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 1.4f 3200iso to 22f 50iso auto timelapse controler 
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Joined: Tue Jan 17, 2012 12:52 am
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Location: Sydney,Australia
Post 1.4f 3200iso to 22f 50iso auto timelapse controler
Ive designed and built a standalone timelapse controller with dual axis stepper motor mount/dolley contol, multistep linear and S curve move ramps and full 1.4f 3200iso to 22f 50iso auto exposure interval bulb mode control (with a 5d mk2/24mm f1.4) with exposure times controlled by flash output feedback (for accurate exposure times at the short end). Also several exposure meter (external) and exposure time rate filters depending on AM/PM or bi-directional sky lighting conditions. Its been a long painfull project, I have yet to use the finished product for a killer timelapse in the field unforch.

Rather than launch on the boring detail, Im wondering why there arnt many (any?) timelapse controllers on the market that dont offer full auto AP/ISO control in manual bulb mode?. It seems to me an advantage for instance to be able to automatically image from full daylight to full dark automatically on a sunset sequence rather than say the manual little bramper method?. Im wondering now if Ive wasted time on this. Is auto AP/ISO control of interest in the Timelapse community?.

Cheers
Fred


Tue Jan 17, 2012 1:25 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Welcome Fred.

Very impressive. Would be interested to know how you're dealing with the change of ISO in your standalone device? Is it PC/Mac based or microcontroller? In terms of what's out there already that automates the ramping, I know of only GBTimelapse (PC based - http://www.granitebaysoftware.com/Produ ... tures.aspx) or the Magic Lattern Unified firmware. For the latter, a 5D2 version is currently in beta and I believe it contains an AP/ISO bulb ramping feature (http://www.eoshd.com/content/6640/eoshd ... 5d-mark-ii)

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Tue Jan 17, 2012 2:32 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
colinmlegg wrote:
Welcome Fred.

Very impressive. Would be interested to know how you're dealing with the change of ISO in your standalone device? Is it PC/Mac based or microcontroller? In terms of what's out there already that automates the ramping, I know of only GBTimelapse (PC based - http://www.granitebaysoftware.com/Produ ... tures.aspx) or the Magic Lattern Unified firmware. For the latter, a 5D2 version is currently in beta and I believe it contains an AP/ISO bulb ramping feature (http://www.eoshd.com/content/6640/eoshd ... 5d-mark-ii)


Thanks Colin, and for the links, very interesting.

Phil Hart is taking a unit to Canada, it'll be very interesting to see what he does with it :-).

It's a standalone micro controller, PCs and lappies arnt tough enough.


Tue Jan 17, 2012 3:08 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Fred wrote:
Phil Hart is taking a unit to Canada, it'll be very interesting to see what he does with it

Wow, amazing! Was just chatting to Phil the other day on all things bramping and relating my experiences running the Little Bramper at -15C last year in Canada. Small world! Sounds like you've done well if you've packed all that functionality into a micro controller. Probably the first to go all the way (+ ISO)?

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Tue Jan 17, 2012 3:15 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Yeah I think quite a few of us would be interested in a controller like that

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Tue Jan 17, 2012 6:44 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Where should I send my money and how much do you want for one?

Dude, EVERYONE has wanted one of these since like forever!

If it really does what you say, it kicks butt AND you're a rock star.

Nuff said. I expect one of the first ones for the endorsement.

Got my checkbook out right now. You take Paypal?


Tue Jan 17, 2012 8:32 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
OK, well thats encaraging then, I was wondering. Thanks for the replies guys. It hasn't done much work yet, and as always , reliability in the harsh field is the key to success. I don't think it's going to be a commercial product really , I'm more interested in doing time lapses with it, enough work already :-). Hopefully Phil Hart will have some success with it in Canada (he collaborated on the design), and I hope to post a flick too soon.


