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azemerov

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Posts posted by azemerov

    Why use dilutions?

    in Black & White Practice

    Posted

    <p>What is the practical reason to use diluted developer vs. non-diluted? I can make only two possible explanations -<br />1) diluted developer can be more economical, especially if you prefer use fresh stuff.<br />2) diluted developer probably provides less contrast pictures.<br>

    Am i right in my guesses?</p>

    Metal finishing restore

    in Pentax

    Posted

    <p>Hi,<br>

    I have several old cameras including Asahi Spotmatic. They work fine, but I also want to restore original appearance as much as possible. Cameras have some dark spots and signs of weariness on metal parts. I want to restore the finish. Can it be done at home or requires professional service? What is correct term for metal finishing used in old cameras (not black, but "silver" ones)?<br>

    Thank you</p>

    Clouds

    in Nature

    Posted

    Hi,<br>

    I'm living in Dallas, TX. This area is very interesting for it's fast and

    dramatic changes of cloud formations. I've never seen so many interesting and

    beautiful clouds before. So I want to capture their beauty on camera. And I'm

    not talking about "traditional" landscapes where clouds are just some elements

    of the composition - I want to take pictures where clouds are key and central

    elements.<br>

    And here my two problems. The first question is artistic one - what kind of

    composition should be used for such pictures (and what kind of focal length is

    suitable for that)? If I take shot of cloud only without first and second plan

    details the image looks too plain. If include some elements - alone tree,

    electric pole, etc. - I'll distract attention from the clouds because they are

    always on the back plane. Do you have any thoughts or experience? May be I can

    ask differently - how to put clouds on the first plan? Remember, I'm living in

    Texas and have no possibility to make picture with mountains _behind_ clouds :(<br>

    Another problem is technical. All my experience with cloud shots give me

    images where clouds appear dull - they miss fine details and halftones.

    Polarizers help me to increase contrast, but detailization still struggle. I

    shut in digital and thinking about HDR. But may be my problem can be solved in

    different, more traditional way?<br>

    Here is an example of picture where I struggle with both problems - clouds are not

    key element and they detailization is far from the desirable/original - <a

    href="http://lh4.ggpht.com/azemerov/R37c-ua3rDI/AAAAAAAAASk/kTB7gw5YeaI/imgp2538.jpg?imgmax=640">(link).</a><br>

    Thank you.

    Vivitar 2800D flash on K100d?

    in Pentax

    Posted

    BTW, don't rely completely on somebody's experience with "the same flash model". Manufacturers have tendency to modify flashes keeping the same model name. For example, Vivitar 285 (not HV, but the old good one) was produced for so many years (actually decades) at different locations and with some schematic modifications. It is not surprise to find so many different results of this flash voltage - from 6 to 300V.

    Old vs new 500mm

    in Pentax

    Posted

    Jim,

    the question was about non-mirror lenses.<br>

    I am also curious about quality of Opteca tele lenses. Obviously they have simple optic and mechanic construction, have no AF and exposure metering support. I don't care about automatization - the quality of picture is decisive factor. My filing is old lenses have much better quality (same for mirror ones), but it will be nice to know opinion of experienced owner.

    Vivitar 2800D flash on K100d?

    in Pentax

    Posted

    Be aware - cheap multimeters have very low input resistance. As result when you try to measure voltage on a flash with high output resistance (almost all old flashes) the voltage drops almost to zero. You have to use a multimeter with high input resistance (at least 1 kOm, check with multimeter manual) to get reliable result.<br>

    I have an old Sears flash which voltage was show as low as 2 V on cheap multimeter, same time when I tried to "measure" it with my naked fingers it hurt me very much! :) Its actual voltage happened to be about 100V.<br>

    If you have a minimum experience in electronic you can make a simple adapter - <a href="http://www.chemie.unibas.ch/~holder/nikonflash/coolflash.jpg">link</a>. All parts ordered on mouser.com + shipment cost me about $10. Adapter allowes you to use _any_ old flash with your digital body (tested with my K100D).

