Unsharp photos at 840mm using 1.4x teleconverter

[george013]

Every other lens I own is a Canon but the Tamron 150-600 is affordable for that focal length. This second generation lens is performing quite well. No problems with the lens. It's the teleconverter which I am exchanging. If the second one doesn't work, then it'll get returned for a refund. I'll still be happy with the lens. I believe the warranty is 6 years.

A teleconverter doesn't cause motion blur by itself. That's caused by the stuff between camera/lens and the ground and the smaller aov. I think the motion blur due to movements of the lens is lineair with the focal length. So a 1.4 converter will enlarge that blur 1.4 times. Everything else constant of course.
I'm curious if you tried with mirror up. I don't think this will be of a practical help for you in the nature, but still I wonder. Using mirror up and remote control should be sharper as with the remote control alone.

George

[Shadowman]

Every other lens I own is a Canon but the Tamron 150-600 is affordable for that focal length. This second generation lens is performing quite well. No problems with the lens. It's the teleconverter which I am exchanging. If the second one doesn't work, then it'll get returned for a refund. I'll still be happy with the lens. I believe the warranty is 6 years.

Good to hear it's only the teleconverter; hopefully. And good to hear you got a long term warranty.

[William W]

Picking nits - but important nits:

Re using the Left hand (or other weight) for downward pressure when using long lens – this has been mentioned a few times:

There are basically two scenarios – using the camera shutter release and using a remote release.

1a. Using the Camera Shutter Release - it is important to have the pressure above and forward of the point of the Tripod Head and Lens Mount - and NOT "pressure downward on the camera" - because a salient point is when using a long lens the TRIPOD HEAD MOUNT should be connected to the LENS MOUNT and NOT the CAMERA MOUNT. Downward pressure forward of the Tripod (or in the case of the example the Monopod), assists in counter balancing the downward pressure of the trigger hand on the camera’s Shutter Release.

1b. Using the Camera Shutter Release - see an example below of the correct Technique of Left Hand downward pressure shown here, using Monopod, when the Camera Shutter Release is used - (bloke shooting Canon, left of screen, however, bloke using Nikon, if shooting at that time, is exhibiting incorrect technique):



***

2a. If a Remote release is used then the downward pressure by Hand or Sandbag or whatever, should be above the point of the TRIPOD HEAD MOUNT – (and of course this should be on top of the lens and not the camera).

2b. If a Remote release is used then see the “Sandbag Sandwich” image in Post #55 and (as I do not have the time to make another image) pretend the lens is longer and also mounted on a tripod – the top sandbag would be situated on the lens with its weight equally distributed front and back of the Lens’s Tripod Mount

WW

All Images © AJ Group Pty Ltd Aust 1996~2016 WMW 1965~1996

[William W]

A teleconverter doesn't cause motion blur by itself. That's caused by the stuff between camera/lens and the ground and the smaller aov

Certainly Camera movement blur is a result of the 'stuff' between the camera/lens and the ground - e.g. the tripod.

HOWEVER - the addition of ANY additional element added to the Camera and Lens's physical connections can and often does add to the resultant Blur in the Image caused by Camera Movement - noted here previously:

(post #22) . . . and remember that the extender as well as adding length also adds a little bit of “wobble” to the camera/lens connection.

“ANY additional element added to the Camera and Lens physical connections” could be a tele-converter; extension tube; bellows; as well as additional elements added to the front of the lens such as: a mat-box; and Filter Holders can cause issues too.

For the sake of this discussion, the Tamron being such a (physically) long lens, the strength, rigidity and machining tolerances of the male mount of the lens and the male and female mounts of the Tele-extender would almost certainly have much weight in this discussion concerning Camera Movement Blur. (pun intended).

So when Terri gets the replacement Extender, if she can compare these factors with the previous copy that would probably be useful to her assessment as to whether or not she will persist with using it.

