Camcorder & Skywatching Questions

Originally posted by dainoyfb
I just wanted to quickly mention that I generally agree with CHRLZ's review of the Panasonic SD60. It is a logical and accurate assessment. One thing that confuses me however is his statement about the 1/4.1 image sensor. This is a particularly small sensor as far as mid range camcorders are concerned...

As I said earlier, I'm not an expert on current camcorders, but my reading suggested many low-to-mid range camcorders used the smaller 1/6" sensor. To get to the bigger (than 1/4") sizes, I thought it was mainly the much higher end or 3-ccd models, which are a fair bit dearer. Do you know of any cameras with a larger than 1/4" sensor in that price range?


Superiorraw, yes, DSLR's with video capability are advanced cameras and you should probably work your way up.. plus by waiting, some cheaper models may become available, along with a decent secondhand market. They are pretty new to the market, so it probably isn't the best time to buy.

And I still reckon you need to rethink using the Hitachi, if it can't be set to infinity focus..

reply to post by CHRLZ


Well for a non expert you certainly have an excellent awareness of the topic.

I haven't done specific looking around at prices but some of the cannon mid range camcorders such as the very sensitive VIXIA HV40 have larger FPAs. The HV40 has a 1/2.7 FPA. It is listed at Amazon presently for $650.

Originally posted by dainoyfb
reply to post by CHRLZ

 

Well for a non expert you certainly have an excellent awareness of the topic.

I haven't done specific looking around at prices but some of the cannon mid range camcorders such as the very sensitive VIXIA HV40 have larger FPAs. The HV40 has a 1/2.7 FPA. It is listed at Amazon presently for $650.

Thanks! I don't claim to be a camcorder expert, but I will immodestly claim to know digital *still* cameras very well indeed.. and they have a lot in common..

As for that Canon - wow! I'm surprised to see that one. It looks very good on paper, except for one possible deal breaker - no manual focus? It would seem strange for a camera with such excellent low-light performance not to have at least an infinity setting, so maybe I'm missing something in the specs. I had a bit of a look around, maybe the HG20 might be the better choice - not quite as large a sensor, but still decent, and it has manual focus.

By the way, I also found this:
www.dpreview.com...
Doesn't solve anything right now, but that is a VERY interesting development. FTR, 'Micro' 4/3 sensors, despite their name, are quite large.

For anyone puzzling over this sensor size obsession, the larger the better. Here's a nice comparison:
en.wikipedia.org...

You'll notice that the smallest sensor shown there is 1/2.5" - the Canon camera mentioned above, has a sensor just a fraction smaller than that. 1/4" and 1/6" sensors are smaller again... The diagram also includes a 4/3 sensor - that's exactly the same size as Micro 4/3, and then the DSLR sensors (APS-C, 35mm full frame) are bigger again.

As the sensor size increases, you get:
- higher 'real' resolution
- much lower noise
- much better low-light ability
- much better dynamic range (ie the ability to capture very bright and very dark areas)

Thanks for your replies on the videocamera

I am so pleased this thread has been so helpful to me, and I hope that my questions might of been asked by other inexperienced members of ATS and they would of got something from reading as well.

I will have to read through those examples. I'm in the process of reading up a report at the moment but when I am done with that i'll follow up on the links posted here.

Thank you for your time and opinions guy, its very helpful

I also will reconsider the Hitachi, especially because webcams are quite cheap. Alot will depend on the setup when i get the new videocamera and laptop I will look at a second camera to use. Only then will i begin to look at the possibility of the stereoscopic setup laid out by dainoyfb. I think its a really good idea and offers many awesome advantages.
In friendship
Richard

Ok.
Having considered my options and taking into account I'm about halfway (saved up) to affording a Panasonic SD60. I'm now thinking a little further ahead to my setup. I know I want something similar to what I have now. Whereby I can record directly to laptop, however I do also now realise that if I get the Panasonic it uses it's own memory card as such I wont need to stay where the laptop is, It means I can afford to be a little more mobile.

Let me consider a few things, laptop aside, I have 2 questions.

1. What would be a good secondary cam? I am definately considering a 2 cam system. Which would be the most effective way to synchronize them and mount them?

2. Is there anything you could buy, say, erm.. an estimator? something like a distance calculator that measures distance via zoom used? I'm just wondering about actual approximate distances. Something I always have trouble with is distance. If someone asked me to calculate or speculate a distance I saw an object hovering i'm really not that confident in my own guesswork.

Which brings me to the question in itself, there have been many good example videos as discussed already here on ATS, where by they have been discredited because its not been possible to tell the distance from the observer to the object.

