FAQ FAQ  Forum Search   Events   Register Register  Login Login

Have Teleconverters become obsolete?!

Page  <1 34567>
Author
Davethehiker View Drop Down
Senior Member
Senior Member

Joined: 22 August 2011
Country: United States
Location: Eighty Four, PA
Status: Offline
Posts: 370
Post Options Post Options   Quote Davethehiker Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 15:49
I said I was not going to bother to do this but here goes:

Some of the streaks you see are caused by my crappy HP printers with clogged heads. The ISO was set to automatic so it changed when I put the TC on the camera.

Original taken with 300mm lens

300mm

Date Taken: 2017-05-17 15:12:27
Camera Make: SONY
Camera Model: ILCA-99M2
Lens: 300mm F2.8 G
Focal Length: 300 mm
Mode: Manual
Aperture: f/2.8
Exposure Time: 0.002 sec (1/640)
ISO: 400

Cropped from above

crop

Date Taken: 2017-05-17 15:12:27
Camera Make: SONY
Camera Model: ILCA-99M2
Lens: 300mm F2.8 G
Focal Length: 300 mm
Mode: Manual
Aperture: f/2.8
Exposure Time: 0.002 sec (1/640)
ISO: 400

300mm lens plus 1.4X TC

300mm plus 1.4X TC

Date Taken: 2017-05-17 15:09:32
Camera Make: SONY
Camera Model: ILCA-99M2
Lens: 300mm F2.8 G
Focal Length: 420 mm
Mode: Manual
Aperture: f/4.0
Exposure Time: 0.002 sec (1/640)
ISO: 1000

Cropped from the above that used the 1.4X TC

TC

Date Taken: 2017-05-17 15:09:32
Camera Make: SONY
Camera Model: ILCA-99M2
Lens: 300mm F2.8 G
Focal Length: 420 mm
Mode: Manual
Aperture: f/4.0
Exposure Time: 0.002 sec (1/640)
ISO: 1000
My name is Dave, and I'm an Alphaholic.
Sony:A99II,A900,A77M2,RX100M2|18~70f3.5~5.6 DT|11~18f4.5~5.6 DT|24-70 f2.8ZA SSM|50f1.4|100 f2.8 Macro|70-300 f4.5~5.6 G SSM|300f2.8 G|500f8 Reflex|Minolta600
 



Back to Top
Shearwater View Drop Down
Senior Member
Senior Member

Joined: 20 October 2009
Location: United States
Status: Offline
Posts: 259
Post Options Post Options   Quote Shearwater Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 18:22
Interesting discussion - as a sidelight, I have read that the new GM 100-400 lens is compatible with the Sony 1.4 and 2.0 teleconverters and will autofocus with them.
Back to Top
sybersitizen View Drop Down
Senior Member
Senior Member

Joined: 04 August 2006
Country: United States
Location: California
Status: Offline
Posts: 13255
Post Options Post Options   Quote sybersitizen Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 19:25
Originally posted by Davethehiker Davethehiker wrote:






I would think you need to enlarge (upsample) the first image by 1.4x for a meaningful comparison with the TC version (and not allow the ISO to change).

Just to clarify ... those of us who have found some lens+TC+camera combinations to be better than cropping have to accept a light loss (and a correspondingly slower shutter speed) and in many cases loss of AF. For me with my gear, even if a slight improvement with a TC is observable, the 'pickiness' factor is a high cost in terms of convenience; and if pressed to get something done I would just shoot without a TC, then crop and upsample later anyway.
Back to Top
Davethehiker View Drop Down
Senior Member
Senior Member

Joined: 22 August 2011
Country: United States
Location: Eighty Four, PA
Status: Offline
Posts: 370
Post Options Post Options   Quote Davethehiker Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 19:38
Originally posted by Shearwater Shearwater wrote:

Interesting discussion - as a sidelight, I have read that the new GM 100-400 lens is compatible with the Sony 1.4 and 2.0 teleconverters and will autofocus with them.


