Regarding the whole full frame vs APS-C argument

[CAT-THE-FIFTH]

OK,regarding sensor size,a good article to read up on:

https://www.ephotozine.com/article/complete-guide-to-image-sensor-pixel-size-29652

That is the difference in physical surface area between a 35MM frame sensor,and an APS-C sensor. Its over 2.27 times bigger.

Having said that the actual metric you need to look is the photodetector size.

So a 24MP sensor like that in the D600,D750,various Sony cameras has a 6 microns pixel size,and the 16MP sensor like in D7000,XT1,etc is at 4.7 microns. A 24MP sensor like in the D7200 has a 3.9 micron size.

Assuming things like similar technology levels,stabilisation and similar equivalent light amounts,this is why full frame is generally "better" in low light and wider DR situations,as each of those photodetectors has more surface area and can detect more photons of light.

How does this related to noise?

Noise is a by-product of the semiconductor technology used to make sensors - in terms of a "digital sensor" it is basically an electrical signal not produced as a result of light hitting the sensor.

Some of this is down to temperature and some of its down to flaws in the physical characteristics of the sensors themselves.

Why is more light then important??

Its all about the output electrical signal - if there is more light the signal is larger and it swamps the low level "aberrant" signals produced as a result of the factors behind noise.

Less signal,ie,in low light and the difference between the signals is much less,and it is further compounded when its amplified to try and produce a usable signal.

Even the 36MP and 42MP 35MM frame sensors have larger pixel size at 4.9 microns and 4.5 microns when compared to a modern 24MP APS-C sensor.

However,as I mentioned technology levels can help. You heard of things like microlenses?? They are there to try and collect more light,and the same goes with more sophiscated mechanisms to try and process the image in-camera,or more sophisticated amplification mechanisms,etc.

Another factor is that even if you have a pair of F2.8 lenses,the physical aperture on the full frame lens will be actually physically larger(you can test this by manually opening the aperture on two lenses and looking at the actual diameter of the opened aperture).

So take it into to consideration if you are really interested in low light work!

 

[strang3r]

I have a Sony A6000 and a Sony A7, when it come to low light and high ISO the A7 wins hands down.

 

[Drollic]

The internet is absolutely full of opinions and information re noise, lens quality, sharpness, sensors and so on. When you actually start regularly looking at photos on sites like flickrs explore though for example, composition, crop, processing technique and settings for the given image often simply 'could easily be better with minor changes'. People seem to get so hung up on the former it seems, when the latter is even more important. Just as an example, if you look regularly at the info uploaded, you will see no end of landscape photos taken at something around f8-f11 and 16-35mm (APS-C lets say) where the shutter speed is something like 1/160+ up to around 1/500 and the ISO as a result is 400+. You look at the image and there is no reason for it to not be taken at 1/60 to 1/80 max, even without OIS and therefore a much lower ISO and better quality. You have to wonder if these are the sample people who constantly seem to go on about image sharpness and noise?

 

[LiE]

I'm really happy with my mirror-less APS-C, it's a really good size for taking out for family trips. I think someone else said it best - you will always have to compromise on something with a camera.

 

[CAT-THE-FIFTH]

The internet is absolutely full of opinions and information re noise, lens quality, sharpness, sensors and so on. When you actually start regularly looking at photos on sites like flickrs explore though for example, composition, crop, processing technique and settings for the given image often simply 'could easily be better with minor changes'. People seem to get so hung up on the former it seems, when the latter is even more important. Just as an example, if you look regularly at the info uploaded, you will see no end of landscape photos taken at something around f8-f11 and 16-35mm (APS-C lets say) where the shutter speed is something like 1/160+ up to around 1/500 and the ISO as a result is 400+. You look at the image and there is no reason for it to not be taken at 1/60 to 1/80 max, even without OIS and therefore a much lower ISO and better quality. You have to wonder if these are the sample people who constantly seem to go on about image sharpness and noise?

I am perfectly fine using my APS-C camera or even a prosumer compact,as its smaller and much lighter than my 35MM frame one,but the fact of the matter it still suffers in high DR and very low light conditions by comparison especially hand held,having used both side by side. OTH,a smaller and lighter camera,means it will be carried more often and as they say the "best camera is the one you have with you".

Part of the reason I made the thread,is also since I think people expect way too much from APS-C systems compared to something like 35MM frame system,and if you already a 35MM frame camera,and are thinking of downsizing due to weight,an APS-C system will still have some limitations in comparison. I have seen posts on more than one forum,over the last few years of people complaining about the switch and blaming the new system,but realistically its less to do with the system and more down to the fact APS-C systems do have limitations for that greater portability.

Like I showed,a 24MP 35MM frame sensor and a 24MP APS-C sensor,have a size difference of 50% or thereabouts,and TBH APS-C cameras still do pretty good in most conditions despite this!!

I just want to show people why 35MM frame sensors seem to do better in more extreme conditions. People talk about sensor size,when its actually photodetector surface area,which is the more important metric. If anything if you move outside of consumer imaging,that metric is actually discussed more than the physical size of the entire chip.

Remember,why are they called APS-C?? That is because it was named after the smaller APS film form factor which was developed as a smaller alternative to 35MM film.

 

[EsaT]

Another factor is that even if you have a pair of F2.8 lenses,the physical aperture on the full frame lens will be actually physically larger(you can test this by manually opening the aperture on two lenses and looking at the actual diameter of the opened aperture).