I just want to make sure i am considering all options so that if i do get a 'unique' moment and video it, i have every possible angle covered.

I'm sorry if question 1 appears to be we are repeating what is already discussed, however looking back I am a tad confused about the 'syncronization' of the 2 cameras. - as confused as I am, i'm still willing to learn

So please dont give up on me just yet. My enthusiasm is still as full 100% switched on as it was at the beginning of the thread.

[edit on 16-4-2010 by Superiorraw]

I have two pairs of binoculars the best ones for me are the Celestron 15x70 Skymasters I paid 80 US for them and they are super! They are rather large so I use a tripod w/ them. I can free hand them however. I also have a pair of Bushnell 7x35 that I use for a quick grab and look see these are also excellent and I got them for free! (be sure you get binos that have "porro-prisms" and "do not get binos with rose colored lenses") For camcorders I have a Samsung D-382 w/42x optical zoom and 1200 x digital zoom it's a good CC but doesn't have a slot for a data card, it utilizes tapes for storage. I bought this as a refurb for 90.US. I'm going to look for one that is 100% digital and uses cards only for storage and not tapes. That's it for my grab and run sky watching stuff. I have an observatory as well....well actually it's my deck and I have a few telescopes and cameras (ccd) that I image the moon and planets with. I am in the city as well and deal with light pollution to. I'm working on moving 130miles south of where I am now to a rural area for better quality viewing. GB seems to have allot of UFO activity plus there's the monoliths and earth works like St Michaels Tor etc. not to mention crop circles. At any rate happy hunting and take care. P.S. If you would like to discuss this subject more you can U2U me if you like.

Hi Superiorraw,
I think some of the confusion may be in the terminology.

Setting up the cameras so they point in the same direction is called alignment. For your purposes the two cameras do not have to be particularly well aligned (it can be a tedious process to do properly anyway). The reason they don't have to be aligned perfectly is that once they are solidly mounted their alignment can be referenced by taking a few seconds of steady footage of a known distant object. Producing this reference image will provide researchers a way to extrapolate distance to object information from the footage. The further apart the two cameras are mounted and the higher their resolution, the more accurate the distance information will be and the greater the distance that can be measured. Once distance is known, size and speed are also known.

The other term is synchronization. This means that when you play the footage from the two cameras back at the same time you have some way of knowing which video frames from camera 1 match the timing of the video frames from camera 2. Again the easy way to create synchronization data on the footage is to have two small LEDs (one in view of each camera) that are running off of the same pulse circuit. This produces a timing pulse in the corner of each image frame that can be matched up in editing so that the videos play together and so that stills of certain events can be pulled from the footage together. It also provides another time reference to confirm the frame rate of the footage. These pieces of information are important for determining the speed of objects among other things.


Edit for typo

[edit on 16-4-2010 by dainoyfb]

A few additions...

Originally posted by Superiorraw
1. What would be a good secondary cam?

Imo, any still camera with infinity focus, if you want something now. Then save for a good quality 'bridge' camera like the Pana FZ35 later.

2. Is there anything you could buy, say, erm.. an estimator? something like a distance calculator that measures distance via zoom used?

Not really, but you can use 'photogrammetry' on *known* objects, like aircraft. Eg if you can identify an aircraft as, say a 767, and you have the focal length (zoom) reading (normally recorded in EXIF on a still camera, on a video, you would have to take note of it, or make sure you are at maximum zoom) then yes, you can work it out. Happy to help when you get to that stage. However, if you don't know how big the object is, and if it is beyond 'stereo ranging' then it becomes very, very difficult.

I saw an object hovering i'm really not that confident in my own guesswork.

That shows very creditable wisdom and honesty. Many folks make silly claims about how high objects are, but truly experienced sky observers will happily admit that in reality it is not possible to make sensible guesses of distance if the object is unidentifiable. Sometimes there may be clues, eg if it is still visibly above or below a certain type of cloud band.., but that doesn't help all that much.

Which brings me to the question in itself, there have been many good example videos as discussed already here on ATS, where by they have been discredited because its not been possible to tell the distance from the observer to the object.

Unfortunately, for a distant and unidentifiable size object, that's just the way it is. Stereo ranging can assist for nearby objects and proving it isn't a toy hanging from a fishing rod.. but once you get more than few hundred metres away all you can really measure is angular velocity..

reply to post by Superiorraw


There are other considerations.

Whether you film in daytime or night time you'll need a camcorder with good low-light capability. Most modern camcorders are not very good at this. This is because they come in 1/8 " CCD. For good low-light filming you need 1/4 " CCD.

That leaves only two possibilities : Old analogue and Digital 8. You can find min illumination .7 and 1 lux cameras on Ebay . Unfortunately analogue cameras will let you down when you try to upload to your PC. Hence, you only have one choice : Digital 8. That is the one you should go for.

