700D quality on wide angle lenses

[C700d]

Hi all,

Still desperately trying to create useable footage this camera and ML. With a 50mm lens I'm producing some nice footage. However with my Wide angle lens (Canon EF-S 10-18mm f/4.5-5.6 IS STM Lens) the quality is worse than a potatoe.

https://ibb.co/4ZL6JHV - I don't even know how to explain the quality issue, it's not sharp, it looks off and smudged and weird. It is like this on many different builds.

Will a sharper wide angle lens correct this issue?
I've also realised that to stop frame skipping from happening I lower the resolution; fair enough, but how can I record at a lower resolution without it cropping the area of recording on the live view screen? It's almost impossible to see what's being recorded in frame while on a gimbal etc.

Thank you for your advice

[Walter Schulz]

We have no idea which mode (H.264/RAW uncropped/RAW cropped) you are using. Same for postprocessing.

http://www.catb.org/esr/faqs/smart-questions.html

That said I doubt your issue is lens related. It looks like heavy aliasing (720p mode?) and workflow not able to master it.

[C700d]

Apologies, I will try to answer those questions.

Recording mode as far as I understand is - RAW - no cropped mode, can't even find any options in the menu apart from "Movie crop mode" which is off. No crop builds being used. Current build is nightly.

Workflow is currently - MLVapp to dng then After Effects. 50mm footage is clear in good light and very useable. 

Thank you for your fast reply!

[Walter Schulz]

Video mode in Canon menu? 720p or 1080p?

And aliasing is an issue with raw non-crop mode because of line skipping. Discussed often in post-processing forum.
Either use something like VAF (anti-aliasing filter) in non-crop mode or switch to crop mode (no line skipping) or try to counter/reduce aliasing effects in post. Have you tried to use MLVapp's anti-aliasing techniques?

Issue in not lens related.

[C700d]

Thanks Walter,

In the first clip I was testing 60 fps so it was in 720p. My mistake.

Here is an image from 1080p 30. - https://ibb.co/vXHr0bx - Better, but still smudgy.

Could you advise me as to where the option is to switch to crop mode? All I have is movie crop mode but it says it's for the 600D.

Also, more information. I am recording at a rate of around 38mbps which is the max I can do for 20 seconds before frame skipping.

[Walter Schulz]

Could you advise me as to where the option is to switch to crop mode?

Press loupe button.

[C700d]

If you mean the magnifying glass (not heard of loupe before) then it zooms in but has no effect on cropping the recording, just makes the view finder go black and white.

I am using MLV app's anti- work arounds but I am unaware of any extra help for that problem in say, Premiere Pro apart from noise reduction maybe.

I will have a look around the forums for anti-aliasing help. Thanks, any more info fire away!

[Walter Schulz]

Turn on cam in movie mode with mlv_lite or mlv_rec module loaded.
Make sure to have MLV mode on (Movie tab).
Press magnify button twice in liveview screen.
Optional: Adjust resolution in MLV settings.
Start recording.

If it doesn't work try
Movie tab menu -> Crop Mode ON

[C700d]

Thanks Walter, literally just came across these steps!

May I ask how I get back out of crop mode? It's messing up my aspect ratio grid on the live view now.

Edit: Nevermind, got it. I will make a short edit from the clips I got today and come back!

[dfort]

@C700d - Walter's suggestion will certainly help with the aliasing by using 1:1 sampling instead of 3x3 horizontal binning and vertical line skipping. The downside is that it uses only a small portion of the sensor. I see you're a new user or at least new to the forum and this might be a little confusing. However, depending on how deep you want to go into the Magic Lantern rabbit hole, an experienced 700D user has created a build that gives very high quality without aliasing or cropping:

https://www.magiclantern.fm/forum/index.php?topic=22818.msg206134#msg206134

[Levas]

I don't think the second example looks that bad 

You could try not to use sharpest/best settings for diaphragm of the lens, better go for fully closed diaphragm, probably f22.
Or fully open, but probably not possible on a sunny day...

When in MLVapp:
-To remove colored speckles use 'chroma smooth' option, for example 5x5
-Don't use 'sharpen' slider, this will make things worse 
-On export in MLVapp, try one of the 'smooth aliasing' options, never tried it, but this function is made for the examples you show here.

[ilia3101]

Workflow is currently - MLVapp to dng then After Effects. 50mm footage is clear in good light and very useable. 

Also try out just MLV App without after effects, you may be pleasantly surprised (also make sure you download latest 1.4 Christmas version)

[C700d]

Thanks for the tips everyone.

I will look at the post from the person who has great quality but all that binning and cropping and a squashed live view seems way out of my depth, espcially the live view issues, I need to see it to be able to see what I'm recording!

Here is a small test video I made (I'm aware there's a lot of issues, motion blur, juddering, frame issues etc), but I'm not too disappointed with the quality!

What do you think?

[Walter Schulz]

Stopped viewing at 00:12 because of aliasing issues in lower left quadrant (wires mostly).
I'm not that much involved in video production but from a consumer's standpoint (mine) I feel disappointed. Sorry.

