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Old 18-09-2019, 11:00 PM
casstony
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Need widefield advice

I tried the newly arrived Nikon D750 and 15mm fisheye out tonight, taking a bunch of 60 sec exposures at ISO 400 and f2.8. I now realise that stacking would be problematic since the landscape will be blurred.

What's recommended in terms of exposure length and ISO for these types of shots?

This is a single 60 sec shot with no editing.
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Old 18-09-2019, 11:13 PM
Ukastronomer (Jeremy)
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Have you simply tried bracketing ?

shoot one at 20 seconds 15 seconds, one at 10 seconds one at 5 seconds etc

Up the iso, if noisy use noise cancelling software, google "noiseware FREE community edition)

Did you choose a fisheye over a rectilinear lens for a reason ? where you get the same full image but avoid the fisheye effect
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Old 19-09-2019, 04:49 AM
Merckx (James)
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Perhaps look into Sequator. I haven't used it much but the website claims this:


Quote:
Sequator is a free software which can track stars on multiple images, align stars and stack them.

If you don't have an equatorial mount, by stacking non-blur star images in short-time exposures, the result will be almost similar to long-exposure on an equatorial mount. However, Sequator can control the exposure properly by auto-brightness or HDR-mode output, in 16-bit TIFF for further post processing. Additionally average random noises, rather than over-exposed on a physical equatorial mount.
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Old 19-09-2019, 05:51 AM
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One way is as Jeremy suggested and another is to treat it as a composite. Stacking all of your exposures just as you would when doing deep sky imaging. Then remove the foreground from the final stacked image and replace it with the foreground from one of the single exposures. Then blend the new foreground edges into the background using a slight motion blur to emulate the movement found in a long exposure image.
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Old 19-09-2019, 05:58 AM
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Quote:
Originally Posted by LostInSp_ce View Post
One way is as Jeremy suggested and another is to treat it as a composite. Stacking all of your exposures just as you would when doing deep sky imaging. Then remove the foreground from the final stacked image and replace it with the foreground from one of the single exposures. Then blend the new foreground edges into the background using a slight motion blur to emulate the movement found in a long exposure image.
This is probably the best way. You take a shot for the foreground without tracking and then a lot with tracking to stack for the sky.
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Old 19-09-2019, 08:01 AM
casstony
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Originally Posted by Ukastronomer View Post
Did you choose a fisheye over a rectilinear lens for a reason ? where you get the same full image but avoid the fisheye effect
Hi Jeremy, the lens was part of a used camera deal. I bought the camera to modify and use with a telescope. I've never done any widefield lens shots so I'm giving this a go while I decide whether to keep the lens.
What is the normal use of a fisheye lens?

Thanks everyone for the advice. Since I've already got a bunch of images I'll try the stacking/foreground insertion method.
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Old 20-09-2019, 06:59 PM
Sunfish (Ray)
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I have used Sequator for these panorama wide field shots and it does a good job. I have also just aligned and stacked in PS and not worried too much about the tracking blurring the trees a little. Sequator will produce a full 360, there are many options depending on your aim.

The iceman has tuturiols for stacking a flattened shot with a separate foreground but elsewhere here in the nightscapes section you will see great shot with a tracked foreground made crisp using the foreground features of Sequator , that I am yet to try , but it looks stunning.

Read post 10:

http://www.iceinspace.com.au/forum/s...d.php?t=177302
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Old 20-09-2019, 07:05 PM
Sunfish (Ray)
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Ps. I suppose that it is harder starting with a fisheye rather than my Samyang 14 but Sequator will straighten just about anything, or you can just go with the curve.
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Old 20-09-2019, 07:13 PM
casstony
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That looks good Ray and I've got some cloudy nights ahead so I might give it a try. I took my images at iso400 so I can probably bump that up too next time.
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Old 20-09-2019, 07:42 PM
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Nikolas (Nik)
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This video is essential for what you want
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Old 21-09-2019, 10:09 AM
casstony
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Thanks Nik I will check that out.
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Old 21-09-2019, 04:45 PM
Ukastronomer (Jeremy)
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Quote:
Originally Posted by casstony View Post
Hi Jeremy, the lens was part of a used camera deal. I bought the camera to modify and use with a telescope. I've never done any widefield lens shots so I'm giving this a go while I decide whether to keep the lens.
What is the normal use of a fisheye lens?

Thanks everyone for the advice. Since I've already got a bunch of images I'll try the stacking/foreground insertion method.
A fisheye produces the round effect YOU see in your image, see image, where as the one of the car shot with my 14mm Nikkor is similar to rectilinear, what a rectilinear lens would look like

Believe it or not the car was shot from just 12" in front

Meaning with a wide angle rectiliniar lens you get the full sky in BUT flat not curved/distorted
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