-= 90D owners unite! Discuss and Post Photos

I wouldnt shoot a brick wall...it wont tell you if something is sharper in front of or behind your target.(just read at an angle, so it would. Still wouldnt do it)..throw a couple boxes with writing at different planes....put the lens on a tripod. Shoot in live view, and then shoot thru the viewfinder...if the results arent the same something is off.

norelec wrote in post #18992393
I have not. Unfortunately I do not have the Tamron Tap-In Console adapter.

Another option that may or may not be attractive to you is to send your body and lens to Tamron for MFA. If the lens is still under warranty it is free, aside from the postage to Tamron. Their turnaround time is very short. I did this with my 150-600 G2, as I was having a difficult time with the infinity focus. For me, given how much I use this lens, it was worth it to have the lens dialed in at all distances and focal lengths.

DreDaze wrote in post #18992477
I wouldnt shoot a brick wall...it wont tell you if something is sharper in front of or behind your target.(just read at an angle, so it would. Still wouldnt do it)..throw a couple boxes with writing at different planes....put the lens on a tripod. Shoot in live view, and then shoot thru the viewfinder...if the results arent the same something is off.

John's method should work well if shooting the right kind of plane surface at a slight angle. So should your "cereal box" method. The main message is to approach the issue analytically to find out what the problem actually is.

Archibald wrote in post #18992543
John's method should work well if shooting the right kind of plane surface at a slight angle. So should your "cereal box" method. The main message is to approach the issue analytically to find out what the problem actually is.

My approach guarantees that *something* will be at maximum focus. That lets you know right away of what the lens is capable of.

Setting things up so that they only exist at discrete differences does not necessarily show you maximum sharpness possible with the lens.

John Sheehy wrote in post #18992719
My approach guarantees that *something* will be at maximum focus. That lets you know right away of what the lens is capable of.
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Yes, but the implementation can sometimes be difficult, because suitable walls can be hard to find (especially here in Calgary currently where it is -30°C now).

John Sheehy wrote in post #18992719
My approach guarantees that *something* will be at maximum focus. That lets you know right away of what the lens is capable of.

Setting things up so that they only exist at discrete differences does not necessarily show you maximum sharpness possible with the lens.

using live view will show you the maximum sharpness possible since there is no chance of the AF being off...that's why i said to take a shot with live view, and compare it to through the viewfinder...and use the different planes to figure out which way you need to adjust the focus

DreDaze wrote in post #18992806
using live view will show you the maximum sharpness possible since there is no chance of the AF being off...

That's not completely true. Live View AF has less accuracy problems, but is not totally without them.

My suggestion takes no time at all to set up, if you are in the right situation.

I often do what you suggest for the extra information, don't get me wrong, but I always do the angled surface test first, because it tells you in one shot (if shutter speed is good and ISO is reasonable) just how sharp the lens can be with whatever RAW conversion is used. It's a quick no-brainer that lets you know potential right out of the gate. A camera on a tripod at a slow shutter speed chosen for a low ISO in low light, BTW, is not as stable as a hand-held steady shot at a high shutter speed. Tripods oscillate, and never give maximum sharpness unless shutter speeds are used that would also give sharp hand-held shots. Tripods simply restrain motion within a smaller angle than the free drift range otherwise possible, hand-held. I have rarely seen tripod shots at slow and moderate shutter speeds that are as sharp as my best hand-held shots, even with mirrorless or live view, where the shutter curtains are the only mechanical motion.

Yes, but you don't know what the best possible focus is with the lens, making it harder to know if you're achieving it. That's why my first move is the angled surface, so you know what to expect. The softer the lens is, optically, the more difficult it is going to be to precisely MFA it, and it's good to go into any MFA process knowing what you've got.

John Sheehy wrote in post #18992881
That's not completely true. Live View AF has less accuracy problems, but is not totally without them.

My suggestion takes no time at all to set up, if you are in the right situation.

I often do what you suggest for the extra information, don't get me wrong, but I always do the angled surface test first, because it tells you in one shot (if shutter speed is good and ISO is reasonable) just how sharp the lens can be with whatever RAW conversion is used. It's a quick no-brainer that lets you know potential right out of the gate. A camera on a tripod at a slow shutter speed chosen for a low ISO in low light, BTW, is not as stable as a hand-held steady shot at a high shutter speed. Tripods oscillate, and never give maximum sharpness unless shutter speeds are used that would also give sharp hand-held shots. Tripods simply restrain motion within a smaller angle than the free drift range otherwise possible, hand-held. I have rarely seen tripod shots at slow and moderate shutter speeds that are as sharp as my best hand-held shots, even with mirrorless or live view, where the shutter curtains are the only mechanical motion.

Yes, but you don't know what the best possible focus is with the lens, making it harder to know if you're achieving it. That's why my first move is the angled surface, so you know what to expect. The softer the lens is, optically, the more difficult it is going to be to precisely MFA it, and it's good to go into any MFA process knowing what you've got.

What possible accuracy focus can happen in live view?

MONARCH BUTTERFLY ON LANTANA BLOSSOM

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DreDaze wrote in post #18992947
What possible accuracy focus can happen in live view?

You left a word or two out of your sentence, perhaps.

Are you suggesting that it is perfect? I doubt that we are there yet, and even if we were, it only applies to a perfectly flat matte surface with one wavelength of light. It takes time to focus perfectly, so the camera has to just say "good enough" at some point when light is good, and fast focus gets you close enough, quickly.

Call me a skeptic, but when other people say, "we have arrived", I just say, "we are now closer".

Anyway, my main point was not that Live View AF is wrong; it is pretty good with the 90D, and reliable for photography; my point was simply that in order to get a handle on just how sharp your lens is, it is valuable to just take a shot where something *must* be in maximum focus.

VSS2011 wrote in post #18992002
Not sure whether to post here or the Flash sub-forum, but as it's camera specific here seems to make sense (Mods, please redirect if not)

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Can anyone recommend a suitable compatible flash as an alternative to the Canon Speedlite 600EX II-RT. I really can't stretch to £500+.

Thanks.

Check out used or refurbished 600 EX-RT version 1.

Got the 90D begin of this month with the EF 100-400mm II. Now is a good time to learn and practice with the new gear to be ready for the spring. I'm very happy with the results I'm getting now, even in low light.
Here is a Red squirrel, no crop and almost no post processing, just minor adjustments in DPP4 and sharpen in Affinity Photo.

My first Merlin!!! Lousy light!! But got a great clean shot

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anyone have low light sports pics
football especially
trying to decide between a 90d and a used 1dx

Glossy Ibis with the 90D and 100-400II. I had quite a few AF failures with this subject, because it is dark, I think. But this shot was OK.

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Photo from Archibald's gallery.