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davidb59
member
Reged: 07/11/07
Posts: 82
Loc: Hopkinsville, Ky.
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Ok, this is where it started:
1) Found a photo of the milky way from a star party in PA. I want pics like that!
2)Found a great dark site 45 minutes away to camp at and actually saw the milky way without a scope (not like the photo, but just as good as I see through my 10" Dob at home).
3) So I took my Canon A40 to the woods and took some pics at ISO 100 (to reduce noise)with 15 second exposures(my longest possible with my camera). I got a lot of stars and some very faint clouds(with some imagination). Not satisfied.
So... with some reasearch I found that these kind of shots and some single shots through a scope were taken at higher ISO speeds with longer exposures.
4) So I went shopping for a digital SLR camera. I came across some Fujifilm cameras that capture Infrared as well as UV light but only have top ISO speeds of 1600 and exposure times of 30 seconds.
Question is: Will having the ability to capture UV and Infrared light get great shots at ISO 1600 and 30 second (max) exposures?
Please keep in mind I am not a photographic expert, I just want to get some good non-scope shots as well as some decent single shots through my scope.
Thanks, David.
PS. The photo below was taken at ISO 3200 with a 55 second exposure.
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60mm Walmart special
114mm Celestron FirstScope
10" Zhumell Dob
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FoxK
Carpal Tunnel
Reged: 11/07/07
Posts: 1760
Loc: Cape Cod, MA
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I'd say no....in fact, in my imaging I use a UV/IR BLOCKING filter to help eliminate bloating etc. Your looking to capture light at a variety of wavelengths...capturing only UV and IR really minimizes any light reaching the recording medium. In general, you can get similar results (in a perfect world) by doubling the exposure time when using ISO 1600, in order to get similar results as ISO 3200. Therein lies the problem....your image of the same subject as above would require a 2 minute exposure...now your talking about seeing some star trailing etc. To compensate for this, imagers often take many exposures at the less than 2 minute time (your image will prolly look too dark and without much MilkyWay detail) but process it in photoshop by adjusting "curves and levels"...some failr advanced image processing technique
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Orion 80mm ED Apo Refractor
8" Classic Dob (used as Newtonian on CG5 mount)
Meade 70-AZ-A 70mm Guider using PHD
LS60TCaK/B600/C
CG-5 Advanced GT Mount
Nikon D40x with T-Adaptors
Philips SPC900NC
Imaging Source DMK 21AU04.AS
Dome=the box my mount came in so I can see my solar images in bright sun lol
- click for cloud prediction for Plymouth, MA. area
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cam1936
sage
Reged: 08/01/08
Posts: 240
Loc: Alberta, Canada
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If your going to go and spend money on a DSLR seriously consider a Canon or Nikon. They both offer excellent cameras at excellent prices and both have a very large selection of lenses. As for your question any DSLR camera should have a bulb setting where the shutter stays open for as long as you hold down the shutter button. While captureing IR light is good for astrophotos it makes for poor daytime photos and the ability for a camera to capture IR/UV light will not speed up exposures. If you want to take photos like that one you will need a tripod a remote shutter switch and any camera with a bulb setting and an ISO speed of 1600 or 3200.
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C8-SGT
Nikon 10x50 Action Ex
Canon 350D
Manfrotto tripod
Various EPs and accesories
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smasraum
sage
Reged: 01/13/08
Posts: 492
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You should try your shot again, with the same camera, but do several. Do 4 at each ISO level you have at 15secs. Then, not only can you see the difference that ISO will make, but you can stack your 4 images and get the equivalent of 60 second exposures.
Stacking reduces noise and increases the brightness/detail of the main subject.
Stick with the camera that you've got for now, but if you're going to get a DSLR, as has been stated, get a Canon or Nikon.
I'm partial to Canon myself, but really, I'd say they are equals. Each has different strengths and weaknesses, but they are so close that they are always in close competition with each other.