I wonder if the e-mount TCs suffer from the same limitations as their A-Mount big brothers? They are of a more recent design, but who knows?
My name is Dave, and I'm an Alphaholic.
Sony:A99II,A900,A77M2,RX100M2|18~70f3.5~5.6 DT|11~18f4.5~5.6 DT|24-70 f2.8ZA SSM|50f1.4|100 f2.8 Macro|70-300 f4.5~5.6 G SSM|300f2.8 G|500f8 Reflex|Minolta600
Back to Top
Roger Rex View Drop Down
Senior Member
Senior Member

Joined: 30 September 2005
Country: United States
Location: North Florida
Status: Offline
Posts: 6635
Post Options Post Options   Quote Roger Rex Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 19:51
Since TC use vs. cropping is one of those topics that is almost endlessly debated, several years ago I bought the Sony 1.4 for my a700 and ran carefully controlled, tripod mounted tests for several lenses, most notably the Sony 70-200. I found the cropped images to be equal to or superior in IQ to the TC images. I do know that several wildlife shooters I know (I am not one) use the 1.4 and 2.0 because it does help them see the subject better/closer through the viewfinder, particularly when it is a small subject like a distant bird.
Every photograph is a self-portrait. http://rogerrex.zenfolio.com/
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 1566
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2017 at 19:57
Originally posted by Shearwater Shearwater wrote:

Interesting discussion - as a sidelight, I have read that the new GM 100-400 lens is compatible with the Sony 1.4 and 2.0 teleconverters and will autofocus with them.

My A5000 will AF A-mount glass at an effective max aperture of F/16 when using A-mount Kenko DGX teleconverters with the LA-EA1--stacking a 1.4X and 2X on an F/5.6 lens. I don't have a slower combination to try.
A65 30M 35 50 16-50 16-80 16-105 18-135 18-250 55-200 55-300
A5000 LA-EA1 16 20 16-50 18-55
Maxxum 70: 20 24 28 50 85 100M 135 28-135 35-70 35-105 35-200 70-210 75-300 100-200 100-300D
 



Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 2242
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 11:03
I have also done a lot of tests on various lenses with and without various TCs, though not the lens or TC that Davethehiker has, and all on the A58 which has a similar pixel density to the A99M2. My general conclusions were:

1. Focussing well enough to distinguish line pairs near the camera resolution is non-trivial task. The AF system certainly is not good enough (SLRgear wrote an article about this), though *some* lens/camera combinations do a better job than others. You need to take a lot of pics with focus bracketing to be sure you're testing lens resolution and not the AF/MF system.

2. As others have said, it is the lens/TC combination which works or doesn't, but this isn't random. There are definite things you can say about each.

3. Good medium-length telephoto lenses and long macro lenses like the Tamron 90mm f2.8 macro have vastly higher resolution than long camera telephoto lenses in the 300mm+ range, and in their sweet spot they can easily out-resolve any current FF or APS-C sensor. They usually have higher contrast, too. But of course you would need to add a TC onto a short lens to make it equivalent to a long one if you put your target at a given distance for all lenses.

4. Lots of cheap TC, even 2x ones, will show an increase in resolution on good medium-length telephoto lenses, so it is simply wrong to say that just because your lens doesn't show an increase in res with your TC, that the TC is necessarily rubbish (though in your case it might be, Dave!)

5. Most long lenses I've tried (300mm and over) barely resolve any more then the A58 sensor as the contrast at the sensor resolution is very low, and it is even rarer for them to do this at full aperture. They usually sharpen up around 1-2 stops down on full, which may be f8, but with a TC added this puts them at f11-f16 which makes them diffraction-limited. At full aperture you're into the problem of making a series of large refracting elements work accurately over their whole diameter which is very difficult. And this is why most astronomical telescopes use mirrors ...





A900, A58, 5d, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras . . .
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 1566
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 16:12
It just depends on the specific lens and teleconverter used.

