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Andrew Reid

Panasonic GH5S 4K / 240fps low light monster

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3 hours ago, Emanuel said:

I'd say ISO12800 is the 3200 on GH5, that is, the new territory to avoid, so ISO10000 on GH5S the new 1600 limit on GH5; as my most optimistic bet... about 2 stops and a half for lowlight, not bad. Imagine a f2.8 to let you see light as could be a f1.2 pick. With about 1.15x of crop coupled to SB 0.64x XL version, the new GH5S is the new FF* in town!

 

Question, where are you getting 1.15x crop? 2 x 0.64 = 1.28, or about aps-h. The image circle in DCI doesn't change the crop factor, its still 2, same for 4/3 or 3/2, the diagonal is alway the same - the diameter of the circle. The m43 diagonal in all aspect ratios is 21.63mm, that never changes, right? You can see from the image below, all the aspect ratios are still within the m43 image circle, so they all have the same diagonal. Unless I'm looking at this wrong, but people seem to be calculating things based on the horizontal width, not the diagonal.

Screen Shot 2018-01-13 at 8.32.06 PM.png

p.s. There's a mint GH5 'Classic' (my new name for the original) for $1500 on Fred Miranda if you prefer IBIS. This is a good time to buy. http://www.fredmiranda.com/forum/topic/1525431

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EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

I think it was said to be a 1.86x crop somewhere and I went with that.

 

Still not buying the "it makes it FF" routine.       Sure it makes a LENS faster and shorter.

Someone who knows please answer Dr Caldwell.

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3 hours ago, JordanWright said:

What 2.8 zooms with IS would be a good pairing?

Lumix 12-35mm & 35-100mm.

Without IS (no OIS will save the grace, so couple the Zhiyun Crane-2 gimbal) you have the Tokina 11-20mm or the previous 11-16mm; Canons (all mark II) 16-35mm, 24-70mm and the stabilized 70-200mm. In the MFT camp, the Olympus 7-14mm & 40-150mm.

Without mention the mandatory Sigmas (f/1.8 though, so you get 1 extra stop and a third) 18-35mm & 50-100mm (less than the first one).

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25 minutes ago, Emanuel said:

@Trek of Joy No, you sound right! I hadn't thought about it. I was lazy and took the value from @Mattias Burling without thinking twice. My bad.

Something seemed odd with the claims floating around the speed booster brings it to almost FF FOV, its closer than the gh5 since there's no crop on the gh5s when shooting video, but its still basically 1.3 (1.28) relative to FF. If my math is correct, but no guarantees since I was a journalism major and skipped algebra for statistics.

Cheers

Chris

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4 hours ago, Emanuel said:

Lumix 12-35mm & 35-100mm.

 

No no no no no to 35-100mm... Have you ever used this lens? The ois is absolutely worse than useless for video because of the micro jitters or in the case of V2 the shakes when panning. IF someone made a decent 35-100 f2.8 with ois, m43 without Ibis would be palatable for those needing IS.  As it is there is no good 35-100 lens with IS for video.

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5 hours ago, Emanuel said:

@Trek of Joy No, you sound right! I hadn't thought about it. I was lazy and took the value from @Mattias Burling without thinking twice. My bad.

I just quoted the source, take it up with them. 

https://www.43rumors.com/exact-crop-factors-caluclated-new-gh5s-multiaspect-sensor/

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8 hours ago, Emanuel said:

Lumix 12-35mm & 35-100mm.

Without IS (no OIS will save the grace, so couple the Zhiyun Crane-2 gimbal) you have the Tokina 11-20mm or the previous 11-16mm; Canons (all mark II) 16-35mm, 24-70mm and the stabilized 70-200mm. In the MFT camp, the Olympus 7-14mm & 40-150mm.

Without mention the mandatory Sigmas (f/1.8 though, so you get 1 extra stop and a third) 18-35mm & 50-100mm (less than the first one).

My requirement is no focus-by-wire.  My current target is the Canon 24-70 L II f/2.8.  Would be great for events, workshops, etc. I currently tend to flip between the Sigma 18-35 and a longer lens (often a Samyang 85mm).  I'm eager to ditch the lens changes.

