R5 - Star trails, heat and battery life

JPAZ

If only I knew what I was doing.....
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All,

I am a "future" R5 photographer (hoping to get one once the dust settles* after selling some gear). Curious to get any feedback on one of my planned shots. Were I to do a 1 1/2 or 2 hour exposure with long exposure NR active (say "star trails"), the camera would be running for 3 or 4 hours. Has anyone had a chance to try anything like this and if so, is the battery life adequate (or would I need to get us the USB C power or a grip with extra batteries) and would the R5 get too hot? I am hoping someone tries this out and gives us all some feedback. Thanks in advance.

* is a bad pun on a photography site ;)

JPAZ
 
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Nov 12, 2016
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I did a 24 minute long sky exposure with my R5 a few days ago. It looks pretty good. I did notice this though. Please bear in mind this is a 1:1 crop on a 45mp photo, so this point is very small in the actual photo. You can see there's a few other faint ones in this crop also. At first I assumed it was a hot pixel, but could these be satellites in geosynchronous orbit or something? Quickly looking over the photo, I didn't see any points of light this noticeable other than this one. So if the R5 gets hot pixels during long exposures, you'd think there would be more than just this. Also I did see a lot of color noise in the extreme corners, but I had the sky framed by trees along the edges, so these were very dark areas of the photo, and I'm not surprised to see some funky colored pixels when pushing the shadows so much on such a long exposure.

As far as battery life, I forget exactly how much battery this used, but suffice it to say the battery wasn't fresh when I started the 24 minute exposure, and I don't think it was dead when I was finished. It was also a very cheap third party battery from Amazon. So take that for what it's worth. After having just a little time with the R5 and getting a sense of its battery life in general use, I would recommend getting a battery grip or external power source if you're going to be doing multiple hour exposures. But seriously, wouldn't you do that with pretty much any digital camera if you're doing multi-hour exposures?

1R5_0532-2.jpg
 
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SteveC

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I did a 24 minute long sky exposure with my R5 a few days ago. It looks pretty good. I did notice this though. Please bear in mind this is a 1:1 crop on a 45mp photo, so this point is very small in the actual photo. You can see there's a few other faint ones in this crop also. At first I assumed it was a hot pixel, but could these be satellites in geosynchronous orbit or something? Quickly looking over the photo, I didn't see any points of light this noticeable other than this one. So if the R5 gets hot pixels during long exposures, you'd think there would be more than just this. Also I did see a lot of color noise in the extreme corners, but I had the sky framed by trees along the edges, so these were very dark areas of the photo, and I'm not surprised to see some funky colored pixels when pushing the shadows so much on such a long exposure.

As far as battery life, I forget exactly how much battery this used, but suffice it to say the battery wasn't fresh when I started the 24 minute exposure, and I don't think it was dead when I was finished. It was also a very cheap third party battery from Amazon. So take that for what it's worth. After having just a little time with the R5 and getting a sense of its battery life in general use, I would recommend getting a battery grip or external power source if you're going to be doing multiple hour exposures. But seriously, wouldn't you do that with pretty much any digital camera if you're doing multi-hour exposures?

Any geosynchronous satellite would have to be over the equator, which means if you are in the northern hemisphere, you will see it against the southern sky, south of the celestial equator (and vice versa for our Aussie friends). [if it were at infinity, and I really mean infinity, it would be ON the celestial equator.]
 
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SteveC

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Naw, those definitely don't show up as single points in long exposure photos.


Satellites not geostationary tend to move fast; they're in low earth orbit, usually, so if one "flies" overhead it's 1-300 miles away, moving at roughly five miles a second. Even if they're a bit further up, they definitely move against the background of space.

A geostationary satellite will appear to stand still even as the stars move, but there are very strict requirements; it has to be over the equator in a circular orbit with zero inclination, (otherwise it will draw a figure eight, or if it's in an elliptical orbit, an even wackier shape, against the sky once a day), not just any 24 hour (um, technically, 23 hour 56 minute) orbit will do.
 
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SecureGSM

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Well then what the heck is it? I noticed it seems like it has purple fringing, leading me to believe it's more than just noise from the camera. But who knows.
Well, zoom in all the way on it. the object is square in shape within a 4 point star... with some blotches or colour surrounding the object. So.. call it UFO for a no better terms :D
 
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Joules

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I did a 24 minute long sky exposure with my R5 a few days ago. It looks pretty good. I did notice this though. Please bear in mind this is a 1:1 crop on a 45mp photo, so this point is very small in the actual photo. You can see there's a few other faint ones in this crop also. At first I assumed it was a hot pixel, but could these be satellites in geosynchronous orbit or something? Quickly looking over the photo, I didn't see any points of light this noticeable other than this one.
It may be a dead pixel. As was pointed out, it doesn't seem exactly round. What program did you use for debayering the RAW? If it is a dead / damaged pixel, it should show up if you do another exposure with similar settings. In that case, it should probably be mapped out.

