Help on Teleconverter for Pentax A* 600mm f/5.6

kulas3VII · 08-20-2013, 05:30 PM

Thanks a lot...

Here are the images taken with A* 600mm f5.6 sits on Winberley Gimbal Head.

Attached Images

stormtech · 08-21-2013, 06:23 AM

What I am seeing on the pics posted above they are soft or out of focus. Adding a TC to that lens is going to make them look twice as bad.

I would concentrate on getting a sharp image from the lens before even thinking of adding a TC.

kulas3VII · 08-21-2013, 07:54 AM

Originally posted by stormtech

What I am seeing on the pics posted above they are soft or out of focus. Adding a TC to that lens is going to make them look twice as bad.

I would concentrate on getting a sharp image from the lens before even thinking of adding a TC.

Thanks a lot and you ahve a good day.

reeftool · 08-21-2013, 09:08 AM

The first law of bird and wildlife photography states, "Whatever lens you are using, it is always at least 100mm too short".

goubejp · 08-21-2013, 10:31 AM

Originally posted by RKKS08

The Pentax 1.4x(L) and 2x(L) are the only TCs which are really designed to get everything possible out of the Pentax >=300mm lenses.

Correct, but these teleconverters were designed in 1983 (I bought one to attach to my A*300 at that time) and not refreshed for 30 years now. A more modern design with modern coating (during he same period of time Canon release 3 different versions of 1,4 extender) and of course AF compatibility (not for yours, unfortunately) is expected, it is on the roadmap, hope we'll see it quickly now.

goubejp · 08-21-2013, 10:39 AM

Sorry I didn't saw your pictures. Sorry to say that, they don't look as sharp as they should, is it an effect of the compression ?
A 600 mm on a gimball head should be as sharp as that :

100 % crop

You should try to improve your skill and technique before adding a teleconverter. Some tips : use a remote wire cable, use an OM-53 magnifier for a more accurate focus

kulas3VII · 08-21-2013, 12:15 PM

Originally posted by goubejp

Sorry I didn't saw your pictures. Sorry to say that, they don't look as sharp as they should, is it an effect of the compression ?
A 600 mm on a gimball head should be as sharp as that :

100 % crop

You should try to improve your skill and technique before adding a teleconverter. Some tips : use a remote wire cable, use an OM-53 magnifier for a more accurate focus

Thanks a lot and appreciate your comments.

I did some touch-up to the exposures and added more contrast may be cause it blur with a thin dof. Also playing around with lens adjustment set to +8. Will try more.. basic. BTW, no offense.. my honest opinion your exposures are underexposed.

You have a good one.

Last edited by kulas3VII; 08-21-2013 at 01:08 PM.

goubejp · 08-21-2013, 01:47 PM

I Wonder that you played with lens adjustment; it's relevant for AF lenses only and your 600 is manual focus. The issue with these lenses is to achieved precise focusing as the depth of field is very, very narrow. More difficult for you as it is an F5.6 lens; stop the lens down to F8 and try an OM-53 magnifier, this will give you better results. For me all your shots are slightly out of focus. Adding contrast has never added blur.
Regards

kulas3VII · 08-21-2013, 01:52 PM

Originally posted by goubejp

I Wonder that you played with lens adjustment; it's relevant for AF lenses only and your 600 is manual focus. The issue with these lenses is to achieved precise focusing as the depth of field is very, very narrow. More difficult for you as it is an F5.6 lens; stop the lens down to F8 and try an OM-53 magnifier, this will give you better results. For me all your shots are slightly out of focus. Adding contrast has never added blur.
Regards

Thanks a lot to your input.

Have a good one.

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08-20-2013, 05:30 PM	#16
kulas3VII Veteran Member Join Date: Jun 2008 Location: Somerville, NJ USA Photos: Gallery Posts: 354 Original Poster	Thanks a lot... Here are the images taken with A* 600mm f5.6 sits on Winberley Gimbal Head. Attached Images

08-21-2013, 06:23 AM	#17
stormtech Veteran Member Join Date: Jan 2011 Location: In the boonies (NW Penna) Photos: Gallery \| Albums Posts: 5,744	What I am seeing on the pics posted above they are soft or out of focus. Adding a TC to that lens is going to make them look twice as bad. I would concentrate on getting a sharp image from the lens before even thinking of adding a TC.