Still light intensity is always same per focal plane surface area unit at same f-ratio.
And if stopped down for same depth of field overal amount of gathered light is equal for different systems.
Basically also bringing diffraction limited max resolution to same, because that physical diameter of aperture is same.

The internet is absolutely full of opinions and information re noise, lens quality, sharpness, sensors and so on. When you actually start regularly looking at photos on sites like flickrs explore though for example, composition, crop, processing technique and settings for the given image often simply 'could easily be better with minor changes'. People seem to get so hung up on the former it seems, when the latter is even more important. Just as an example, if you look regularly at the info uploaded, you will see no end of landscape photos taken at something around f8-f11 and 16-35mm (APS-C lets say) where the shutter speed is something like 1/160+ up to around 1/500 and the ISO as a result is 400+. You look at the image and there is no reason for it to not be taken at 1/60 to 1/80 max, even without OIS and therefore a much lower ISO and better quality. You have to wonder if these are the sample people who constantly seem to go on about image sharpness and noise?

Indeed when even small cellphone/compact camera sensors can do better than that analog 35mm film it's lot more often photographer's lack of knowledge/understanding which limits taking images more than sensor.

 

[CAT-THE-FIFTH]

Still light intensity is always same per focal plane surface area unit at same f-ratio.
And if stopped down for same depth of field overal amount of gathered light is equal for different systems.
Basically also bringing diffraction limited max resolution to same, because that physical diameter of aperture is same.


Indeed when even small cellphone/compact camera sensors can do better than that analog 35mm film it's lot more often photographer's lack of knowledge/understanding which limits taking images more than sensor.

This thread is about people on forums who have had both,and downsized from a reasonable 35MM frame digital system,and have been surprised that in testing conditions the APS-C system does not do as well,even if equivalent types of lenses are used. So that means things like similar relative apertures,OIS,etc.

I have seen people blame the systems on forums,when its nothing to do with the systems,but all to do with the fact you are comparing vastly different sensor sizes. A 35MM frame sensor is 2.27X larger than an APS-C one. That is a gulf in size.

So I do wish people stopped blaming the system,and realise the compromises you gain from going to a more compact system.

Like I said I have no issue using a smaller sensored camera,as they tend to be more compact,and easy to carry about,but at the same time they do have limitations. My D600 when compared to my XT10,is better for low light work,and some of the wider DR stuff I have done,but its heavy and a brick,so I can live with the XT10 being more limited as its easier to carry with me.

Photodetector area will have a consideration especially in low light situations where flash,OIS(it can still add motion blur) or a tripod cannot be used though,or in situations where a wide DR is required,and its demonstrated even in the phones you talk about,even comparing different ones.

Its about how many photons in total will still be hitting the sensor - you talk about light intensity,but that is going to be something like the number of photons per mm2 in practice hitting the sensor. So what happens when you have a larger physical aperture and a larger physical surface area of the sensor,with the physical photodetectors having larger surface area??

Plus how many people are there are going to be stopping down to exactly the same depth of field on their APS-C camera against a 1/3" phone sensor??

You are doing a portrait shot indoors,and want low depth of field - you cannot achieve that with a phone,hence why they all do artificial post-processing to simulate it.

That is the most important thing to consider - things like OIS,lower shutter speeds,etc are all about maximising the amount of photons hitting the sensor,since it maximises the current produced,otherwise the current base will be too near that produced as a result of non-specific interactions.

Even with mobile phones - look at the difference between mobile phone modules,using the same physical sensor chip,but with different lens assemblies,some using higher refractive index lens elements and wider apertures which all exist to try and gather more light. Look at the difference in RAW output quality. Its all down to the amount of light,ie,photons hitting the sensor.

Look at the LG V30(IIRC),they made a big song and dance about using higher refractive element lens elements,and a larger relative aperture to let more light in- yet they dropped the sensor size,and by extension the photodetector area. The phone in testing conditions still is not as good as some of the best,which is not surprising as they have greater photodetector area,but imagine if the competitors equalised to a similar relative lens??

Then look at electric IS - that is basically amping up the gain to increase the output current,and then applying more NR to compensate.

Also another consideration is dynamic range - have you ever considered why smaller sensors at a similar technology level have worse dynamic range in general looking at the unprocessed output(RAW to RAW)?? Smaller photodetector area leads to more issues with them being oversaturated,ie,what is known as clipping.

What do you think those multishot stacking HDR algorthms are doing on phones?? They make a very brief high speed exposure,which limits the light hitting the sensor to preserve highlight information,and another exposure which is lower,to gain shadow data.

Fuji experimented with extended DR with their S3/S5 ranges which had greater DR than many cameras for years - they were approaching the issue in a different way. Two different area photodetectors,each tuned to one end of the spectrum.

Look at something like astrophotography,and then look all the way upto from a consumer grade setup to something like a large research telescope,etc.

Its all about maximising the amount of photons hitting the sensor used and hence the output signal.

Its also why the sensors are cooled - it actually reduces one major type of noise being produced,and it was same with the research CCDs I was using.

There is a reason why larger photodetector area is actually a consideration for certain types of scientific imaging,as it does have an impact if you are doing certain types of work(so does resolution,but that is beyond the scope of this TBH).