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A though on star trial photography using P40/65+

mAlKhamis

New member
Hey guys what's up,,

Yesterday we had a photo seminar about star trials photography using 35mm systems.
so i went home, and i was thinking what would be the most efficient way to use to use the P40+ for star trial photography when i get it ?!
let's not forget that the P40/65+ are limited to 1 min exposure time

but i think it doesn't matter at all, why ???

First of all taking a nice circular star movement would need at least 1 hour 30 min from my personal experience. if something went wrong such as a beam of light or a car passed by your camera it immediately trash your photo from a single exposure shot.
However, taking a contentious number of shots 30 sec for 1hr 30min would more efficient and then stack them using a PS CS4 action know as start trial link below
http://www.schursastrophotography.com/software/photoshop/startrails.html

would be more efficient, in which you can remove any unwanted frames in the sequence.
now !! another problem, it would need at least 80-120 shot to have a nice star trial shot, so if were to use the full sensor resolution 60 mp or 40 mp would take huge amount of space and it would need a super computer for blending process.
Now with sensor+ technology in the P40/65+ ,,, taking a sequence for star trial shots would be the most efficient way for space and memory saving. :thumbs:



This is a shot taken by 5D mark II + 14mm F/2.8 II

the problem with this shot is that i had to use the JPEG mode for the sequence, to save space and memory on my imac, i couldn't blend 120 raw.
shots. but it turned to be that the 5D mark II JPEG processing is rubbish for both image processing and printing as well :mad:

your outputs, tips and additions will be so appreciated !!

cheers!

Moh
 

mAlKhamis

New member
Shoot raw then process and convert to jpg, then blend.
Thank you Ben, 120 shot; 21mp per shot maybe acceptable , 40 or 60 mp per shot will really take huge amount of space for my backup drives !!! i will need to purchase extra $$ 2TB hard drives for that :confused:

shooting with sensor+ raw will be straight forward and space saving !! thats my point , now 10mp or 15mp from DMF will be defiantly far more superior from 10mp or 15mp DSLR. and better in dynamic range and tonal color range than the 21mp of the 5D mark II, is that statement correct ??

cheers!

M
 

Guy Mancuso

Administrator, Instructor
Sensor + makes a lot of sense here and having a back that can do it myself have to say your not going to run into a quality issue. I'm very impressed with sensor + and i'm not easy to impress.
 

Jack

Sr. Administrator
Staff member
The action link itself is broken... They are obviously batching, and I am guessing they blend the stack using the "lighten" mode and flatten as they go? Anyway, pretty easy to add a batch process to the action that takes your pile of tiffs and first converts them to jpegs which would be a lot smaller -- and for that type image blend, a high-quality jpeg is probably fine. Another place to save horsepower would be to reduce your history states to 10 before running the batch...
 

mAlKhamis

New member
Sensor + makes a lot of sense here and having a back that can do it myself have to say your not going to run into a quality issue. I'm very impressed with sensor + and i'm not easy to impress.
actually guy, after downloading the sample images of sensor+, i myself was also shocked of it's exceptional quality, i think it's the best innovative idea and it really have added more potentials to MF digital backs !!!
 

Jack

Sr. Administrator
Staff member
Your link to that page works, it's the link off that page to the action that is broken... If you have the action, you can upload it as an attachment file to a post here...
 

Guy Mancuso

Administrator, Instructor
actually guy, after downloading the sample images of sensor+, i myself was also shocked of it's exceptional quality, i think it's the best innovative idea and it really have added more potentials to MF digital backs !!!
As you have seen in my little mini review on sensor plus i am totally happy with that technology available to me when i need it. I have even uprezed them some without any real degradation.
 

Jack

Sr. Administrator
Staff member
Thanks Dave working now --- tried that earlier and it didn't work...

It is just a simple action to copy a frame and paste it to another, then change the blend mode to lighten, then flatten. Should work fine. If you un-check the flatten command you will have a very large layered file, but then can edit each layer as needed... Maybe run the action on 10 frames at a time, edit that and flatten, then repeat for the next 10...
 

mAlKhamis

New member
Thanks Dave working now --- tried that earlier and it didn't work...

