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08-25-2008, 08:49 AM   #436
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QuoteOriginally posted by Derridale Quote
Nice ones Javier

But let's not start the "My lens is bigger than your lens" thingy - we could generate a whole new line in spam.....

Re my whale shots above - that last one of the whale's tail - that was at full stretch on the 18-250, and I just wish I'd had the TC on to frame it better.

Any of you experts think that the definition and resolution would be better or worse by:

(a) tighter framing with a 1.4x TC, with the slight optical degradation of the TC (maybe)

or

(b) using the shot as taken, then crop and enlarge.

Which would give the better photo - theoretically?
Thanks, I am not a fan of using the TC on super zooms. I have done it and image quality is ok, but it is so slow to focus. I can't imagine catching a whale with the 18-250 and 1.4tc attached. If I am not mistaken that 250mm is at F/6.3 and consider you will loose another stop of light after that.

08-25-2008, 09:20 AM   #437
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Good point Javier, and one that I had thought to make with the turtle-pic but decided that except for dawn/dusk situations Pete's whale shots should be OK with the 18-250 and TC. BTW, since your shots above were with a 135-400, what exactly is the definition of 'Super Zoom'?
08-25-2008, 03:22 PM   #438
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QuoteOriginally posted by John Kovarik Quote
BTW, since your shots above were with a 135-400, what exactly is the definition of 'Super Zoom'?
John, Good point. I guess in my own head, these are my thoughts and will use three lenses as examples...Since we know that the Tammy 1.4 will cost us a full stop to use, the penalty for using it on a super zoom is much more in the overall scheme of things...

Tamron / Pentax 18-250 superzoom. F/3.5-F/6.3
Sigma 135-400 F/4.5-5.6 std zoom
Sigma 100-300 F/4.0 What I call a zoom prime. (don't shoot me for this heresy)
08-25-2008, 03:33 PM   #439
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Glad we got that cleared up! Ha1

08-25-2008, 04:52 PM   #440
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My definition of a superzoom (and probably the accepted one) is any lens that has a greater than 7 zoom range. The 18-250mm has a zoom range of 13.8, so it's a superzoom. The Tamron 28-200mm, which I believe is one of the earliest, if not the first, superzooms has a zoom range of 7.1.

The Sigmas 100-300mm and 135-400mm both have a zoom range of about 3.

In general, the smaller the zoom range, the better the IQ of a lens.

As a side note, the Bigma is a superzoom, as its zoom range is 10 (50-500mm). The reason its IQ is so good, is because there was little compromise when it came to adding weight to it (more/better glass). If they had made it lighter it would have sucked.
08-26-2008, 03:53 AM   #441
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Thanks for the replies, troops All very good points, duly noted.
I might have to try the TC on the Bigma....

I guess the main contenders for use with the Tammy 1.4x TC would be the DA* series (I have the 16-50 and the 50-135). If, or when, I spring for the DA*200 and 300, then the TC on those as well could add just another dimension to the useable range.

Thanks again for the comments - you lot are a great resource
08-26-2008, 07:26 AM   #442
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QuoteOriginally posted by Derridale Quote
Thanks for the replies, troops All very good points, duly noted.
I might have to try the TC on the Bigma....

I guess the main contenders for use with the Tammy 1.4x TC would be the DA* series (I have the 16-50 and the 50-135). If, or when, I spring for the DA*200 and 300, then the TC on those as well could add just another dimension to the useable range.

Thanks again for the comments - you lot are a great resource
I really wasnt going to post in this thread since it was all pretty well covered but since you mentioned using the Tamron 1.4x with the Bigma I thought I'd post an example. I posted this in the moon shot thread. The combo would not AF since it was early dawn. The sky was just getting blue. First photo is full size image reduced for the forum. Second is a crop from the first.



08-26-2008, 07:31 AM   #443
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QuoteOriginally posted by Mr Hyde Quote
I really wasnt going to post in this thread since it was all pretty well covered
The more opinions the better. How is the auto focus speed on the bigma with the TC?
Does it hunt allot?

08-26-2008, 08:43 AM   #444
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Very nice pix, Mr. Hyde. Since Jay has raised the matter, does anyone have experience and/or opinions in comparing the Tamron 1.4 with the Sigma 1.4 in IQ and AF performance?

Also, has anyone ever determined why Sigma doesn't offer HSM for PTX mounts?
08-26-2008, 08:46 AM   #445
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Because SDM has only been around since sometime last year and it takes Sigma time to reverse engineer the mount and then figure out how to get some HSM lenses into their production schedule, etc.....

Last I heard was sometime in August (September here we come!)

QuoteOriginally posted by John Kovarik Quote
has anyone ever determined why Sigma doesn't offer HSM for PTX mounts?
08-26-2008, 11:56 AM   #446
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Mr (Scott) Hyde, that is a very nice Moon shot, and I love the deep blue colour of the sky. The resolution is very good, but I wonder if you could bring out even more detail with some localized contrast (as with the 'clarity' slider in ACR).

How easy/hard was it to manually focus this shot?
08-26-2008, 04:15 PM   #447
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Miserere, could you clarify your point there, please? ACR is that a program, as in the programs I have used I have not come across "clarity" at all.
Thanks from a rather little educated computer newbie
08-27-2008, 07:19 AM   #448
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QuoteOriginally posted by jgredline Quote
The more opinions the better. How is the auto focus speed on the bigma with the TC?
Does it hunt allot?

For me this all depends on the amount of light available. If it's really bright out I really dont see a difference. For the moon shot it would not AF at all and I had to switch over to manual.
08-27-2008, 07:26 AM   #449
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QuoteOriginally posted by Miserere Quote
Mr (Scott) Hyde, that is a very nice Moon shot, and I love the deep blue colour of the sky. The resolution is very good, but I wonder if you could bring out even more detail with some localized contrast (as with the 'clarity' slider in ACR).

How easy/hard was it to manually focus this shot?

My software photo editing skills are a bit lacking, I only stick to the basics. I guess I really should delve more into the software huh?

Anyway... Manual focus was fairly easy. Camera & Lens was mounted on a tripod. I just dialed in the focus until I had the clearest view in the viewfinder and I also got the focus indicator confirmation.

QuoteOriginally posted by Bramela Quote
Miserere, could you clarify your point there, please? ACR is that a program, as in the programs I have used I have not come across "clarity" at all.
Thanks from a rather little educated computer newbie
I believe Miserere was refering to Adobe Camera Raw (ACR)
08-27-2008, 08:59 AM   #450
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QuoteOriginally posted by Mr Hyde Quote
My software photo editing skills are a bit lacking, I only stick to the basics. I guess I really should delve more into the software huh?
Well...yeah, you should

QuoteQuote:
I believe Miserere was refering to Adobe Camera Raw (ACR)
Yes he was.
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