Hoka Hey
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Veteran Member
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Posts: 3,046
Re: To: Hoka Hey - imaging with the Ra+RF 85mm (PICS)
Marco Nero wrote:
Thanks again Marco.
Hoka Hey wrote:
The deep space images are beyond anything I would have expected. There are folks spending vast amounts of money and huge chunks of their time to produce images like that, and you are doing it with 6 second JPGs.
Put simply, I could probably just adjust the brightness of a JPEG from this setup and it would exceed what I could get from an EOS 6D with a similar lens and the same settings. I could NEVER get the blue star colors or any dust lane reflections to show up on my other gear. I was all set to start image stacking this year but now it looks like I might be able to just use an EQ Mount to enable longer exposures and to just blend a couple of shots together if I need to. Those shooting RAW will presumably have evenmore room to play with during pp.
I have to admit that I'm a little angry at you, but in a good way. 🙂 I have wanted both the Ra and the RF 85, but I have been able to overcome those impulses up til now. I frankly hadn't thought of using them in combination. This changes things. Now, I can "justify" getting them.
I was annoyed that hardly anyone was using the Ra online and only a few members here had the RF 85mmL lens but hadn't used it for astro.
My plan has been to astro mod my R once I get the R5. So, I have not gotten the Ra. Also, I'm frustrated that the Ra and R lack an Interval Timer. It's a trivial niggle, but it has kept me from taking the plunge with the Ra. Now, I wondering whether the Ra may be better than a modded R.
So I had to base my research on what I could find on the internet. I did find this image from PetaPixel to be useful in demonstrating one of the differences between RF and EF lenses for Coma Control ...
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https://petapixel.com/2019/06/17/canon-this-is-why-rf-lenses-are-outstanding/
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If you get a chance and have one, could you use an x-rite color checker passport and see how that works for color correction of the Ra? The dual illuminant profile does a nice job (in my opinion) with the R for skin tones and I'd love to see how close it would get with the Ra.
I don't have an x-rite color checker passport here. I did do a Custom WB using a white-card shot in direct sunlight whilst overhead. Then when I took some shots with this Custom WB, I wasn't as happy with the results (on the LCD) so I ended up returning to Auto WB.
As always, thanks.
Best,
I've been here on the forums since March 2003 and I've always followed the same principal of sharing any experiences or observations with others here. The shots of the Carina nebula caught be by surprise when I first reviewed the images while the camera was still on the tripod. To get shots like this with a 6 second exposure (limited only due to the 85mm focal length) has caught me completely by surprise. I did not expect these types of results without stacking dozens of longer exposures (eg 160x 150sec exposures). Normally we'd have to use a smaller aperture (at least f/4) to prevent the stars from bloating or generating coma and CA complications. The only thing I'm not getting at these wide apertures is diffraction spikes on the brighter stars. Presumably, with longer exposures using smaller apertures, the results will be even better.
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This was the playback view from the older EF 50mm f/1.2L USM lens on the EOS Ra Note the colors and detail captured. This was also an under-performing lens.
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I was saving this for another thread where I could post some product photography (terrestrial indoor shots) alongside it, but here's an example of what I did the other night. Note that astro images tend to require editing compared to terrestrial shots like portraits etc. But most people tend to have to add colors and push levels of contrast and color into the realms of fantasy. In this instance, I've tried to retain the colors captured with Auto White Balance... which is still quite a bit off from the ideal "proper" white balance needed for the Milky Way with an astro-modded camera.
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This is a set of three JPEGs I took of the Milky Way's core that I only just finished working on yesterday. Because the RF 85mm lens doesn't distort much at this focal length, (and because coma is greatly reduced in this lens) I only needed a very slight overlap.
My best astro lens for coma, CA and night sky colors is the EF 35 1.4 Lii. It's my only lens that has the BR element that the RF 85 1.2L has. I've always wondered why it was so much better for astro than my other lenses. Pretty clearly the BR element is a huge part of it.
