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05-09-2010, 09:00 PM   #1
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Why not a 60-250mm f2.8 instead?

If only can have the minutes of the meetings when they decided the lens should be F4 rather then F2.8 like a lot of people expected.

izzit possible that such a lens will drop sales of 50-135 f2.8?

05-09-2010, 09:03 PM   #2
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QuoteOriginally posted by Reportage Quote
If only can have the minutes of the meetings when they decided the lens should be F4 rather then F2.8 like a lot of people expected.

izzit possible that such a lens will drop sales of 50-135 f2.8?
#1: Size. #2: Cost.
05-09-2010, 10:09 PM   #3
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Yeah, I doubt a 60-250/2.8 would have even been considered. There are no 4X f/2.8 zooms I am aware of (but I'll bet someone will correct me on this if I'm wrong!). Assuming it's even possible, as much larger and more expensive as the 60-250/4 is compared to the 50-200, that's about how much larger and more expensive still a 60-250/2.8 would be compared to the 60-250/4.
05-09-2010, 11:49 PM   #4
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Maybe they should make the DA*100-300/4 or 135-350/4 as the existing offers overlap each other, and the 60-250/4 doesn't seem popular (though partly due to SDM which Pentax should drop asap imho).

05-10-2010, 12:46 AM   #5
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On the left, the Pentax SMCP 50mm f/1.7. On the right, the Pentax SMCP 50mm f/1.2 you will notice that one lens is much bigger than the other. The question is, which one would you most likely want to drag around with you every day for a month?

The same rules apply for zoom lenses especially fast ones as the speed goes up so does the size....the the DO technology from canon was surprising...but those lenses have bokeh that reminds me too much of the bokeh produced by mirror lenses.

Last edited by Digitalis; 04-29-2011 at 05:09 AM.
05-10-2010, 01:05 AM   #6
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QuoteOriginally posted by Reportage Quote
If only can have the minutes of the meetings when they decided the lens should be F4 rather then F2.8 like a lot of people expected.

izzit possible that such a lens will drop sales of 50-135 f2.8?
Size, weight and cost.

An f2.8 60-250 lens would require a front element of at least 90mm, which would not only mean that the lens was big, but also that it would be heavy and also quite costly, which is not really in keeping with the idea of APS C.

Now, if you can make a lens which is sharp wide open, then there is little need for it to be fast. Added to that, 250mm at f4 is actually quite fast when you consider that it is really a 375mm f4 lens when compared to FF, notwithstanding DOF concerns of course. Having said that, f4 at 250mm on APS C and an equivalent of 375mm on FF still has quite a narrow DOF for those times when you require a narrow DOF.

So, if we did get a 60-250mm f2.8 lens with a 90mm front element, then the cost would probably be double what the DA*60-250 f4 is now and quite possibly double the weight as well. Who is prepared to pay for that let alone lug it around as an all purpose carry around zoom? Not this little black duck!
05-10-2010, 04:36 AM   #7
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I have both the 50-135/2.8 and 60-250/4 and before I bought either one I kind of wished I could merge them together into a 60-250/2.8, even if it meant the lens was the same price as the two lenses together. But as others have pointed it would be a beast of a lens (size wise) and likely be more than the cost of both the 50-135 and 60-250 put together. As it stands now, I can grab the 50-135 when I want the extra speed (and don't need the extra reach) or grab the 60-250 when I need the extra reach (and can live without the extra stop).

Don't get me wrong, there are times when I wish the 60-250 was just a little faster or that the 50-135 had just a little more reach. But for (hypothetically) the same amount of money I could make an argument why having the two seperate lenses makes sense given the physical size a 60-250/2.8 would be.
05-10-2010, 05:18 AM   #8
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If you want a f2.8 60-250, why not get the f2.8 50-135 and the f2.8 200 mm? You'll have a good part of the same range covered, for much less than what the hypothetical ultrazoom would cost and weigth.

