Sigma 150-600 Garbage

[xenskhe]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

 

[jcdeboever]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

Why is it doing that? What the heck is that? Is that something else I have to fliipin learn?

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[xenskhe]

Could be the camera mirror slightly out of alignment. The AF uses a small secondary mirror underneath the main one. The lens focusses off the mirror. Correct? On older Nikon SLRs there were two hex screws - one for AF one for MF. From memory clockwise corrects back focus. But the adjustment is very minimal using with a 2mm hex spanner. With a more normal prime size lens you could get a 30cm ruler and place it on a table (end on towards/away from you). At full aperture, MFD focus on 15cm mark. Calibrated ok it should give you 15cm sharp and twice as much blur transition beyond that point than in front. Zooms are harder to get sorted. TBH I gave up on reflex cameras for this reason :/ It started to drive me nuts.

 

[480sparky]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

Why is it doing that? What the heck is that? Is that something else I have to fliipin learn?

Sent from my XT1254 using Tapatalk

Oh, the price we pay for mass-production.

Not every lens is exactly, precisely like every other one of it's counterparts. Manufacturing tolerances are allowed. Otherwise, 'perfect' lenses would be prohibitively expensive.

Adjusting for backfocus is kinda like setting the sights on a firearm. Each lens is slightly different, and the camera must have the ability to take back- (or front-) focusing into account if you are to correct for it. It's not hard to do, it just takes time. But when once done, you generally don't have to worry about it.

 

[jcdeboever]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

Why is it doing that? What the heck is that? Is that something else I have to fliipin learn?

Sent from my XT1254 using Tapatalk

Oh, the price we pay for mass-production.

Not every lens is exactly, precisely like every other one of it's counterparts. Manufacturing tolerances are allowed. Otherwise, 'perfect' lenses would be prohibitively expensive.

Adjusting for backfocus is kinda like setting the sights on a firearm. Each lens is slightly different, and the camera must have the ability to take back- (or front-) focusing into account if you are to correct for it. It's not hard to do, it just takes time. But when once done, you generally don't have to worry about it.

WHAT? I have to learn how to get this turd to focus? Crap, I am over this photography art medium then. I need to go back to my wax, pigment, and substrate.

Sent from my XT1254 using Tapatalk

 

[xenskhe]

You're right. But it ended up different for each lens. JC if live view cures the problem i'd assume it's the mirror. If notm it may be the lens. Can you try a different lens?

 

[480sparky]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

Why is it doing that? What the heck is that? Is that something else I have to fliipin learn?

Sent from my XT1254 using Tapatalk

Oh, the price we pay for mass-production.

Not every lens is exactly, precisely like every other one of it's counterparts. Manufacturing tolerances are allowed. Otherwise, 'perfect' lenses would be prohibitively expensive.

Adjusting for backfocus is kinda like setting the sights on a firearm. Each lens is slightly different, and the camera must have the ability to take back- (or front-) focusing into account if you are to correct for it. It's not hard to do, it just takes time. But when once done, you generally don't have to worry about it.

WHAT? I have to learn how to get this turd to focus? Crap, I am over this photography art medium then. I need to go back to my wax, pigment, and substrate.

Sent from my XT1254 using Tapatalk

Sorry to spoil it for you. But I don't think you'll live long enough to learn everything.

 

[xenskhe]

f/36 and be there!

 

[jcdeboever]

Here is a crop of #1, I don't know, doesn't seem to good to me. I am missing something. It's not to far away, maybe 30 yards?

Looks like it's back focussing.

Why is it doing that? What the heck is that? Is that something else I have to fliipin learn?

Sent from my XT1254 using Tapatalk

Oh, the price we pay for mass-production.

Not every lens is exactly, precisely like every other one of it's counterparts. Manufacturing tolerances are allowed. Otherwise, 'perfect' lenses would be prohibitively expensive.

Adjusting for backfocus is kinda like setting the sights on a firearm. Each lens is slightly different, and the camera must have the ability to take back- (or front-) focusing into account if you are to correct for it. It's not hard to do, it just takes time. But when once done, you generally don't have to worry about it.

WHAT? I have to learn how to get this turd to focus? Crap, I am over this photography art medium then. I need to go back to my wax, pigment, and substrate.

Sent from my XT1254 using Tapatalk

Sorry to spoil it for you. But I don't think you'll live long enough to learn everything.

What? You said something about a back focus issue which I know nothing about. Does this lens auto back focus or something? Do I need to know how to compensate for it? I guess I am a stupid mtf'r

Sent from my XT1254 using Tapatalk

 

[jcdeboever]

You're right. But it ended up different for each lens. JC if live view cures the problem i'd assume it's the mirror. If notm it may be the lens. Can you try a different lens?

Tried that if you look on earlier in the post.

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[jcdeboever]

Could be the camera mirror slightly out of alignment. The AF uses a small secondary mirror underneath the main one. The lens focusses off the mirror. Correct? On older Nikon SLRs there were two hex screws - one for AF one for MF. From memory clockwise corrects back focus. But the adjustment is very minimal using with a 2mm hex spanner. With a more normal prime size lens you could get a 30cm ruler and place it on a table (end on towards/away from you). At full aperture, MFD focus on 15cm mark. Calibrated ok it should give you 15cm sharp and twice as much blur transition beyond that point than in front. Zooms are harder to get sorted. TBH I gave up on reflex cameras for this reason :/ It started to drive me nuts.

Shoot me in the head now

Sent from my XT1254 using Tapatalk

 

[xenskhe]

Try it at full aperture on a tripod. Then you can at least rule out focus shift due to stopping down the iris.

 

[Peeb]

Try it at full aperture on a tripod. Then you can at least rule out focus shift due to stopping down the iris.

Or just return it, which is what I would do.

 

[480sparky]

What? You said something about a back focus issue which I know nothing about. Does this lens auto back focus or something? Do I need to know how to compensate for it? I guess I am a stupid mtf'r

Sent from my XT1254 using Tapatalk

Your education can start here.

Unfortunately, I don't think the D3300 has the ability to compensate for FF or BF.

 

[jcdeboever]

Try it at full aperture on a tripod. Then you can at least rule out focus shift due to stopping down the iris.

Or just return it, which is what I would do.

That's what I am going to do.

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