[dfort]

Yeah, power lines really show the aliasing.



Hard to get rid of that without a VAF filter or using 1x1 or 1x3 sampling or using a 5D3 -- that is the only ML enabled camera that uses vertical pixel binning instead of line skipping.

[C700d]

Completely fair comments, I know I'm limited in terms of producing quality that is consumer worthy, and quite frankly it's not good enough.

My current goal is just to create something that can showcase quality in terms of mainly editing, cinematography (at least barebones framing, I don't have an ARRI ALEXA in my rucksack to solve the aliasing) and story-telling for possible employers, like a showreel just to show what I can do (The above being just a test in getting the best recording quality I can).  Though deep down I know without a better video camera I'm ******, especially if people are turned off after the first 12 seconds.... But without time or money this is what I'm stuck with unfortunately.

The ML videos on the 5D3 do look gorgeous and I've thought about that being my next purchase. Until then, should I just give up?

[dfort]

Well a 5D3 would certainly give you a better experience than any of the other ML supported cameras but shooting raw video on it takes more effort and resources than H.264.

Instead of giving up (on the 700D I assume) how about finding out how others are dealing with aliasing. The most obvious is to use a Video Aliasing / Moiré Filter (VAF) but there's also things you can do in post production. Check out the Experiment - reducing aliasing in post using optical flow and Reducing aliasing in post using enfuse/hugin align_image_stack topic topics. In addition, there are new experimental resolutions that allow the use of Dual ISO without aliasing on the 700D, and other cameras. Sure, this stuff is experimental but the developers are working on making these techniques available for all users, take MLV App for example.

If you don't want to work that hard at getting a good looking image then Magic Lantern might not be the best fit for you. By the way, most productions shooting on the Arri Alexa these days are shooting ProRes, not raw. Just a fun fact--it takes a lot of resources to shoot raw video.

[C700d]

Thanks for the tips and links dfort.

The link with the dual ISO and the guy with the build with no aliasing was one of the first I tried and spent a long time trying to get working. The Dual ISO mode would first give me an error (which I sorted) but then would give flickering video which I could not figure out how to fix. The cropping and binning I do not really understand, and there is the problem of the liveview grid being cropped or difficult to use for framing, which is essential.

Although the aliasing was like sour milk to Walter, I do think the video quality is passable (obviously not to consumers or professionals, but to realise my vision and ideas) on smaller screens and is the best I will be able to get.

[IDA_ML]

C700d,

You seem to have difficulties understanding the basics of video image capturing.  The EF-s 10-18 STM is an extremely sharp lens capable of resolving a lot of very fine detail.  However, you are trying to capture that detail with very few pixels available to cover your entire sensor area - in your case 1736x976 = 1694336p which is less than 1,7 Mp.  This is less than 10% of the 18 Mp available from your 700D sensor.  The reason why the frame resolution is limited to 1,7 Mp is that your little camera cannot handle the bandwidth required to transfer the 18 Mp image of your sensor 24 times every second of your video - this is an enormous amount of data.  This is the reason why only one of every 10 pixels of your sensor is used to capture the highly detailed image of your 10-18 lens.  So, 90% of the fine detail captured by your wide angle lens is basically lost between the pixels and in addition to that you get these ugly aliasing artefacts as a result of data loss.  The end result that you see on your video is very similar to black and white images printed in old newspapers which consist of a limited number of black and white dots (pixels) as required by the printing techniques used in older times.  Please find an old newspaper, observe one of its images under a magnifying glas and you will see these pixels.

Longer focal length lenses, say 50 mm, on the other hand, magnify the fine detail of the scene in such manner that it occupies a much larger area of your sensor, therefore, it does not appear so fine as with a wide angle lens and less of it is lost between the pixels.  Therefore, the 1,7 Mp available can resolve much more of it.  The result is much better quality of the final image.

So, what is the solution of your problem?  The simpliest one is called "crop recording".  In this mode only a small part of the sensor in its central area is used for image capturing but all the pixels available on that area are used to capture the image.  No detail inbetween the pixels is lost.  This allows very high image quality and no aliasing artefacts but the price to pay is that you lose the wide angle of your lens and the vision of the big sensor in its full area.  So, if you chose to film at a crop factor of 2,0, your 10-18 mm lens will become a 20-36mm one.  You can still film your shrine but you will have to step back a bit.  And guess what, video quality will be stunning!  Here is a video sample that I shot with the 100D (its sensor is identical to the 700D) and a 35mm lens at 2520x1080 resolution and 24 fps using Crop recording:

As you see, you do not necesserily need the 5D3 to shoot high-quality RAW video. With your 700D you can also achieve very high quality and do not even need the VAF filter that is even more expensive than the camera itself. 

This explanation is not absolutely precise and scientific but I hope it will help you understand how to get the best out of your 700D.