It is just a simple action to copy a frame and paste it to another, then change the blend mode to lighten, then flatten. Should work fine. If you un-check the flatten command you will have a very large layered file, but then can edit each layer as needed... Maybe run the action on 10 frames at a time, edit that and flatten, then repeat for the next 10...
Actually Jack the best way to run this action while drinking a glass of good Napa wine :D is by the following steps:

1. Download StarTrails from http://www.startrails.de/html/software.html. We will also be using Adobe Photoshop CS4 (although you can use CS3, CS2 or even Elements 7).

2. Open StarTrails and go to File –> "Open Images" and select all of the frames except for the dark frame and foreground frame.

3. Go to File —> "Open Dark Frames" and select your darkframe

4. Click Build —> Star Trails and give it a few minutes. You can watch as the star streaks grow.

5. Save as a .tiff file and open the .tiff in Photoshop

6. Also open the foreground exposure jpeg and paste it as a new layer on top of your stacked .tiff file in photoshop

7. Create a black mask on the foreground layer and paint in the foreground carefully (see graphic above for example).

8. Apply curves, noise reduction and other editing adjustments and your done!

I learned these amazing steps from a master in Star trials know as Daniel Newton

this is the original link if some is interested:

http://www.jpgmag.com/stories/12961

cheers!
 

dougpeterson

Workshop Member
Stacking frames for star trails is what I did as part of my senior thesis in college.

http://doug-peterson.com/anachronistic.mov

The other huge (not obvious benefit) is that you can shoot star trails in areas and in scenes with more ambient light than a 1 hour exposure would allow.

The post processing can be pretty intense but you can get images that would be otherwise impossible.

I'd still rather see a P45+ doing this work. The cleaner the shadow quality the more stars you will be able to bring up from above the noise floor. With proper level clipping you'll be shocked at how many stars you'll be able to pull out. Especially if you use the technique I did of first-in-first-out stacking of 2 captures (over the course of the time I calculated the stars would move about 1 pixel during) to average out the noise to be as close as possible to the noise floor and then used very careful level clipping to hit that eliminate all the noise at that noise floor but significantly boost the stars that sat above it.

Knowing what I know now about the noise floor in images from a P45+ and a 5DII and the Nikon I used for that project I really wish I had a 45+ for that project!

O, and convenience aside I cannot imagine doing this project in JPG - I used raw and it had an extraordinary on how well I was able to control the noise floor. Once you've converted the raws you can always throw them out (perhaps anathema for most types of shooting but time lapse and star trails generate a LOT of data), but if you shoot JPG you can never get back to the raw.

Doug Peterson (e-mail Me)
__________________
Head of Technical Services, Capture Integration
Phase One, Leaf, Cambo, Canon, Apple, Profoto, Eizo & More
National: 877.217.9870 *| *Cell: 740.707.2183
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mAlKhamis

New member
Looks very cool. Also looks like it doesn't run on Mac...
Actually jack it work well with me, I'm using OSX snow leopard with PS CS4

I processed lots of images using this technique, however with the JPG files the printing was awful !!! even when using sRaw mode in the 5D MK II
 

mAlKhamis

New member
Stacking frames for star trails is what I did as part of my senior thesis in college.

http://doug-peterson.com/anachronistic.mov

The other huge (not obvious benefit) is that you can shoot star trails in areas and in scenes with more ambient light than a 1 hour exposure would allow.

The post processing can be pretty intense but you can get images that would be otherwise impossible.

I'd still rather see a P45+ doing this work. The cleaner the shadow quality the more stars you will be able to bring up from above the noise floor. With proper level clipping you'll be shocked at how many stars you'll be able to pull out. Especially if you use the technique I did of first-in-first-out stacking of 2 captures (over the course of the time I calculated the stars would move about 1 pixel during) to average out the noise to be as close as possible to the noise floor and then used very careful level clipping to hit that eliminate all the noise at that noise floor but significantly boost the stars that sat above it.

Knowing what I know now about the noise floor in images from a P45+ and a 5DII and the Nikon I used for that project I really wish I had a 45+ for that project!

O, and convenience aside I cannot imagine doing this project in JPG - I used raw and it had an extraordinary on how well I was able to control the noise floor. Once you've converted the raws you can always throw them out (perhaps anathema for most types of shooting but time lapse and star trails generate a LOT of data), but if you shoot JPG you can never get back to the raw.