Tue Jan 17, 2012 2:05 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Here is an interesting controller coming out soon...

http://www.kickstarter.com/projects/eli ... -timelapse


Wed Jan 18, 2012 12:08 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
First time I've seen that device, VERY interesting:

BULB ramping - shift exposure smoothly during the timelapse (to be implemented)

Auto BULB ramping based on the light meter (to be implemented)

JB


fotoman69 wrote:
Here is an interesting controller coming out soon...

http://www.kickstarter.com/projects/eli ... -timelapse


Wed Jan 18, 2012 6:31 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
jimbr549 wrote:
First time I've seen that device, VERY interesting:

BULB ramping - shift exposure smoothly during the timelapse (to be implemented)

Auto BULB ramping based on the light meter (to be implemented)

JB


fotoman69 wrote:
Here is an interesting controller coming out soon...

http://www.kickstarter.com/projects/eli ... -timelapse


Yes, the bulb ramping with external light meter is interesting. Pity it cant ramp AP/ISO too ;)


Wed Jan 18, 2012 11:32 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Fred wrote:
Pity it cant ramp AP/ISO too

Fred, are you doing anything special on the Aperture ramping front? The issue we normally face is flicker due to the aperture opening and closing for each actuation. I understand Magic Lattern Unified has a "sticky" option that locks the aperture blade in place, but it's still in beta for the 5D2 so haven't tried it yet.

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Thu Jan 19, 2012 12:08 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Well, I had flickering at f22-19, but once I included flash output feed back (start exposure timing on flash output) the flicker pretty much disappeared, on a 5dmk2 anyway, the variability of shutter timing may vary bettween models. I think the firmware preshutter preperation code variation on exposure command is more of a problem. This was at exposures of less than 150ms odd BTW. After that it seemed less of a problem. The fixed shutter delay on a 5d mk2 is some 33ms I think, which seems to be constant.

colinmlegg wrote:
Fred wrote:
Pity it cant ramp AP/ISO too

Fred, are you doing anything special on the Aperture ramping front? The issue we normally face is flicker due to the aperture opening and closing for each actuation. I understand Magic Lattern Unified has a "sticky" option that locks the aperture blade in place, but it's still in beta for the 5D2 so haven't tried it yet.


Thu Jan 19, 2012 12:55 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Hi Fred,

How are you doing metering? I.E. is it TTL, incident, reflective, or ambient? In my experiments several years back, I found that the form of metering used was critical for each individual shot, and that the only one that seemed to work the most effective for the most shots was TTL. However, doing TTL metering was often limited by where the sensor could be placed, and ultimately, mostly was only capable of through-the-viewfinder, which had very limited resolution due to the very reduced light.

I am of course, very curious as to the level of success you have achieved for varying types of shots, as no one has reported back yet in the past couple of years a good general purpose strategy.

Thanks!

!c


Thu Jan 19, 2012 7:34 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
shutterdrone wrote:
Hi Fred,

How are you doing metering? I.E. is it TTL, incident, reflective, or ambient? In my experiments several years back, I found that the form of metering used was critical for each individual shot, and that the only one that seemed to work the most effective for the most shots was TTL. However, doing TTL metering was often limited by where the sensor could be placed, and ultimately, mostly was only capable of through-the-viewfinder, which had very limited resolution due to the very reduced light.

I am of course, very curious as to the level of success you have achieved for varying types of shots, as no one has reported back yet in the past couple of years a good general purpose strategy.

Thanks!

!c


Ambient. 2 LDRs in a small black can clipped into the flash shoe pointing the same way as the lens. 2 LDRs were required loaded differently to allow for the dynamic range from day to night. This works for 24mm wide angle sky shots, no other format was tried. The LDR readings are converted to exposure times and AP/ISO selections via hand crafted lookup tables, so again is only usefull for the f1.4 24mm lens and 5Dmk2 used.

There are also several filters to smoothen this lightmeter. A settable time based rolling average (1 to about 16mins), exposure time ramping bettween table look ups and a "AM/PM latch" ie exposures can only get longer for sunset or shorter for sunrise sequences (to prevent flickering). Everything is optimised for a 12sec period for an entire mutistep program ,so about 10sec max exposure times to allow for motor move, image download and ap/iso selection for the 2 seconds minimum left. We found that max 10sec exposures at f1.4 iso3200 at 24mm on a 5dmk2 were pretty much ideal for astro at a dark site. For day or night only, either the LDR metering and no latch are used, or a fixed exposure time (programmed step). The heavily filtered ambient lightmeter was found to be the most usefull, rather that per image evaluation, far less flickering. The dynamic range/low noise of 5dmk2 RAWs easily handled periods of slight over/underexposure.

