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07-14-2007, 07:19 AM   #16
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I agree with your conclusion.

IMHO, i think the shot taken with the DA 14/f2.8 is very good, perhaps better than the DA 50/f1.4 can ever do (with extension tube, etc).

07-14-2007, 06:56 PM   #17
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Haha Raider, yes the DA14mm is a great lens but so is the 50mm/1.4. Extension tubes are a great way to enhance the close up focusing ability of the lens.



A set of Ricoh K Mount extension tubes that I bought recently.

I have the SMC Pentax-A 50mm f1.4 whos optical formula's the same as your FA50/1.4. The minimum focusing distance as marked on the lens is 0.45m.

This is what that looks like. These following shots are all taken with SMC A 50/1.4 turned to the closest focal distance (at 0.45m), f4, handheld ISO 400.


Just the 50/1.4


the 50/1.4 with the 12mm extension tube


the 50/1.4 with the 20mm extension tube


the 50/1.4 with the 36mm extension tube


the 50/1.4 with all extension tubes (36mm+20mm+12mm)

Hope this shows what you can do with extension tubes.
07-14-2007, 07:20 PM   #18
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Very impressive!! This are the best pictures so far on the net that I have seen which illustrates the effect of the use of various sizes of extension tubes on the 50/f1.4!

I am impressed!!

On another note, I noticed you are using a K-mount extension tube. does it have an 'A' contacts? If I get the same tube for my DA 50/f1.4, can I do AF? Can the K100D tell what is the aperture of the DA 50/f1.4 with the extension tube? Can we then use Av mode on the K100D?

Do we need an aperture lever to allow the lens at its widest aperture?

Can this extension tube fit the bill? eBay Australia: Extension Tube Macro Ring for Pentax dslr K100D K10D (item 160136242586, end time 16-Jul-07 19:18:53 AEST)

Thanks

Last edited by raider; 07-14-2007 at 07:31 PM.
07-14-2007, 07:41 PM   #19
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Its just an ordinary K Mount extension tube meaning there are no electrical contacts niether are there AF slot screws. (I don't know if they even made any like that)

So you will have to manually focus the lens and use stop down metering. Lenses that do not have an aperture ring will automatically revert to f22 or f32 (depending on lens).

The extension tubes I have do link the aperture lever so the lens will be held at widest aperture by the camera until the moment the shot is taken.

Thanks for your comments. I'm glad I could be of help. Frankly, I didn't find much info either about extension tubes especially those on ebay. Alot of those are the cheaper types where you have two seperate mount specific ends and basic screwthread tubes in between. Its a more cost effective design although, when you stop down, the viewfinder will go dark. (lack of aperture level linkage). You'll also have to screw on/unscrew the tubes in order to adjust extension length which might get a bit tedious.

There is a neat trick I think one of the forum members here did with those types of tubes that enabled him to use lenses from other mounts simply by switching the mount ends. If you are confused..ignore this paragraph haha.

07-14-2007, 07:50 PM   #20
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Thanks for your reply.

Ok. I searched the net and I came across this

Kenko Digital Extension Tube 25 (Nikon Mount) ShaShinKi.com : Malaysia Online Camera Shop

It is an extension tube for nikon mount but the online store confirmed it is available for pentax mount as well.

Would you mind take a look to see if this has the A-contact, can control the apertures, etc? If this is acceptable, I might just take the plunge and buy it.

Thanks
07-14-2007, 07:56 PM   #21
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QuoteOriginally posted by raider Quote

Let me understand this correctly - if I add an extension tube to my 50/f1.4, I can then aim the lens at the subject with the separation distance being approximately 10-15cm and yet the image is at the same size and perspective as the DA14/f2.8? The perspective is important to me as my friend's DA14/f2.8 can make small size object look like a lifesize object (refer the tasmanian devil pic)
No. Extension tubes will allow an increase in image size because you can focus much closer. However, the 14mm lens has a much wider field of view than a 50mm lens. For a given image size, the perspective will be different (because the camera to subject distance will be different). However, if the camera to subject distance is the same, then the perspective will be the same, but the image size will be different (because the wide angle has a wider field of view, so the subject appears smaller).

Confused? Find a book in the bookstore, camera store or library where there is a discussion on the relationship between camera to subject distance, perspective, image magnification and lens focal length. I have a little book from Kodak that it explains it quite clearly. But it is more than I could try to include in a message here.
07-14-2007, 08:05 PM   #22
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QuoteOriginally posted by raider Quote
Thanks for your reply.

Ok. I searched the net and I came across this

Kenko Digital Extension Tube 25 (Nikon Mount) ShaShinKi.com : Malaysia Online Camera Shop

It is an extension tube for nikon mount but the online store confirmed it is available for pentax mount as well.

Would you mind take a look to see if this has the A-contact, can control the apertures, etc? If this is acceptable, I might just take the plunge and buy it.

Thanks
Ok..that picture is a N-AI version and it communicates lens data and AF....but....remember..this is 1 tube only..and you paying $113.46 AUD ($104CAN or $99USD) IMHO, its a very high price to pay.

Like ivoire just mentioned, if you like macro alot, you should perhaps just invest in a real macro lens. The kenko extension tube only gives like half magnification and you gotta get at least two to get the 1:1 magnification.

The recommended Vivitar S1 105mm is a great buy. You can probably find other macro lenses for cheaper but to go for an electric+AF extension tube is not worth the money.
07-14-2007, 08:12 PM   #23
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Good point.

I think I am going to just save up for a real macro lens then and forget about using extension tubes with 50/f1.4, in view that extension tubes are not that cheap anyway as compared with a real macro lens.