08-21-2013, 07:54 AM	#18
kulas3VII Veteran Member Join Date: Jun 2008 Location: Somerville, NJ USA Photos: Gallery Posts: 354 Original Poster	Originally posted by stormtech What I am seeing on the pics posted above they are soft or out of focus. Adding a TC to that lens is going to make them look twice as bad. I would concentrate on getting a sharp image from the lens before even thinking of adding a TC. Thanks a lot and you ahve a good day.

08-21-2013, 09:08 AM	#19
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,555	The first law of bird and wildlife photography states, "Whatever lens you are using, it is always at least 100mm too short".

08-21-2013, 10:31 AM	#20
goubejp Veteran Member Join Date: Oct 2007 Location: France Photos: Albums Posts: 804	Originally posted by RKKS08 The Pentax 1.4x(L) and 2x(L) are the only TCs which are really designed to get everything possible out of the Pentax >=300mm lenses. Correct, but these teleconverters were designed in 1983 (I bought one to attach to my A*300 at that time) and not refreshed for 30 years now. A more modern design with modern coating (during he same period of time Canon release 3 different versions of 1,4 extender) and of course AF compatibility (not for yours, unfortunately) is expected, it is on the roadmap, hope we'll see it quickly now.

08-21-2013, 10:39 AM	#21
goubejp Veteran Member Join Date: Oct 2007 Location: France Photos: Albums Posts: 804	Sorry I didn't saw your pictures. Sorry to say that, they don't look as sharp as they should, is it an effect of the compression ? A 600 mm on a gimball head should be as sharp as that : 100 % crop You should try to improve your skill and technique before adding a teleconverter. Some tips : use a remote wire cable, use an OM-53 magnifier for a more accurate focus

08-21-2013, 12:15 PM	#22
kulas3VII Veteran Member Join Date: Jun 2008 Location: Somerville, NJ USA Photos: Gallery Posts: 354 Original Poster	Originally posted by goubejp Sorry I didn't saw your pictures. Sorry to say that, they don't look as sharp as they should, is it an effect of the compression ? A 600 mm on a gimball head should be as sharp as that : 100 % crop You should try to improve your skill and technique before adding a teleconverter. Some tips : use a remote wire cable, use an OM-53 magnifier for a more accurate focus Thanks a lot and appreciate your comments. I did some touch-up to the exposures and added more contrast may be cause it blur with a thin dof. Also playing around with lens adjustment set to +8. Will try more.. basic. BTW, no offense.. my honest opinion your exposures are underexposed. You have a good one. Last edited by kulas3VII; 08-21-2013 at 01:08 PM.

08-21-2013, 01:47 PM	#23
goubejp Veteran Member Join Date: Oct 2007 Location: France Photos: Albums Posts: 804	I Wonder that you played with lens adjustment; it's relevant for AF lenses only and your 600 is manual focus. The issue with these lenses is to achieved precise focusing as the depth of field is very, very narrow. More difficult for you as it is an F5.6 lens; stop the lens down to F8 and try an OM-53 magnifier, this will give you better results. For me all your shots are slightly out of focus. Adding contrast has never added blur. Regards

08-21-2013, 01:52 PM	#24
kulas3VII Veteran Member Join Date: Jun 2008 Location: Somerville, NJ USA Photos: Gallery Posts: 354 Original Poster	Originally posted by goubejp I Wonder that you played with lens adjustment; it's relevant for AF lenses only and your 600 is manual focus. The issue with these lenses is to achieved precise focusing as the depth of field is very, very narrow. More difficult for you as it is an F5.6 lens; stop the lens down to F8 and try an OM-53 magnifier, this will give you better results. For me all your shots are slightly out of focus. Adding contrast has never added blur. Regards Thanks a lot to your input. Have a good one.