The Milky Way

[invisible]

You need to relax. It really isn't that serious. We have differing opinions, obviously. Go get and drink or whatever you need to do. It's not bad advice to use remote + mirror lock up for night exposures. Chill out. Go take some pics or whatever you need to do. When I go out in a few days to the dark site near my house I will be doing exactly what I stated with the remote and setting exposure as I need to. I will use the remote + mirror lock up to reduce chance of vibration. Critical when I'm using a Celestron C8-SGT, less so on 11-16mm lens. But when I'm going for all the sharpness I can get it doesn't hurt to use it. It's really a small detail to b1tch over. Don't like it? Don't use it.

Reading your reply made me want to borrow your avatar – facepalm goodness.

 

[TheFantasticG]

*edited out beginning* From my experience it depends on what I'm shooting, at what focal length, what look I'm going for, etc. Tim's formula, I think, I s a great starting place for setting exposure but I wouldn't consider it gospel. I am curious, though, Mr Invisible what ISO you consider too high to shoot a 5 sec exposure at a F2.8-F4 on a night scape? I regularly use 800-3200 on the 60D and I suppose I could get away with 6400 on the D7000 with the right PP.

Yesterday I installed a dovetail on top the C8. Should be nice as the CG-5 GoTo, if aligned properly, can track quite nicely so I will be able to use lower ISOs for the same length exposure.

 

[invisible]

I am curious, though, Mr Invisible what ISO you consider too high to shoot a 5 sec exposure at a F2.8-F4 on a night scape? I regularly use 800-3200 on the 60D and I suppose I could get away with 6400 on the D7000 with the right PP.

It depends on the conditions – not all nights and locations are the same. By default I approach nightscapes with 2.8, 30s, ISO 800 and then I up the ISO if I need more light. If your lens only allows you to shoot a 5-second exposure, that means you'd need six more stops of ISO – I'll let you do the math. Your ISO tolerance might be different than the next photographer's – different cameras, different post-processing workflows, different uses for the photos, etcetera. I need files that are good for big prints (24x36) and stock, so my tolerance for noise is relatively low.

 

[TheFantasticG]

I need files that are good for big prints (24x36) and stock, so my tolerance for noise is relatively low.

Ah. That explains everything. Just a hobby for me.

 

[invisible]

I need files that are good for big prints (24x36) and stock, so my tolerance for noise is relatively low.

Ah. That explains everything. Just a hobby for me.

Hobby or not, I wouldn't expect any kind of usable files at ISO 51200 (if my math is right). I've never tried anything higher than ISO 3200 but I assume the noise one would get at ISO 51200 will most likely be brighter than any star.

 

[TimGreyPhotography]

Tim's formula, I think, I s a great starting place for setting exposure but I wouldn't consider it gospel. I am curious, though, Mr Invisible what ISO you consider too high to shoot a 5 sec exposure at a F2.8-F4 on a night scape? I regularly use 800-3200 on the 60D and I suppose I could get away with 6400 on the D7000 with the right PP.

I agree with the formula not being gospel. But it is always good to have something to go off of. I think the exposure goal that the OP should be aiming for is getting as long as an exposure possible while shooting wide open without creating noticeable star trails. But at the same time you might have to sacrifice some of that exposure time in order to use a usable ISO that doesn’t create to much noise. The ISO you are willing to use is also going to depend on the size you plan on printing. Also invisible makes a good point with the fact that 51200 ISO isn’t going to make anything pretty. Checking the ISO performance of the particular camera you are shooting with is always a good choice before choosing your ISO as well. For instance I get the same amount of noise at 12800 ISO on my 5DMK3 as my 60D shoots at 800 ISO.

 

[Garbz]

Okay, I just went out and took a few test shots. One problem I am having is that it is not extremely dark where I am at currently, and I do not see many stars, nor can I see the Milky Way without looking carefully, and it looks like the moon is only going to be showing us more light for the duration of my trip.

Light pollution can be treated as noise. If you have a good signal to noise ratio you can cut through it with an appropriately horrendous looking curves adjustment.

I would use the mirror lock up and drop the ISO to 1600 and leave the shutter open for 30 seconds....

If you need to leave the shutter open for 30 seconds the mirror lockup does absolutely nothing for you and I say this with a Celestron C8 attached to my camera. The benefit of using it depends entirely on the length of your exposure. Setup your camera as you would and take an exposure of 1/8th of a second. What you see in the frame (nothing) is what is contributing to camera shake. If you need more than 1 second to get something in your exposure then mirror lockup is a waste of time and suggesting to use it all the time is bad practice as it prescribes a HOW and does not inform WHY. So yes suggesting to use mirror lockup when not needed is actually bad.

Oh btw TheFantasticG if you're really having issues with vibration due to mirror slap on a C8-SGT I suggest giving the mount a service. It should not be anywhere near that sensitive to vibration at those subs. Planetary photography with 1/20-1/200 exposures yes for sure mirror lockup is critical there if you're game enough to try taking photos on a sill camera rather than video camera, but really unless you're shooting some ludicrously high ISO (6400+) even bright stars shouldn't be blurry as a result of mirror slap.

Stic, is your WB off or do you have blue stars in NZ?

I'd hope we all have some blue stars, and white stars, and orange stars, and red stars

 

[exemplaria]

I would also add that while the rule of 600 is certainly correct, I don't think it's the worst thing in the world if you violate it a bit. This was an 87 second exposure at ISO1600, f4.5 at 8mm, and while you can certainly see some star movement on the periphery, I think the extra stars and depth gained in the middle are worth it.


Untitled by exemplaria, on Flickr

 

[tevo]

So I am currently staying at a location with much less city light and much more clarity in the stars. Here's one I just took:


Day 3 by theofficialtevo, on Flickr

Thank you everyone for your help!

 

[molested_cow]

Well I wish I have access to dry dark places for star shots. I am currently by the coast right on tropic of cancer. The humidity is always high, so on starry nights, if I crank up the exposure, like aperture or ISO, all I will get is reflection of the humidity, not brighter stars. Therefore I have more success shooting star trails than star shots.

 

[j-digg]

I can't wait until late May, I'll be in the middle of nowhere in Peru . Providing both a different perspective of the Milky Way and very little light polution, I've heard it's incredible. I'm thinking about getting my ( sort of ) broken XSi modded for astrophotography for a couple hundredish bucks. Has anyone here done this?