[Sagitta]

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No use for lots of pixels if they are fuzzy. Better with fewer sharp ones. Images get published from 1mp DSLR's....

Go ahead and crop a 1MP camera's image down by 2/3's and get back to me about how usable the final image is.

I'll wait.

[Pål Jensen]

...I don't think that was what I suggested. Current Pentax DSLR's have 20 or 24mp. Lots of room for cropping.

[pathdoc]

I have a 3X in K-mount. Its not actually horrible, but I certainly wouldn't spend any huge amounts of money on one. As mentioned above, they work MUCH better with macro shots or anything really that's less than infinity shooting.

With infinity shots, lets just say "I hope you enjoy seeing every lick of dust hiding on that sensor of yours." Diffraction is also nasty (even wide open as even an f5.6 lens is going to shoot up to f11 (if I did the math right) and have an extra glass element thrown in. Adding those three stops means the things are only really useful with lenses that have wider apertures, and are decent at those wide apertures, because any little flaw or defect in either the TC or the lens is going to become noticeable, fast. Since you're also disconnecting the lens from the body by shoving the TC (which will likely have no contacts) in the middle, you're killing the ability to stop down meter as well. Its wide open or nothing.

Heres my particular beastie.



And here are some shots taken with it with the Bower 35mm f/1.4.



This is the same stack of change shot at MFD with the same lens, sans the 3X TC.


Note that the Samyang 35 isn't a macro lens, it just has a decent MFD of about a foot. I really should try one of the pseudo-macros (really, they're more close focus than anything) I have with this thing one of these days.

Sagitta, I went looking further and, without knowing it at the time, ended up buying a particular beastie identical to yours (mostly because I already have manual-focus K-mount lenses with aperture rings and can put the converter to work immediately, biding my time until the best screw-mount lenses appear and making my choices carefully).

Before that, however, there were a couple of other particular beasties I saw, and with my needs now fulfilled, I offer this for the attention and benefit of anyone who's interested in odd or bizarre items of technology and would like to give it a try.

[Sagitta]

Sagitta, I went looking further and, without knowing it at the time, ended up buying a particular beastie identical to yours (mostly because I already have manual-focus K-mount lenses with aperture rings and can put the converter to work immediately, biding my time until the best screw-mount lenses appear and making my choices carefully).

Before that, however, there were a couple of other particular beasties I saw, and with my needs now fulfilled, I offer this for the attention and benefit of anyone who's interested in odd or bizarre items of technology and would like to give it a try.

With the 3X TC, my best advice is to use whatever lenses you may have that are sharp and have minimal aberrations at their widest aperture. I popped some of my old 80's pseudo-macro lenses on that thing and I'll just say the modern 35mm was leaps (and bounds, and transcontinental air flights) better than the rest.

[normhead]

Hey Sagitta, why not crop that image for us. I would be interesting to see what you get. I've proved TC gets you more resolution than cropping with my own gear and test images. O found the increases to be pretty linear, more FL meant more detail, whether or not a TC was used to achieve the detail made no difference. But I don't have a 3x TC, and both TCs used were Pentax TCs, the 1.4 and 1.7.

[Kerrowdown]

Can this be for real?

It's real enough, but not something I would choose to use.

I have Rear Converter-A 2x-S and I can probably count on both hands the times of used it, to get me out of fix when I needed more reach due to unforeseen circumstances, which usually involved power tripping individuals.

[THoog]

I have an old Vivitar-branded 3X-22 TC, almost identical to Sagitta's (except the mount is painted black), and I have a Samyang 35/1.4, so I thought I'd give it a quick try.

35/1.4 on 3X TC @f/1.4 & MFD on K-S1, 1/160 with off-camera flash, WB adjusted in post, 20MP rescaled to 800pix wide:


35/1.4 @f/1.4 & MFD on K-S1, 1/160 with off-camera flash adjusted to get roughly the same lighting, WB adjusted in post, 20MP rescaled and cropped to match 3X TC shot:


In my case, the 3X TC introduces some hazy softness. Even if I could get a better match on the illumination, I think the crop is a little sharper.

[Sagitta]

I have an old Vivitar-branded 3X-22 TC, almost identical to Sagitta's (except the mount is painted black), and I have a Samyang 35/1.4, so I thought I'd give it a quick try.