WW

[William W]

ASIDE -

Not difficult. . .
And (this is the key point George) . . . if the Subject to Camera Distance remains the same, then the BLUR will take up MORE SPACE in the image made by the CROP camera - hence it will be more noticeable.

and

If the blur takes 10 pixels in crop mode, than it will take 10 pixels in FF mode too. Using the same camera of course. In both situations the blur is 10 pixels. And when viewing on the monitor at 100%, 10 pixels become 10 pixels. You're talking about printing to a same size. Yes, than the crop image has to be enlarged 1.5 or 1.6 times, and also the blur. But NOT when viewing on the monitor at 100%. And that's what one does when examining a new gear, viewing at 100% on the monitor. The "image sizes" are different.

Actually, you're misquoting and misrepresenting, again -

> Using TWO cameras WAS mentioned.
> NOT changing the Shooting Distance WAS mentioned
> Printing was NOT mentioned.

but suffice to state that if the same camera were used - once in "FF Mode" and once in "crop mode" and the Subject Distance was not changed, then the resultant image files, when each is separately viewed at 100% and set side by side, there would appear more blur due to camera movement in the file of the image when the camera was in 'crop mode' - for exactly the same reasons as have been already outlined.

WW

[george013]

ASIDE -



and



Actually, your misquoting and misrepresenting, again -

> Using TWO cameras WAS mentioned.
> NOT changing the Shooting Distance WAS mentioned
> Printing was NOT mentioned.

but suffice to state that if the same camera were used - once in "FF Mode" and once in "crop mode" and the Subject Distance was not changed, then the resultant image files, when each is separately viewed at 100% and set side by side, there would appear more blur due to camera movement in the file of the image when the camera was in 'crop mode' - for exactly the same reasons as have been already outlined.

WW

The blur between a ff and a crop viewed at 100% is exactly the same. You're viewing at equal magnifications but different sizes.

You're mixing up 2 situations. The first one was about 1)the difference between ff-camera and a crop-camera and 2)the second is dealing with different focal length.


1). What is the difference between a ff and a crop camera or lens? It's the sensor size and image circle the lens produces. Less glass, smaller sensor and so cheaper. In this situation when analyzing the blur it's not relevant if it is a ff or crop camera. Ts is analyzing a lens with or without a converter. Quite certain she is looking at the image on a monitor at 100%. In that case there is no difference between ff or crop. The light cone that hits the sensor is the same for the both. Crop is nothing more as what it means: crop. You can do it in pp or as some ff camera's do in-camera, the optical quality doesn't change.

2). When adding a converter your focal length is changing. The light cone to the sensor has changed, the aov has changed and the sensor size has not changed. And now the blur will be captioned different.

Let's assume the camera moves 0.25 degrees during the time of the Shutter Release, thus the blur length any edge of the Subject will be about 131mm (relative to the FRAMING dimensions). 131mm Blur is about 10.5% of the width of the Horizontal Framing.

Unsharp photos at 840mm using 1.4x teleconverter

If we now put that Lens and Tele-extender on a 7D and shoot the same Subject at the same distance of 30 metres, the FRAMING at the Plane of Sharp Focus is about 788mm x 524mm.



If the Camera moves the same 0.25 degrees during the Shutter Release, then the Blur length will still be about 131mm, (relative to the Framing) BUT that blur will now be about 16.6% of the Horizontal Framing and as such more obvious to the Viewer’s Eye.

So it doesn’t matter if the two images are viewed at 100% or whatever, if the Subject to Camera Distance is the same and the camera movement is the same, then the relative blur length will always be greater when using the “crop” camera.

Make a same drawing but then with the other side of the lens, so the image distance. Let's assume the object is far away and the lens focuses at infinity. Image distance is the same as focal length. Now change the focal length with a factor 1.4. Focusing is still at infinity. Image distance is still focal length but 1.4 times as big as before. And now some gonio again. I know it's not exactly what it should be but as an example.
Blur is the linear movement, r is the angular movement. Tg(r)= blur/distance. This is on the object side.
Now the image side. tg(r)=blur/focal length. Blur = tg(r)*focal length. If the focal length grows with a factor 1.4, than the blur too.



