Optimum camera for high ISO Milky Way shots (D850/810/800E, etc.) - data?

[Ed Hurst]

Hello all,

I produce high-resolution Milky Way pictures, mainly using my Pentax 645Z and 25mm f4 lens. The results are good, but due to the f4 lens, I am generally using ISO6400 - so noise (while amazing) is still an issue. Since the advent of the Sigma Art 14mm f1.8, I am wondering if the D850 might allow better results. Although the sensor might not be quite as good in itself, the ability to use faster apertures would allow the use of lower ISO which might produce better results overall. The pixel count is similar.

But then I noticed that the D850 seems to be coming up in tests with somewhat poorer results at high ISO than I had hoped for (though I am wary of tests!). Some people are suggesting the camera is optimised for performance at lower ISOs and perhaps the D800E/810 may be better at high ISOs (even allowing for lower pixel count).

So the question is, which full frame DSLR camera would produce the best overall results in the ISO range 1600-3200? Taking into account noise, resolution and any other factors. I am prepared to trade pixels (by using D800E/810) if the noise is much better than the D850. In the end, it's the 'clean detail' that is obtained overall through resolution and noise, etc. that I am looking for. Do I dismiss the D5 because, while there is probably less high ISO noise, resolution is also much lower.

And (<<gulp>>), would any other manufacturers' cameras provide anything better still for this precise application?

Any views/data/examples to help?

Thanks,

Ed

 

[GrahamWelland]

Hands down, D810A - if you want stars and Milky Way hydrogen line images then this is the winner in my book.

if you want D5 performance then also consider the Df. Same high ISO capabilities at 16mp. Ignore the retro stuff and consider it Nikon’s hybrid DSLR.

 

[sc_john]

Any views/data/examples to help?

Thanks,

Ed

Ed,

I have really enjoyed your astrophotography! Thanks for sharing your experience and results.

Not an example of a sensor, but an example of lens coma... from lenstip.com (one of the few sites I've found that analyze coma). FWIW, according to them Sigma 14/1.8 is best used in DX format for pinpoint stars...https://www.lenstip.com/506.7-Lens_review-Sigma_A_14_mm_f_1.8_DG_HSM_Coma__astigmatism_and_bokeh.html I have not used the lens, so I cannot confirm or deny their findings.

John

 

[Jack]

Ed,

A little more on the D810A:Just in case you weren't aware, Nikon made it specifically for Astro imaging, and in addition to H-band sensitivity, it apparently has superb noise capability even at very high ISO's. More from Nikon's website here: Nikon D810A | DSLR Designed Exclusively for Astrophotography

As re lenses, Paul will hopefully chime in as he's done a lot of testing looking for the ideal coma-free astro wides.

 

[tcdeveau]

I'd poke around on Adam Woodworth's blog if you're looking for data/examples. He does some comparisons between the D750/D810/D810A and has samples from the D850 as well:

https://adamwoodworth.com/blog/

It's a tough call. The D850 has some improvements over the D810/810A like articulating screen and illuminated buttons that improve function with astro work, but I haven't read enough about performance yet. I'm also not sure what is going on with the D810A. It's been backordered for what seems like forever at B&H, so I wonder if it's been discontinued or if they're going to do a refresh and come out with a D850A.

Also, if you want D800E samples to play around with, I could probably find some .NEF astro shots in my LR catalog with the D800E at ISO 3200 and 6400. PM me if interested.
-Todd

 

[Paul2660]

Hi Ed,

Coming from Pentax, you also should strongly look at the K1. With astrotracer you can trace up to 5 minutes. Huge advantage over any current DSLR, but this being the Nikon form, PM me if you would like more info on the K1.

Reference to D810A, unless you are looking for deep space objects, via telescope, I am not sure it's that great an advantage. Currently the D810A is out of stock most places and I personally believe it's no longer being made, but based on Nikon's inablility to ship D850's in any volume anyone's guess. Yes the files a a bit cleaner than say a D810, but IMO no cleaner than the D750 albeit 24mp vs 36mp. The D810A also has mixed use outside of Astrowork with a base ISO of 200 and possibly problematic use for outdoor work. I have seen outdoor shots from it however which seem OK. My only issue is availability, and price being 3.8K. The D810 with a fast lens is very good up to around 3200 ISO and it can get to 5K, but you need to consider starting to use LEN as heat build up can cause issues.

Lenses,

For my work, I only use wides, and wider the better. One thing to remember is most wides are retrofocus, thus you will start to see elongation of stars even in short exposures towards the edges of the frame, and the faster the wide the better.

Sigma 14mm 2.8 wide open very low if any coma, not a bad hyperfocal, cheap to purchase. Many times off center on infinity so expect to go through a few before getting a good one.

