paulinventome

Initially it reminded me of using canon lenses many years ago where the electronic aperture was not 100% accurate from frame to frame. But then further investigation shows that this just appears to be in the shadows. (Although it could just that it is more observable in the shadows). The two screens show the shadow data changing quite obviously. There are two 'modes' that it appears to be flicking between It doesn't appear to be an overall exposure change. So is this identical in 8 bit, 10 bit and 12 bit? Because one finger could point at the encoding. If it's the same on all of those i would have to suggest the body itself or it's something that we're all getting but not noticed (and i would notice this!) The fact that it doesn't do it in all the ISOs is unusual as well. Are you able to swap the body? Or borrow one to check? cheers Paul

Did you post a couple of DNGs before? I think you did? What would be interesting is that in the DNG there is a value called Brightness Value which i noticed changes with ISO. If this is being changed in the DNG by mistake then it may explain the data. Have you still got the same DNGs handy? cheers Paul

I would try with a dumb lens because it will eliminate something at the very least. It could be an odd setting. It could be the lens communication. I think it's pretty much limited to you, so setting or the body. who knows cheers Paul

So between 320 and 3200 it flickers still? Which is the worst and what lens? cheers Paul

Thanks for all this. I had a bit of a forehead slapping moment. I was really just trying to get aperture working as it's a Zeiss ZE. But i would move the f stop control and the screen would lighten and darken but the iris didn't move. It just dawned on me that the camera moves the iris when you take the photo in still mode. Then in cine mode is it always on as expected. Duff user syndrome. And of course the ZE is manual focus anyway... (i have no AF lenses!) cheers Paul

Here's a left field question Is anyone using the MC21 adaptor? I sort of assumed that it would allow me to use my Zeiss EF lens, at least control aperture but i think that maybe it is hobbled to only work with Sigma EF lenses. Is this the case - has anyone used any other EF lenses with it? Cheers Paul

Well i am hoping that the next small update in a few days is a bug fix. I just care about - getting a tone curve for 10 bit, as they have done for 8bit, so that 10 bit has the same shadows as 12 bit. And means i can shoot full quality at 25p - getting some other crops, like DCI 4K - maybe some settings over scaling quality (sharper vs smoother) I think if all those that agree email and twitter then they can see that the demand is there. None of the above strikes me as a difficult development job. If the firmware was open i'm sure we could do it. cheers Paul

Kazuto answers the emails too, he's an asset for sigma. I'm so not fussed about this though! In terms or priority - we're saying there's enough headroom to perform a full frame distortion in real time but we can't scale better? I suppose it evidences there is juice available for additional processing though. But i assume this works with a very limited set of lenses... cheers Paul

I'd bet good money this is MOV only. Resolve has OFX plugs for lens stuff but if you're serious about you should shoot lens grids and flat surfaces. I'd prefer to do my own work as if it doesn't work then you've a problem. The lightroom profile for the 50 summicron is totally wrong with the vignetting, drives me nuts - and i don't think i can fix it. cheers Paul Awesome, i may give this a go then! cheers Paul

That's really cool! IMHO one of the biggest annoyances is the VF. I'd pay good money for an EVF but there are no small ones - portkeys and zacuto are the smallest but they are still too unwieldy. There is a collapsable VF from GGS Foto but having a very tough time getting any decent info about it. I wonder whether a VF with different optics to get it closer to the screen is possible... cheers Paul

No chance on 14 bit video at all at the kind of resolutions/rates we're talking about. There's no prosumer/stills sensor that will do this at the hardware level, they're all 12 bit movie mode as far as i can see.I don't see a huge difference between stills and 12bit cDNG though. If the sensor is the Sony one then there is one read out mode, a crop mode that does do 14 bit but as i said, i really don't see that much between 14bit stills and 12bit. The sensor is being read out at 6k, but whether the camera has enough juice to dump that out to USB i don't know. That is a possibility. More crop modes would be awesome, that's true. And yes, some kind of visualisation of RAW data would be very useful. I don't know what the base iso is though, where did you get 200? cheers Paul

The sensor internally might be dual ISO and maybe Sigma run it in different modes depending on ISO. I have just done a bunch of tests seeing whether i can match exposure and workflow to be able to cut the footage into Red footage and actually got it pretty close - close enough that i know it will intercut. One observation is that the ISO to match is 2.5x - so if the Red is at 1000ISO then the Sigma needs to be at 2500ISO to match exposure. I also notice that in the RAW files Sigma is changing the default brightness level for different ISOs, so that different systems may use that default (like where 18% should be) in different ways. This is something i am still looking at. The example being that if you shoot in ISO400 and look then the shadows are raised and banded but ISO 1600 has the *same* overall exposure level but the shadows are richer. So in each DNG file Sigma is adding a different exposure level to compensate. You may expect the ISO1600 to look brighter overall but that isn't happening if the RAW viewer is using that value - what it is doing is pinning 18% in a different place and giving more under stops than over stops. cheers Paul

I've always emailed and always had a polite thoughtful reply back, even if it's thanks but we can't talk about xyz. I would urge as many users as possible to email with their needs - that way they can prioritise them. AFAIK v2 won't have other frame frames and resolutions and i'm disappointed with that. I don't see how much work it would be to add a tone curve to 10 bit for example when they have it for 8 bit. That would sort out quality issues. But if more people email in then they know that really is something we want... cheers Paul