I must say, I have yet to produce the difinitive timelapse with it, but tests were promising. On reflection I may not have eliminated flicker at f22-19 with very short exposures due to mechanical apature repeatability mentioned previously, but flash feedback made a huge difference. A ND filter at the bright end to allow wider apature would fix this, but then my system is no longer completely auto with the need to remove the filter at some set time, although that is only one manual action that wouldnt be hard.


Thu Jan 19, 2012 3:02 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Fred wrote:
Ambient. 2 LDRs in a small black can clipped into the flash shoe pointing the same way as the lens. 2 LDRs were required loaded differently to allow for the dynamic range from day to night. This works for 24mm wide angle sky shots, no other format was tried. The LDR readings are converted to exposure times and AP/ISO selections via hand crafted lookup tables, so again is only usefull for the f1.4 24mm lens and 5Dmk2 used.

There are also several filters to smoothen this lightmeter. A settable time based rolling average (1 to about 16mins), exposure time ramping bettween table look ups and a "AM/PM latch" ie exposures can only get longer for sunset or shorter for sunrise sequences (to prevent flickering). Everything is optimised for a 12sec period for an entire mutistep program ,so about 10sec max exposure times to allow for motor move, image download and ap/iso selection for the 2 seconds minimum left. We found that max 10sec exposures at f1.4 iso3200 at 24mm on a 5dmk2 were pretty much ideal for astro at a dark site. For day or night only, either the LDR metering and no latch are used, or a fixed exposure time (programmed step). The heavily filtered ambient lightmeter was found to be the most usefull, rather that per image evaluation, far less flickering. The dynamic range/low noise of 5dmk2 RAWs easily handled periods of slight over/underexposure.

I must say, I have yet to produce the difinitive timelapse with it, but tests were promising. On reflection I may not have eliminated flicker at f22-19 with very short exposures due to mechanical apature repeatability mentioned previously, but flash feedback made a huge difference. A ND filter at the bright end to allow wider apature would fix this, but then my system is no longer completely auto with the need to remove the filter at some set time, although that is only one manual action that wouldnt be hard.



That's interesting - I would presume you would use one intensity to frequency IC over several LDRs (e.g. the TSL230R or related) to get the resolution needed, unless of course your uC has a > 16bit A/D converter. (E.g. doing frequency counting from an IC can get you a 32-bit value up to your maximum cycles/millisecond.) Another problem I found with LDRs was that they often don't have full spectral sensitivity data posted, but this likely varies from ldr to ldr.

When you say you use a hand-crafted lookup table, did you do your calculations on a black body radiator/planck's law, or with the CIE photopic tables? When I previously worked on this problem, I used the CIE tables for luminous efficiency of the eye, and found them to be highly effective (along with the right target illuminant for spectral power distribution) without needing to map. I.e. doing the gaussian function in real-time. You've probably already seen it - but if you haven't, I published a tutorial on the on-demand conversions that may be helpful to you: http://roamingdrone.wordpress.com/2008/ ... nversions/

The latch-based approach for limiting is interesting, I had done rolling samples over 1second periods, with limitations on swing (e.g. maximum swing of 0.01 EV per change period). One of the key things I was trying to eliminate was minor deviations from cloud coverage, for example. Of course, in the city there's a big problem in that the light source doesn't stay sun (e.g. moonlight) as the sun sets, but switches to one of several forms of incandescent light, each with a different SPD map. If you attempted to use image evaluation, I can only presume you had an ARM processor or something similar available? =)

!c


Sat Jan 21, 2012 7:47 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
shutterdrone wrote:
Fred wrote:
Ambient. 2 LDRs in a small black can clipped into the flash shoe pointing the same way as the lens. 2 LDRs were required loaded differently to allow for the dynamic range from day to night. This works for 24mm wide angle sky shots, no other format was tried. The LDR readings are converted to exposure times and AP/ISO selections via hand crafted lookup tables, so again is only usefull for the f1.4 24mm lens and 5Dmk2 used.

There are also several filters to smoothen this lightmeter. A settable time based rolling average (1 to about 16mins), exposure time ramping bettween table look ups and a "AM/PM latch" ie exposures can only get longer for sunset or shorter for sunrise sequences (to prevent flickering). Everything is optimised for a 12sec period for an entire mutistep program ,so about 10sec max exposure times to allow for motor move, image download and ap/iso selection for the 2 seconds minimum left. We found that max 10sec exposures at f1.4 iso3200 at 24mm on a 5dmk2 were pretty much ideal for astro at a dark site. For day or night only, either the LDR metering and no latch are used, or a fixed exposure time (programmed step). The heavily filtered ambient lightmeter was found to be the most usefull, rather that per image evaluation, far less flickering. The dynamic range/low noise of 5dmk2 RAWs easily handled periods of slight over/underexposure.