Zeiss Milvus 15mm, EXCEPTIONAL lens, period. Better hyperfocal than the Nikon 14-24 wide open and just overall sharper everywhere. I thought my 14-24 was good, until I tried this lens. However very expensive. Come is there wide open but not the traditional butterfly wing look more of horn shape and not as pronounced

Zeiss Milvus 18mm, Exceptional lens also, but not quite as sharp (at least the one I tried as the 15mm), also I had a stranage elongation of stars towards the edge of the frame, may be been a lens issue, Como nominal wide open

Nikon 20mm 1.8, Plagued by Coma all the way to around F 3.5 to F4, but sharp.

Rokinon 20mm 1.8 Plagued by astigmatism, by far the worse I have seen, and not corrected until F 4.5 or so.

Rokinon 24mm 1.4 Coma wide open, and by F2.2 pretty usable, lenses are like the 14mm, hit and miss due to quality control

Nikon 24mm 1.4 THE WORST COMA of any of the fast 24mm I ever tried. Fabulous lens, tack sharp, but coma is present up to F 5.

Sigma Art 20mm 1.4. A winner, sharpest of the art glass I have tried, there is some coma wide open but by F2.0 pretty nice. (most times lens is not wide enough for me)

Sigma Art 24mm 1.4 Sharp, light lens, but very strong coma wide open until F 4.5 to F5. Also I went through 3 before I found a centered one. Would rival the Nikon for overall sharpness

Lowa 12mm 2.8mm Sharp, not distortion free as claimed, instead pretty harsh retrofocus elongation towards edges. Coma present wide open, by F4 gone.

Nikon 14-24mm Saved this one for last. Still a player after all these years, pretty much coma free wide open (some claim focus shift issues I have never found any with over 20K frames with this lens). Foreground hyperfocal is weak at F 2.8 but coma is nominal. Lens is prone to destructive flare even at night, so watch it.

You also have to look for CA issues, as each and every star depending on the lens can have fringing. Sometimes the fringing is worse than the coma, i.e. harder to correct. For example the Nikon 24mm 1.4 is very CA free, but has very strong coma, so if you are willing to crop into the frame, the focal range works it still might be a good player as there is no coma on center. LR with the eye dropper tool works better than C1 on this at least for my work. ACR has no eye dropper for fringing, just the sliders.

Noise, coming from the 645z you may be a bit disappointed, maybe not. That is very clean camera. The D810 will still get some white dots over time along with stuck pixels. LR can't correct this C1 can (single pixel noise reduction, an amazing tool for astro work). The D750 is very clean up to ISO 6000 and on a cooler night easily will out perform the D810 for noise. For me 24MP is fine for astro work, the use of more pixels tends to be a waste as most of the shots just get web play.

The best camera for this work, simply stated is the Sony A7SII, just amazing what it can do at night with a C1 raw conversion. I have been tempted many times, but 12mp is really low pixel count, thus I would not be using it for much else, again a big investment for something I would only use at night, however it's by far the cleanest out of the gate. check out lonelyspec.com, I think that is right he uses the Sony a lot.

Intervalometer, still need something here. But you can use use the Nikon remote and hand release. The D810A has a working intervalometer up to 15 minutes the rest of the cameras on the market give you no timer function, thus "built in intervalometers" will not work with bulb, but the good news for milky way work is your longest exposure would be around 30 seconds and with a wide about 15 to 17" so most of the in camera intervalometers will work.

From what I have seen the D850 is about the same as the D810, in regards to night work, I fully expect to see the D850A sometime next year, announced mid 2018 and shipping by 2019!.

D810A's on ebay are there and I have considered a few but I have not pulled the plug on one yet, as they hold their value close to new ones.

Hope this helps a bit

Paul Caldwell

 

[Ed Hurst]

Wow, everyone. What a wonderfully helpful and informative set of responses. I am simply blown away. Thank you.

A couple of initial responses...

Firstly, this kinda depends on using a fast 14mm or 15mm lens for it to be worth anything to me. The 645Z with 25mm f4 is very good already (at ISO 6400) and moving to a full frame alternative would only be better, I think, if I can go wider than f2.8 and use a lower ISO. I think an f2.8 lens, used at ISO 3200 would probaby not beat the 645Z combo for noise or resolution. So it all hinges on how good the Sigma Art 14mm f1.8 lens (or other options in this range I cannot think of) perform.

Secondly, I really do feel that I need a high resolution camera here. I do exhibit and sell large prints of these images, so the point made above that these shots are only viewed on-screen doesn't apply. For me, this means at least the resolution of a D800E/810. If the D850 can do well at its higher resolution, all good.

The Pentax K1 was also something I thought about, but there seems to be no way of using the Sigma Art lens on it (not available in the right mount, or even one that can readily be adapted). Otherwise I would certainly favour it for its built-in tracking capabilities.

