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Forum: Lens Clubs
05-01-2013, 05:55 AM
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Nice try. But why did you stop down the aperture that much and use such a long exposure time, then? With a focal length of 400mm I would always try to stay at 1/250th at least - the shorter the better. And I cannot imagine, that the lens works best at f/18. With a shorter expsoure and an aperture of 5.6-8 you will get much sharper images.
Ben
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Forum: Lens Clubs
10-13-2012, 03:50 PM
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No special wiring required, you can use a standard cord. The built-in trigger does the shorting, albeit just to trigger the shutter and no half-press function.
Ben
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Forum: Lens Clubs
10-11-2012, 02:10 PM
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You should find a trigger button in the front grip and a socket for a simple trigger cord on the right side above the rear (focusing) grip. You can trigger your camera electrically, just as with a wired remote! Only drawback is, that Novoflex sports only a 1-step trigger and you cannot switch on the metering before you take it shot. In A mode the auto-exposure works ofcourse, but you cannot see the expsoure time in the viewfinder in advance. I asked Novoflex, but they won't make a 2-step trigger for these lenses anymore. I also contacted Bushawk, because they do make a 2-step-trigger for their shoulder rests (even more resembling a gunstock than the Novoflex) and the owner was very helpful. You could order the needed parts at BUshawk, as you are in North America. The European distributor did not even answer my order and I was too lazy to get the things from the US...
If I ever find the Novoflex manuals I'll scan them and make a PDF - but that won't be in the near future...
Anyway, if you need further info, feel free to ask.
Ben
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Forum: Lens Clubs
10-10-2012, 11:43 AM
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Hi Arjay - you don't need extension tubes! The Novoflex has a built-in sliding tube, which gives you much more extension than any set of additional tubes would provide. So can focus down much nearer, than you think.
The tube needs to be unlocked with the collar at the rear end of the lens, just in front of the camera mount. If you turn the collar the tube can just be pulled out and in as you require.
Ben
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Forum: Lens Clubs
10-05-2012, 02:41 PM
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I have the same setup and the Novoflex shoulder rest works wonders. I made a test series with the 400/5.6 Noflexar, which is a slightly sharper head than the 600mm (three lens elements versus 2) and could handhold 1/30 of a second with sharp results in about 50% of shots and got more than 80% sharp shots at 1/125s, which is very good for a 400mm lens on a cropped sensor. The Novofles lenses were very popular among nature photogs back in the 70s, before AF took over. But when shooting birds or other animals, where twigs, branches and other obscuring objects will mislead the AF, the Novoflex rapid focus system is still a strong contender.
Ben
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Forum: Lens Clubs
07-10-2012, 12:00 PM
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If you would have read my post entirely, you would have seen there is no need for your reply.
Ben
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Forum: Lens Clubs
07-09-2012, 12:17 PM
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Sorry, are we now in self-censoring mode here at Pentaxforums? I haven't got a chance to view your image, so I can't comment on its technical or compositorial qualities. But deleting an image following the exchange of opinions above is nothing short but censorship. If you feel you need to protect the identity of the pilot, you could simply have blurred or painted the ID of the plane, just as we are all expected to do when photographing cars. That should be enough.
Ben
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Forum: Lens Clubs
06-13-2012, 12:46 PM
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Ken, I must say, this is just another example of your masterly skills. Your images are outstanding not only in technical terms, with a clarity and vibrancy and sharpness, most of us will be hard pressed to achieve. But also, the composition is always spot on, like the birds would give you a portrait session. Absolutely stunning.
I guess, I am way too impatient to even come near this kind of bird photography.
Ben
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Forum: Lens Clubs
10-01-2011, 09:20 AM
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The A* is a beautiful lens, even smaller than the 200/2.5 and much lighter on top. It is really a sharp lens and due to its size can reside in the bag almost all times.
I completely agree with your experience, that with long you very often use MF anyway. There are often too many features in the field of view (twiggs or whatever) that make AF unreilable and AF is my preferred method than as well.
Ben
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Forum: Lens Clubs
10-01-2011, 09:18 AM
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I have used the KT6-2x with several lenses. It is mediocre in general, but a good match for a few old lenses, like the K 300/4. The later Pentax -L and -S modells are much better, especially the -L convertes, though they can only be used with a few lenses.
