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bert_krages1

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Posts posted by bert_krages1

  1. Provia F has good reciprocity characteristics which is an advantage since long exposures are often required when using a macro lens at the higher f-stop values. The increased saturation is good for flowers. Velvia can work even better although the exposure needs to be increased by about 50 percent for exposure times exceeding ten seconds to correct for reciprocity failure. In overcast conditions, you will need to use a 81B filter to avoid a blue cast to the images.
  2. <P>The camera adapter and a t-ring for Nikon can be found at <A HREF="http://www.telescope.com/shopping/product/detailmain.jsp?itemID=73&itemType=PRODUCT&iMainCat=6&iSubCat=29&iProductID=73">Orion.</A>.

     

    <p>I do more widefield than telescope work. Digital cameras are not good at the really long exposures required for most telescope photography nor is the Celestron CR-150 considered a good set-up for astrophotography. You may not be able to be able to get enough back focus to make the camera adapter work. On the other hand, Orion sells another kind of adapter that allows for afocal photography where you position the camera lens immediately in front of the telescope's eyepiece.You should be able to get some good images of the moon and perhaps some brighter objects.

     

    <p> You might find that with a D100, a better way to get started in astrophotography is with a standard 50mm lens. Here is a link to some photographs of the

    <A HREF="http://www.krages.com/leonid.htm">Leonid Meteor Showers, November 17, 2001.</A>

  3. It is going to depend on the particular lens or telescope. The inexpensive models tend to be terrible. The better models can be quite good. I had a Celestron 300mm MC lens that was very sharp. The Apex 127 from Orion is fairly compact considering the focal length. While I cannot vouch for the image quality, I suspect it would be quite good. Note that because of the secondary mirror on the Cassegrain designs, the effective aperture (the amount of light that your camera will see) will be about one stop higher than the nominal aperture (i.e., f/12 will be more like f/16 in terms of light transmission). Also, most people don't like the donut shaped highlights you get with mirror lenses.
  4. I have the same scanner that I originally procured around 1998 and used with a computer with SCSI and Win95. I upgraded to a newer computer in 2002 with Windows XP. I took the SCSI card from the old computer and installed it in the new one. I don't remember whether I used the original driver or downloaded another one but the scanner works fine on my system with the HP software. I use some other scanners as well but the old Photosmart gives nice results and the HP software is easy and effective to use.
  5. <p> Exposure times for star trails will vary depending on the kind of composition you desire and the condition of the sky. Tonight there will have a slightly gibbous waning moon that rises at 10:22 PM so you will likely want to take your photographs before the moon�s brightness washes out the sky. Star trails become more circular but shorter as the image approaches Polaris, the North star. If you include Polaris in the image, the trails will appear to revolve around Polaris.

     

    <p> To be effective, star trail photographs do not have to be lengthy. For example, a five minute exposure of Polaris will show the revolving effect to good measure. Some photographers seem to assume the longer the exposure the more dramatic the effect. The risk you take as the exposure time gets longer is that the sky will wash out and you will lose the fainter trails. A wider aperture will capture fainter stars but also causes the sky to wash out faster. A good starting point is two f-stops higher than the maximum for the lens. In the end, there is no �correct� exposure and it all comes down to subjective preferences. You might want to experiment with different exposure times and f-stops to see what you like.

     

    <p> Also, you might want to try some fixed star images using short exposures. For example, at 6:30 PM, the constellation Orion will be at the east-southeast and about 15 degrees in the sky. If you are not familiar with this constellation, it looks like an hour glass with three stars forming a neat line at the center (Orion�s Belt). Use exposure times of 10 to 15 seconds using a 50mm lens at f/2.8 and you should be able to pick up nicely with both Provia 100F and your monochrome film. More information on the nuances of imaging stars with conventional equipment can be found in <A HREF="http://www.krages.com/hb.htm">Heavenly Bodies: The Photographers Guide to Astrophotography</A>.