I will check out the vivitar s1 105mm but I think this is a manual lens which cannot do AF?

Would macro shots be better using an AF lens?

07-14-2007, 08:20 PM   #24
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Well, if you don't do macro alot, the manual K Mount tubes are a good alternative. (not the $100 auto+AF ones you asked about lol.)

People doing macro shots tend to have more time to spare. Like setting up the tripod, lighting equipement etc.. and tend to favour manual focus for the control aspect. So AF is not really necessary.

I think you should use MF when ever you can for any shot. It just makes the SLR experience that much richer being in control of the focus.
07-14-2007, 08:25 PM   #25
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Perspective comment

GaryML makes an excellent point on the perspective issue. If you decide on tubes, you will most likely use manual focus and an autofocus tube will most likely hunt forever until you position the lens at the correct focus distance. look on ebay for a kiron/kino made macro lens. they are very good optics and usually inexpensive. lenses made by them (for vivitar) will have serial #s beginning with 22 or 28. befor bidding/buying, ask if there is an 'A' on the aperature ring. this will allow auto aperature, metering, etc. heres a link for the best made by kiron:

Kiron

One of the finest af macro lenses on the market is the Tamron AF 90mm f2.8 SP Macro Di. expect to pay $300+ for one

Last edited by ivoire; 07-14-2007 at 08:36 PM.
07-14-2007, 08:40 PM   #26
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I primarily want a macro combo which can do the followings:

1) Take close-up picture of small objects at a close distance. (pls. refer to the Tasmanian devil shots I posted earlier). This also apply to static things like flowers, leaf, etc

2) Take close-up picture of bugs/insects but at a further distance (I fear they might jump at me )

Based on my understanding so far, extension tubes and macro adaptor will increase the size of the picture but the distance between the object and the lens has got to be relatively close. This is useful for my point 1 above but useless for point 2.

For point 2, I would need a real macro lens such as the Pentax 100/f2.8 or the Tamron 90/f2.8.

Is my understanding correct? If so, then I guess I have no choice but to settle for a real macro lens instead of the extension tube/macro adaptor combo with the 50/f1.4
07-14-2007, 09:19 PM   #27
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I know I am going around in circles...please bear with me and hear me out

But first, thank you for the vivitar macro lens advice. It is around 50% of the cost of new pentax 100/f2.8. The savings in cost is great.

If putting extension tube on the 50/f1.4 will not increase the working distance, how about putting the extension tube on the 50-200mm? I am also referring to another post in this forum about fake macro (https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/9517-fake-macro-50-200-a.html)

Then I did some search on youtube and this video came out:
YouTube - Intro to macro

In essence, the video is about taking macro shots on a leaf using a canon 50-200mm and the guy say it is also acceptable to use an extension tube for the job.

Hence, I am looking at this in this aspect:

1) If I use the DA 50-200mm and set to 100mm, the working distance should be the same as a pentax 100/f2.8, no?

2) If I put extension tube on the DA 50-200mm, chances are that I might find it difficult to focus (as suggested by another thread) and the DA 50-200mm will then act as a manual focus lens - exactly like the vivitar series 1 105mm macro, no? If I can get back my AF, then this is a bonus.

3) The combination of extension tube with DA 50-200mm will solve my desire for point 1 and point 2 as previously mentioned, no?

Thanks again!!
07-14-2007, 09:34 PM   #28
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You should be able to distance yourself from bugs with a longer lens and some extension tubes.

I used a very economical SMC- M 135/3.5 for these photos. Sorry about the dark photos, I messed up the white balance which threw off the metering. Aperture wide open for all shots.


M135/3.5 at closest focusing distance - marked 1.5m. (Camera was just under 5ft or about 1.5m away from subject.)


M135/3.5 at infinity + 36mm extension tube. (Camera was just under 3ft or around 80cm away from subject.)

Hope it helps.

Ok I tried my vivitar 75-205 under the same conditions to give you an idea what its like at 200mm

Vivitar 75-205 (205mm zoom setting) at closest focusing distance + 36mm ext. tube. (Still the same 80cm away from subject)

Last edited by FotoPete; 07-14-2007 at 09:48 PM.
07-14-2007, 09:48 PM   #29
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Bingo!! I think this is it!!

I already have the DA 50-200 and assuming the extension tube will make this lens lose its AF, I will end up with a manual lens, which is exactly like your M135/f3.5 (already a manual lens by default).

So, the extension tube can indeed let me take closeup pictures and at the same time let me stand some safety distance away from bugs! This is good news!!

Thanks!!!

In this case, can I just get this cheapo extension tube for AUD$19.49? eBay Australia: Extension Tube Macro Ring for Pentax dslr K100D K10D (item 160136242586, end time 16-Jul-07 19:18:53 AEST)

It will at least work with manual focus right? I can set the aperture and shutter speed on the K100D as well right?
07-14-2007, 09:55 PM   #30
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Before you run off to buy, your DA 50-200 will lose ability to control aperture (lack of electrical contact...and lack of an aperture ring.)

That picture on the ebay link you gave with the DA50-200 on the tube is deceiving.

Secondly, your choice of extension tubes maybe a bad one because its the cheaper version with no aperture lever linkage. So you will be looking through your DA50-200 at f32. You won't be able to see anything. You'll need a lens with an aperture ring to use with either type of extension tubes.

eBay Australia: Pentax K Mount Extension Tubes 13,21,31mm Made In Japan (item 220130299689, end time 18-Jul-07 06:59:47 AEST)
These are the extension tubes with aperture level linkages. But either way, the problem remains that the DA50-200 lacks an aperture ring.

Alternatives would be to get lenses with aperture rings or get Vivitar 105 or some other macro lens as mentioned.
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