I don't know where 2 camera's was mentioned. It's totally not an issue in this thread. I just mentioned "using the same camera of course" to get rid off a discussion of pixel density etc. on the forehand.

When you're talking about framing it's the same as talking about a print: looking at the image as a total. But that's not the issue. The issue is the optical quality of the lens on a tripod. Is a line sharp as a line sec and not in a picture or frame. And with a reference kader ts has build for herself.

George

[dem]

The blur between a ff and a crop viewed at 100% is exactly the same.

George, in addition to the same lens and the same camera-subject distance, you are also assuming the same pixel pitch.

Take two full frame cameras. One with 12 Mpx and the other with 36 Mpx. Are they going to show the same blur at 100% magnification? No.

EDIT. I think George is talking about "100% magnifiction" as in pixel-to-pixel view of a small part of the image on the monitor, whereas Bill is talking about viewing the image at 100% - the whole image on the monitor screen. Both of course are 100% correct with their conclusions.

[george013]

George, in addition to the same lens and the same camera-subject distance, you are also assuming the same pixel pitch.

Take two full frame cameras. One with 12 Mpx and the other with 36 Mpx. Are they going to show the same blur at 100% magnification? No.

With all respect.

I don't know where 2 camera's was mentioned. It's totally not an issue in this thread. I just mentioned "using the same camera of course" to get rid off a discussion of pixel density etc. on the forehand.

This thread is dealing with just one camera.
George

[terrib]

A teleconverter doesn't cause motion blur by itself. That's caused by the stuff between camera/lens and the ground and the smaller aov. I think the motion blur due to movements of the lens is lineair with the focal length. So a 1.4 converter will enlarge that blur 1.4 times. Everything else constant of course.
I'm curious if you tried with mirror up. I don't think this will be of a practical help for you in the nature, but still I wonder. Using mirror up and remote control should be sharper as with the remote control alone.

George

This thread has gotten very long so just restating to clarify. The teleconverter is going back because autofocus was inconsistent. One set of tests it worked and the next set (after I started this thread) it failed every time. Tamron customer service confirmed that it should have worked under my lighting conditions, camera settings and camera/lens combo. They suggested an exchange. That's a separate issue than my original post. So between that and the weather, my ability to test any of the suggestions has been put on hold. Once I have a working teleconverter (provided of course that it can actually do what Tamron claims as far as autofocus) then I can make adjustments to technique, settings or equipment or whatever and determine if it is workable for me in the field.

Some of you have put a lot of time in this thread so I will definitely update when I get the replacement. Thanks!

[William W]

. . . Bill is talking about viewing the image at 100% - the whole image on the monitor screen.

Bill is and always has been talking about the topic of comparing the viewing of a FF and Crop sensor image at 100% exactly as it was introduced by George in Post #15. (see quote of post #15 below).

Bill's response to Post #15 was Post #20.

WW

[William W]

. . . I don't know where 2 camera's was mentioned.

You.

Your post #15 introduced the comparison of viewing two images at 100%, one image from a FF and the other from a crop sensor.

For reference that post is reproduced in full here:

When analyzing a photo on the monitor at 100% the crop factor isn't an issue. The motion blur for a ff and a crop sensor is the same.

George

WW

[William W]

It's totally not an issue in this thread. . . .

I agree.

But, the point is George - even though it is "totally not an issue in this thread" it was you who began this tangent discussion.

Post #20 responded because your Post #15 contained potentially misleading and erroneous statements.

You subsequently have chosen to continue this discussion.

You state that you now want to get rid of these side discussions which are 'totally not an issue in this thread', even though you started them.

I’ll stop now.

Can you do that too?

WW

[george013]

You.

Your post #15 introduced the comparison of viewing two images at 100%, one image from a FF and the other from a crop sensor.

For reference that post is reproduced in full here:



WW

I don't see any indication of 2 camera's.
I think you just don't want to understand me. Again, for the purpose of evaluating the lens and converter only the light cone aperture-sensor plane is important. And viewing at 100% there is no difference between a crop or ff camera. In another post I tried to simplify it by using a ff camera which can be set in crop mode. The same camera and the same sensor.

