[enyaw]

Please answer wildman's query first. I needed to know sharpest because I need sharpest. I know about bokeh. It's for pseudo macro and flowers etc. That's what I'll be shooting mostly. Thanks for all the input

[photoptimist]

@ wheatfield, thanks but that would take quite awhile. and I thought each lens has a sweet spot so to say. I'd be happy with that instead of shooting 100 pics just to see where each lens is sharpest and I might even get that wrong. Normhead thanks for the link to that lens site, I'm going to bookmark it. I'm looking for center sharpness or the highest # on the scale that you pasted in your response. That is what I'm aiming for. rawr I'll look at those sites too. I think I'm well armed now

thanks,

ps, I thought those lens testing sights were to be taken with a grain of salt because their results/comparisons aren't consistent. ie diff bodies, diff..... etc

Yes, any lens testing site (or anyone's statements about their experience with any lens) must be taken with a grain of salt because lenses vary from copy to copy. Your copy of the lens may have a different sweet spot than their copy. As labor intensive as it is, the only way to know the true sweet spots of your lenses is to test your lenses. (You'll want to test your lenses anyway to ensure they all live up to your requirements for sharpness).

Also, there's lots of definitions of sharpness. The aperture that creates the sharpest pictures of stars might not be the aperture that creates the sharpest picture of a page of text. And sharpness might vary with distance -- the sweet spot might be different at infinity versus the minimum focus distance.

One solution is to use aperture bracketing on critical images -- taking pictures with different apertures on either side of the the rule-of-thub sweet spot.

[Wheatfield]

@ wheatfield, thanks but that would take quite awhile. and I thought each lens has a sweet spot so to say. I'd be happy with that instead of shooting 100 pics just to see where each lens is sharpest and I might even get that wrong. Normhead thanks for the link to that lens site, I'm going to bookmark it. I'm looking for center sharpness or the highest # on the scale that you pasted in your response. That is what I'm aiming for. rawr I'll look at those sites too. I think I'm well armed now

thanks,

ps, I thought those lens testing sights were to be taken with a grain of salt because their results/comparisons aren't consistent. ie diff bodies, diff..... etc

Some of this stuff really is work. You have the choice of doing it yourself and knowing the results, or letting someone else do it for you and pretending you know, while having learned nothing.

[enyaw]

I'm going to do 2 lens this Friday. My zooms Tokina 80-400mm and Nikon 70-300mm start from 5.6-11 and be happy with that. Those are my birding lens, not the ones listed. They are Nikon lens. Probably shoot a sign and use a monopod.

[clickclick]

I'm going to do 2 lens this Friday. My zooms Tokina 80-400mm and Nikon 70-300mm start from 5.6-11 and be happy with that. Those are my birding lens, not the ones listed. They are Nikon lens. Probably shoot a sign and use a monopod.

Use a tripod, get it setup, and just change the lenses. The more control you put into up front, the better an idea you will have. Even passing clouds changing the lighting can change the look and your impression of a lens. I've found it amazing how much difference there is in color/contrast/etc. with lenses that you would think would be the same or close. And use a remote release - control as many variables as you can. Once you've done the work to setup everything, just click through each aperture if you really want to know how your lenses perform. It really isn't that much more work once the camera is sitting there on the tripod to push the remote button 10-12 times instead of 3-4 times.... It's a lot more work to have to haul it all back out and set it all up again when you realize you'd like to know more about the performance. You might find you really want to know the wide open performance as you're chasing a bird with a telephoto and need a higher shutter speed to eliminate blur from motion.

[enyaw]

I'm going to use a tripod, but I don't know about the remote. I decided not to use the monopod. They are both zoom lens and I'm interested in the long end performance. Is 5.6-11 enough or should I go higher to 15? Friday is supposed to be sunny. What if I use 2 second delay as well? When I'm actually out shooting I will be using the Monopod without the delay and I won't have the remote.

[clickclick]

I'd say once set up, go all the way - shoot every aperture you've got. Any/everything you can do to take variables out like shake, e.g. by using remote, tripod, mirror lockup with delay, etc. will give you better info. And remember, you're trying to figure out what the lens is capable of, so even though you might go out with the monopod, the more you can do to make your test shots without variables, the better info you'll have about what the lens is capable of. I've found myself running the gamut on aperture and shutter speed while birding. Sometimes it's dimmer than you think, you need it wide open, and you can barely hold it steady enough. Then next thing you know, it'll be bright sun, and you need to stop it way down. Some lenses hold pretty consistent though the range of apertures, and others will really get crisp/go fuzzy at certain points. And each copy of a given lens will be different. Also, look at the results, and if they don't make sense, go shoot it again. I'm doing some comparisons of an SMC 15 Limited and an HD 15 Limited right now, and just did some shots that didn't make sense. Set everything up again, retook them, and the results the second time around made more sense. First batch with the HD 15 were too soft based on past experience. What did I do wrong? Not sure, but more tests will be done tomorrow sorting it out. Crazy? Perhaps, but if suffering from LBA, might as well get your money's worth.

[normhead]

I'm going to use a tripod, but I don't know about the remote. I decided not to use the monopod. They are both zoom lens and I'm interested in the long end performance. Is 5.6-11 enough or should I go higher to 15? Friday is supposed to be sunny. What if I use 2 second delay as well? When I'm actually out shooting I will be using the Monopod without the delay and I won't have the remote.