Monopod is all the stabilisation I need - has been working just fine up till now (not to say that IBIS wouldn't have opened up other options mind you).

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On January 1st, when the GH5s was still unannounced and subject to speculations on this forum, I wrote:

"Panasonic will release the GH5s as a camera that will have a native 4K sensor, resulting in about 1 stop more light sensitivity and 1 stop more dynamic range, and perfect Vlog compatibility (since the Vlog curve was designed for cameras with higher dynamic ranges than the GH4 and GH5). However, lack of oversampling will result in a less detailed image with more moiré problems. In addition, the camera will cost a hefty premium over the GH5, catering to buyers who want a compact b-cam to a Varicam or EVA."

Got a bit of beating for this, but it turns out that my speculation was rather right. Here's a test chart comparison based on GH5s (left) and GH5 (right) by the - excellent - German video site slashcam:

file.php?id=22400&mode=view

 

 

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Well, this is the image they posted on their article, which kinda looks suspicious (doubt the article image actually reflects proper test result).

4DLBPg9.jpg

And this is the one in the database for the GH5:

6sPONbG.jpg

Here a comparison on DPReview: https://www.dpreview.com/reviews/image-comparison/fullscreen?attr18=daylight&attr13_0=panasonic_dcgh5&attr13_1=panasonic_dcgh5s&attr13_2=sony_a6500&attr13_3=sony_a7sii&attr15_0=jpeg&attr15_1=jpeg&attr15_2=jpeg&attr15_3=jpeg&attr16_0=400&attr16_1=400&attr16_2=400&attr16_3=400&normalization=full&widget=1&x=0&y=0

Here you can compare some still life shots: http://www.imaging-resource.com/IMCOMP/COMPS01.HTM

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I guess for me, with the whole IBIS vs low light thing - stabilisation is not a *problem* at the moment, whereas sensitivity often is.  IBIS would give me an improvement in an area that I'm currently comfortable with, whereas the improved ISO performance will remove the biggest problematic limitation I currently have with my setup (and in fact, only serious drawback to using the system IMO).

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1 hour ago, Cinegain said:

Well, this is the image they posted on their article, which kinda looks suspicious (doubt the article image actually reflects proper test result).

4DLBPg9.jpg

And this is the one in the database for the GH5:

6sPONbG.jpg

Here a comparison on DPReview: https://www.dpreview.com/reviews/image-comparison/fullscreen?attr18=daylight&attr13_0=panasonic_dcgh5&attr13_1=panasonic_dcgh5s&attr13_2=sony_a6500&attr13_3=sony_a7sii&attr15_0=jpeg&attr15_1=jpeg&attr15_2=jpeg&attr15_3=jpeg&attr16_0=400&attr16_1=400&attr16_2=400&attr16_3=400&normalization=full&widget=1&x=0&y=0

Here you can compare some still life shots: http://www.imaging-resource.com/IMCOMP/COMPS01.HTM

Well, DPReview and Imaging Resource compare stills, Slashcam actually tested video quality.

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With the GH5, some photographers would say that ISO 1600 is usable, others ISO 3200. A very few would even argue that ISO 6400 is usable. Now, with the GH5s, reviewers who've had a chance to shoot with the pre-production model are claiming anywhere from 1-1/2 - 3 stops improvement. But seldom do reviewers talk about the relationship between noise and how you intend to deliver your video. Looking at the master file of my most recent video for example, shot with the GH5 - mostly at ISO 400-500 - the image looks pretty good on my 27" 5K iMac. If I look carefully at things like walls in the picture, I can see noise, but it's nothing overly distracting. But upon examining the same video uploaded to YouTube, the noise is already starting to detract from my enjoyment of the image. If I just look at the walls or the sky in some shots, it looks like swarms of tiny insects crawling around or something. If I were to say, invite someone over to watch some of my clips, I'd definitely want them to see the original master file, not the horribly compressed YT version. So I think if you're aiming for a clean image uploaded to a video sharing website, it's probably best to shoot at a lower ISO. If your aim is to screen your work at film festivals, I think the amount of noise that looked acceptable when viewed on a small monitor or even a laptop, might also become objectionable when seen in a theater. Apparently, noise can also take on many appearances, with some being more or less film-like, others less pleasing to the eye. I'd also be interested in learning why there appears to be a considerable difference in brightness, particularly at lower ISOs, between the GH5s and the GH5. I think it's also worth repeating that Panasonic ISO 6400 is not equivalent to Sony ISO 6400 - Panasonic overstates their ISOs, and there are as many as half a dozen different ways manufacturers come up with these numbers.