From post 21.

If you can change your camera from FF to DX, the moving of the image will stay the same. And since she is using one camera, a difference in sensor density is not involved.

George

[george013]

I agree.

But, the point is George - even though it is "totally not an issue in this thread" it was you who began this tangent discussion.

Post #20 responded because your Post #15 contained potentially misleading and erroneous statements.

For the clarity post 15. The light cone for a given focal length and the motion blur are identical
for crop and ff.

When analyzing a photo on the monitor at 100% the crop factor isn't an issue. The motion blur for a ff and a crop sensor is the same.

You subsequently have chosen to continue this discussion.

You state that you now want to get rid of these side discussions which are 'totally not an issue in this thread', even though you started them.

I’ll stop now.

Can you do that too?

WW

I think you're playing unfair by quoting out of the context.

I don't know where 2 camera's was mentioned. It's totally not an issue in this thread. I just mentioned "using the same camera of course" to get rid off a discussion of pixel density etc. on the forehand.

By the way, do you've any remarks on my calculation concerning motion blur and changing focal length? Where I advised you not to look at the object side but at the image side? I miss that while that's the most important in this thread.

George

[William W]

This thread has gotten very long so just restating to clarify. The teleconverter is going back because autofocus was inconsistent. . . Once I have a working teleconverter (provided of course that it can actually do what Tamron claims as far as autofocus) then I can make adjustments to technique, settings or equipment or whatever and determine if it is workable for me in the field.

It is understood that you are sending the Teleconverter back because of Autofocus issues, but just in case you missed these points which pertain as to how the addition of a tele-converter can detrimentally effect the other "Camera Shake Blur" issue that we are discussing:

“ . . . the addition of ANY additional element added to the Camera and Lens's physical connections can and often does add to the resultant Blur in the Image caused by Camera Movement . . .

“[this] could be a tele-converter; extension tube; bellows; as well as additional elements added to the front of the lens such as: a mat-box; and Filter Holders can cause issues too.

“For the sake of this discussion, the Tamron being such a (physically) long lens, the strength, rigidity and machining tolerances of the male mount of the lens and the male and female mounts of the Tele-extender would almost certainly have much weight in this discussion concerning Camera Movement Blur. (pun intended).

“So when Terri gets the replacement Extender, if she can compare these factors [of rigidity etc] with the previous copy that would probably be useful to her assessment as to whether or not she will persist with using it.

REF: Post #64, first referenced Post #22.

WW

[terrib]

I promised an update on this since many spent much time on the discussion. I will have to apologize though, that I have no useful information to report on the original question. The replacement teleconverter arrived while I was packing up to move. Between moving and the holidays, I had very little time to test before my 30 day return window closed. The teleconverter simply did not autofocus as Tamron said it would so it was returned. I will go into that further below. However, to test all of the suggestions everyone posted in this thread reference camera shake, I could have used manual focus but I simply ran out of time since I had to return the product.

A separate issue from the original question was whether the 1.4x would autofocus. Tamron's website says this:

"Autofocus and VC (Vibration Compensation) features are retained with compatible lenses. Autofocus functions normally with compatible lenses. (Please refer to Compatible Tamron Lens List below.) VC (Vibration Compensation) performance is maintained."

Their compatibility list at this point only includes the 150-600 G2. The above is also what both the Adorama and B&H sites said when I bought the TC. However, B&H has since changed their description to say this:

"Dedicated design retains full electronic communication between the lens and camera to support AE and VC functions, as well as autofocus at select focal lengths depending on specific camera's autofocus sensitivity."

I had also talked to people at Tamron describing my exact settings, camera/lens combo with lens set at 600mm and they said AF should work. I had also looked at a compatibility chart HERE (which I mentioned earlier) and saw under AF column that my camera/lens would work. However, what I missed was above the chart it says that AF only works at f8 or faster. The 150-600 goes to f9 at 400mm. (Saorsa actually said in his post #35 that perhaps the long end was out of the lenses AF ability but at that point I was going by what I'd read on Tamron's & B&H's websites).