35/1.4 on 3X TC @f/1.4 & MFD on K-S1, 1/160 with off-camera flash, WB adjusted in post, 20MP rescaled to 800pix wide:


35/1.4 @f/1.4 & MFD on K-S1, 1/160 with off-camera flash adjusted to get roughly the same lighting, WB adjusted in post, 20MP rescaled and cropped to match 3X TC shot:


In my case, the 3X TC introduces some hazy softness. Even if I could get a better match on the illumination, I think the crop is a little sharper.

It could be less haze, and more "taking whats already a sliver thin DOF and reducing it even more." Since the TC neutralizes the ability to catch focus, the only real scientific way would be to have to tripod mount, focus in live view, and do the whole 'remote mirror lock up' bit and pray nothing gets jostled in the process. I'm seeing less haze and more missed focus with that first shot.

Also, you shot both shots with the same camera, same settings. The argument posed was that a 1MP camera resized would yield the same results as a shot made with a 24MP camera when resized.

Its kind of a fascinating discussion, and I'm realizing I'm coming across ass defending this thing, but I really wouldn't recommend an old school 3X teleconverter at all except as a novelty item (much like a Holga lens). While it yields nifty results, the drawbacks far, far outnumber the advantages.

Pro: With the proper lens you can get some pretty amazing results
Con: Not many of those lenses exist. I tried a couple shots with my 28mm macro, 135mm macro, 70-210 macro and all were awful since those lenses are designed to be stopped down, and you can't stop down with a 3X TC attached

Pro: They're cheap
Con: They're cheap for a reason

I just fired off a few more test shots (for some reason I never saved the shots I had before as DNGs - I wanted some raw files to play with for this), I'll see how my crops and resized shots compare in a few.

[Na Horuk]

I have an old Vivitar-branded 3X-22 TC, almost identical to Sagitta's (except the mount is painted black), and I have a Samyang 35/1.4, so I thought I'd give it a quick try.

Great test! Heh, seems like the 3x TC gives you a "soft focus" lens

[Sagitta]

Great test! Heh, seems like the 3x TC gives you a "soft focus" lens

I just tried my 35mm with a couple coins and gave up and swapped over to using paper currency. The depth of field gets reduced to thinner than the difference between the coin's surface and whatever is stamped on it. The result is soft because you quite literally have what seems like a tenth of a millimeter that's actually sharp. I was using an old 10 Pence coin and I was watching the focal plane shift back and from the lion's face to the text on the coin. It was insane.

---------- Post added 04-16-15 at 03:27 PM ----------

OK, these aren't perfect (and I forgot to save a full size copy pre-crop of the non-TC shot, so the exposure is off (I did an auto-everythingf or it after the fact). It should give a rough idea of whats going on.

I think the enlarged image IS better for a few reason - first, there were no sharpening algorithms applied as the image was enlarged. Its a straight "WYSIWYG" out of camera shot. I could probably sharpen it up just as nicely as the other shot if I put any effort at all into working over the raw file for it. Second, the depth of field for the enlarged shot is much, much larger. Its not so noticeable with shots of paper like this, but if there was any dimension at all to the subject (coins, bugs, rocks, whatever) then you'd see fuzziness hit almost immediately simply because most of the subject would be sitting outside the focal plane. If I could figure a way to actually stop down the lens attached to the TC, I think we'd see a dramatic difference in quality.

The end result is the enlarged image IS better, but only because its has post work done to it simply through the act of enlarging it.

Original, uncropped shot from the 75-260 (I used this lens because its my best macro lens as far as being able to get close. Its not my best lens IQ-wise, but its the one that allows me to get closest to whatever I'm shooting.) Both shots were taken using a 5500k LED desk lamp for lighting, and tripod mounted with the mirror locked for the shots (really, I put way more effort into this than I should have... LOL). Focus was made in live view to get it as decent as possible. It was while trying this with the coins that I realized coin shots weren't going to work due to the too-small focus plane. Focus was on the 'Z' in Zimbabwe on the hundred trillion dollar bill.

Uncropped:


Cropped and enlarged (No TC):


3X TC shot:


---------- Post added 04-16-15 at 03:30 PM ----------

I'm sitting here wondering how hard it would be to Frankenstein an aperture onto the TC now.

Yeesh.

[THoog]

It could be less haze, and more "taking whats already a sliver thin DOF and reducing it even more." Since the TC neutralizes the ability to catch focus, the only real scientific way would be to have to tripod mount, focus in live view, and do the whole 'remote mirror lock up' bit and pray nothing gets jostled in the process. I'm seeing less haze and more missed focus with that first shot.

