paul_ong1
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Posts posted by paul_ong1
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<p>Oskar, Thanks. Looks like I will have to do some experimenting to figure out the best combination and approach.</p>
<p>Dave and Albin, thanks for the book recommendations. Will have to make my way to the library.</p>
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<p>Alex, thanks for the response. Will stay away from zoom lenses. Right now, the two I have in mind are the Nikon 105mm micro and the 24mm, both AIS. Will keep the 105mm wide open and adjust the aperture on the 24mm. Both have a 52mm filter ring, so I am going to buy a 52mm-52mm macro coupler ring.</p>
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<p>Jose, thanks. Very useful information. When just using the 105mm, I will use in normal position.<br>
Albin, you and others have convinced me to experiment with a shorter lens in front of the 105mm when I have time and the right adapters. I have a 24mm. How do you attach the two lenses? Thanks.</p>
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<p>Oskar (and others), I think I will try a shorter focal length in my next iteration. I had a wonderful 55mm micro but gave it as a present to my nephew. Sorry I did that, but he loves the lens.</p>
<p>Jose, thanks for the insight into using the PB-6 with the 105mm lenses. I am using a Pentax bellows with extension tubes. Also thanks for the advice on the Cokin adapter. I just got back from my brother's place to look at his Cokin system. I guess I now have another project for the future.</p>
<p>Alex, I have not tried the "diopter" approach because I have read that it has an adverse impact on IQ. I am happy for now to work in the range between 1:1 and 3:1. My bellows with extension tubes seems to be about to achieve that.</p>
<p>Les, thanks for the great link. A very useful thread.</p>
<p>Lil, yes agree that one of the reasons to use the 105mm is more distance from the subject. Have the 105mm micro AIS f/2.8, a Pentax bellows (with adapters) and Kenko extension tubes. Seems to work. Just want to know if I should buy a reverse lens adapter for the 105mm to improve IQ.</p>
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<p>John, thanks. Will keep your advice in mind when using shorter lenses.</p>
<p>Mike, I have a bellows and extension tubes, and so far, I have been about to used the combination by using the tubes both between the camera body and bellows, and between the bellows and lens to minimize the stress. Not sure if I will go to 4x.</p>
<p>Jose, OK, will keep that in mind. I am mainly exploring at this time going greater than 1:1. Most of my previous macros have been a less than 1:1.</p>
<p>Richard, thanks. I have a couple of enlarger lenses, but I have not figured how to mount it on the bellows. I have mounted them on a large-format camera, but did not reverse. The problem with reversing is that the aperture control is behind the lens board. Any suggestions on mounting to a 35mm bellows?</p>
<p>Kent, unfortunately not the f/4 AIS. It is the f/2.8 micro AIS, which Bjorn Rorslett gives a high 4.5 to 5 rating, although it has to be stopped down a couple of stops when using extension tube or bellows. </p>
<p>Bottom line based on people's useful comments, will try initially without reversing. I will place an order for a reverse lens adapter for later.</p>
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<p>I want to do some macro photography at greater than 1:1 with the Nikon Micro 105mm AIS lens. For most lenses, it is recommended to reverse them. Is that necessary or desirable for the 105mm? Thanks.</p>
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<p>For those interested in updates on the Mamiya-Toyo-Nikon hybrid camera, you are invited to check the link below. I will try to update once a month. My goal is to share the experience for those who want to pursue something similar so not to repeat what I learned through trial and error, and to receive input and ideas from others.<br>
http://www.flickr.com/photos/9476880@N02/sets/72157621949266496/<br>
Paul Ron, again I am sorry that you feel insulted. I am an amateur and have no problem stating and admitting that make mistakes, which happens often as a part of the learning by doing process. That is why I seek help and assistance, and when I do so, I try to be as accurate and precise in describing the situation. It is impossible to document what is not present (the aperture), although I can document what is there (the rust). But I think that is moot. Best of luck on your photographic efforts.</p>
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<p>Paul Ron,</p>
<p>I don't mean you. My understanding is that you got the broken lens from another owner, so I am referring to the original owner. I am truly sorry that I was not clearer on that. I really do not mean any disrespect to you. In fact, in earlier posts, I went out of my way to thank you to providing the lenses.</p>
<p>I am total in error in my wording in using "previous owner" rather than "original owner", and I take all blames.</p>
<p>As for the problems, no I did not open the cell before. I only opened up once to check to see if the lens was backwards, as suggested by another poster, and only after I got a diagram to check how the lens suppose to be placed. As indicated in my earlier posts, I usually do not start disassembling until I have some diagram, which I have requested from other posters.</p>
<p>As for the iris, yes one it was missing. And yes, on one of the other lenses, the blade assembly did come apart, but I was able to put it back together. A good learning lesson.</p>
<p>I do share my experiences with the goal of providing information for any future reader. One of my frustration is not finding enough information on the web, and when I do find information, I am very appreciative that the posters were willing to do that as a service. I thought I would return the favor. However, if it is not useful, I certainly will stop.</p>
<p>So, my apologies for my offenses.</p>
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<p>Steve, thanks for the info. Many new terms that I will have to look up.<br>
I also made a better image of the KL 90mm diagram (along with pre and post example of photos using the lens) and posted at:<br>
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<p>Jim, I have now taken apart and reassembled (or partially reassembled and modified for the hybrid camera) over a half dozens lenses. I am still learning how to do this efficiently and precisely. The forum has been very helpful.</p>
<p>Thanks for the KEH suggestion. I now have an "as is" link in my bookmarks so it is easy for me to check every day. It took me a few tries to learn how to use the search function effectively. I wonder how often KEH refreshes its "as is" inventory.</p>
<p>Andre, perhaps a sleepy previous owner. However, that element is in a removable sleeve that can house the lens in either direction. If a person does not carefully document each step or has a diagram or manual, it is easy to make the mistake. In fact, reversing the lens seems to fit the sleeve better.</p>