Are you sure you are on the latest firmware? This was a bug in the first release but was fixed quite a while ago? cheers Paul

Thanks to @cpc for actually reading what you were asking. I am always syncing audio from separate recorder so never think of cDNG being anything other than just frames. cheers Paul

Should be okay, works fine for me. What type of fp DNGs are you compressing? Try to use the 10 bit log option and i think what happens is Slim RAW has pad the 8 bit into 10 bit which is what works with Resolve... cheers Paul

PS i find those tree images a bit over sharpened, is that default? The resolving capability of the fp is very very good when paired with a good lens. Comparing say a 50 cron with the CV 50 showed a huge difference, the cron works beautifully on the fp, better than on the Sony cheers Paul

Which 28mm M? Is it the cron and if so which version? I am looking for a 28mm but i am aware that the first ASPH cron has some issues in corners with fliter stacks, especially on Sony A7x. The new ASPH (2016) has a new optical formula and that works much better across all. However, i can get the first version used, whereas the new version is too new for that. And on an fp there is no OLPF so the issues that plagued it on Sonys and other cameras might not be an issue. Hence my curiosity. cheers Paul

This was announced a while back and i was understanding it would be released beginning of March at the CP show - but that show was cancelled and for some reason the release pushed back a few weeks. Lets hope it was pushed back to fix a few more things... cheers Paul

VLC on Mac is a bit odd to say the least. I would highly recommend 'Screen' for mac as an awesome player (although VLC does attempt more formats). I would point the finger at VLC in this case. I don't use AF so have no experience of that. Sigma is guilty of being very open with the camera in the sense it's very RAW. Which i think is awesome. The reality is that all sensors are going to have missing pixels but 99% of the time you wouldn't know because they're dealt with automatically or in the factory. Even the Reds have missing pixels that get mapped out. If you fly a lot then your sensor will get hit all the time and degrade. Cheap P&S have much smaller pixels so i wonder if it's not as noticeable on them but i would pretty much guarantee that those cameras map out anything odd during the internal processing phase of the camera. cheers Paul

Are you able to upload or send the DNG? This looks like a workflow issue more than a camera one. Or was this shot in the first place with a .mov format? If it is then it would be a bug by the look of it unless VLC is doing something odd. Does it look the same in other applications? cheers Paul

I believe so, i would have thought this was the number one thing. I will double check but clearly it would be too late for the next firmware if not. I suspect HDR is baked video only - for a moment i wondered if they could so something cool in RAW. But thinking more about it i doubt it/ I sort of expected that which is a shame. If they opened up the image pipeline you would have such an amazing culture of people squeezing every last drop out. Individuals are happy to take risks that a large company cannot (so push the performance boundary) I totally don't see the point of that with this camera. You're not going to get any more out of it than you do already and you're going to need an Atomos or similar. I have used the sigma as my stills camera since i got it. Seeing if it will/can replace my A7sII and i've decided that it can. I enjoy using it with manual focus lenses. Save for the exposure issues it's nice to use. My biggest downside is really the size with the optical VF, if i could find a better solution i would but so far i'm really enjoying it for stills. But the firmware does need some serious fixes in there before most people would feel the same i think. cheers Paul

Im away at the moment so not had a chance to catch up. They are aware of the DNG flickering and hope it will be in the next firmware last i heard. They've now announced the SDK which could be of massive interest, depending on what access the SDK gives you - for me this *could* be the feature that really propels Sigma out there because they're not protecting a line of cine cameras and if the SDK gives full or wide access to the camera then the possibilities could be endless. On the other hand if, like Sony, it's a limited SDK then that's of less use. I really want an EVF. I don't mind using the optical VF (gotten used to people looking) but it's bulky for a camera so compact. I was wondering if a better optic would work - like half the size but i've not found anyone that has done that. Or a compact EVF would also work - the smallest i'm aware of is the Zacuto stuff but it's still too big. Anyone found anything of interest? The Video HDR function seems interesting, i wonder what that is... cheers Paul

Good you've passed it on. I hear there is hopefully a firmware release at the end of this month/early next. I reviewed all the footage I shot and some of it quite low light but didn't see *any* flickering. So i may have just been lucky or it's a combination of settings that brought it on. For you does it flicker all the time or just at the start? I see in the data that the black level can go lower than the black level adjustment, meaning that the blacks can be a bit clipped. In Resolve i don't know if it assumes the black level value in the DNG or if it adjusts it accordingly. I'm going to have a closer look because it might be there's a little more data in there sometimes. cheers Paul

Okay, so you're right - there's something going on here. Although my 800 is stable and i got a quick flicker in 400, just once at the start of recording. There was a fix to the original firmware that 'stopped' something that sounded like this. But clearly hasn't. Although it's not something i've seen in the footage i've shot - so i can't say it's always happening. I've gone to the source of the files and i believe there's some scaling to the channels that is the cause, in which case there's hope to fix the data before debayer if it has caused a problem. In the DNG's there is a value called black level, which is subtracted from the image. I see different minimum values for this across two DNGs and i can compensate for that in RAW Digger to see. Even doing that i believe there is a scale going on with the channels. If it's something that can be sorted it would be best to sort this before debayer in the RAW DNG files. I will have a word with them to add to any other reports sent. What we should work out are the circumstances under which the camera does this... cheers Paul EDIT: So i've passed on the files to sigma and see what they say. Useful for others that have similar files to do the same.