I mostly agree - I didn't have time to set up the gear to do the test "scientifically" (plus I'd want a set of macro rails to do it right). The haze/contrast loss is consistent with my 3X TC - that shot is about as good as it gets. I think you have a better copy.

[Sagitta]

I mostly agree - I didn't have time to set up the gear to do the test "scientifically" (plus I'd want a set of macro rails to do it right). The haze/contrast loss is consistent with my 3X TC - that shot is about as good as it gets. I think you have a better copy.

I think mine could have been new old stock when I picked it up. Came with the box, Vivitar paperwork inside the box, etc etc. The glass in the thing appears flawless

[pacerr]

Life becomes a lot easier when you stop thinking of a TC as a cheap means to acquire an expensive telephoto lens and accept it for what it is -- a relatively cheap and small way to get the results of a long FL lens of the optical era in which it was built. Life's a compromise - so 're TC's.

I carry a TC for one reasons only and use it solely with the best, longest FL lens at hand at the time of need. The reason? To achieve the PERSPECTIVE/POV of a longer lens when I can't otherwise gain position to do so.

[normhead]

I find the HD DA 1.4 TC useful on any sharp glass. I use it on the Sigma 70 macro and Tamron 90 macro for additional magnification, I use it with the DA*60-250. The HD TC is 4 elements in 3 groups. The DA* 300 ƒ4 is 8 elements in 6 groups. Together that are a 420mm ƒ 5.6 lens with with 12 elements in 9 groups. The fact that part of the combination is a TC means absolutely nothing.

The FA* 400mm ƒ 5.6 is 9 elements in 8 groups. One might expect the DA*300 + TC to be a little better corrected and 20 mm longer. And given the rating of the FA*400mm ƒ5.6, I'd certainly hope it would be a little better corrected. For cheaper TCs, I'm not sure you can make the same comparison. The two ways of achieving 400mm and ƒ5.6 and just looking at the stats, there's even a possibility the 420 combo is better. But as a light weight kind of guy, using the 300 and TC is way lighter and more flexible than using the FA*400 and DA*300. This isn't about cheap. It's about functional. Of the guys I shoot with, about half of them have TCs on their cameras almost all the time. TC for birds and small mammals., no TCs for mooses.

I'd hate to see a bunch of people passing on the HD DA 1.4 TC because of a bunch of nonsense posted in a thread like this, where people lump all TCs together. That's like me telling folks to pass on zoom lenses, because ,a Sigma 70-300 is weak in the long end, like the DA*60-250 doesn't exist. Oh wait, people do that too... ok, I'll shut up now.

[Sagitta]

I find the HD DA 1.4 TC useful on any sharp glass. I use it on the Sigma 70 macro and Tamron 90 macro for additional magnification, I use it with the DA*60-250. The HD TC is 4 elements in 3 groups. The DA* 300 ƒ4 is 8 elements in 6 groups. Together that are a 420mm ƒ 5.6 lens with with 12 elements in 9 groups. The fact that part of the combination is a TC means absolutely nothing.

The FA* 400mm ƒ 5.6 is 9 elements in 8 groups. One might expect the DA*300 + TC to be a little better corrected and 20 mm longer. And given the rating of the FA*400mm ƒ5.6, I'd certainly hope it would be a little better corrected. For cheaper TCs, I'm not sure you can make the same comparison. The two ways of achieving 400mm and ƒ5.6 and just looking at the stats, there's even a possibility the 420 combo is better. But as a light weight kind of guy, using the 300 and TC is way lighter and more flexible than using the FA*400 and DA*300. This isn't about cheap. It's about functional. Of the guys I shoot with, about half of them have TCs on their cameras almost all the time. TC for birds and small mammals., no TCs for mooses.

I'd hate to see a bunch of people passing on the HD DA 1.4 TC because of a bunch of nonsense posted in a thread like this, where people lump all TCs together. That's like me telling folks to pass on zoom lenses, because ,a Sigma 70-300 is weak in the long end, like the DA*60-250 doesn't exist. Oh wait, people do that too... ok, I'll shut up now.

I would love to pick up a modern TC if I could justify it. The fact I have no modern lenses however kind of makes it a wishful thinking kind of thing.

Out of curiosity, if I have a modern TC attached with an old 'A' or "M' lens, would the camera be able to be stopped down? Thats the one glaring weakness with the old TCs I've used. Unless I'm using a preset lens, I'm stuck at whatever maximum aperture the lens is at.

I certainly wouldn't call the old TCs useless, just limited due to the advancement of technology over the years.