Finally, thanks, Todd, for the offer of D800E files, but I already have quite a few of my own (I used one for astro before getting the 645Z) - appreciated though

So I think it all comes down to this: is the Sigma Art 14mm f1.8 good enough on full frame, right into the edges, when used at (say) f2? And does the D850 (or D810 or D800E or D810A) produce better results with the lens, when used at (say) ISO 2000-2500 than the 645Z at ISO 6400 (in terms of actually rendered detail, taking resolution and noise into account)? If so, which of the four does so best in that ISO range?

Warmest regards,

Ed

 

[Ed Hurst]

Ed,

I have really enjoyed your astrophotography! Thanks for sharing your experience and results.

P.S. Thanks John!

 

[GrahamWelland]

Btw, D810A shoots perfect normal images with the addition of a Kolari hot filter. That will nuetralize the hydrogen line sensitivity for normal shooting.

As Jack mentioned, it is also a noise Meister.

if stars are your thing (and vibrant sunsets/sunrise) then I can absolutely recommend this camera. Get it while you can or wait for an equivalent D850 version in a year or two.

 

[Ed Hurst]

Btw, D810A shoots perfect normal images with the addition of a Kolari hot filter. That will nuetralize the hydrogen line sensitivity for normal shooting.

As Jack mentioned, it is also a noise Meister.

if stars are your thing (and vibrant sunsets/sunrise) then I can absolutely recommend this camera. Get it while you can or wait for an equivalent D850 version in a year or two.

Thanks Graham - good advice! Wish the camera (D810A or, in time, a D850A) were available for hire here in Sydney. I am happy with my 645Z and am only looking at this for MW shots, which I do often enough to care, but rarely enough for hiring to work.

 

[GrahamWelland]

TBH I hate 3:2 35mm format so if it were ME, I’d seriously consider seeing if someone could adapt another 50mp 4:3 sensor camera with the filter. Maybe talk to Kolari / LifePixel etc.

 

[Ed Hurst]

TBH I hate 3:2 35mm format so if it were ME, I’d seriously consider seeing if someone could adapt another 50mp 4:3 sensor camera with the filter. Maybe talk to Kolari / LifePixel etc.

That would work if such a camera system existed with a fast super-wide but (to my knowledge) it does not. So I'd end up with responsiveness like a D810A but no further advanced in terms of my ability to capture detail at lower ISOs than at present. There would be less noise (as there is with the D810A), but I still want to lower the ISO.

 

[Ed Hurst]

Two plusses in the D850 to note when doing very low light work or stars:

1. The VF is noticebly brighter and optically better than the D810 so I find I can compose a low light / starlight shot much easier and often without shining a light on the foreground.

2. The low light ability of live view is markedly better in the D850 than any other camera I have used to date which means it is much easier to hit critical focus in night shots. I think it might even be three full magnitudes better in terms of star brightness, I was actually seeing nebulosity in the Orion Nebula when viewing it through my 105 1.4E the other night.

That sort of usability improvement is very welcome (rather like the illuminated buttons mentioned above) but I would base the decision on the actual sensor performance and regard these considerations as 'nice to have'. Partly because I usually set up my Milky Way shots in daylight and wait for the darkness (madness, but that's what I do!).

 

[Ed Hurst]

Of course, that is why they were listed as pluses rather than core criteria for deciding. If it is the sensor you are after, all I can say is that is is clearly ahead of the D810 in noise and in regards to the 750 is on par or at most, a 1/2 stop behind it in the highest non-extended range.

Fed proper inputs, the D850's additional resolution over the 810 is readily apparent in every kind of shot, including stars.

Thanks mate. Helpful.

I will see if I can somehow compare 645Z + 25mm (using f4) @ ISO 6400 with D850 with Sigma Art 14mm f1.8 (using f2) @ ISO 2500. Looking for extent of clean detail rendered and the various aberrations into the corners. If I get results on this, I will report back to you all!

 

[Paul2660]

A bit of info on the 14mm Art 1.8 14mm.


https://www.lenstip.com/506.7-Lens_...f_1.8_DG_HSM_Coma__astigmatism_and_bokeh.html

Also if you have not already, take a look at

www.adamwoodworth.com

His approach for night skies is different (use of multiple exposures), but very effective and need for faster glass is not as important.

Paul Caldwell

 

[Jan Brittenson]

Just to note, my experience with the Nikon 14-24 is it has significant curvature of field which worsens dramatically at the wide end. It doesn't matter much at infinity, but for near-far compositions it can make it practically impossible to bring field foreground into crisp focus. In particular the corners easily look soft in the 14-18mm range, simply because they're out of focus. For how I use it this is an issue since I almost always want a wide lens to create a sense of space, not so much to bring in a large distant scene (like I'd imagine you would in milky-way type shots). This is a reason I'm seriously considering the Zeiss Milvus 15, but my main beef with it isn't price as much as weight and size; the 14-24 is pretty compact for what it does (as is the trusty and super compact ZF 18 I'd pair the 15 with). But my interest is general photography more than anything astro... so, much closer distances. And, as has been noted the 14-24 is prone to ghosting, more so than veiling flare, which the nano coating handles very nicely.