So bottom line. IMO Tamron's website is misleading. Their writeup clearly says "AF functions normally" and does not have footnotes referring you to their compatibility chart where the "f8 or faster" note is. You only find the compatibility chart referenced as a link in the user manual. In addition, talking to Tamron directly doesn't get you the right information. And second to that, what is the point of AF working only at focal lengths less than 400mm on a 150-600mm lens? Adding 1.4x to lengths less than 400mm only gets me to 560. I might as well use the lens without the TC. So basically AF doesn't work at anything useful and Tamron stating that AF functions on that lens is complete crap. I realize that some people will still find the TC to be beneficial to get to 840mm even with manual focus but I'm not one of them.

Again I apologize for not testing all the suggestions you guys made. I hope you don't think it was a waste of time to make your responses. I don't because I think it was still a good discussion with lots of information people can use to do their own tests in similar situations. Thank you for your time!

[Manfred M]

their compatibility chart where the "f8 or faster"

Terri - that is a property of your camera, and it will vary somewhat between camera models and brands. While I agree, based on your description of what Tamron has said, that the information could be more clear, ultimately the issue related to how your camera was designed to operate; something that Tamron has no control over. I know that my camera manual covers this. As an aside, f/8 is about as good as it gets, some cameras won't autofocus below f/5.6.

This was definitely a concern when we bought the Sigma f/5 - 6.3 150 - 500mm lens for my wife's Nikon D90, which suggested a minimum aperture of f/5.6. Fortunately for her, the camera spec was "conservative", so things worked and that 1/3 stop over the published maximum limit on her camera wasn't the limit we had feared. We tested the lens at the store to ensure that this was the case before we bought it.

[DanK]

Terri,

I think that is being a bit unfair to Tamron. I don't think their website is misleading, although I agree with Manfred that it would have been better to include some caveat. I found this on their website:

Autofocus functions normally with compatible lenses.

What's "normal" AF? That depends on the camera. Normal on your camera is that AF will work with apertures at least as wide as f/8. As Manfred pointed out, it depends on the camera. With my 7D I, AF works only to f/5.6. My 7D will therefore not focus my Canon 100-400 at 400 mm with a Canon 1.4x teleconverter; the lens is f/5.6 at 400mm without the converter, so the extra stop taken by the converter causes AF to fail. That is normal AF for my camera, and it is what I expected (but hoped wouldn't be true) when I bought the lens.

That they gave you incorrect information when you called is more problematic, IMHO. That's very disappointing.

Dan

[terrib]

Terri - that is a property of your camera, and it will vary somewhat between camera models and brands. While I agree, based on your description of what Tamron has said, that the information could be more clear, ultimately the issue related to how your camera was designed to operate; something that Tamron has no control over. I know that my camera manual covers this. As an aside, f/8 is about as good as it gets, some cameras won't autofocus below f/5.6.

You are right, of course. What I think confused me was that the chart shows the Canon 7dII as compatible and not the Canon 7d. I first purchased based on their description alone, then later based on my discussion with Tamron. Ultimately when I saw the compatibility chart (but not the note about f8) and saw that the Canon 7dII was on the list but not the 7d, I thought the difference in the two cameras was the key. It wasn't until I received the 2nd TC that I started double checking to see what I'd missed and found the f8 reference. Certainly a few lessons learned. I read manuals but I must read things they reference much more carefully. I also can't trust going to the company for clarification because I got bad info. (like asking the IRS tax questions!) I don't feel alone though. Apparently B&H has had enough issues that they felt the need to reword their description.

[george013]

It happened and you, and others, learned of it, or worked as a reminder. But seeing that with the tc2 af was impossible should have ring a bell.
I don't know if it was mentioned before, but your camera settings allows shooting without being in focus. If not being in focus blocks shooting, then the question would be different.
Good luck with the lens, without converter.
George