And if you should be able to hack the Digital 8 camera and get extra features, then you will not be disapointed.

Follow the white rabbit. Rawedge is an anagram.

Originally posted by crowdedskies
Whether you film in daytime or night time you'll need a camcorder with good low-light capability. Most modern camcorders are not very good at this. This is because they come in 1/8 " CCD. For good low-light filming you need 1/4 " CCD.

Did you actually read the thread? - this was covered in some detail earlier, and the model he is considering IS a 1/4". (Also, most of the low-end camcorders use a 1/6" sensor, not 1/8".) While I agree that >1/4" is desirable I would not dismiss a 1/6" model if my budget was limited. Other features and general camera/lens quality may well outweigh the sensor size - I'd much rather have a good 1/6" than a bad 1/4"...

That leaves only two possibilities: Old analogue and Digital 8. You can find min illumination .7 and 1 lux cameras on Ebay.

We have already given some examples of 1/4" and larger cameras that may be within the OP's budget. Yes, he could also try second hand, but I would not be considering a low-res analogue unit, given his intended use.

Unfortunately analogue cameras will let you down when you try to upload to your PC. Hence, you only have one choice : Digital 8. That is the one you should go for.

Again I disagree, and would suggest he aims at a ~1/3" HD camera like the canon examples given earlier, or simply stick to his SD60 choice, given it is one of the better 1/4" models and is HD. Dropping back to the lesser resolution of Digital 8 is a backward step imo. After all, we are talking about capturing distant small objects - resolution is also a very important factor.

And if you should be able to hack the Digital 8 camera and get extra features, then you will not be disapointed.

What, like more resolution? Better low-light performance? What camera, what hack?

Follow the white rabbit. Rawedge is an anagram.

Oh, I see. "I know more than you guys but I ain't tellin'..." Sigh. Yes, 'rawedge' is an anagram, of 'wagered' and 'ragweed'.

Your point being...?

reply to post by CHRLZ


Hi CHRLZ

I am new to this ATS blog. In fact I am not a blogger but do get passionately interested in some topics and occasionally feel I should make a contribution.

I did not read the threads fully . If I had, I would have realised that the 1/4 " was covered. I was only speaking from my own experience in capturing unidentified objects and the trial and errors of trying different cameras, capture cards, etc.

The cryptic ending was meant for Superiorraw as I thought he might understand it. It was meant to be outside the main content of my post.

ATS deals with very controversial and elusive topics. I thought the cryptic puzzle was in the spirit of this. I was obviously wrong.

Originally posted by crowdedskies
reply to post by CHRLZ

 

Hi CHRLZ

I am new to this ATS blog. In fact I am not a blogger but do get passionately interested in some topics and occasionally feel I should make a contribution.

I did not read the threads fully . If I had, I would have realised that the 1/4 " was covered. I was only speaking from my own experience in capturing unidentified objects and the trial and errors of trying different cameras, capture cards, etc.

The cryptic ending was meant for Superiorraw as I thought he might understand it. It was meant to be outside the main content of my post.

ATS deals with very controversial and elusive topics. I thought the cryptic puzzle was in the spirit of this. I was obviously wrong.

Ok, I apologise for what was probably a harsh tone (after dealing with a particularly unpleasant person on another forum).

But why the need for a 'cryptic puzzle'? If it is ontopic, do please explain.

Anyway, no hard feelings. Carry on!

No problem and no offense taken.

I have been interested in UFOs for a long time. My views have changed over the course of my life .

First I thought it was aliens from outer space, then it became more Jungian and psychological , now it is more Quantum mechanics and esoterics. It seemed like a normal progression.

My particular approach to daylight UFO hunting makes it important to use IR on nightshot cams. A well-known practice for UFO hunting.

I will probably get laughed at by some. Well... we all have our views.

Originally posted by crowdedskies
No problem and no offense taken.

I have been interested in UFOs for a long time. My views have changed over the course of my life .

First I thought it was aliens from outer space, then it became more Jungian and psychological , now it is more Quantum mechanics and esoterics. It seemed like a normal progression.

My particular approach to daylight UFO hunting makes it important to use IR on nightshot cams. A well-known practice for UFO hunting.

I will probably get laughed at by some. Well... we all have our views.

No laughter here - I welcome weird ideas, as long as people will discuss with an open mind..

I liked your 'normal progression'..!!??!!, I had a little chuckle at that.. - I haven't reached the quantum level yet! But, yes, I guess you could say I've also moved beyond aliens. That doesn't mean I don't believe in other life out there, and I would love to see a genuine visitation...