Look up DXOMark's lens testing on the 5DS R. The highest P-MP prime is the Canon EF 300mm f/2.8L IS II USM. It may be more difficult to achieve a sharp, long telephoto lens, but it is certainly possible.

It does look like the copies of the Sony 500mm F4 G SSM and 300mm F2.8 G II that DXOMark have are not good candidates. The later has the lowest P-MP rating on the A77II of all the primes they've tested. Both of the Canon 300mm F2.8s are at the top of the P-MP list on a 760D. There may be better Sony 300/2.8s, and their Canons may just be exceptionally sharp copies.
A65 30M 35 50 16-50 16-80 16-105 18-135 18-250 55-200 55-300
A5000 LA-EA1 16 20 16-50 18-55
Maxxum 70: 20 24 28 50 85 100M 135 28-135 35-70 35-105 35-200 70-210 75-300 100-200 100-300D
Back to Top
Jonas A-R View Drop Down
Senior Member
Senior Member

Joined: 29 December 2007
Country: Denmark
Location: Denmark
Status: Offline
Posts: 1118
Post Options Post Options   Quote Jonas A-R Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 18:16
Minolta 200/2.8 on 1.54Ám pixels

No TC upsampled 1.4X using bicubic smoother


TC 100% crop


Although it is difficult to exclude focusing errors, this result does not exclude the possibility that a 360MP FF sensor would undersample this old lens.

I think the results presented in this thread cannot be generalised to all lens/TC combinations

a900 16/2.8 fish 20/2.8 24/2Z 35/1.4G 50/1.4Z 85/1.4Z 100/2.8 macro 135/1.8Z
a7r 24-70/4Z

Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 2242
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 18:44
Quite.
And you can't tell everything important about a lens from charts
I find most of my 300mm+ lenses show haze/veiling at full length and full aperture.
It goes away one stop down.
It may be nice in portraits, but on foliage it looks awful.
Interestingly, the mirror lenses don't, and the only non-mirror I have which doesn't is the Min 100-300 APO. It is noticeably better wide open than the Sony 55-300
A900, A58, 5d, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras . . .
Back to Top
Davethehiker View Drop Down
Senior Member
Senior Member

Joined: 22 August 2011
Country: United States
Location: Eighty Four, PA
Status: Offline
Posts: 370
Post Options Post Options   Quote Davethehiker Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 18:45
Originally posted by Jonas A-R Jonas A-R wrote:


I think the results presented in this thread cannot be generalised to all lens/TC combinations


I don't think anyone is attempting make a generalization. I have only expressed my experiences with the Minolta 600mm f/4 and the Sony 300mm f/2.8 lenses when mounted on an A99II. I found that with my copy of the Sony 1.4X TC, it was better NOT to use it.

It is difficult to be sure it not a focus inconsistency. To prove to myself that is was not a focus problem, I took a lot of photos in the "Extra Fine" mode so I could use the 2X magnifier when I manually focused. Still the TCs did more harm than good. In general I find that the Auto-Focus on the A99II does as good, or better than I can do manually.

I own both a 2X and 1.4X TC. The 1.4X is not as bad as the 2X.

    
My name is Dave, and I'm an Alphaholic.
Sony:A99II,A900,A77M2,RX100M2|18~70f3.5~5.6 DT|11~18f4.5~5.6 DT|24-70 f2.8ZA SSM|50f1.4|100 f2.8 Macro|70-300 f4.5~5.6 G SSM|300f2.8 G|500f8 Reflex|Minolta600
Back to Top
Davethehiker View Drop Down
Senior Member
Senior Member

Joined: 22 August 2011
Country: United States
Location: Eighty Four, PA
Status: Offline
Posts: 370
Post Options Post Options   Quote Davethehiker Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 19:02
BTW, I think the 600mm f/4 is a great portrait lens! Here is photo of my buddy standing next to me while we both photograph eagles. No cropping needed. The A99II was on full automatic. It found his eyes and focused on them.

