Canon EOS R5 Unite and Discuss!

tpatana wrote in post #19124909
Maybe I've misunderstood, but I thought the normal ISO range 100-51200 is changing gain on sensor, and at least on some earlier camera for 50 the sensor gain is same as 100 and it'll basically post-process 1 stop to make it look like 50. Which would be identical for LR/PS 1 stop change, and hence doesn't make sense to do in-camera. Or have I misunderstood?

A camera can use various analog gains for various ISOs, but there is no reason it has to. As long as there is sufficient headroom not to blow matte whites, a camera can legitimately do whatever it wants. ISO is about only one thing: the exposure level of a middle grey in the capture that becomes middle grey in the default conversions. The gain used for ISO 100 is also used for 50 in most Canons that have ISO 50, and ISO 200 with HTP uses it also. They are all real ISOs; the HTP just has one more stop of RAW headroom than ISO 100, and ISO 50 has 1 stop less than ISO 100, but still has as much as slide film, whose ISOs you would probably not doubt.

Some converters understand what ISO 50 and HTP are, and some may not, and may require you pulling or pushing with the sliders.

digital paradise wrote in post #19125029
Because then I don’t have to remember to press the BBF or shutter before bringing it to my eye. I’d only use it when there is a lot of action. If I do proceed I’ll probably make a quick install adapter.

I’ve never really liked the DOF for anything. I find it very awkward. Since I never record that button is pretty convenient. Easy to put back to recording if I do.

I like how Ron used illumination button to toggle between screen and EVF.
Don

LJ3Jim wrote in post #19124864
I bought a couple of LP-E6NH batteries from my local camera store a few days ago. It looks like https://www.kenmorecam​era.com/ still has them in stock.

I was really surprised to find two of them in stock at our local Best Buy yesterday

Littlefield wrote in post #19125051
I like how Ron used illumination button to toggle between screen and EVF.
Don

Yes that is a good option I’ll try out when I get the R5.

RDKirk wrote in post #19124649
The raw data itself is not effected. The metadata for the file records the camera settings, and these will be used by Canon DPP for the initial presentation of the RAW image for conversion to JPEG or TIFF.

Hmm, I thought also that the NR setting doesn't impact RAW but this link says otherwise:

TeamSpeed wrote in post #19125002
https://www.dreamstime​.com …-priority-explained-40542

To make the best of your camera, you need to keep in mind what affects RAW files.

1) Long exposure noise reduction - recommended setting: Auto

2) High ISO noise reduction - recommended setting: standard (high will slow down your camera)

3) Highlight tone priority - recommended setting: subject for another whole article

My control ring adapter came today!

John Sheehy wrote in post #19125050
A camera can use various analog gains for various ISOs, but there is no reason it has to. As long as there is sufficient headroom not to blow matte whites, a camera can legitimately do whatever it wants. ISO is about only one thing: the exposure level of a middle grey in the capture that becomes middle grey in the default conversions. The gain used for ISO 100 is also used for 50 in most Canons that have ISO 50, and ISO 200 with HTP uses it also. They are all real ISOs; the HTP just has one more stop of RAW headroom than ISO 100, and ISO 50 has 1 stop less than ISO 100, but still has as much as slide film, whose ISOs you would probably not doubt.

Some converters understand what ISO 50 and HTP are, and some may not, and may require you pulling or pushing with the sliders.

How does that work?
Going to ISO 200 sets an amplifier gain to some level. If exposed properly, a bright pixel would be stored as a value of 16,383 (the maximum value 14 bits of data could hold). If highlight tone priority gives a stop more "headroom", that implies a value of 32767, which won't fit into 14 bits. Note that traditional stops are also powers of 2.

Capn Jack wrote in post #19125082
How does that work?
Going to ISO 200 sets an amplifier gain to some level. If exposed properly, a bright pixel would be stored as a value of 16,383 (the maximum value 14 bits of data could hold). If highlight tone priority gives a stop more "headroom", that implies a value of 32767, which won't fit into 14 bits. Note that traditional stops are also powers of 2.

You're incorrectly assuming that the same bright pixel that would be about 16383 with plain 200 would also be 16383 with 200/HTP, when it would actually be about 8192, due to half the gain compared to plain 200 (or the same as plain 100). I say "about" because zero or black is actually 512 at low ISOs and 2048 at higher ISOs with current Canons, so you have to subtract these numbers, do your math, and then add it back.

John Sheehy wrote in post #19125180
You're incorrectly assuming that the same bright pixel that would be about 16383 with plain 200 would also be 16383 with 200/HTP, when it would actually be about 8192, due to half the gain compared to plain 200 (or the same as plain 100). I say "about" because zero or black is actually 512 at low ISOs and 2048 at higher ISOs with current Canons, so you have to subtract these numbers, do your math, and then add it back.

So, you are really losing a stop on the bright end, or the bottom? Scaling 16383 to 8191 using HTP means we only use 13 of our 14 bits to store the data (2^13-1 = 8192). That still seems like we lose a stop of dynamic range.

Ohhh now I am really excited. I got the call!!! I will get my R5 in a few hours and that is from the second dealer I pre-ordered from just 6 weeks ago. The dealer I pre-ordered at in march says november delivery.

Capn Jack wrote in post #19125525
So, you are really losing a stop on the bright end, or the bottom? Scaling 16383 to 8191 using HTP means we only use 13 of our 14 bits to store the data (2^13-1 = 8192). That still seems like we lose a stop of dynamic range.

200/HTP has a stop more headroom than ISO 100, relative to a middle grey metered for that ISO, and a stop less "footroom" than ISO 100.

200/HTP has a stop more headroom than ISO 200, relative to a middle grey metered for that ISO, and almost a stop less "footroom" than ISO 100.