Lately, I've been lazy and have been using a Sigma 14mm 1.8 so that I didn't have to shoot as many subs to make a pano, but this post reminds me that my best MWs come from the EF 35 1.4Lii and I need to get back to using it.
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The three original unprocessed JPEG images from the Ra + RF 85mm f/1.2L USM lens.
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Now these colors and details appeared a bit brighter on the LCD but I didn't want to over-expose since I was deliberately shooting in JPEG.
It would be interesting to see how much effort it takes to PP the single RAWs to look like what the PPed JPGs. I'm wondering if there is some magic (Canon fine-tuning for astro) in those JPGs that would be hard to reproduce even with good PP.
Looking at the original JPEGs above, you can see that the colors and details are essentially all there in the singular shots. There's light from the yellow star Antares illuminating the dust lane next to it on the right. The pale blue glow of Rho Ophiuchi with a triple star grouping in the core is there - and this is something I've normally failed to catch in the past. I can even make out the blue hue of the lesser horse head reflection nebula (IC 4593) in the upper right. Any coma from corner stars is so subtle that it's not noticeable, even here at f/1.4 . Essentially, all the colors and details were captured in the JPEGs. RAW might have offered a little more but I wanted the camera to use its lens corrections and any automated color corrections, sharpening, contrast etc settings to see what I could get.
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The settings used were as follows:
[CAMERA] : User Defined Setting: "Fine Detail" | 10-sec self timer
[SETTINGS]: 6 Seconds | ISO 5000 | f/1.4 | Auto WB
What, if any, in-camera noise reduction was set? If I were shooting single images, I'd be tempted to try Long Exposure Noise Reduction as it does a nice job in the R with long exposures of more than 6 to 10 seconds.
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My method of editing these JPEGs was to merge them together into a panorama using Photoshop's automated feature. Then, I create layers that enable me to tweak and manipulate the highlights and shadows. Colors are sampled directly from the captured data in the images. No noise reduction or sharpening was needed. The process I used enabled me to darken some areas of the dust lanes and raise illumination in other areas. The lack of color noise, even at ISO 5000 was interesting. It's there in some areas (especially in the top left) but it was subdued. I only worked on this image for a few hours the other day when I was on a fairly long hands-free phone call. When I was finished, the results were as follows:
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EOS Ra + RF 85mm f/1.2L USM - a three-shot JPEG panorama - shown after editing.
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[Editing]:
* Color Saturation (two manual, selective passes with a Wacom Tablet/Pen)
Which Wacom are you using?
* Contrast Adjustments (once)
* Levels (once)
* Curves (twice)
* Manual Shadow enhancement (via Wacom Tablet/Pen)
* Manual Highlight enhancement (via Wacom Tablet/Pen)
* Forgot to apply proper correction for Light Falloff (!)
* Brightness Adjustment in Center of image.
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The reason for the washed out area in the extreme left is because when I have rotated the panorama from vertical to horizontal. When I took these pictures, the bright lights of the city of Sydney were adding to the glow on the horizon. That's where this glow was coming from... light pollution. The White Balance isn't exactly perfect but it was good enough for this test. I hope to try this again when I can use a tracking EQ mount to enable smaller apertures and longer exposures. For a singular JPEG image, the results were just fine and better than anticipated. A challenge I had was keeping the layered PSD files under 2GB in order to keep saving them without having to resort to a PSB (Large Document format).
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This was the eye-opener for me...
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Part of me was concerned that the cost outlay for this lens and camera was more than I wanted to be spending money on at this time. I reasoned that I could try out the EOS Ra for terrestrial use and may later purchase an EOS R6 for general use with the same RF lenses. The reason I bought the RF 85mm lens was because I knew it would vastly outperform my older EF variant (which was an exceptional copy that I regret having to part with). But since the R is Canon's future-proof system, this seemed to be the right decision for me at this time.
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Where I see this camera (EOS Ra) as being useful for me is for
* landscapes & nightscapes with the Milky Way in the background
* mounted directly to a telescope.
* mounted on an EQ Tracking Mount with longer lenses.
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Best,