[Levas]

To me it looks like the user is not using the full resolution potential of the 700d.
The aliasing is much more visible than one might expect from ML raw.
The example picture uploaded in 1080p 30fps mode is 'only' 1184 x 666 in resolution...
https://ibb.co/vXHr0bx
Looks like the perfect resolution to get almost unlimited recording time in 1184 x 666 x 30fps in 14bit raw  (not lossless).
1184 x 666 upscaled to HD makes the aliasing very visible.
Also the sharpening in post is very visible, looks like the footage has been sharpened in 1184 x 666 resolution and after that blown up to 1920 x 1080.
So here is much to gain.

First thing to do, download and use a Magic Lantern build that has the lossless compression option, available on the experimental builds download page:
https://builds.magiclantern.fm/jenkins/job/crop_rec_4k/80/artifact/platform/700D.115/magiclantern-crop_rec_4k.2018Jul22.700D115.zip

Now you have within the raw video menu a 14 bit lossless option, and even some that are lower for example 12 bit lossless option.
Now if you want to get almost the same recording times as you are having now with 1184 x 666 x 30 fps x 14 bit, try using this:
1736 x 976 x 30 fps x 12 bit lossless

It should give you the same experience, while recording TWICE the amount of PIXELS   

The above helps a lot and is probably even sufficient for a while.
Once you want more, you can go explore crop mode (2.5K resolution without aliasing, but with crop factor), and after that, you can dive into the SD-UHS hack module, giving you higher writing speeds,  handy for high resolution crop modes 

[dfort]

The example picture uploaded in 1080p 30fps mode is 'only' 1184 x 666 in resolution...

That's most of the problem right there. Should be using 12 bit with lossless compression and 1736 x 976 resolution. I'd also suggest shooting at 24fps (it is actually 23.976fps) with as close to a 180 degree shutter as possible. That should give continuous recording and eliminate much of the--"juddering?"

[C700d]

Thanks everyone, I really appriciate the detailed replies! I was getting somewhere with another build last night which had an auto UHS-SD hack and I was able to record in higher quality and at higher speeds.
This is the build I used - magiclantern-Nightly.2018Jun17.700D115_sd_uhs by Dannes or something similar.

I've taken on your advice and went with a clean install but that 4k build does not have a UHS-SD hack module and for the life of me I cannot find where or how to install it without it preinstalled in the above build. I did copy the modules and LUA script file from the build above but then I was getting "Unable to detect RAW" errors.

With this 4k build I am unable to even choose 1736 x 976 resolution. The max it will let me choose 1728x972 at 16:9 (I need this aspect ratio for framing compostion) at 30fps and the write speed is 84mbps and skips frames immediately.

On the build with the UHS-SD hack I am able to select 1736 x 976 x 30 fps x 14 bit lossless and I have done three tests, all exported through Premiere at their respective FPS apart fromthe picture example which is a screengrab from MLVapp.


First test. 1736 x 976 x 30 fps x 14 bit lossless and 60 shutter speed. https://vimeo.com/308489397

The second clip is an attempt at shooting in crop mode? No idea if it's working correctly, I pressed zoom in 5x, live view is black and white, hit record.

In my opinion the aliasing is still pretty bad at in the first clip but in the second; in crop mode, it appears to be better on the powerlines, however there is noticable juddering on the cars now....


Lastly I tried shooting in crop mode at 2520x1080 x 24 fps x 12 bit lossless and 48 shutter speed - https://i.ibb.co/jwBLNyw/vlcsnap-2018-12-28-10h36m18s722.png - little under exp I know.


How am I doing? I don't know, it still feels pretty poor on the wide angle lens, I understand that technically there is no issue with the lens but it still looks bad doesn't it?

P.s I must say that I am notlooking for unlimited recording time anything from 10-15 seconds would be fine and that I always shoot in either 24/48 or 30/60. I am using the sandisk extreme pro 4k 90mbps card.


More issues:
1. If crop mode is working correctly, then how do you compose your frame when recording, especially if you are moving with a gimbal? I understand there are trade offs with ML, though is a slow black and white liveview one of them in crop mode recording? - Am I using crop mode correctly?

2. What is this in the top right hand corner, I understand it's recording time usually but what is the number on the right? Am I losing frames? https://i.ibb.co/KV4SLFB/frae.jpg

EDIT: Now I can't record in crop mode at 2520x1080 x 24 fps x 12 bit lossless and 48 shutter speed without instant frame skipping..... come on need a break.

[dfort]

Hard to tell from compressed streaming video and screenshots of your computer monitor. There seems to be a big improvement on the aliasing. I'm also not noticing the "juddering" on the cars.

There are like a zillion possible settings on that build you are using. One of them should work for you Have you seen this test on the EOSM?

[C700d]

Yeah that's an issue, I wish I could upload the huge 8gb+ files.

[dfort]

You can trim it down to just a few frames.

mlv_dump

Code: [Select]

  -f frames           frames to save. e.g. '12' saves frames 0 to 12, '12-40' saves frames 12 to 40

You can also do it with Switch and I believe MLV App might be able to do it too.