If your existing camera will go to 1600, then you could take 8 images at 15 seconds, and you should end up with a similar image. You'd probably have more noise, and it may not look the same because most AP guys do a fair amount of post-processing in something like photoshop to really bring out the details and color and minimize the noise.
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Steve
Houston (Friendswood), TX
 Space Center Houston
8" Zhumell Dob - Woo Hoo!!
Celestron C102 f/5 - Thanks Tim!
21mm, 13mm Hyperion
2.5x TV Powermate
Canon Rebel XT
Nikon 7x35
Bushnell 10x50
Edited by smasraum (09/24/08 11:06 PM)
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davidb59
member
Reged: 07/11/07
Posts: 82
Loc: Hopkinsville, Ky.
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You guys are great. I knew I could get some good advice here.
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60mm Walmart special
114mm Celestron FirstScope
10" Zhumell Dob
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Tony Flanders
Carpal Tunnel
Reged: 05/18/06
Posts: 2062
Loc: Cambridge, MA, USA
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Quote:
If your existing camera will go to 1600, then you could take 8 images at 15 seconds, and you should end up with a similar image.
Six or eight years ago, the advertised ISO ratings of point-and-shoot cameras were actually meaningful. My Canon A80 delivers quite respectable pictures at its maximum ISO rating of 400, though I get equally good results (maybe a tad better) by shooting at ISO 200 and then "pushing" one stop in my photoprocessing software.
Nowadays, even the most respectable manufacturers advertise ISO ratings that are utterly useless in practice. My daughter just bought a very nice Nikon point-and-shoot with an advertised ISO 2000. But in fact, the pictures from this camera at ISO 400 are a lot grainier than from my old A80 at the same speed. ISO 2000 is advertising hype, neither more nor less.
Point-and-shoot cameras have actually gotten considerably worse at low-light shooting because all the emphasis has been on miniaturization and long zoom ranges. Both trends push toward smaller sensors, and smaller sensors collect fewer photons. You can't beat the laws of physics! I don't think there's a point-and-shoot camera on the market today that can deliver a decent Milky Way shot -- not even if you stack 20 frames.
To get a really respectable Milky Way with my DSLR, I shoot one minute at ISO 1600, f/3.5. 30 seconds and even 15 seconds work OK, but the resulting Milky Ways are quite grainy. Four 30-second shots stacked works fine too. Mind you, this is a true ISO 1600, not advertising fluff. My DSLR is less grainy at ISO 1600 than my Canon A80 at ISO 200 -- or many modern point-and-shoots at ISO 100.
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Tony Flanders
eyeglasses
6x15 and 8x32 monoculars
8x25, 7x35, 10x30 IS, 10x50, and 15x70 binoculars
70mm and 100mm achromatic refractors
4.5", 7", and 12.5" Dobs
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Protheus
Vaguely offended
Reged: 09/01/07
Posts: 4643
Loc: Illinois, US
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Quote:
Nowadays, even the most respectable manufacturers advertise ISO ratings that are utterly useless in practice. My daughter just bought a very nice Nikon point-and-shoot with an advertised ISO 2000. But in fact, the pictures from this camera at ISO 400 are a lot grainier than from my old A80 at the same speed. ISO 2000 is advertising hype, neither more nor less.
I was going to bring this up, but I guess I'm too late. The higher speed settings in digital cameras will capture more noise as well as more light. My DSLR is useless above ISO equiv. 1600 without frame stacking. Of course, you can stack frames and cut out some noise, but if you're looking to capture a good single frame, you'll need to look at slower speeds on any digital camera; possibly any camera at all.
Chris
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"To tread the sharp edge of a sword;
to run on smooth-frozen ice,
one needs no footsteps to follow..."
"Well, people sometimes ask me 'how did you get involved in astronomy?' I said 'I got born, what's your problem?'" -- John Dobson
"In discussing the large-scale structure of the cosmos, astronomers sometimes say that space is curved, or that the universe is finite but unbounded. Whatever are they talking about?" -- Carl Sagan
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