Use some kind of target, maybe something with lettering on it. Back the lenses out 10 feet at a time. 5 test images for each lens ,manual focus the lens out to infinity after each image, make it seek focus all over again each time, unless it's a manual lens. With a manual lens focus as best you can come a little closer and then do five very small turns of the lens to focus through the optimal focus point.

If you want to know what the best the lens can do is you''ll shoot ƒ4, ƒ5.6 and ƒ8 at each position. The two second delay is essential, watch the tripod to make sure it isn't vibrating in the wind. If you can't find anything with lettering at least go for something with texture, like a teddy bear with an eye you can focus on.

You won't learn anything past ƒ11 you don't already know.

[enyaw]

Thanks guys, I'll use the 2 second delay with a remote release. I was thinking of a sign. Maybe with some leaves in the background to get a feel for depth of field as well. Can't I stay in one position? ie 50/100 feet away and at max zoom? I won't go beyond f11. Refocusing was a nice tip.

ideal distance from sign, 300mm and 400mm?

[clickclick]

I can understand wanting to narrow down the distance some. I'd go for what you anticipate to be representative of what you'll really shoot. So if you plan on hanging out on the back porch with a bird feeder 20 feet away, then I'd do something like that, but I'd also run through a set at something approaching infinity. I've got a DAL 50-200 kit lens that was surprisingly good at 15 feet or so, and really sucks at infinity. It was definitely worth the effort of shooting some close up test pictures as well as some infinity ones with that lens - I really was expecting more out of it at infinity based on what it did close, which was better than I expected. In fact, it was so far off my expectation at infinity, I feel like I should run through some more shots just to be sure I didn't mess up. Back to why the tripod, remote release with delay etc. all becomes important in narrowing down the variables. Lens testing can be obsessive, but it also can be pretty interesting and fun once you wrap your head around it.

[BrianR]

Ideally the distances from the sign should reflect how you plan to use the lenses. But as a default, you might try them at their minimum focusing distances and move back in steps of 5 to 10 feet or more (you can definitely increase the step size as you move back, performance at 40' and 50' won't be vastly different). Keep in mind that as distance increases, so does the effect of atmospheric conditions (e.g. heat shimmering), so a calm clear day is ideal.

If you clamp a ruler to the sign, you can get a more accurate idea of the magnification you're getting at given distances, and you might even clamp objects that represent the size of the things you plan to photograph to the sign.

[enyaw]

BrianR, that is another good idea. Why don't I bring something from home and put it on a park bench and try to photograph it. Why don't I bring a test chart that i printed out it's 8 x 11 black and white. And I don't know what I'm supposed to be looking for lol? I printed out 2 diff kinds. I don't want to get too in depth. Just a fairly good idea of where each lens performs best. As I get better. I might get into more depth.

[enyaw]

as far as I can see pun intended. the results are as follows

nikon 75-300mm f4.5-5.6 (f8-11) f13 degrading

Tokina atx 80-400mm f4.5-5.6 ( f7-13)

sigma 150-500mm f5-6.3 (f9-13) stopped all tests at f13, shot a sign in a park surrounded by trees. 2 sec delay with a remote on a tripod

[photogem]

Don't shy away from your M42 primes. Assuming they are Pentax, you probably have some nice lenses there. Do get a real Pentax adapter if you don't have one already. It's tempting to buy a cheap one of eBay. You really do get what you pay for. I have a real one I bought years ago, and decided to grab a cheap one just to see. No comparison. Even though pricey, the Pentax adapter is worth it.

I have 3 original Pentax M42 adapters and I have about a dozen cheap chinese ebay adapters.

Yes, the original (quite expensive) Pentax is the very best and I would recommend just this one if one is going to change the adapter every time onto a different M42 lens.

BUT: I use many M42 lenses (mostly Takumars) and I love them. I simply modify those cheap chinese adapters by inscrewing this tiny spring which is not needed if one accepts that then the lens will sit slighty off on the body.* I never encountered any problems doing so but I can use my Takumars
like K lenses and I don't need the green botton methode but can use the Tv auto-mode.

I don't want to change the adaptor each time, those chinese adaptors are that cheap that it is worth using them on all M42 lenses.

*with very very few old lenses one has to be careful because they could sit/sink too deep into the body though!

[clickclick]

I have 3 original Pentax M42 adapters and I have about a dozen cheap chinese ebay adapters.

Yes, the original (quite expensive) Pentax is the very best and I would recommend just this one if one is going to change the adapter every time onto a different M42 lens.

BUT: I use many M42 lenses (mostly Takumars) and I love them. I simply modify those cheap chinese adapters by inscrewing this tiny spring which is not needed if one accepts that then the lens will sit slighty off on the body.* I never encountered any problems doing so but I can use my Takumars
like K lenses and I don't need the green botton methode but can use the Tv auto-mode.

I don't want to change the adaptor each time, those chinese adaptors are that cheap that it is worth using them on all M42 lenses.

*with very very few old lenses one has to be careful because they could sit/sink too deep into the body though!

I have two of the Chinese adapters that fit flush, and I have removed the springs. They still bind. Close examination reveals that there is metal on the side of the adapters that was only partially machined away when compared to the Pentax adapters. So, I would say proceed with caution, as the quality appears to vary. And of note, I have two of the flanged adapters, and they can just spin in the camera when trying to remove them (no "stop" so the alignment of the flanges to remove is sketchy at best), plus they are no good with most lenses if you need infinity focus. I would say proceed with caution. YMMV