Lake Photos - Why are these not better???

[OrionsByte]

Set the ISO to the max. Not sure what the 450D does, but crank it. I do 25000 on my camera, you might be able to do 12000. It's going to look like Dog S***, but that's ok. We just want to make sure our composition and focus is good and we have a picture to gauge exposure from.

...

OK, cool, so the exposure at ISO 25k is 4 seconds and f/2. Perfect!

Now we crunch the numbers down to the equivalent exposure at a lower ISO like 200 and stop the lens down a bit too, I did f/2.8 because that's more than enough DOF for this.

So the same exposure at ISO 200 and f/2.8 would be about 32ish minutes. That's where the cable release and the eyepiece shutter comes in. For such long exposures the camera won't automatically go past 30 seconds, and the eyepiece shutter keeps light from leaking in.

I never thought of taking a high-ISO shot as a baseline for a low-ISO shot, but it makes TOTAL sense. Unfortunately my D70 only goes up to 1600 ISO but that's still 3 stops worth of time-saving (so under these same circumstances my test exposure would be closer to 4 minutes instead of a half hour... right?). Might take me longer to find the right exposure but it's better than wasting a half hour at a time!

Thank you very much for your incredibly useful post!

Actually I may be doing the math wrong but I come up with different numbers, so maybe you can help me figure out what I'm doing wrong:

Your test shot: 25600 ISO, f/2, 4 seconds

25600 ISO to 200 ISO = 7 stops
f/2 to f/2.8 = 1 stop

So that's an adjustment of 8 stops, so:
4 seconds + 8 stops = 1024 seconds = 17 minutes

So it seems like your final exposure was close to a full stop over the test exposure, which is fine because it looks great and the test shot looks a little underexposed; did you intentionally add a stop, or did I miss a stop in my calculations somewhere?

 

[Sw1tchFX]

Set the ISO to the max. Not sure what the 450D does, but crank it. I do 25000 on my camera, you might be able to do 12000. It's going to look like Dog S***, but that's ok. We just want to make sure our composition and focus is good and we have a picture to gauge exposure from.

...

OK, cool, so the exposure at ISO 25k is 4 seconds and f/2. Perfect!

Now we crunch the numbers down to the equivalent exposure at a lower ISO like 200 and stop the lens down a bit too, I did f/2.8 because that's more than enough DOF for this.

So the same exposure at ISO 200 and f/2.8 would be about 32ish minutes. That's where the cable release and the eyepiece shutter comes in. For such long exposures the camera won't automatically go past 30 seconds, and the eyepiece shutter keeps light from leaking in.

I never thought of taking a high-ISO shot as a baseline for a low-ISO shot, but it makes TOTAL sense. Unfortunately my D70 only goes up to 1600 ISO but that's still 3 stops worth of time-saving (so under these same circumstances my test exposure would be closer to 4 minutes instead of a half hour... right?). Might take me longer to find the right exposure but it's better than wasting a half hour at a time!

Thank you very much for your incredibly useful post!

Actually I may be doing the math wrong but I come up with different numbers, so maybe you can help me figure out what I'm doing wrong:

Your test shot: 25600 ISO, f/2, 4 seconds

25600 ISO to 200 ISO = 7 stops
f/2 to f/2.8 = 1 stop

So that's an adjustment of 8 stops, so:
4 seconds + 8 stops = 1024 seconds = 17 minutes

So it seems like your final exposure was close to a full stop over the test exposure, which is fine because it looks great and the test shot looks a little underexposed; did you intentionally add a stop, or did I miss a stop in my calculations somewhere?

I crunched it too and you're exactly right!

What i probably did was looking at the initial exposure guesstimate that it was about a stop dark, so i exposed for a stop longer. That's the only thing i can think of because the ISO 25000 shot is a little dark compared to the 200 shot.

 

[Morpheuss]

for the op i would just edit them slightly maybe see what the auto white balance does and maybe play with the contrast and brightness a little depending on how the white balance goes