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09-17-2012, 12:58 PM   #31
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QuoteOriginally posted by PushTheRedButton Quote
Maybe I missed this, but will this work for Sigma's 70-200 f/2.8? I've heard issues with the AF not working with a TC.
this is as good a place as any

the SMC-F 1.7x AF Converter is not a typical TC. it has its own focusing elements, and therefore, it has the ability to focus within the range of movement of those elements. You focus close, manually and it does the rest. It also makes corrections to the aperture values fed through to the camera to correct for the impact (aperture wise of the TC) therefore you get reliable metering including P-TTL flash.

As for Sigma TCs, they work only with screw drive AF systems not HSM.

09-17-2012, 10:22 PM   #32
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QuoteOriginally posted by PushTheRedButton Quote
Maybe I missed this, but will this work for Sigma's 70-200 f/2.8? I've heard issues with the AF not working with a TC.
I've used Sigma 70-200 mm f/2.8 EX DG HSM II + Pentax-F 1.7x AF combination and it works just fine. The only glitch of the combo is that aperture info you get to EXIF is incorrect although exposure is correct (true aperture wide open is about 4.5, camera shows and EXIF has 9.5). Same thing with Sigma 17-70 mm f/2.8-4 DC OS HSM + P-F 1.7x combo also. I guess this happens with many Sigmas (at least newer ones). And like said earlier, HSM isn't "working" but the TC's AF does instead.
09-18-2012, 05:11 AM   #33
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QuoteOriginally posted by komit Quote
I've used Sigma 70-200 mm f/2.8 EX DG HSM II + Pentax-F 1.7x AF combination and it works just fine. The only glitch of the combo is that aperture info you get to EXIF is incorrect although exposure is correct (true aperture wide open is about 4.5, camera shows and EXIF has 9.5). Same thing with Sigma 17-70 mm f/2.8-4 DC OS HSM + P-F 1.7x combo also. I guess this happens with many Sigmas (at least newer ones). And like said earlier, HSM isn't "working" but the TC's AF does instead.
interesting note about aperture. I guess this is because sigma does not license the mount so it reverse engineers things. on older lenses and pentax lenses the aperture reports correctly. however, aside from slight metering errors that would be constant across each lens, P-TTL flash will behave badly
09-18-2012, 01:25 PM   #34
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QuoteOriginally posted by komit Quote
I've used Sigma 70-200 mm f/2.8 EX DG HSM II + Pentax-F 1.7x AF combination and it works just fine. The only glitch of the combo is that aperture info you get to EXIF is incorrect although exposure is correct (true aperture wide open is about 4.5, camera shows and EXIF has 9.5). Same thing with Sigma 17-70 mm f/2.8-4 DC OS HSM + P-F 1.7x combo also. I guess this happens with many Sigmas (at least newer ones).
QuoteOriginally posted by Lowell Goudge Quote
interesting note about aperture. I guess this is because sigma does not license the mount so it reverse engineers things. on older lenses and pentax lenses the aperture reports correctly. however, aside from slight metering errors that would be constant across each lens, P-TTL flash will behave badly
My experience with Sigma lenses and the 1.7x AFA is similar, and I think that Lowell is correct about the reverse engineering. I use the AFA frequently with a Sigma EX 300 f2.8 APO and an EX 180 f3.5 APO DG Macro, and both report incorrect aperture values. I found that I can correct this, or at least get a lot closer to actual values by insulating pairs of contact pins on the front (lens) side of the AFA. I use 3M eletrician's tape because the adhesive they use doesn't get gummy over time like the cheaper brands. Scotch Magic Tape also works, but has less longevity.

I used the information on pin functions on this page:

http://www.robertstech.com/matrix.htm

then experimented a bit to get the best combinations.

Scott

09-18-2012, 01:39 PM   #35
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Here are a few more examples, this time with the K-5, a Canon FD 300 f4 L converted to K mount, and an f 1.7x AFA. These were shot using a very lightweight tripod setup consisting of a Fotopro CF travel tripod, a very lightweight Vanguard ABH series ball head and a Wimberley Sidekick (the whole thing including the gimbal weighs @ 4 lbs 6 oz total, and the tripod and ball head set me back less than $265).

