Sony A7C focus question

[ajohnw]

Toying with a change of camera idea. There are several factors about the A7C I like but it seems to lack a focus feature I use from time to time. Focus, lock that and reframe. Generally via a 1/2 shutter button press using a central focus area.

On this camera the 1/2 press seems to activate focus. A separate button can also be used but no signs of an ability to lock the focus when reframing. Sony's main manual on the camera is a lot of web pages. Maybe I have missed something in that on a feature I feel a camera should have.

Maybe there are some A7C users around or some one has played around with one. From reviews tracking is excellent but not what I always want,

[DanK]

I've never used a Sony, but the way I have always accomplished what you are trying to do with Canon bodies is to take AF off the shutter button entirely, leaving only metering on that button. I then use back button focus for AF. No need to push anything to lock focus: when focus is where you want it, just release the back button.

I use this somewhat less now that I have an AF system that will find eyes and track, leaving me with less need to focus and recompose. However, I still use this when I need it, and I'm used to back button focus.

[ajohnw]

That's the aspect I am not clear about. It can be taken off the shutter button but not sure what the AF button does. I looked again though and came across a separate comment on af tracking on
[Tracking On + AF On] is assigned to the AF-ON button when shooting still images in the default settings. The camera tracks and keeps the focus on the subject while the AF-ON button is being pressed. Shoot images by pressing the shutter button all the way in while holding down the AF-ON button.


Sounds odd ball to me, If tracking wanted the 1/2 press shutter button makes more sense but it sounds like it is an AF on / off button. For my use anyway.

The description of the button
For shooting: AF-ON (AF On) button
[Tracking On + AF On] is assigned in the default settings.

[ajohnw]

For anyone else that may have an interest going on a free ebook and other comments it looks like the camera can be used in the way I would like to but still not entirely clear on how but enough for me to sort out a number of buy buttons for camera and lenses. Then I looked at lens performance.

[DanK]

which of your cameras would you be replacing, and for what use?

[ajohnw]

My use is pretty general. No specific area. Thoughts about replacement largely relate to the E-M1 retaining weight aspects but looking for a higher dynamic range. That is my main camera. The 80D is purely for macro work with a long focal length macro lens. I also have a couple of lenses from Canon's first DSLR that I can use on it. Resolution is not up to modern standards but ok for reasonably sized photo's and no aberrations that indicate processing problems to recover shadows and other factors. One even has IS, A rather early version.

OK so I look at alternatives. Unlike Oly who basically only produce pretty decent lenses others seem to have gone in a different direction. I do have a beef about Oly in terms of there pro lenses. For instance I use a 12-100 for walk about when in real terms a 12 to 50 would be fine and lighter unless they upped it to 2.8 but do I need 2.8 - no. The numbers game has always figured in cameras of all types. The aim on smaller lighter stuff with decent sized sensors seems to be to attract bloggers etc. Also to try and even pull people away from phone photo's and compacts.

[DanK]

yes, there is a substantial difference in DR between MFT and FF. Not surprising, given the size of the photosites. During the months I dithered about this, the lightweight camera I narrowed it down to is the OM-1, which seems to be the best MFT for stills currently. However, it's not much better in terms of DR than what you have. Below is the chart of DR vs. ISO from photonstophotos.net for the E-M1 (black), the new OM-1 (blue), and the FF Canon R6 II, which is what I ended up with (green):



At any given ISO, the difference between the OM-1 and R6 II is only roughly one stop, but at base ISO (100 for the R6, 200 for the OM-1), it's two stops. Two stops is enough to matter occasionally, for what I do. However, this has essentially no impact when the DR of the scene is less than the DR of the sensor, which is much of the time.

I finally gave up and decided to stay with FF for all but macro (for which I use an old 7D), as long as I am able. The market for APS-C, which is a logical compromise in theory, is unfortunately very limited now.

[ajohnw]

The best way forward for me after much looking is to update the E-M1 to the MkIII So glad I looked at lenses on other brands.

[ajohnw]

yes, there is a substantial difference in DR between MFT and FF. Not surprising, given the size of the photosites. During the months I dithered about this, the lightweight camera I narrowed it down to is the OM-1, which seems to be the best MFT for stills currently. However, it's not much better in terms of DR than what you have. Below is the chart of DR vs. ISO from photonstophotos.net for the E-M1 (black), the new OM-1 (blue), and the FF Canon R6 II, which is what I ended up with (green):.