And yes, IR can be an interesting tool - it's a bit sad that 'real' IR is now very hard to get in cameras.

Quantum Mechanics, Jungian Psychology and occult teachings are closely related. I will probably get lynched for saying that, especially by the physicists and the psychologists

Just to let you guys know I do appreciate the help you've given me in this subject/topic. I hope that others reading can contribute chime in with their own experiences and techniques to help capture night time or day time ufos on their videocameras.

I havent forgotten about this, infact i've hit a financial brick wall at the moment so saving is becoming difficult. I am hoping to sort the issue out within a month or so and i should be able to make my purchase.

I'll be posting up some photographs and some footage when I do get it. I'll also need to read back through what dainoyfb has posted up regarding the synchronization with another videocamera.

I truely believe that if an unidentified object does come into our airspace and we have the technology, as civilians we should be doing all we can to get better footage. Also In tackling the issues that prevent a clear identification for future sightings and videos such as CGI / editing and distance or size of the object. I am attempting to counter these problems by finding solutions with the videocamera. I know that Chrlz is working on a guide to ufo sightings at the minute which i think would be great if the mods could sticky it.

Using both the guide and the advice here I think its only going to be a matter of time before someone gets something truely geniune. I really would like to see a big improvement on the submission quality of ufo sightings/videos.

In friendship

reply to post by dainoyfb


thanks for explaining. I know this might seem like alot to ask and you probably might not have the time to do it, but i was wondering if you could either illustrate the process in a drawing or maybe photograph the setup so that I could see for myself, I'll then be able to use that to replicate the process when I have the Panasonic SD60.

Thank you so much for your advice so far and your contributions to this subject.

Richard

Hey Guys
I have another question that you might be able to help me with. I was wondering what the best way for someone on the ground (in this case a civilian) to judge, estimate/measure height / distance of something?

I know that way back in primary school, when we done school projects we measured stuff with metre sticks and trundle wheels, which is great for ground based research, but what about aerial measurments and distances?

How do I estimate objects in mid air? Isn't there anything I could make or buy that would help me estimate these calculations more accurately?

Originally posted by Superiorraw
Hey Guys
I have another question that you might be able to help me with. I was wondering what the best way for someone on the ground (in this case a civilian) to judge, estimate/measure height / distance of something?

I know that way back in primary school, when we done school projects we measured stuff with metre sticks and trundle wheels, which is great for ground based research, but what about aerial measurments and distances?

How do I estimate objects in mid air? Isn't there anything I could make or buy that would help me estimate these calculations more accurately?

I hate to be a bit pessimistic, but... Without radar or laser ranging (I don't know if there's anything affordable around that will get out to any decent distance, and you can get in trouble for pointing lasers at things!..) once you get more than several hundred metres away, it becomes *extremely* difficult. Here's a quick summary of the issues:

Parallax, ie the ability to detect the difference in angle via your eye separation, or even widely separated cameras, becomes mathematically very difficult, and then simply impossible as you get out to a kilometre or three.

If the object was very slow moving, then you might be abe to change your position and then carefully examine the difference against the background stars, but you'd have to move quite a way, and if the object was also moving, that becomes very difficult to do.

If you are seeing a small light source of unknown shape/size, then you have no depth perception clues of the object itself, nor any easy way to recognise and therefore identify it. If you've identified it, eg as an aircraft/bird, then your previous experience with seeing other similar aircraft/birds kicks in, and by its angular velocity you can get a bit of an idea how high it might be. But of course if you know what it is, then you probably don't need the information!

In daytime, cloud layers might be a help, but even then, you'll have to know your clouds, and also you'd have to be pretty lucky for the object to be clearly above/below a particular layer.

All in all, it's just very difficult, most often impossible. And even if you have a LOT of experience in observing, you would be kidding yourself if you trusted your own judgement on such things.

I'd be interested to hear dainyofb's (or anyone else's!) opinions - but I'd also ask that if folks believe they have some methods to accurately determine distances to UAP's, they show us exactly how it works on something *known*. Eg try the method out on a distant object in *daytime* and post the results (and maths if applicable).

Sorry, due to a couple of rush projects I've only been able to pop in occasionally and have been unable to spend any time on posting.

I would be happy to illustrate a design for you as soon as I have a minute.

As for range finding I generally agree with CHRLZ, except that perhaps a few hundred meters might be a bit pessimistic. I think what you have to do is determine the a value of error vs distance by testing your rig Even knowing the size or speed of something within a range of error can be very useful for narrowing down the possibilities.

I will also direct you to this thread of mine which explains a method for determining the size and velocity of an object if known background objects are present in the scene.