I don't think a geostationary sattelite is ruled out yet though. From the straightness of the lines, this section is close to the celestial equator?
 
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Joules

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I am wondering if the electronic shutter may be a better option for getting star trails. Taking a lot of short exposures over the course of hours leaves small gaps between the trails / stars, which need to be addressed in software. And it eats up shutter actuation (Although that's not an issue with the R5 shutter rating of course).

I'm not quite sure, but I would think lots of short exposures will show less dark current noise than one long one? Certainly If you plan to use the in camera long exposure noise reduction. That's just a single dark frame to subtract, meaning the hot pixels will be removed, but other noises likely added. With shorter exposures, it would be easier to take a set of ~50 darks, as taking those would require less total time than the single long dark taken by the long exposure noise reduction feature. It would require you to go out to the camera to put the lens cap on though.

Can the electronic shutter be used with intervalometers? How long is the shorted achievable gap?
 
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I do a lot of night photography and shoot mostly 30 second exposures- and probably don’t get more than 200 shots per battery on my Eos R.

I have done a few 15-20 minute exposures and while it does drain the battery more, I’m guessing the R5 would be able to do a 90 minute exposure on a full battery. You’ve got me curious- I’ll try one tonight and see how my R manages.
 
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SteveC

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I don't think a geostationary sattelite is ruled out yet though. From the straightness of the lines, this section is close to the celestial equator?

I don't think it's ruled out either, but we don't have enough info, and I was trying to lay out what I'd need to know. If I came off as saying "no it's not, absolutely not," I apologize for not being clear.

Technically, we are talking about a geostationary satelllite, not a geosynchronous one. The latter is any orbit with a 23 hour, 56 minute period (relative to the stars); that will synch up with the earth's rotation. However, the orbit could be inclined or elliptical, which means the satellite will trace some sort of figure eight in the sky--but return to the same location every 24 hours. If the orbit is perfectly circular and has zero inclination (i.e., it lies in the equatorial plane) then you have a geostationary satellite, it will appear to us, co-rotating in 23 hours, 56 minutes, to be stationary. (The four minute difference between that and 24 hours has to do with the difference between a mean solar day and a sidereal day; if you need/want that explained, please check with wikipedia--it'd be a long digression here.)

The proper altitude for such an orbit would be 35,786 km above some point on the equator. If you are anywhere on the equator, the satellite will appear to be on the celestial equator (hopefully above the horizon!).

But if you are north of the equator, the satellite will appear to you to be south of the equator, because its MUCH nearer to us than the stars on the celestial sphere. Even though it is in the plane of the earth's equator, it's close by and you are looking at it at a slant. Thus, I wouldn't conclude from the straightness of the lines that it's on the celstial equator, unless the photograph was itself taken near the equator. In fact, if the photograph was taken from (say) England or the United States AND the star trails around it are perfectly straight, then it is absolutely NOT a geostationary satellite; it's way too far "north" for that.

One other thing that makes me suspicious of the idea it might be satellite is the magenta color. I find that to be an odd color for a satellite to be reflecting. Again, not impossible, but it seems easier for me to believe the red and blue are somehow "hot" in that pixel while the green is not.

Another fact that might help narrow it down is to determine whether a hypothetical geostationary object at that spot would have been in the earth's shadow at that time. If so, it'd not be shining like that, unless someone has been putting magenta beacons into GEO.
 
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Joules

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I don't think it's ruled out either, but we don't have enough info, and I was trying to lay out what I'd need to know. If I came off as saying "no it's not, absolutely not," I apologize for not being clear.

Technically, we are talking about a geostationary satelllite, not a geosynchronous one. The latter is any orbit with a 23 hour, 56 minute period (relative to the stars); that will synch up with the earth's rotation. However, the orbit could be inclined or elliptical, which means the satellite will trace some sort of figure eight in the sky--but return to the same location every 24 hours. If the orbit is perfectly circular and has zero inclination (i.e., it lies in the equatorial plane) then you have a geostationary satellite, it will appear to us, co-rotating in 23 hours, 56 minutes, to be stationary. (The four minute difference between that and 24 hours has to do with the difference between a mean solar day and a sidereal day; if you need/want that explained, please check with wikipedia--it'd be a long digression here.)

The proper altitude for such an orbit would be 35,786 km above some point on the equator. If you are anywhere on the equator, the satellite will appear to be on the celestial equator (hopefully above the horizon!).

