Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-14-2016, 12:15 PM - 3 Likes   #1
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
DA*60-250 with stacked HD DA 1.4 TC and F1.7 AF adapter stacked to get to 600mm

K-3 and stacks HD DA 1.4TC and F1.7 AF adapter.

250 x1.4x1.7 gives me pretty much 600mm

One last reach experiment... after getting pretty much stellar results with the DA*200 ƒ2.8 and stacked TCs I decided to test my reach options. The A-400 and 1.7 which would give me 680, was a pretty dismal failure. I had trouble locking focus (and I had great light) and the best images weren't good enough. So after completing that, I realized I hadn't tried stacking with the DA* 60-250. So back out again.

I got far fewer keepers and often had considerable trouble locking focus, as much as with the A-400, the difference being, when I did lock focus the images were good.







So from my perspective, this becomes the poor man's way to get to 600mm ƒ6.7. Really, not to shabby.

I guess I could point out that some have sold their Pentax gear and bought whole new systems to get to 600. And with full AF I'm sure those systems are more functional, but if you're on a budget and you own a DA* 60-250, this could be for you. I'd love to be able to try it out with a DA*300, also an ƒ4 lens. I would expect similar results, similar trials getting images and similar joy with the results when successful.

714mm and ƒ6.7 would not be too shabby, with this kind of IQ.


Last edited by normhead; 04-14-2016 at 01:01 PM.
04-14-2016, 12:33 PM   #2
Site Supporter
VoiceOfReason's Avatar

Join Date: Jun 2010
Location: Mishawaka IN area
Photos: Albums
Posts: 6,124
I know the 1.4 works flawlessly (for me at least) with the 150-450, which gets you past 600. Now I want to give it a shot with the 1.7 in the middle.
04-14-2016, 12:33 PM   #3
Otis Memorial Pentaxian
photolady95's Avatar

Join Date: May 2009
Location: Cruising the forum watching his back
Photos: Gallery | Albums
Posts: 12,712
These are great Norm. TFS

I've been looking for a 1.4x or 1.7x to use with my Pentax 50-200 but haven't been able to locate either so far. I really like your results from stacking two TCs together.
04-14-2016, 12:33 PM   #4
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
But wait, everyone knows that TC's degrade the image quality and make for poor images. And everyone knows you cannot stack two TC's...........

How can you post images and disrupt conventional 'wisdom' like that?

More seriously, what are you using for a tripod? I would think vibrations of any kind would be the real problem at that focal length. Whatever, you did good.

04-14-2016, 12:45 PM   #5
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
Original Poster
QuoteOriginally posted by jatrax Quote
But wait, everyone knows that TC's degrade the image quality and make for poor images. And everyone knows you cannot stack two TC's...........

How can you post images and disrupt conventional 'wisdom' like that?

More seriously, what are you using for a tripod? I would think vibrations of any kind would be the real problem at that focal length. Whatever, you did good.
I have an old Blacks tripod out in the blind, that is basically out there because I'd be embarrassed to be seen by real photographers with it.
The usual caveats about needing extra care with a longer lens apply.
04-14-2016, 12:49 PM   #6
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by normhead Quote
K-3 and stacks HD DA 1.4TC and F1.7 AF adapter.

250 x1.4x1.7 gives me pretty much 600mm

One last reach experiment... after getting pretty much stellar results with the DA*200 ƒ2.8 and stacked TCs I decided to test my reach options. The A-400 and 1.7 which would give me 680, was a pretty dismal failure. I had trouble locking focus (and I had great light) and the best images weren't good enough. So after completing that, I realized I hadn't tried stacking with the DA* 60-250. So back out again.

I got far fewer keepers and often had considerable trouble locking focus, as much as with the A-400, the difference being, when I did lok focus the images were good.







So from my perspective, this becomes the poor man's way to get to 600mm ƒ6.7. Really, not to shabby.

I guess I could point out that some have sold their Pentax gear and bought whole new systems to get to 600. And with full AF I'm sure those systems are more functional, but if you're on a budget and you own a DA* 60-250, this could be for you. I'd love to be able to try it out with a DA*300, also an ƒ4 lens. I would expect similar results, similar trials getting images and similar joy with the results when successful.

714mm and ƒ6.7 would not be too shabby, with this kind of IQ.
That is amazing, Norm !
If you don't mind me asking: what is the order in which the TC's are stacked? Or does it matter?
I have the DA*300/4 and both of those TC's, so it could be fun to try that!