Ruby Throated Hummingbird, f5.6 at the lens, ISO 1600







These were shot from about 10 feet, cropped maybe 20% to 8x10 and PP'd to taste.

Cedar Waxwing shot with the same setup, but at about 30 feet. f5.6 at the lens ISO 1600



This one is a veritcal crop of a landscape shot, PP'd to taste.

Scott
09-19-2012, 04:37 PM   #36
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Nice set, snostorm!
09-24-2012, 06:40 AM   #37
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QuoteOriginally posted by snostorm Quote
Here are a few more examples, this time with the K-5, a Canon FD 300 f4 L converted to K mount, and an f 1.7x AFA.

Scott
It would be an interesting comparison to take your canon 300/4 and the AF TC and compare similar shots to my K300/4 and AF TC. I am always interested in comparing older glass and since we have the same cameras, and comparable lenses it would be a good way to compare.
09-24-2012, 11:24 AM   #38
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QuoteOriginally posted by Lowell Goudge Quote
It would be an interesting comparison to take your canon 300/4 and the AF TC and compare similar shots to my K300/4 and AF TC. I am always interested in comparing older glass and since we have the same cameras, and comparable lenses it would be a good way to compare.
Hi Lowell,

I'd tend to say that the Canon FD 300/4 L is a bit better optically, especially in the area of CA/PF control. I base this on a few assumptions though. I've owned the A* 300/4, and the first assumption is that the A* was a tad better than the K. I know that it's smaller, so they don't share the same optical formula. I've compared the A* 300 f4 to the FA* 300 f4.5 side by side, and found the FA* to be slightly sharper, and controls CA/PF considerably better, presumably mainly because of the inclusion of ED glass . The Canon "L" version uses "ultra low dispersion" glass elements, and IMO performs very very close to the level of the FA* in all respects that are most important to me -- center sharpness, contrast, and CA/PF control. The Canon's MFD is longer, at just under 10 ft (3m), which splits the difference between the FA* (2m), and the K, M*, and A* Pentax versions at 4m.

I'd be happy to participate in comparison, but don't know what would be involved. I suppose shooting a commonly available subject (I'd suggest similarly dimensioned UPC codes), tripod mounted, sunlit outdoors or popup flash indoors from the same distance (in this case 4m since it's the lowest common denominator in distance) at different apertures and posting 100% crops would work, and wouldn't be too difficult or cumbersome. I would imagine using default setting "Natural" jpgs straight out of the camera would be a good way to provide a standard image.I'd also suggest a centered subject only because getting representative edge samples would be much more difficult to set up without alignment errors -- I hate trying to set up precision tests . Let me know what you think. I could also repeat the process with my FA* for another comparison.

If we could successfully do this, it occurs to me that establishing standard setups to use with specific FL lenses might be a useful tool for forum members. If enough members participated with different cameras and lenses, we could build a real life user based database of lens, and/or lens/body combination comparison shots. Of course, user error would be present, but if enough members participated, then we could come to some conclusions by comparing best to best.

Scott

09-24-2012, 02:04 PM   #39
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QuoteOriginally posted by snostorm Quote
Hi Lowell,

I'd tend to say that the Canon FD 300/4 L is a bit better optically, especially in the area of CA/PF control. I base this on a few assumptions though. I've owned the A* 300/4, and the first assumption is that the A* was a tad better than the K. I know that it's smaller, so they don't share the same optical formula. I've compared the A* 300 f4 to the FA* 300 f4.5 side by side, and found the FA* to be slightly sharper, and controls CA/PF considerably better, presumably mainly because of the inclusion of ED glass . The Canon "L" version uses "ultra low dispersion" glass elements, and IMO performs very very close to the level of the FA* in all respects that are most important to me -- center sharpness, contrast, and CA/PF control. The Canon's MFD is longer, at just under 10 ft (3m), which splits the difference between the FA* (2m), and the K, M*, and A* Pentax versions at 4m.