kevin

Camera on full auto. 600mm f/4 lens.
Date Taken: 2017-04-10 12:01:01
Camera Make: SONY
Camera Model: ILCA-99M2
Lens: 600mm F4
Focal Length: 600 mm
Mode: Shutter speed priority AE
Aperture: f/6.3
Exposure Time: 0.002 sec (1/640)
ISO: 100
My name is Dave, and I'm an Alphaholic.
Sony:A99II,A900,A77M2,RX100M2|18~70f3.5~5.6 DT|11~18f4.5~5.6 DT|24-70 f2.8ZA SSM|50f1.4|100 f2.8 Macro|70-300 f4.5~5.6 G SSM|300f2.8 G|500f8 Reflex|Minolta600
Back to Top
Jonas A-R View Drop Down
Senior Member
Senior Member

Joined: 29 December 2007
Country: Denmark
Location: Denmark
Status: Offline
Posts: 1118
Post Options Post Options   Quote Jonas A-R Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2017 at 19:21
Originally posted by Davethehiker Davethehiker wrote:

Originally posted by Jonas A-R Jonas A-R wrote:


I think the results presented in this thread cannot be generalised to all lens/TC combinations


I don't think anyone is attempting make a generalization. I have only expressed my experiences with the Minolta 600mm f/4 and the Sony 300mm f/2.8 lenses when mounted on an A99II. I found that with my copy of the Sony 1.4X TC, it was better NOT to use it.

It is difficult to be sure it not a focus inconsistency. To prove to myself that is was not a focus problem, I took a lot of photos in the "Extra Fine" mode so I could use the 2X magnifier when I manually focused. Still the TCs did more harm than good. In general I find that the Auto-Focus on the A99II does as good, or better than I can do manually.

I own both a 2X and 1.4X TC. The 1.4X is not as bad as the 2X.


Your statement: I wonder if the e-mount TCs suffer from the same limitations as their A-Mount big brothers? They are of a more recent design, but who knows?

Certainly gave the impression that you thought you had discovered something general.

You may well have of course although I remain a bit sceptical of your testing procedure and conclusion. I am not saying that it is an easy task to test this conclusively though
a900 16/2.8 fish 20/2.8 24/2Z 35/1.4G 50/1.4Z 85/1.4Z 100/2.8 macro 135/1.8Z
a7r 24-70/4Z

Back to Top
Davethehiker View Drop Down
Senior Member
Senior Member

Joined: 22 August 2011
Country: United States
Location: Eighty Four, PA
Status: Offline
Posts: 370
Post Options Post Options   Quote Davethehiker Quote  Post ReplyReply Direct Link To This Post Posted: 20 May 2017 at 11:51
Originally posted by Jonas A-R Jonas A-R wrote:



I remain a bit sceptical of your testing procedure and conclusion. I am not saying that it is an easy task to test this conclusively though


I know of two other people besides me who happen to own both the A99II and the Sony TC. All three of us have came to this same conclusion.

Some others here on Dyxum has stated that their Canon TC work fine. Maybe they do but it was not clear to me that their camera had the same or better resolution than the A99II.   

I have met other people at a nearby lake where photographers gather to photograph eagles in a nest. These people are using Canon or Nikon and their advice has been "Don't bother with TCs."

So far no one has taken my challenge of using the same printed resolution test pattern with and without a TC to prove me wrong, with any brand.
My name is Dave, and I'm an Alphaholic.
Sony:A99II,A900,A77M2,RX100M2|18~70f3.5~5.6 DT|11~18f4.5~5.6 DT|24-70 f2.8ZA SSM|50f1.4|100 f2.8 Macro|70-300 f4.5~5.6 G SSM|300f2.8 G|500f8 Reflex|Minolta600
Back to Top
Dyxum main page >  Forum Home > Equipment forums > Lens Talk > Adapters and converters Page  <1 34567>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.064 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Find us on Google+

Feel free to contact us if needed.