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7 minutes ago, jonpais said:

...there appears to be a considerable difference in brightness, particularly at lower ISOs, between the GH5s and the GH5. I think it's also worth repeating that Panasonic ISO 6400 is not equivalent to Sony ISO 6400 - Panasonic overstates their ISOs, and there are as many as half a dozen different ways manufacturers come up with these numbers.

Is the GH5S brighter or darker at same exposure and iso than GH5 or Sony?

The new Star Wars movie in 4k theater has added noise which looks like GH5 iso1600-3200.

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5 minutes ago, jonpais said:

Lie is a strong word, but I think you're right, they do tend to exaggerate their ISOs as well. 

If it was a little off it would not be so bad. But to be off close to or a Whole stop well...

 

Conclusion

By now, it is a pretty known fact among the photography community that Fuji underexposes its images by around 2/3 of a stop to a full stop when compared to other cameras when shooting RAW and using most commercial RAW converters. There are all kinds of theories out there, with some people claiming that Fuji does this on purpose to look better, while others attribute this difference to Fuji’s X-Trans sensor and the demosaicing process. I have to say, that despite my attempts to normalize the RAW files by making adjustments, Fuji still looked pretty darn good compared to other cameras. The main source of this is reduced chroma noise, which is evident when you look at RAW files from both the above comparisons and other sources, such as DPReview’s studio comparison tool. That’s the main reason why Fuji looks so clean for an APS-C sensor. I do not know exactly how Fuji achieves this, but the X-Trans sensor and its demosaicing process are probably the reason for the reduced chroma noise we see in images.

Update: Thanks to some awesome people like Iliah Borg, we now know the reason why Fuji RAW files appear darker. Turns out that Fuji has a special tag (0x9650) in its RAW files that highlights the necessary midpoint compensation for RAW files to interpret and make necessary changes. Below are the values for the Fuji X-T1:

ISO 200 / 0.72EV
ISO 400 / 0.72EV
ISO 800 / 0.72EV
ISO 1600 / 0.72EV
ISO 3200 / 1.38EV
ISO 6400 / 2.38EV

So keep the above in mind when looking at Fuji RAW files and comparing them to other cameras. If you are using a RAW converter from Adobe (and potentially other RAW converters), make sure to look at the above table for adjustments needed to make images appear as they should. Big thanks to Iliah Borg and the LibRaw team for discovering the Fuji tags and letting us know!

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On 1/13/2018 at 9:36 PM, Trek of Joy said:

Question, where are you getting 1.15x crop? 2 x 0.64 = 1.28, or about aps-h. The image circle in DCI doesn't change the crop factor, its still 2, same for 4/3 or 3/2, the diagonal is alway the same - the diameter of the circle. The m43 diagonal in all aspect ratios is 21.63mm, that never changes, right? You can see from the image below, all the aspect ratios are still within the m43 image circle, so they all have the same diagonal. Unless I'm looking at this wrong, but people seem to be calculating things based on the horizontal width, not the diagonal.

Here's where the logic comes in:

2 x 0.64 = 1.28, similar to APS-H, as you say.

But you're not comparing apples-to-apples if you're using an FF camera to shoot video. Because they have a 3:2 sensor, if you want to shoot DCI 4K, you've actually got a ~1.07x crop factor with any FF camera.

So 1.07 vs. 1.28 is only a 1.2x relative crop factor. Which is of course noticeable, but very small. And given that the GH5S has a much more robust codec than any of the FF video cameras currently available for under $10K, and the new sensor appears to have higher quantum efficiency as well, you can call that 1.2x difference essentially negligible.

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