Why I dont like fixed aperture zoom lenses..

Msmoto

The subject....Why folks do not like fixed aperture zoom lenses....mmmm....

heartyfisher

There was a question asking me to substantiate a statement i made. But I cant remember where that was and we were discussing something else at that time.. so I will put it here as it is some what related.

The statement I made I believe was to do with the lenses manufacturers not taking advantage of the DX format and producing lenses with wider apertures than the FX format cameras. I suggested that due to the smaller Image circle you can produce DX lenses with a wider aperture than the FX equivalent..

The only "evidence" i really have is circumstantial. Although i have a "gut feeling" that there is a real physical explanation .. I will need to think it through a bit more before I can present a theory.. However, the evidence I have is as follows.

* For M43 cameras that have an even smaller sensor than DX, they are producing lenses that are up to 1 stop or more brighter than their FX equivalents .
** eg ; Olympus : 50-200mm f2.8-3.5. FX equivalent to 100-400 which are about 4.5-5.6 aperture

* The Fujiflim DX sensor lenses like the 18-55 are F2.8-F4 and the 55-200 is F3.5-F4.5. the nikon DX equivalent lenses are half to 1 stop disadvantaged.

In both these cases they do not need to produce "weaker" dx lenses to "protect" the PRO FX lenses.
Note also that they are variable aperture lenses and therefore taking advantage of the wider focal lengths to produce wider apertures. Ie they are not "hamstringing" the wider end artificially.

Msmoto

I am going to guess one of the reasons the DX format lenses are not faster, taking advantage of the smaller coverage needed, is almost entirely an economic decision. The majority of DX users are using cameras which are far less expensive than the full frame counterparts. One can purchase a D3200 which will be an excellent camera for almost all situations, and costs a few hundred dollars. Folks who buy these want to have several lenses available and not have to pay two or three times the cost of the body.

As one gets smaller with the format, i.e., Micro 43, it becomes less costly to produce a slightly faster lens, up to a point. The Olympus 12-60mm f/2.8-4 ED SWD Zuiko Zoom Lens for Olympus Digital Cameras looks great, but costs about $1000....My Olympus E-PL2 cost me $200 at Ritz on the last day.

heartyfisher

The FX equivalent of that lens is also over 1,000.. and the Oly has F2.8-4.0 (there another +1 for Variable zoom!) vs the 24-120 F4.0.

You get the same great lens with a cheaper body ! .. that's a plus no ?
Yeah, I agree its the marketing guys that is to blame for this!

Msmoto

Well, yes....

And, I agree, getting the equivalent to the 24-120..also a lot lighter weight, mmmm maybe I need to think about this. I really like the Olympus 14-35mm f/2.0 ED SWD Zuiko but this is $2400. Or the Zeiss 28-80mm T2.9 Compact Zoom CZ.2 Lens (MFT Mount)...but this is more than the new Nikkor 800mm

I could not find the f/2 primes for the Micro 4/3, but something in the 18-24mm prime would be nice.

Maybe I will just get the "F" adapter. Oh, new thread....