Thanks!
04-14-2016, 12:49 PM   #7
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
Original Poster
QuoteOriginally posted by photolady95 Quote
These are great Norm. TFS

I've been looking for a 1.4x or 1.7x to use with my Pentax 50-200 but haven't been able to locate either so far. I really like your results from stacking two TCs together.
Wo there, I'm not recommending stacking with anything less than an ƒ2.8 lens. Using the stacked TCs on the ƒ4 lens was dicey. With the 50-200 at ƒ5.6, everything I've done suggests you can't even use the 1.7 TC by itself. You could try the 1.4, but I wouldn't recommend it. By far the most functional stack I've used was the DA*200 and stacked TCs, I've used the DA*60-250 and would try it in a crunch, but it didn't give me the kind of reliable AF the DA*200 ƒ2.8 did.

It's unfortunate but you really do have to have the best glass to use stacked TCs.

QuoteOriginally posted by jpzk Quote
That is amazing, Norm !
If you don't mind me asking: what is the order in which the TC's are stacked?
Or does it matter?
Thanks!
I don't know if the order matters. I've always put the 1.4 on the camera and the 1.7 in the middle. That's what made sense to me. With the 1.4 turning the 1.7, both TCs are working for you. If you put the 1.7 on first, the 1.4 will be stationary, at whatever it's set to. But, who knows, maybe it would work equally well either way.


Last edited by normhead; 04-14-2016 at 12:58 PM.
04-14-2016, 12:54 PM   #8
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by normhead Quote
Wo there, I'm not recommending stacking with anything less than an ƒ2.8 lens. Using the stacked TCs on the ƒ4 lens was dicey. With the 50-200 at ƒ5.6, everything I've done suggest you can't even use the 1.7 TC by itself. You could try the 1.4, but I wouldn't recommend it. By far the most functional stack I've used was the DA*200 and stacked TCs, I've used the DA*60-250 and would try it in a crunch, but it didn't give me the kind of reliable AF the DA*200 ƒ2.8 did.

---------- Post added 04-14-16 at 03:52 PM ----------



I don't know if the order matters. I've always put the 1.4 on the camera and the 1.7 in the middle. That's what made sense to me. With the 1.4 turning the 1.7, both TCs are working for you. If you put the 1.7 on first, the 1.4 will be stationary, at whatever it's set to. But, who knows, maybe it would work equally well either way.
Great.
Now, let's wait for birds .... still pretty scarce around here. Seems like Spring has decided not to sprung.
04-14-2016, 12:54 PM   #9
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by normhead Quote
but it didn't give me the kind of reliable AF the DA*200 ƒ2.8 did.
Auto focus smokous. Who cares about AF, the fact that you got what I would think are printable images with that rig is amazing. Very good technique I'm sure and good light but still, well done.

I assume the 60-250 was at f/4?

Have you tried the A-400 and the 1.4x? Curious if the IQ was fine though no AF of course.
04-14-2016, 01:00 PM   #10
Otis Memorial Pentaxian
photolady95's Avatar

Join Date: May 2009
Location: Cruising the forum watching his back
Photos: Gallery | Albums
Posts: 12,712
Whoa! I said and/or, not both. I have no intention of stacking two on a 50-200mm lens at it's f stops. But I have a Vivitar 2x and it will not allow autofocus to happen because the lens at 200mm is f5.6 and it needs to be less than f4 for a 2x TC to work.
04-14-2016, 01:06 PM   #11
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,398
QuoteOriginally posted by normhead Quote
Wo there, I'm not recommending stacking with anything less than an ƒ2.8 lens. Using the stacked TCs on the ƒ4 lens was dicey. With the 50-200 at ƒ5.6, everything I've done suggests you can't even use the 1.7 TC by itself. You could try the 1.4, but I wouldn't recommend it. By far the most functional stack I've used was the DA*200 and stacked TCs, I've used the DA*60-250 and would try it in a crunch, but it didn't give me the kind of reliable AF the DA*200 ƒ2.8 did.

It's unfortunate but you really do have to have the best glass to use stacked TCs.



I don't know if the order matters. I've always put the 1.4 on the camera and the 1.7 in the middle. That's what made sense to me. With the 1.4 turning the 1.7, both TCs are working for you. If you put the 1.7 on first, the 1.4 will be stationary, at whatever it's set to. But, who knows, maybe it would work equally well either way.

I'm confused. The 1.4 is always stationary. It only passes AF power or screw drive shaft power. Putting the 1.7 anywhere as long as AF shaft powers it gives focusing options. I always added it to the camera first. But typically my stacks involved non-AF Teleconverters. So an FA* 300 with 2x-s and then the AF 1.7x. My rationale was that the AF 1.7 would have the most focusing impact placed last in the optical path.
04-14-2016, 01:15 PM - 1 Like   #12
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
Original Poster
QuoteOriginally posted by jatrax Quote
Auto focus smokous. Who cares about AF, the fact that you got what I would think are printable images with that rig is amazing. Very good technique I'm sure and good light but still, well done.

I assume the 60-250 was at f/4?

