Thank you Ian, Your advice is most welcomed and hopefully I can make good use to those extension tubes. It is more of an experiment than a sort of have-to-use basis since I have purchased a 100/2.8 macro to do most of my macro work. And it has served me exceptionally well. I'm fairly new to macro work (naturewise) since I had been taking shots of products or close-up of products in a room without the nature interfering with the shots. But as a biologist, I do like to take pictures of the wild and especially the little things which we usually missed (I can't take photos of bacteria even though I am a microbiologist "grin", that'll take more than a macro lens...) I hope I can start getting some good pictures and put it up in PUG to share with all of you! I can't believe I only found you guys a few months ago.... What was I doing all these years?
Cheers Andy -----Original Message----- From: Ian bromehead [mailto:[EMAIL PROTECTED] Sent: Sunday, January 04, 2004 11:42 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: Extension tube Andy I am just as gullible as you, and couldn't resist buying one of these sets On ebay. I bought the Extension Tube K set, which is A compatible to stop down the aperture But no auto-focus compatibility So far I don't regret it, but they are clearly less practical than a good macro. Just before I read your pdml email this morning, I was outside relaxing in the morning california sunshine. I spied heavy dew on the leaves behind me and used them to take a few photos. My biggest learning by trial and error has been that of DOF. Clearly this is one way to really understand how to use and control DOF and the necessity to take one's time in composition and think carefully in your mind's eye where to stand vs natural light to get the right image content. The guy I bought them from advised me to see "...the ultimate book for macro photography is John Shaw's Closeups in Nature. It's a great read and has wonderful photos too.." I have yet to purchase it, but he's probably right. I bought a small tripod which is absolutely essential for work with them in all cases. Also I picked up tips from folks much more experienced than I on this and other pdml's. Tips such as using cardboard to shield the subject from winds and draughts, crucial given the highly restrictive DOF. I saw Rod's reply to you, and thought it might be useful to give you my experience, which as he says is probably lens dependant. For f stops I have found that I loose 0.6EV sequentially with each unit, used mostly with my SMC-n 50mm, 1:1.7. Just to remind myself of this, I re-tested again today. @ ISO 200, I focused at f16, 1/125mm on a neutral subject in full sun. I then inserted ET K tube 1, lost 0.6EV, and subsequently lost 0.6EV for ETK tube 2, and 1 full stop when I added ETK tube 3 which is the longest. How much you loose will depend on which sequence you use these in, you doint have to use them in this sequence of course. I use a PZ-1P and an older Kodak Dc280 digital. Clearly the capacity to "mess" with glass and accessories is missing from the fixed, snapshot digital, but the capacity to make mistakes and throw them away is attractive with digital, and I miss it. So I'm really anxious to see prices come into my range before I'll switch to SLR digital. In between times, the PZ-1P is a wonderful instrument, solid and big enough even when fixing the extension tubes with a long telephoto or my Tamron 28-300mm zoom. It makes for a long lever in front of the camera, but the PZ-1P is a hefty build so I don't have any issues, and a tripod is required of course. Welcome to macro photos, see some of my work in my portfolio on photo.net, not sure exactly How to direct you. Cheers Ian Date: Sat, 3 Jan 2004 21:12:22 +0800 From: "Andy Chang" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Subject: Extension tube K Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi guys, A belated Happy holiday to you all!!! I have just acquired a Pentax Extension Tube set K. I had no idea what it does first but after looking at Boz's web site, I have some idea how it works. It was a bargain and I couldn't resist bidding for it. According to Boz's site, it is a manual extension tube set and I guess the differences between the Auto set and the manual set is about the A position on the A and later lenses. If you remember, I have asked about losing F stops using teleconverter. I'm just wondering if it also applies on the extension tubes. By adding extension tubes behind the lens, do I have to adjust the exposure accordingly? Thanks Andy