Lets put some simple hypothetical numbers on this. If ISO 100 has 14 stops of DR, and ISO 200 (without HTP) has 13.5 stops of DR, and these non-HTP ISOs have 3 stops of headroom above middle grey, then we have 11 stops of "footroom" and 3 stops of headroom at ISO 100, and 10.5 stops of footroom and 3 stops of headroom at ISO 200. Since ISO 200/HTP uses the ISO 100 analog gain and same digitization, then 200/HTP has the same 14 stops of DR as ISO 100, but gives 4 stops for headroom, and only 10 stops for footroom.

Without all the English grammar, for our hypothetical simple model we have:
100 DR=14.0 headroom=3.0 footroom=11.0
200 DR=13.5 headroom=3.0 footroom=10.5
200/HTP DR=14.0 headroom=4.0 footroom=10.0


Of course, Canon does not always maintain a singular headroom value across the entire ISO range (it can range about 1/4 stop), and in some past cameras 100 is lacking full headroom compared to others, and now we have dual conversion gain in the R5, which complicates matters of footroom tremendously with 400/500/640/HTP in this camera, giving a "weak spot" there in footroom, but remember, the noise that varies the footroom with HTP is the post-gain noise, and it is weak and random to begin with the R5, so most shadows that need to be pushed no more than 2 stops are likely to not visibly show any problem with HTP at 400/500/600, unless an extreme white balance is required, which may have one very weakly recorded color channel.

When I get my R5, I will have to test how much difference HTP makes in deep shade (lacking red light) at ISOs 400/500/640, visibly. I might stop using HTP in some situations, then if the difference is easily visible. At much higher ISOs, it is usually a no-brainer, if exposure is a wild-card and hard to control; HTP is a win/win, because there is almost no difference in measured footroom with or without HTP.

huntersdad wrote in post #19124877
I haven't noticed this issue. What I will say is that the AF doesn't start working when you bring it to your eye UNTIL you press the shutter/AF-ON button. You can be focused in LV, but bringing it to your eye doesn't carry the focus over. I have yet to run into a situation where this would be a concern to me.

The other issue he mentions with the screen freezing up also has not happened to me. I don't shoot with a 400, but do use a 300 and have not encountered that problem. This I could see being a bigger issue, but certainly not the 30-45 seconds he mentions. Screen locks, pop battery, reinsert, move on.

Screen has been freezing up on my R5 also, 300 f2.8 mkii, 500 f4 mkii and RF 70 200 F2.8. Others report 100 400 mkii and RF 100 500

Seems like an issue with the R5 with any lens ,happens to me maybe once on a full 6 hour wildlife shoot, pop out battery to unfreeeze

I have close to 5k actuations on my R5 and haven’t had it lock up on me once. All using the EF glass in my profile. I wonder what the cause is. It can’t be I’ve got the only magical R5.

Mine is being shipped in the 23rd so I should get it by the end of the month.

John Sheehy wrote in post #19125722
200/HTP has a stop more headroom than ISO 100, relative to a middle grey metered for that ISO, and a stop less "footroom" than ISO 100.

200/HTP has a stop more headroom than ISO 200, relative to a middle grey metered for that ISO, and almost a stop less "footroom" than ISO 100.

Lets put some simple hypothetical numbers on this. If ISO 100 has 14 stops of DR, and ISO 200 (without HTP) has 13.5 stops of DR, and these non-HTP ISOs have 3 stops of headroom above middle grey, then we have 11 stops of "footroom" and 3 stops of headroom at ISO 100, and 10.5 stops of footroom and 3 stops of headroom at ISO 200. Since ISO 200/HTP uses the ISO 100 analog gain and same digitization, then 200/HTP has the same 14 stops of DR as ISO 100, but gives 4 stops for headroom, and only 10 stops for footroom.

Without all the English grammar, for our hypothetical simple model we have:
100 DR=14.0 headroom=3.0 footroom=11.0
200 DR=13.5 headroom=3.0 footroom=10.5
200/HTP DR=14.0 headroom=4.0 footroom=10.0

Of course, Canon does not always maintain a singular headroom value across the entire ISO range (it can range about 1/4 stop), and in some past cameras 100 is lacking full headroom compared to others, and now we have dual conversion gain in the R5, which complicates matters of footroom tremendously with 400/500/640/HTP in this camera, giving a "weak spot" there in footroom, but remember, the noise that varies the footroom with HTP is the post-gain noise, and it is weak and random to begin with the R5, so most shadows that need to be pushed no more than 2 stops are likely to not visibly show any problem with HTP at 400/500/600, unless an extreme white balance is required, which may have one very weakly recorded color channel.

When I get my R5, I will have to test how much difference HTP makes in deep shade (lacking red light) at ISOs 400/500/640, visibly. I might stop using HTP in some situations, then if the difference is easily visible. At much higher ISOs, it is usually a no-brainer, if exposure is a wild-card and hard to control; HTP is a win/win, because there is almost no difference in measured footroom with or without HTP.

I still don't see how you are getting more dynamic range. It should be less. By this reply below:

John Sheehy wrote in post #19125180
You're incorrectly assuming that the same bright pixel that would be about 16383 with plain 200 would also be 16383 with 200/HTP, when it would actually be about 8192, due to half the gain compared to plain 200 (or the same as plain 100). I say "about" because zero or black is actually 512 at low ISOs and 2048 at higher ISOs with current Canons, so you have to subtract these numbers, do your math, and then add it back.

The dynamic range should be half. Dynamic range is the ratio between the largest and smallest values a value can take. Going from 16K to 8K reduces the ratio by two, or one stop. There's something missing in the explanation.