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A7RII 15-30s milky way exposures from Joshua Tree

spence

New member
I've read quite a bit about how the A7RII shows thermal noise at longer exposure times. So, I headed to Joshua Tree with a couple of wide angle lenses for some milky way shots (my first ever.) Went fairly well. Below are some botched raws (badly framed, perhaps underexposed, etc.) that may nevertheless be useful for reviewing noise performance.

FE 28mm at f2, 15 seconds, ISO 3200. Just the milky way:
Same lens and settings, Milky Way plus some underexposed foreground:
Rokinon 14mm at f2.8, 30 seconds, ISO 1600, Milky Way plus some underexposed foreground:

No bulb, single shot mode, LENR was off, manual mode. No dark frame averaging (too lazy.) My overall impression, even on underexposed shots: better than I was expecting. I processed using C1, default sharpening and noise reduction settings. There were very few warm/hot pixels that I could see in the starfields, even when exposure was raised. In dark landscape areas, there were certainly some red/blue warm pixels when exposure was raised, but not a profusion of them. Quite fixable IMHO. The Rokinon was beautiful to use because of the hard stop infinity. I had more trouble focusing the FE 28mm f2.

I understand that this addresses only a narrow subset of astrophotography--single 15-30 second exposures. I don't see myself getting into the heavy duty, super long equatorial mount exposures, or stacking 75 exposures over an hour or whatever. So for my purposes, quite acceptable performance, given my somewhat peripheral interest in this genre. If you do primarily astrophotography, it may not be the best choice based on what others have reported.

Final product:
 

dmward

Member
I think it would be even better if you could figure out an easy way to really get the foreground in silhouette.
 

Jack

Sr. Administrator
Staff member
Wonderful shot indeed!

FWIW: In C1 under the NR tool, there is an option for "Single Pixel." If you toggle that, it does an exceptional job of eliminating hot pixels -- and somehow it knows the difference between that and a star ;)
 

k-hawinkler

Well-known member
Wonderful shot indeed!

FWIW: In C1 under the NR tool, there is an option for "Single Pixel." If you toggle that, it does an exceptional job of eliminating hot pixels -- and somehow it knows the difference between that and a star ;)
Thanks Jack for the reminder! :D
 

spence

New member
Thanks all, you are too kind.

And thank you for the tip Jack--the C1 single pixel removal feature works remarkably well!
 

ggibson

Well-known member
Great shot! I agree on the silhouette comment though, I think the red hue on the tree is distracting.

How do you like the 28mm f2 for astro shots? I've been thinking of picking this lens up. How does it compare to the Rokinon 14mm for getting a good shot of the milky way that you can bring out in post?
 

ohnri

New member
Lovely.

I particularly like the red hue on the trees and foreground.

Which lens did you use for the final shot?

-Bill
 

pegelli

Well-known member
Guy, Jack, just in case you're looking. I think this is a great shot to start your "Photo of the week" tradition.

see here if you don't know what I am talking about ;)
 

spence

New member
Graham: I think the colors and contrast from the 28mm f2 are excellent. Would be hard for me to say where it stands WRT the Rokinon 14mm without more outings, but both seem nice enough. Infinity focus is a little easier with the Rokinon's hard infinity stop. There's a good review of the 28mm with an astrophotography focus here, which includes some comparisons to the Rokinon.

Bill: that final shot was the Rokinon 14mm. Pretty terrific lens for $299.
 

Jack

Sr. Administrator
Staff member
I think the Picture A Week thread is a great idea, so I've initiated a place to start it here: http://www.getdpi.com/forum/artful-...ing-nsfw/56185-paw-picture-week-have-fun.html

And I agree that this image is a stellar (ha!) image to start it with!

PS: re the glow on the tree, I like it as it seems natural for the late Sunset afterglow light. I am slightly bothered by the "white" light on the tree top, but do not find it offensive, rather respect it as an artistic choice -- me, I'd tone it down a stop or so, or yellow it up a bit, or both ;)
 

ohnri

New member
I agree the Rokinon looks mighty fine and the price is low enough to consider giving it a go.

Problem is, I have the 16-35. But it is only f/4.

But I have the A7S2 on preorder.

And I will likely never see a sky like that.

Anyway, a truely well crafted image. And though I do really like the red on the tree I agree that the 'white' light at the top may be bit distracting.

-Bill
 
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