I must say, I have yet to produce the difinitive timelapse with it, but tests were promising. On reflection I may not have eliminated flicker at f22-19 with very short exposures due to mechanical apature repeatability mentioned previously, but flash feedback made a huge difference. A ND filter at the bright end to allow wider apature would fix this, but then my system is no longer completely auto with the need to remove the filter at some set time, although that is only one manual action that wouldnt be hard.



That's interesting - I would presume you would use one intensity to frequency IC over several LDRs (e.g. the TSL230R or related) to get the resolution needed, unless of course your uC has a > 16bit A/D converter. (E.g. doing frequency counting from an IC can get you a 32-bit value up to your maximum cycles/millisecond.) Another problem I found with LDRs was that they often don't have full spectral sensitivity data posted, but this likely varies from ldr to ldr.

When you say you use a hand-crafted lookup table, did you do your calculations on a black body radiator/planck's law, or with the CIE photopic tables? When I previously worked on this problem, I used the CIE tables for luminous efficiency of the eye, and found them to be highly effective (along with the right target illuminant for spectral power distribution) without needing to map. I.e. doing the gaussian function in real-time. You've probably already seen it - but if you haven't, I published a tutorial on the on-demand conversions that may be helpful to you: http://roamingdrone.wordpress.com/2008/ ... nversions/

The latch-based approach for limiting is interesting, I had done rolling samples over 1second periods, with limitations on swing (e.g. maximum swing of 0.01 EV per change period). One of the key things I was trying to eliminate was minor deviations from cloud coverage, for example. Of course, in the city there's a big problem in that the light source doesn't stay sun (e.g. moonlight) as the sun sets, but switches to one of several forms of incandescent light, each with a different SPD map. If you attempted to use image evaluation, I can only presume you had an ARM processor or something similar available? =)

!c


Well, what your saying is even more interesting ;-).
I launched into this phase of the project with no regard to resolution, just grabed 2 LDRs and went for it. I only have 10bit A/D, and later compensated for the lack of res by ramping between table lookups, which is tricky as it is a "guessahead" filter of sorts and dependant on rate of ambient light level change. I hadnt thought of frequency counting to increase res,mmmmm, but then the lookup table gets huge too unforch. Im a bit of a Picaxe tragic too (which I used on this), as the project grew it rapidly got out of hand, there are now 5 off 28X2s used in all, which is in a way not too bad, as it allows parrallel processing of sorts ;-). The Picaxe is soo easy to use, I couldnt bring myself to switch to Arduino, the integrated enviroment and one word command hardware drivers in picaxe are hard to beat.There are many limitations of course, like integer only math and limited memory. I can use external eeprom though.

The handcrafted tables are literally Phil Hart logging LDR readings with exposure time, iso and AP during a full sunset sequence (no cloud), so that takes into account spectral and level response non linearity in one hit. Calulations required were in exel only whilst building the table, no calculation is done in the timelapse controller, its look up only. I put a ceiling on swing too, but that went very astray with the latch at the same time so I got rid of that and just relied on the rolling filter.

The spectral differences with different urban lighting types wasnt considered, most timelapses will be taken at dark sites.


Sun Jan 22, 2012 1:12 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Phil Hart has just posted a video taken this controller in the Yukon. http://philhart.com/content/venus-and-jupiter-show

Read about his adventure, its incredible the effort he has gone to to produce this masterpeice.


Mon Apr 23, 2012 3:19 pm
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
I'm not going to pretend I understand everything written in this thread. Nor do I expect that my own timelapse machines will ever be so advanced. But where esle can you learn so much of the subtle science behind getting the very best results from a subject which is such an intricate mix of art and technology? I love Timescapes!

Chardonnay-induced emotional outburst ends here.

Kit


Tue Apr 24, 2012 4:52 am
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Post Re: 1.4f 3200iso to 22f 50iso auto timelapse controler
Amazing bit of kit you're talking about there! Me, as above, does not get everything you guys are talking about, but is very interested in learning more and seeing this product work well!

Great work!

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Tue Apr 24, 2012 10:20 am
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