Have you tried the A-400 and the 1.4x? Curious if the IQ was fine though no AF of course.
My ƒ-stop showed the correct ƒ stop wide open a ƒ6.7, I stopped down to the next full ƒ-stop, ƒ8 just to be neat and tidy I guess. Oops my mistake. The 1.7 on a ƒ5.6 lens is ƒ9.5 so I actually stopped down to ƒ11.

QuoteOriginally posted by photolady95 Quote
Whoa! I said and/or, not both. I have no intention of stacking two on a 50-200mm lens at it's f stops. But I have a Vivitar 2x and it will not allow autofocus to happen because the lens at 200mm is f5.6 and it needs to be less than f4 for a 2x TC to work.
Thanks for spelling whoa, I was wondering how to spell it. My experience says the 1.4 might work on your 200, but probably not well and for the cost of the Pentax TC you could get a 55-300, that would be faster and more convenient.

QuoteOriginally posted by UncleVanya Quote
I'm confused. The 1.4 is always stationary. It only passes AF power or screw drive shaft power. Putting the 1.7 anywhere as long as AF shaft powers it gives focusing options. I always added it to the camera first. But typically my stacks involved non-AF Teleconverters. So an FA* 300 with 2x-s and then the AF 1.7x. My rationale was that the AF 1.7 would have the most focusing impact placed last in the optical path.
That's what happens when you think about things you shouldn't.

You've obviously thought about it a lot more than I have. My thought involved standing in front of the lens and two TC-s lying on the table in my kitchen, wondering which one to put first, staring at the three pieces.

Then when it worked, I saw no point in thinking any further.

You can't get away with nothing around here.

I bought the 1.7 before the 1.4, and it was my first TC. In my mind apparently, all TCs move, whether they claim to be AF adapters or not.

Oh and credit where credit is due, the original idea to try this stuff came from watching my Canon shooting buddies. I know I should probably not say stuff like that but hey.

We were standing around at the place we shoot Gray Jays, me with my old A-400 and one of the guys waved his Canon 70-200 ƒ2.8 with a Canon 2x on it and said, "I've got the same thing with AF and better IQ." The better IQ thing was against forum ideology, but, it's always better to investigate than it is to repeat hearsay. I managed to keep my foot out of my mouth. The thing that took the most time was getting to stacking the 2 TCs. Again, forum wisdom said "don't do that,". I went for quite a while thinking "it's too bad Pentax doesn't make 2x TC, before I even thought of stacking.

I guess the thing I took from the whole experience, is if you pay the price for premium equipment, don't take advice from people who didn't. The 1.7 and 1.4 are both premium pieces of equipment, and work best with premium glass. Any shortcuts are likely to mess up the whole process. Three combined pieces are only as strong as the weakest link.

Last edited by normhead; 04-14-2016 at 05:11 PM.
04-14-2016, 02:51 PM   #13
Veteran Member
bertwert's Avatar

Join Date: Jun 2015
Location: Golden, BC
Posts: 15,173
Great results!

Wouldn't that be f/9.5 fully open instead of f/6.7?
f/4 - 1.5 stop (for the 1.7x) = f/6.7
f/6.7 - 1 stop (for the 1.4x) = f/9.5
04-14-2016, 03:42 PM   #14
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,398
My suggestion is to try it again with the 1.7x closest to the body and see if the results are better. But before you do verify that the glass in the 1.7x won't contact the 1.4x - I did it and I think it works but then again I was a stupid person and mounted a DA 15 to the silly 1.4x once only without damage but found out later it was possible to damage one or both due to the way the glass protrudes.
04-14-2016, 03:56 PM   #15
Senior Member




Join Date: Mar 2016
Posts: 113
QuoteOriginally posted by VoiceOfReason Quote
I know the 1.4 works flawlessly (for me at least) with the 150-450, which gets you past 600. Now I want to give it a shot with the 1.7 in the middle.
That's good to know! Bet the 1.4 would work on full frame just fine with that lens as well... might be fun.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
600mm, af, da 1.4 tc, da*200, f1.7 af adapter, focus, hd da, images, k-mount, lens, norm, pentax lens, results, slr lens, tc and f1.7, tcs
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: DA 60-250mm zoom with extra tripod mount, HD DA 1.4 TC dshombert Sold Items 4 08-17-2015 05:19 AM
Macro Failure to capture With K-x and stacked lenses smf Photographic Technique 21 01-08-2015 01:25 PM
K3 with Stacked 1.4 and F1.7X Rear Converters DDoram Pentax K-3 & K-3 II 14 06-26-2014 12:37 AM
For Sale - Sold: Da 15 ltd, da 70 ltd, dfa 100 wr, da* 60-250, f 1.7x af adapter dltorre Sold Items 11 06-14-2014 07:38 AM
For Sale - Sold: DA* 60-250, DA 35 Macro Ltd, DA 18-55 WR, Kenko 1.5X TC with SDM contacts buzzvic Sold Items 10 09-08-2012 07:35 PM



All times are GMT -7. The time now is 03:19 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top