soft edges with pictures

[G Mac]

Hi all,

 

Thanks for reading.

 

Unhappy camper so far with the A7r ii. Bear with me as I am more familiar with motion cameras and shooting time-lapses with the canon 5D. Shot a test shot last night, noticed the edges were very soft - unusable soft. Did a basic test shoot this afternoon, tried to ascertain the issue. Would put it down as a back focus issue, but I believe lens adapters don't require any focus plane adjustments. Would welcome some feedback. 

 

Wanted to shoot wide open to test the extremities (not noise of ISO). These are from .arw using adobe DNG converter to lightroom, than exporting, than re-exporting to get the image on this forum. 

 

Frame 1. 16mm. Zoomed (camera) in for focus. (shot T2.8 1/60th 1000 ISO)

 

Frame

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

Frame 2. Cropped into top left hand of previous image. Notice focus going soft.

 

 

Frame 3. Zoomed in on the long lens of the zoom. (shot T2.8 1/60th 1000 ISO)

 

 

Frame 4. Cropped into top left hand of previous image. Focus still goes soft on long end of lens.

 

 

I went further and increased the aperture to increase depth of field, and there was still softness (not as great, but still there). I tested the lens with an old camera, the canon 20D, and had no issue. 

 

Equipment used, Sony A7r ii, lens Canon EF 16 - 35mm L USM, Lens adapter Fotodiox Pro EF-NEX Auto (read great reviews).

 

Prior to this day, my first day, shooting with the camera, I took it out to shoot my ball club, I used the same as above with the lens being the Canon 70-200 IS USM with an extender EF 1.4x II. 

 

I bounced around with auto-focus settings and ultimately went with peaking, but still felt all the images were slightly soft. 

 

 

Peaking, also threw me last night, (outdone my upload of images, apologies I can't show you), but the peaking and the image focus was way off. I took the image with a timer, so it wasn't affected by pressing the shutter button too. 

 

Have I purchased a lemon, or and I forgetting something important. 

 

To add, for anyone who does astro shots, being closer to the equator, do you need a faster shutter than 1/30th of a second to get sharp stars?

 

Thanks all,

 

G

 

 

 

 

 

 

[G Mac]

It did attach my last test shot, 'peaking' said the skyline buildings were in focus.

[seb]

do you have any native lenses?

 

I think it's the adaptor (that has issues with the lens), not the camera itself. Old lenses won't work well with AF over adaptors.

 

but on the other hand, if I look at the lens I would expect softness and vigneting on 2.8:

compare your 20D (8MP):

http://www.dxomark.com/Lenses/Canon/Canon-EF-16-35mm-F28L-USM-mounted-on-Canon-EOS-20D---Measurements__281

with a 5DIII (23MP):

http://www.dxomark.com/Lenses/Canon/Canon-EF-16-35mm-F28L-USM-mounted-on-Canon-EOS-5D-Mark-III---Measurements__795

well, then you know how it would shine on 42mp...

If you reduce the 42mp file to the same resolution of your 20D it could be comparable.

[G Mac]

I forgot to add, I also did a test with the APS-C/Super 35mm off and on too. The smaller of the two cropping, had a reduced, but soft edge too.

 

Majority of the tests, I ended up shooting on manual focus (using zoom in function and peak - but that stitched me before with this camera). 

 

I haven't purchased the lenses I was using (trialling them), and I only really require manual lenses (video and time-lapse). Can you suggest any manual lens as opposed to dumping money into canon glass where I don't require the auto capabilities?

 

Cheers

[seb]

the one you used is a good lens but it shines only in the center of the image. no matter which stop nor focal length, the corners are bad. with a 8mp sensor you can't see that, but on a 42mp you'll do. that is the conclusion I'll get out of the dxo-graphs. you can downsample any of the pictures to the size of the 8mp and you won't see any difference.

 

what focal length range is your purpose? only zoom or primes too?

 

and maybe somebody else can help you with that better. I'm not in video and time-lapse and I only use native lenses and some old contax MF primes. I think there isn't a difference between AF and MF in price, because you need a quality lens anyway for the 42mp sensor.

[G Mac]

Just never saw that issue with time-lapse with the 5Dmk3. Even Red at 6K doesn't give that vignetting/softness (don't quote me, but I'm pretty sure my last gig on dragon was canon glass). It seems like a redundant improvement to me. Not only that, the fact that the 'peaking' took out of focus images too. 

 

So you don't think a metabones adapter could have had a better result?

 

Lacking faith, bring me back to the fold please.

 

thx.

 

G

[Guest all8]

Its not the camera. Its either the Lens, or the Adapter ... or you      Why are you even bothering with Canon glass ... try Sony Zeiss models perhaps?

 

Try a native lens, if you don't need zoom then a Loxia is good.

[alastc]

Also note that peaking is a rough guide, you should use the zoom feature in conjunction with peaking to get precise focus.

It is all the more noticeable when you pixel peek on 42mp!

 

Several canon lenses that I thought were fine on the 12mp A7S were obviously soft on the A7R2.

 

The 70-200 f2.8 canon is fine, and the native 55mm and 16-35 are great.

[addicted2light]

1) the 20D is Aps-C, while the Sony is full frame (i.e. the 20D sensor is roughly half the size of the Sony). So the 20D sensor doesn't actually use the external part of the image circle (the soft one), while the Sony does. Other then being, like others already correctly pointed out, just 8Mp

 

2) peaking is just a rough guide, that works better with some lenses than with others; beside you should use it at the "low" intensity for better accuracy

 

3) it looks like the first pictures have been shot with the 16-35/2.8, am I right? If so this lens is famously mushy at the corners, especially the mark I. You MIGHT have better results with the Canon 16-35/4 L IS, but again this is a lens I've seen used only on low-resolution (i.e. not 42Mp) Canon bodies, so to be sure you should try it on the A7r II.

 

4) for astrophotos with sharp stars you should use the "500 rule"; your maximum exposure time should be equal to 500 divided by the focal length you're using. So, for example, using a 50mm lens: 500 / 50(mm) = 10seconds. Keep in mind that for maximum sharpness with the new hi resolution bodies some folks are using now a "300 rule" (same logic as before, just more conservative times).