But if you are north of the equator, the satellite will appear to you to be south of the equator, because its MUCH nearer to us than the stars on the celestial sphere. Even though it is in the plane of the earth's equator, it's close by and you are looking at it at a slant. Thus, I wouldn't conclude from the straightness of the lines that it's on the celstial equator, unless the photograph was itself taken near the equator. In fact, if the photograph was taken from (say) England or the United States AND the star trails around it are perfectly straight, then it is absolutely NOT a geostationary satellite; it's way too far "north" for that.

One other thing that makes me suspicious of the idea it might be satellite is the magenta color. I find that to be an odd color for a satellite to be reflecting. Again, not impossible, but it seems easier for me to believe the red and blue are somehow "hot" in that pixel while the green is not.

Another fact that might help narrow it down is to determine whether a hypothetical geostationary object at that spot would have been in the earth's shadow at that time. If so, it'd not be shining like that, unless someone has been putting magenta beacons into GEO.
Great summary of the info relevant to the question of 'Can this be some kind of sattelite?'. I know most of what you've mentioned, so I did not take your original post as stating that it can't be a sattelite. But as the follow up post to yours sounded like it interpreted you as saying that, I just wanted to point out that it is hard to make a good conclusion about this image without knowing more about the setting, the whole image the section came from and the location it was taken at.

The lines may look fairly straight, but with a resolution as high as 45 MP, even stars above or below the celestial equator may appear to produce a pretty straight line at the high magnification of viewing such a file at 1:1.

In any case I don't think it is an actual flaw of the camera (Flaw as in, something that would not occur with other devices). If it is an issue with a dead or damaged pixel, that is just what it is. My 600D had a similar looking artifact that I only noticed under specific conditions. One noticeable defect out of 18 million possible ones is in line what you can expect with consumer hardware. Using the dust cleaning option in the camera, I was able to map it out and get good results ever since (Although it has gotten very little use since acquiring an 80D).
 
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SteveC

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Great summary of the info relevant to the question of 'Can this be some kind of sattelite?'. I know most of what you've mentioned, so I did not take your original post as stating that it can't be a sattelite. But as the follow up post to yours sounded like it interpreted you as saying that, I just wanted to point out that it is hard to make a good conclusion about this image without knowing more about the setting, the whole image the section came from and the location it was taken at.

The lines may look fairly straight, but with a resolution as high as 45 MP, even stars above or below the celestial equator may appear to produce a pretty straight line at the high magnification of viewing such a file at 1:1.

In any case I don't think it is an actual flaw of the camera (Flaw as in, something that would not occur with other devices). If it is an issue with a dead or damaged pixel, that is just what it is. My 600D had a similar looking artifact that I only noticed under specific conditions. One noticeable defect out of 18 million possible ones is in line what you can expect with consumer hardware. Using the dust cleaning option in the camera, I was able to map it out and get good results ever since (Although it has gotten very little use since acquiring an 80D).

I tried, last night, to photograph Jupiter and Saturn, at first with my M6-II, then after finding I couldn't see them at all through the viewfinder and was shooting blind (and on an inadequate tripod where the camera would droop as soon as I let it go--but this wasn't apparent yet!) switched to the R5. (I thought the M6's higher pixel density would be an advantage, and all other things being equal it probably would have been, but all other things were emphatically not equal). Anyhow, I mention this because when I cranked the M6's ISO all the way up temporarily so I could see lights on the horizon to focus, I noticed the viewfinder had a blue dead pixel in one place, and a red dead one in another. At least I think it was the viewfinder display and not the camera sensor itself.

[I am better off using a DSLR for that, than I am the M6-II, I can see Jupiter through an OVF.]
 
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JPAZ

If only I knew what I was doing.....
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Sep 8, 2012
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I did a 24 minute long sky exposure with my R5 a few days ago.

Thanks for your response.

BTW, I think I'd either map out or just get rid of this "spot" no matter what it is, but that would depend on the entire image and its look.

Did you use in camera NR? And, any issue with heat?

I really appreciate the information and input from everyone here.
 
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Nov 12, 2016
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Ok, I couldn't let this thread keep going knowing that I'm the one person that holds the key to putting this issue to rest. I ran another 24 minute long exposure with the body cap on. Sure enough, there's a magenta spot in about the same place. :confused: But again this is a 1:1 crop. Under normal viewing conditions, this is tiny.

1R5_0750.jpg

Also, JPAZ, I took note of the battery this time. I also used the original LP-E6NH battery that came with the camera instead of the cheap-o knock offs that I usually use in my cameras so you can get a real sense of battery use. I also turned off the IBIS as you would probably want to do if you were doing very long exposures.

The battery started at 96%, and after a 24 minute exposure, it was down to 90%. Pretty good actually! But also be aware that the temperature in my house is 78 degrees right now. So, if you're outdoors at night, lower temperatures might eat into your battery life a little more.
 
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