    How aperture works on Sears AUTO 135mm F:2.8 Macro?

    in Pentax

    Posted

    Rotation of aperture ring doesn't open/close the aperture - it's only sets the stop position. You have to move the lever to see aperture in action<br>

    So, first, set 1/16 aperture and check if aperture closes when you shift lever on unmounted lens. If it opens and closes iris easily - lens is fine.<br>

    Second, you have to enable usage of old lenses with non-A setting in the menu.<br>

    Third, to use step-down metering with such old lenses you should set aperture value on the lens and press AE-L button (on K100D body, not sure about K10D, check with documentation). Don't forget to set the "M" exposure mode.

    how to measure umbrella size?

    in Lighting Equipment

    Posted

    May be it sounds stupid, but how umbrellas are measured? What does it mean -

    45"? The reason I'm asking is - I bought two 45" umbrellas (Westcott and

    Photogenic) from Adorama.com. Both have 42" in diameter (I measured the max

    diameter, between two opposite rods). Is it ok, or I got the wrong items?

    K100D vs K10D

    in Pentax

    Posted

    I agree with Trent. For me AA batteries are the worst part of K100D design (fortunately the only one significant). I use Energizer NiMh batteries. Generally they work fine, BUT buttery indicator is unpredictable - sometimes it shows half and in 5 minutes it shows full charged. If you use build-in flash it is even more difficult to predict when batteries die. Considering the low cost of replacement battery for K10D (less than $20 3rd party) AA batteries don't make sense for me at all. I was very dissapointed when Pentax continued usage of AA in K200D.<br>

    Otherwise K100D is very nice as start up/backup/travel body.

    Opinion on Sears Auto 135mm F2.8 Macro?

    in Pentax

    Posted

    I own this guy. I didn't have a chance to compare it to another 135mm primes, but anyway - it is my favorite lens! Very good quality of construction, smooth focus, nice optical quality...<br>

    <a href="http://picasaweb.google.com/lh/searchbrowse?q=SEARS+135&uname=azemerov&psc=S&filter=0#0+1">Here you can see pictures of the lens itself</a>. Unfortunately I don't have samples taken with lens available online - I'll publish them tomorrow. Check same link latter.

    Unusual Texturing in Photos

    in Pentax

    Posted

    I think your fault was not picking "wrong" camera, but selling your K100D without comprehensive test of new camera. Especially if you new about upcoming events... I also had a problem with my K100D - burned flash circuit - and waited for 1 month for repair, so I understand your feeling.<br>

    Unfortunately, nowadays QC of electronic, cameras, optic, etc. is much worse it used to be let say 20 years ago. "Try and replace" tactic is cheaper than comprehensive QC. Canon and Nikon follow the same approach, but they have much more facilities. So, if you are professional you should consider tech support aspect when choose the system, but also you just must have a backup camera!<br>

    I hope you will enjoy your new body and after several months your grief will fade out.

    Repost of k10D/Sigma 50-500 Shots

    in Pentax

    Posted

    Brad,<br>

    reprocessed Warbler has better colors, but anyway if your picture is out of focus or too soft you can not fix it in PS. Even if you use sharpen tool it doesn't give you details missing in original image :(<br>

    Manual focus is not a problem if camera is adjusted correctly. If you rely on AF confirmation and get constant backfocus (or frontfocus) you probably have a problem with AF adjustment. If you rely on focusing screen and have same problem, screen is not adjusted. In 1st case goto <a href="http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=22023704&page=1">"self focus adjust for dl,ds,ds2,k100d" thread</a>. In 2nd case you can play with thickness of bronze rim laying between focusing screen and frame holding it. In any case don't rush to fix problem before you absolutely convinced you really have it - AF check is not absolutely consistent, neither human eye. Also you can check <a href="http://focustestchart.com/chart.html">focus test chart</a>, but again - don't make fast conclusions, repeat test several times.<br>

    Also there is known problem when different lenses give different AF focus results on the same body. There are lot of speculations, but for me the reason it is more likely in combination of AF precision/adjustment problem plus errors in lens AF feedback. Check <a href="http://www.bdimitrov.de/kmp/technology/AF/index.html">SAFOX description</a> for details.<br>

    Sorry if I went too far from your original question,<br>

    Alex

    K10D/Sigma 50-500 Shoots

    in Pentax

    Posted

    I agree with Peter, first two pictures are too soft for f8. Also I believe they have focus problem. #1 is backfocused, not sure about #2. Colors are also not vivid. #3 is much better despite obstacles, may be because it was taken at 420mm, not 500mm.

    Sharp Manual Zoom Lens

    in Pentax

    Posted

    I have Sigma 80-200 macro zoom. Got it as part of lot, so I can estimate the price as $40 (+shipping). Couldn't find any information about this lens at time of purchase. But I found it quite sharp for such price. If you are interested - I'm ready to get rid of it. Test pictures are available.
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