05-10-2010, 07:01 AM   #9
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its math time

If you consider cost and weight look at what F4 vs F2.8 really does

To meet F4 ar 250mm you need 62.5 mm diameter front element. (probably a 67mm filter but that is just a guess)

to meet F2.8 at 250mm you need an 89.3 mm front element. Not sure about size, but probably the closest standard filter you could get is a 112mm filter. If you go that big then really the maximum focal length should be stretched out to 300mm at F2.8.

Now, I for one would love a zoom that went to 300mm at F2.8, maybe a 100-300.

Sure it would be big, but for a serious wild life photographer, it would be attractive, and it is something lacking in pentax's range, specifically anything at 300 F2.8

If you look at the other lenses in the line up, pentax has been looking to cover ASP-C equivelents for an F2.8 range, that would compare with film.

We had I believe 28-80 (or close) F2.8's in the past as well as 70-210 F2.8's. this is what the 16-50 and 50-135 replace. The 200 F2.8 replaces the 300 F2.8.

Pentax has gone to offer essentually the ASP focal length equivelents of their film range, but has stopped at a replacement to the 300F2.8. Where is the ASP-C version of a 400F2.8 (i.e. a 300 F2.8) or the replacement for the 600F4 and the 250-600 F5.6 zoom.

there are still 3 missing long lenses in the lineup. I would gladly entertain something like a 400 F4, and already have a combo (20-200F2.8 and 2x TC) that gives me 140-400F5.6, but I am sure pentax could do better than sigma if they came out with a 140-400 lens.
05-10-2010, 07:03 AM   #10
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Like the PP said, you should buy the DA* 50-135mm f2.8 and the DA* 200mm f2.8. I have both and really don't feel the need to buy a zoom such as the DA* 60-250mm f4. To be honnest, I don't even feel the need to buy the DA* 300mm f4 since I use my DA* 200mm with a Pentax AF 1.7 adapter with very good results. I also often crop the photos taken with the DA* 200mm and obtain excellent results. Now, hopefully, Pentax will come up with an f4 super tele prime or zoom to complete my collection.
05-10-2010, 11:09 AM   #11
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QuoteOriginally posted by Blue Quote
#1: Size. #2: Cost.
Agreed. For example, look at the Canon 70-200. It comes in f/2.8 as well as f/4 flavors:

EF 70-200mm f/2.8L IS II USM: Weight: 1490g, Price: $2,499
EF 70-200mm f/4L IS USM: Weight: 760g, Price: $1,189

so in this case, 1 stop of max aperture costs double the weight and double the cost.

I think Pentax was smart to go for f/4 on this lens. As Marc indicates, it allows them a wider zoom range (at the cost of a moving barel though), and it keeps the weight and cost within reason for a broader range of customers.

Last edited by PentaxPoke; 05-10-2010 at 11:16 AM.
05-10-2010, 12:15 PM   #12
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Another size/cost comparision

Sigma 100-300mm f4 1440gms ~1000 82mm front filter
Sigma 120-300mm f2.8 2600gms ~2200 105mm front filter
05-10-2010, 12:25 PM   #13
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QuoteOriginally posted by PentaxPoke Quote
Agreed. For example, look at the Canon 70-200. It comes in f/2.8 as well as f/4 flavors:

EF 70-200mm f/2.8L IS II USM: Weight: 1490g, Price: $2,499
EF 70-200mm f/4L IS USM: Weight: 760g, Price: $1,189

so in this case, 1 stop of max aperture costs double the weight and double the cost.

I think Pentax was smart to go for f/4 on this lens. As Marc indicates, it allows them a wider zoom range (at the cost of a moving barel though), and it keeps the weight and cost within reason for a broader range of customers.

PentaxPoke, Have you considered launching one of these into the Stratosphere?
05-10-2010, 01:03 PM - 1 Like   #14
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QuoteOriginally posted by Blue Quote
PentaxPoke, Have you considered launching one of these into the Stratosphere?
not a 70-200. I think the focal length is a bit long, and motion blur would be even more of a problem. I think next time we launch it will be with a wide-angle rectilinear, just to try something new.
05-10-2010, 02:53 PM   #15
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Tamron made a 28-105mm f/2.8, but it was almost universally recognized as a dog. (I know thats only 3.75x, but its close to 4x)
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