with the interval features of a Pentax dSLR. How does timed B(ulb) mode exposures of arbitrary length at set intervals sound?


Steve

(...am a real fan of wired intervalometers...)

02-19-2020, 05:03 PM   #24
Site Supporter
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 7,844
Nice start at astro-photography. Your exposure time is way too short, needs to be in several seconds to minutes, light pollution allowing.
So, you could go for the astro-tracer (not too expensive) or a DIY barn-door (super cheap) or an equatorial tracking mount ($$$)

Cheers.
Mike.
02-20-2020, 08:17 AM   #25
Pentaxian
jack002's Avatar

Join Date: Sep 2014
Location: Missouri
Photos: Albums
Posts: 725
Rudy,
Consider joining our group here. Lots of info you need in there
Astrophotography - PentaxForums.com
02-24-2020, 04:36 PM - 1 Like   #26
New Member
R.udyM's Avatar

Join Date: Feb 2020
Posts: 11
Original Poster
Hi all, a quick update and question, at the risk of sounding quite "nooby" once more, When attempting to stack say 20 or 30 images in DSS what exposrue time for each picture would everyone say is optimal for individual pics of the orion nebula when being zoomed in as much as is feasible?? I'm finding that taking 8 second exposures results in fuzzy pictures despite me setting my lens to being incredibly focussed before taking the pictures. Once more any tips would be gretly appreciated, ive lowered my ISO as was advised in previous posts which did seem to help somewhat during the actual taking of the pictures but once put into the PC they seem vitually equal in terms of fuzziness etc :/

again any and all help is appreciated. I did find that the 300mm was easier to handle than the 400mm lens too if that info is relevant.

Rudy
02-27-2020, 02:30 PM   #27
Pentaxian
jack002's Avatar

Join Date: Sep 2014
Location: Missouri
Photos: Albums
Posts: 725
So are you using a sturdy tripod?
I would try to limit to about 2 second exposures and about 3200 ISO (I'm not the one to say, I'm a noob at this too)
I took this at f 2.0, 2.5 seconds at ISO 1000
(50mm film lens)
Also, you did say you are shooting raw? Do that if you're not
I'd think you can deliberately shoot 1 or 2 stops underexposed. I have seen black raw files come up with detail well, you can pull details out of darkness in post.
(Again,I defer to any of you out there, I'm not that fluent in night shooting)

Also, I said it before, here it is again JOIN US HERE. This is an astrophotography group here. Lots of people there that can help
https://www.pentaxforums.com/forums/groups/135-astrophotography/

Last edited by jack002; 02-27-2020 at 02:36 PM.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, kp, pentax kp, release, rudy, shutter release
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
KP vs K-70 - to KP or not to KP, that is the question OldChE Pentax DSLR Discussion 28 11-02-2019 05:29 AM
HELP Please: Pentax K-x remote shutter not working in Video Mode... Andyvious Troubleshooting and Beginner Help 5 10-02-2011 04:09 PM
Help! MZ-7 shutter release not working Black Magic Pentax Film SLR Discussion 9 08-12-2009 08:56 AM
K10D shutter release button not working well . Any ideas lesmore49 Pentax DSLR Discussion 6 07-19-2009 10:48 PM
Shutter release not working K10 voicelit Pentax DSLR Discussion 10 06-05-2008 12:44 PM



All times are GMT -7. The time now is 03:01 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top