I missed this post some how. Probably down to being annoyed about lens quality on other brands especially on lighter ones. A Sony for me with G lenses isn't on.Olympus seem to have deliberately taken advantage of using smaller pieces of glass. It's an optical fact that this can make achieving some level of performance easier. Same applies to F ratio in many ways. Faster = harder, more glass needed etc.

Bit of history. My first M4/3 camera was an E-PL1. A very active flickr group showed it could give good results in the right hands even with the kit lenses. The 40-150 showed some manageable problems but hard to knock the other one. I bought this one used and the lady who sold it said "hope you enjoy it.", I did but it's a quirky camera much smoothed out on a later E-P3 I bought, I didn't try any of these at high iso levels. Ex film man so 200 - 400 is fine for me,

So decided to change when the E-M5 came out. Early version with a Sony sensor. On this on suitable scenes I would use an iso setting of a 1000. I posted a simple made up scene on one forum at it's max ISO setting. Not much detail needed but it produced a clean image with fairly simple processing. Some thought I had cheated but hadn't. As previously at usual ISO's recovering/brightening dark areas where needed not much of a problem.

Then i bought the initial EM1. The style of iso noise is rather different and harder to get rid of. The question with the MkIII is have they improved this area. Maybe I picked up a poor example of the MkI.

Dynamic range. The indications in the viewfinder help a lot. It's possible if needed to allow rather small areas in say clouds to over expose. Where things get "interesting" is when some over exposure is allowed and dark areas need some degree of recovery. This seems to be more of a problem with the MkI. Often no over under exposure is shown even though I shoot under any conditions. All OK then.

Final image for me is a jpg, Having say 12bit available means squeezing that into less. HDR methods with bracketed exposures can be used for that. Not thrilled with the auto hdr on the EM-1. It would be great fi the camera aligned the shots. Maybe me or the shutter movements.

I'd guess my best solution is to find some high iso EM_1 MkIII raw files and see what they look like.

[ajohnw]

I found a suitable site
https://www.photographyblog.com/revi...oogle_vignette
Their approach seems to be stick to 1/60 sec and wind up ISO to suite.

Can't say as noise appears to be a problem on any I looked at. I chose one for some silly simple work. Covert, no adjustments, heavy sharpen, reduce, slight sharpen, levels and some saturation increase and a bit of clipping added at each end


It failed to capture ripples in the water but they show on some edge reflections. ISO 1600. The camera jpg version looses the sky, The camera has a curves facility that may help with that but never used it as the curve adjustments are rather strange,

Not an exhibition shot obviously but a decent tonal range etc and more work could be done on it.

[ajohnw]

The tree is significantly lighter when I click on the image in firefox than when I view directly on my screen. Same with darker detail.

[pschlute]

The tree is significantly lighter when I click on the image in firefox than when I view directly on my screen. Same with darker detail.

Your picture has a profile RTv4_sRGB. Try changing it to the standard sRGB

Is your Firefox browser set up for colour management ? Your screen too ?

[ajohnw]

LOL I uploaded the wrong version. Had me worried for a while. The RT relates to Rawtherapee used to develop the initial raw file, I used GIMP for the rest which always asks about converting to relative colorimetric, Something to look into - profiles added by that. My machine is way out of date in terms of software.

A bit off topic given the thread title but bit the bullet and upgraded the O-M1 making sure I could send it back. Noise in jog is ok up to a pretty high iso suggesting something can be done with raw but need to take more shots to see. On ISO setting it warns about amplification at some point.

Meanwhile I have been tearing my hair out with Olympus's convolute settings menu. Mostly to get the clipping indication in live view. Finally found a video by a Scandinavian pro. Oly sent him one re pro setting. One problem I had was that pressing the info button cycles through 2 custom setting and another. The another one wont show any of the clipping indications even the histogram. On earlier attempts I was in that mode. So at some point need to look at getting rid of it. Given software that can produce none obvious HDR image merges dynamic range ceases to be a problem. These can also align images, better than a tripod and using the facility in the camera. In many ways it's a better option than bracketing. If the camera didn't have it I would have sent it back.