<p>David, yes learned that when I disassembled the non-C 90mm and the 180mm. I have gotten to the diaphragm both times. (I see I misspelled the word "diaphragm" in my original post.) I have been able to remove it and reinsert it. One time, it fell apart, so I had to learn reassemble the blades. That takes a bit of time and effort.</p>
<p>I will be looking for a very broken Mamiya lens with a functional aperture diaphragm.</p>
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<p>Hi,</p>
<p>As some of you know, I have a Mamiya KL 90mm that was extremely soft. Many here were helpful with suggestions, including that the lens elements could have been incorrectly assembled. I finally tracked down a lens diagram to check whether the individual lenses were properly assembled.</p>
<p>Surprise, the second to the last element in the rear cell was in backwards! I cleaned and reassembled, and now the softness has gone away.</p>
<p>My next step is finding an aperture because the adjustable iris diagram is missing. I think my strategy will be the same, that is to find a broken lens and transplant. </p>
<p>Does anyone know if the the older and newer apertures are interchangeable? I certainly will try MAC, but I think they may be getting tired of me asking so many questions without buying anything.</p>
<p>I am attaching the KL 90mm diagram for others who my find it useful in the future.</p>
<p> </p><div>
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<p>Mervyn, thanks for the comments. I plan to get it from KEH, which is a good source. Product variation is something I forgot to consider, and if the quality control of the older lens is not great, it is a good reason to get the "C" version.</p>
<p>Mag, absolutely right. I shot the one with Mamiya lens originally to test my setup and the sharpness of the lens. A week later, I decided to test the sharpness relative to a Nikon lens. Different time and conditions, but I was struck by the difference in color rendition. Just wanted to mention this as a followup on Paul Ron's comment. In general, I do find the older lenses to produce warmer colors. I also tested a Schneider against a Nikon for sharpness but also found the LF lens to be warmer, which you can see at the link below. Perhaps next time, I will try to more systematically test the lenses for color rendition, although my goal is not to spend the little free time I have on testing. I just do enough to help me understand my equipment.</p>
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<p>John, Jim and Paul,<br>
Thanks for the reply and information. Yes, used lenses are cheap, but unfortunately I am on partial furlough and my wife has not found meaningful employment. Not enough to radically change our lives, but every penny counts at this time. If the image qualities are nearly identical, then I can live with single coating. But if the image qualities are noticeably different, then I am tempted to pay the extra amount.</p>
<p>I plan to use the 50mm both on Mamiya/Toyo/Nikon digital hybrid and on the RB67, so both digital and film.</p>
<p>Interesting point about color rendition. I have been actively testing the Mamiya lens against a Nikon lens for sharpness, and I do see differences in the amount of warmth and coolness. If you want, you can see the result at the link below. Was not systematically testing for a difference in color, but I think it is there.</p>
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<p>Hi,<br>
I am planning on getting a 50mm for the RB67. KEH has both the 50mm and the C 50mm. What are the major differences between the two? I know that the C version has better coating. What about sharpness, contrast and color rendition?</p>
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<p>Jim, Thanks. Will keep trying.</p>
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<p>Jim,<br>
Trying finding it, first using their search engine and then going the the RZ page. Unfortunately, my mojo is not working. Can you give me some direction or link? Thanks.</p>
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<p>A Bruce and Greg, thanks. Wonder what the smaller version (123x123) is for?</p>
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<p>Fantastic buy. Never saw a "grab bag" ad on KEH. For future reference, where is it? Always looking for odds and ends for possible projects.</p>
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<p>Dave, Christoph and Jim<br>
Thanks for the responses. While there is a chance the RZ finder might work, I think I rather not hack the RB. Given that and the battery issue, I think I will wait for a RB PD prism to show up.</p>
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<p>Jim, again a big thank you.<br>
Vitor, hope you get your RB repaired. One suggestion if you need parts, get a "broken" one from KEH, some below $20. I got one for $3 plus $10 shipping. Be sure to ask which parts are broken so you can get the working parts you need.</p>
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<p>Hi,<br>
There is a RZ67 PD Prism on Craigslist. I wonder if it would work on the RB67. I know that the RB67 is mechanical, thus the metering would not work. But, can I use it as a prism?</p>
<p>Thanks.</p>
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<p>Ray,<br>
Thanks. What is interesting is that the 90mm is close to the register length (112mm between the focal plane and flange), so a mildly retrofocus is very much possible. From another thread here, I learned that symmetrical lenses are both easier to build, less costly and performs better in many respects. If nothing else, I am getting a basic education in lens design.</p>
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<p>David, thanks for your response. Yes, I have had a hard time figuring things out from the MCA web site. I will try emailing them next week to see if I can get some help. If I cannot get a diagram, I may get back to ask you if you can describe what you see on the intact lens. The good news is that the non-C 90mm is working out much better than expected after stopping down 2 f-stops. Had a chance to make some panoramas by moving the back standard on the Toyo.</p>
<p>Steve, thanks. That is a good starting point.</p>
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<p>I am looking for a cross-sectional diagram for the Mamiya 90mm KL lens. Basically, the diagram shows the basic shapes of the lens elements and their layout. My RB67 Pro-S manual has that information on the non-C 90mm lens (page 42). The manual for the Pro-SD or the RZ might have a diagram for the KL. I searched the web for a newer manuals and for a lens diagram of the KL, but no luck. I am hoping that someone has the image and are willing to share.</p>
<p>Thanks.</p>
Need help with CS4 color workspace!
in The Digital Darkroom: Process, Technique & Printing
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