Doug Peterson (e-mail Me)
__________________
Head of Technical Services, Capture Integration
Phase One, Leaf, Cambo, Canon, Apple, Profoto, Eizo & More
National: 877.217.9870 *| *Cell: 740.707.2183
Newsletter: Read Latest or Sign Up
RSS Feed: Subscribe
Buy Capture One at 10% off
Personal Work
Doug really amazing what you have did in your thesis

i totally agree with you regarding the use of one exposure shot, however as i said i that i tried the bulb mode for 1 hour but when a car pass by or one opens a flash light your image is screwed and you have to retake it again, i have many photographer friends whom very insensitive :deadhorse: and they screwed my star trial shots many times, i find the blending technique more practical if you were to hang out with friends for camping, but alone yes the one shot long exposure is better :D

This action is magic and does the job very fast if you followed the steps

I'm so curious now about using sensor+ feature for this technique !!
 

bdp

Member
After reading this thread I decided I would like to try it with my Sinar eMotion and Contax combo, but unfortunately I discovered that the Swiss* are a little too thorough when it comes to quality sometimes, as when the camera is set to 16 seconds the back takes a black frame after EVERY capture. So I would end up with one 16 second capture out of every 32 seconds, and the result of layering many captures like this together would be a whole bunch of dotted lines across the sky :D Anyone know if it's possible to turn off the automatic black frame for a series of captures? Probably not.

Ben

* Actually maybe I should say Germans as the eMotion backs were invented and made by Jenoptik in Germany
 
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bdp

Member
After a bit more experimenting it seems the Sinar back doesn't do a black frame after every capture if the exposure is 1 second or shorter. But that may not be long enough to expose the stars, even at a big aperture like f4. Also I think it will eventually stop to take a black frame after continuous shooting for 5 or 10 minutes - haven't tested that one.

Also the black frame seems to take longer than the exposure - an 8 sec exposure takes 14 seconds before it will shoot another frame. A 2 second exposure takes around 7 seconds before another frame. But at 1 second it will shoot with only a short delay between captures, maybe half a second or so.

Shame because I'm going to Fiji for a job in a week and staying on for a few days for a holiday, and there will be no moon for a couple of nights while I'm there, plus no light pollution (being on a island). Another job for the trusty 5D I suppose.

Ben

PS there is an EXCELLENT iphone app called Star Walk which is very useful for star trail photography - it shows you where everything is - horizon, north south etc and will even spin the stars for you!
 

Woody Campbell

Workshop Member
Hmmm . . . . This is very interesting. I'll try 10 or 15 exposures with my h3d 39 next time I have a really clear night just to test the technique. If one of the issues is sensor heating shouldn't I have have the issue running back to back exposures?
 

mAlKhamis

New member
After a bit more experimenting it seems the Sinar back doesn't do a black frame after every capture if the exposure is 1 second or shorter. But that may not be long enough to expose the stars, even at a big aperture like f4. Also I think it will eventually stop to take a black frame after continuous shooting for 5 or 10 minutes - haven't tested that one.

Also the black frame seems to take longer than the exposure - an 8 sec exposure takes 14 seconds before it will shoot another frame. A 2 second exposure takes around 7 seconds before another frame. But at 1 second it will shoot with only a short delay between captures, maybe half a second or so.

Shame because I'm going to Fiji for a job in a week and staying on for a few days for a holiday, and there will be no moon for a couple of nights while I'm there, plus no light pollution (being on a island). Another job for the trusty 5D I suppose.

Ben

PS there is an EXCELLENT iphone app called Star Walk which is very useful for star trail photography - it shows you where everything is - horizon, north south etc and will even spin the stars for you!
hi Ben, thanks for trying, mmmm, i think it's hard if you were using the full resolution of your DB, even if the black frame thing was solved, because with this technique using high resolution raw file gonna kill your computer during the exposure stacking, however i'm curious what are the results of using sensor+ , i guess we gonna have to wait until someone try it here or when i get my baby in few months :D , i assure you, i will certainly keep you posted

another thing, regarding the 5D mark II, it's not that good for startrial photography, when compared to the 1ds mark III or nikon D3 or D3x ,, based on my recent experience

thank you so the application, i've heard it's awesome, it will show you the north star, which is the most important location for a perfect star trial photography :)

cheers! my friend and good luck in your trip

PS: perhaps you can try by renting a P40+ from C.I :p
 
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