  6. I personally would not worry about it. Chloramines are formed when chlorine combines with ammonia and nitrogen compounds. Since chloramines are less reactive than chlorine, they are less likely to interfere with photographic chemicals than the free chlorine residuals in systems that don't rely on chloramine disinfection. In other words, tap water from water supply systems that use chloramine disinfection should work just fine. Also, chloramines won't increase the potency of ammonia-based fixers.
  7. I had a similar situation a few years ago when a bulk loader that I bought on eBay contained a roll of unknown film. I loaded about ten frames worth and bracketed exposures of a printed material (black letters on white paper) in front of some foliage from EI 50 to EI 400 then developed in D-76 for 11 minutes. I figured that I would be able to determine an appropriate film speed in this manner. I actually determined that the film had been exposed to light since the edges were badly fogged. Nonetheless, this might work for you.
  8. The exposure was way too long. Basically, the moon is a large rock illuminated by the Sun although the exposure will also depend on the angle to the Sun (i.e., the moon's phase). For a full moon, the proper exposure at ISO 100 is about 1/125 of a second at f/11. For a gibbous moon, the exposure should 1/60 of a second at f/11 and for a quarter moon, 1/30 of a second at f/11. If you want to get foreground objects exposed at night, you need to add light (e.g., use a flash). If you are interested in more techniques on how to photograph the moon and other celestial bodies, they are covered in my recent book <A HREF="http://www.krages.com/hb.htm">Heavenly Bodies: The Photographers Guide to Astrophotography</A>.
  9. <p> It will be very difficult to find a medium format system that can't make excellent landscape images when mounted on a tripod so you probably should select whichever system appeals to you at the intuitive/preference level.

     

    <p> Another option you may want to consider (and offered in that grand photo.net tradition of suggesting something explicitly contrary to what is stated in the question), would be the Mamiya twin lens reflex system. I recognize that you don�t want a square format but with a little cropping, it is pretty simple to turn 6x6 into 6x4.5. My thought is that two C220 bodies, the 80mm lens, and one of the wide-angle lenses would meet your basic requirements. The bodies are currently inexpensive on the used market, the lenses are interchangeable, and the fixed mirror is more versatile than MLU. Such a system would be bulkier and heavier than the equivalent MF SLR system although probably comparable in size and weight to the typical 35mm SLR nature outfit (based on my experience). It would be also be a lot cheaper and make a good backup system for weddings.

  10. If you don't mind used equipment, you might try getting a Bogen Model 108 heads on eBay. I picked up a pair recently for about $10 each and have found them very serviceable. Make sure that it comes with an adequate number of quick release plates because I don't think that Bogen still sells them. If you get a head that is a little sticky, they are not very difficult to disassemble and clean. Some of the Arca afficianados will tell you that the 108 does not pan nearly as nicely as a $400+ ballhead when using a $6000+ lens and they are undoubtedly right. But the 108 will hold your camera rock steady and you could probably procure two or three of them for the price of a single Arca plate.
  11. You may want to consider switching to pencil and paper if you are looking to develop your perceptual skills. I recommend the book "Drawing on the Right Side of the Brain" by Betty Edwards (or even better, take a community college course based on the book). Slowing down to make images only helps when the reason you are slowing down is to evaluate the visual aspects of the image. Using a slower camera will not necessarily help. If you are looking for a used TLR, Mamiya C220's seem to be going at low prices on eBay these days.
  12. This is basically a trespassing issue. In some jurisdictions, the property owner could recover for emotional distress (e.g., embarassment or humiliation) caused by photographs of the junkers. However, if the cars are visible from public property then this theory of recovery is weak. The photographs would likely constitute evidence of trespassing for which nominal damages can be awarded. Nominal damages are typically a minor amount awarded when a trespass occurs with no other injuries.
  13. I have not used the hex plates but do use the rectangular plates with a CC400. If you replace the OEM bolt with a 1/2-inch long 1/4"-20 bolt, e.g., the kind from a hardware store, the rectanglar plate fits nicely within the base for the CC400 and can be secured better. I can get a little bit of wiggle with the older style cork plate if I try to move the camera but otherwise the connection is stable. However, this plate is worn and a newer would likely fit better.
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