I'd be happy to participate in comparison, but don't know what would be involved. I suppose shooting a commonly available subject (I'd suggest similarly dimensioned UPC codes), tripod mounted, sunlit outdoors or popup flash indoors from the same distance (in this case 4m since it's the lowest common denominator in distance) at different apertures and posting 100% crops would work, and wouldn't be too difficult or cumbersome. I would imagine using default setting "Natural" jpgs straight out of the camera would be a good way to provide a standard image.I'd also suggest a centered subject only because getting representative edge samples would be much more difficult to set up without alignment errors -- I hate trying to set up precision tests . Let me know what you think. I could also repeat the process with my FA* for another comparison.

If we could successfully do this, it occurs to me that establishing standard setups to use with specific FL lenses might be a useful tool for forum members. If enough members participated with different cameras and lenses, we could build a real life user based database of lens, and/or lens/body combination comparison shots. Of course, user error would be present, but if enough members participated, then we could come to some conclusions by comparing best to best.

Scott
Scott

interesting concept. but I would add one or two things to this.

first, and it shouldn't be too hard, would be a 3 UPC code target, with one in the middle, and one in diagonally opposite corners. placement shouldn't be too hard to figure out at 4 meters so that we get it right into the corners.

It would be really interesting to see the impact of fringing and CA in the corners.

Second shot would be more difficult to do, but I think a fine wire 1/4 inch mesh, placed at 45 degrees on a white background, focusing on a center of the frame target (1/2 mesh in front of focus point 1/2 mesh behind focus point) to evaluate the fringing and longitudinal CA as you move in and our of focus.

In fact, the 1.4 inch grid if we could agree on it would be a suitable target for both tests. what about black plastic rain gutter mesh?

Might be interesting to do a couple of shots.
09-25-2012, 04:45 PM   #40
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F 1.7x AF TC & Tamron Adaptall 360B SP 300/2.8 LD (IF)

While we wait for your test results, here's a bluebird I took today.

04-13-2013, 01:45 PM   #41
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Olympus Zuiko 400mm f6.3 w/Leitax adapter and Pentax 1.7x converter with K-5. No cropping but post processing
Attached Images
 
04-15-2013, 10:50 AM - 1 Like   #42
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Pentax A-400 and Pentax 1.7 FA TC

Find the goose....



Here he is....

Last edited by normhead; 05-06-2014 at 07:18 PM.
04-16-2013, 06:27 PM   #43
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Glad to join the club!
Instead of posting several pictures taken with the 1.7x adapter (and DA*300/4), I thought it could be a better idea (for me) to post a Flickr link:

Pentax F 1.7X AF adapter images - a set on Flickr

in which I posted a "set" of images taken that way.

I would of course post right here if that is preferable.

Cheers!

JP
04-17-2013, 03:06 AM   #44
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QuoteOriginally posted by jpzk Quote
Glad to join the club!
Instead of posting several pictures taken with the 1.7x adapter (and DA*300/4), I thought it could be a better idea (for me) to post a Flickr link:

Pentax F 1.7X AF adapter images - a set on Flickr

in which I posted a "set" of images taken that way.

I would of course post right here if that is preferable.

Cheers!

JP
Nice - Was the Red Tailed Hawk in flight manual focus? or does the a.7 AF with the DA*300? Thanks
04-17-2013, 06:57 AM   #45
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QuoteOriginally posted by RockvilleBob Quote
Nice - Was the Red Tailed Hawk in flight manual focus? or does the a.7 AF with the DA*300? Thanks
The lens was set to MF and I left the camera switch on AF.
So, yes in a way this is manual focusing: get approximate focus to the subject with the manually set lens and then the adapter will "kick in" with its AF trick.
The adapter does the AF, not the lens.

JP

Edit: For those using AF lenses with this adapter, do you set the lens to manual and leave the camera switch on AF as I did?
Would leaving everything on MF cause any problems with AF lenses?
Would leaving the AF lens to MF be problematic?

Last edited by jpzk; 04-17-2013 at 07:11 AM.
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