Ben
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Forum: Lens Clubs
09-06-2011, 12:54 PM
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The 60B can be handheld - not easily, but it works. You just need some time to get used to it, during the first weeks, the images will turn out blurred a bit (I needed app. three months, until I started to get sharp handheld images out of that lens).
All in all the best thing about a 300/2.8 in my opinion is, that you can use it with the tcs ands still retain reasonable speed for focusing. I mostly use the 60 B with either the 1.4x or 2x Pentax L converters and both work great.
So, I find a 300/2.8 preferably in principle. BUT the one caveat is, hauling that thing around. If you intend to walk with your equipment or simply make longer hikes with it, it is a real burden. For these occassions I prefer the diminutive A 300/4, which is sharp enough for my needs.
Ben
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Forum: Lens Clubs
06-01-2011, 12:25 PM
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For the Tammy I use the LowePro lens case 5S - a perfect fit. The tc goes into a smaller bag, strapped to the 5S. The same clens case also fits my Bigma, though it is a bit wide for the Bigma.
The Pentax 500/4 goes into a LowePro LensTrekker 600, which offers enough space for the camera body and straps to attach additional pouches for smaller lenses.
The A 400/5.6 is the only real problem, because it is long, but very slim. I can force it into my LowePro Slingshot 300. It fits easily in the Billingham 550, but blocks access to the smaller lenses, lying under the 400. For long travels it fits easily into a LowePro Classik Trekker backpack, though - together with a tremendous amount of other equipment.
I use hard cases only for storage at home or when travelling by car with the LF equipment.
Ben
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Forum: Lens Clubs
04-23-2011, 08:20 AM
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The L-modell fits the A 400/5.6, but does not seem to fit the M 400/5.6. Even on the A it is a tight fit and one needs to overcome some reluctancy and excert some force - but it works without damage.
Ben
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Forum: Lens Clubs
10-04-2010, 01:31 PM
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An 800mm lens will be an 800mm lens on your camera. That's he short version. The longer version is, that on a APS-C camera (like our Pentaxes) the 800mm lens will have a similar field of view a 1200mm lens will show on an full frame (aka 35mm) camera,
It does not matter at all, whether this 800mm lens was originally made for 35mm, 645 or 6x7.
Ben
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Forum: Lens Clubs
10-04-2010, 08:30 AM
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The tape works nicely. I use it on my 500/4.5 and also on an older tripod. It has no sticky adhesive and also makes the lens comfortable to hold when cold and has a nice grip.
Ben
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Forum: Lens Clubs
09-23-2010, 02:19 PM
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A plano-parallel glas (aka filter) will shift the focus behind by about the same amount as its thickness. 1mm filters are fairly recent types, the older filters usually have 2mm thickness. I use internal filters (UV) in the K500 and in my Tamron 300/2.8, where it is officially part of the lens design. The Tamron is one of the few old lenses that requires a thin filter and it took me some time to find a matching one with the small 43mm thread, that would fit the small filter slot.
Ben
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Forum: Lens Clubs
06-27-2010, 12:53 PM
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Tom, birding is not my main photographic occupation, but I enjoy it immensely, if I find the time. So in my (limited) experience anything at least 400mm is advisable, 600mm being more or less perfect (which may be rather different in other locations). I use either primes, like the A-400/5.6 or the Tammy 300/2.8+ tcs or the old K500 or simply my Bigma.
All in all, I have made the experience, that with the K20 I use manual focus mainly. If birds are resting on branches, there are usually so many small details besides the bird or in the near for- and background, that the AF will lock on anything but the bird.
And in flight, birds are often small or the AF-C on the K20 will be too unrelaible to make it useful… Though, I have learned, that the AF-C on the older Pentax DSLRs works best if I set the AF-points to auto, which I usually do not do (for normal shooting I always use centerpoint AF).
May be the K7 or Kx AF is better (the Km shows already some improvement over the K20) and makes AF more usefull for birds in flight. But the locking problem with resting birds will persist.
Ofcourse the longer the focal length, the better your chances, that the bird is big enough to correctly place the AF point onto it.
Ben
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Forum: Lens Clubs
06-17-2010, 08:12 AM
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I simply do not know, whether anybody finds this helpful. I for once have never used that and I have very, very rarely seen any reference to that "magnification" in photographioc books ar mags. Magnification is a term much more related to visual observations with binoculars or telescopes. In binos it is indeed part of the specs, wheras I have seen it only a handful of times mentioned in photographic lens specs during the last three decades.
I find focal length in mm much easier to understand. But as with many other things, this is a personal preference.
Ben
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Forum: Lens Clubs
06-17-2010, 03:30 AM
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The "magnification" is just a convenience tool. It has no real meaning. If you say, the 400mm lens has an 8x magnification, you would compare it to a 50mm standard lens on 24x36mm film format. On APS-C you could base the magnification factor on a standard lens of 30mm and would get something like a 13x magnification or you would simply use the crop factor of 1.5x, as wildman did and get 12x magnification.
And is you use the 400mm lens on a 645 camera where a 80mm lens is the standard lens, you would only have a 5x magnification lens.
So the "magnification" is somewhat arbitrary and wholly dependent on the calculation base, i.e. the standard lens you use as the base.
I personally never used that "magnification factor", as it has really no meaning. THe real measure is the focal length of the lens.
Ben
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Forum: Lens Clubs
06-16-2010, 02:28 PM
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The Lens Discussion Forum is the right place, I would assume. And if I read the answers correctly, you got the right answers already:
The lettering on the lens barrel for the distances has nothing to do with the optical abilities of your lenses. It has more to do with the available printing space on the tube and it has something to do with the mechanical build of the lens. The focusing threads have different throws and if you have a fine pitched thread, you need to turn the focusing ring much more to span a given distance, than on a coarsely pitched thread.
The finer thread would then invite the lens makers to make a more detailed distance scale, wheras a coarser thread will be accompanied by a matching distance scale, which is not as detailed.
Any normal lens* will focus between its nearest focus point to infinity steplessly, in infinity increments. The distance scale is only a visual aid for the photographer when handling the lens.
Ben
* we will ignore fixed-focus lenses or lenses with only a couple of distinct distance settings, which you may find on cheap compact cameras at times…
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Forum: Lens Clubs
05-20-2010, 02:55 PM
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Sounds a bit complicated and there is a basic problem with your guess:
You look through a lens which has a certain aperture. Whether this lens has a short or a long focal length or whether its image circle is small or wide, does not change the relative aperture - and thus all lenses of the same aperture (assuming you look through it wide open for focusing) will provide exactly the same illumination level at the sensor or viewfinder plane (apart from small variations due to numbers of internal lenses, coating etc.)
Ben
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Forum: Lens Clubs
05-20-2010, 01:40 AM
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The increased brightness, you perceive, is probably due to the nowadays much brighter viewfinder screens. The MEs is really old now and the screens much duller than later modells. There was also a marked improvements in screen brightness i the 1970s/80s, for example between the screens for the MX and LX, where the later are so much brighter, that Pentax had to adjust the metering system in older MX's, if one wanted to use the newer LX screens with it. (Or with Intenscreens.)
The pentaprism of these old days has not really been improved, because there is not much to improve, as coatings play a secondary role for this type of prism.
On the other hand, the smaller Pentax DSLRs do not have a prism finder, but one built with mirrors, which reputedly are darker than prism finders. I do not really know that, as I don't have a camera with a mirror finder. But it might well be, that the smaller size of these mirror finders somewhat offsets the lower illumination, contrasted with more black space around in (proportionally).
Ben
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Forum: Lens Clubs
05-18-2010, 05:00 AM
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The more interesting it would be to have a description of the conversion process! Sounds extremely alluring.
Ben
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Forum: Lens Clubs
05-18-2010, 12:25 AM
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Something like that is, what I feared. Not much use for a 300/2.8, if you can'
t close the aperture… I must will look for a listing of all the FD lenses, to see, whether it is worth to further investigate the adaption.
Ben
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Forum: Lens Clubs
05-17-2010, 01:20 AM
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Oula, it would be great if could open a thread about your conversion. Have you made images of the process? I was already wondering about Canon lenses on K-mount, as Nikon seems to be the easy route, but is often still quite expensive, even for old glass. The most cost-effective solution ion all probability would be to use FD lenses, though.
Ben
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