Pentax-DA 560mm F5.6 ED AW

Started Mar 28, 2013 | Discussions thread
awaldram
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Re: Pentax-DA 560mm F5.6 ED AW
In reply to Tom Lusk, Mar 28, 2013

Tom Lusk wrote:

Hi Eric:

Looks like I was confused by the wording.

I'm with you on the "equivalent" deal.

Whenever I read that someone needs more "reach", so prefers not to use a full frame camera with the same size lens, I shake my head.

Given pixel density and sensor size the statement holds water.

You need a 36mp FF to achieve the same 'reach' as a 16mp aps-c with the same lens @ the same resolution.

This lens appears to be a non-starter for me.

My Sigma 500 doesn't require using f8-11 for maximum sharpness, which is a good thing since I rarely get good enough light to shoot such apertures and maintain an appropriate shutter speed.

You must have a special version then, The only lens I've ever come across that isn't at peak 1-2 stops down form max aperture is the da 40 Limited a unique trait of that one lens.

Your Sigma appears slightly below  standard in that respect peaking at f8-11 just like the Pentax as this Resolution chart clearly shows which from an f4.5 start point is unusual should be f6.3-f7.2 but the graph is pretty small so maybe wrong.

http://www.ephotozine.com/article/sigma-500mm-f-4-5-apo-ex-dg-interchangeable-lens-review-4553

The CA as exhibited in some of the sample shots would be a pain and, as I don't use a tripod, the comment about the balance of the lens is discouraging.

Sigma are the masters of CA control whereas Pentax always are weak in this area.

I think they'll have to drop the price significantly, in order to get a decent amount of sales.

No price will achieve decent sales they can sell 1 or 2 @$7000 or 1 or 2 @$5000 it already at the low end for an OEM telephoto, to low and its into the 3rd party range so would lose all the prestige buyers.

It's a niche product and not price critical.

 awaldram's gear list:awaldram's gear list
Pentax Q Pentax K-3 Pentax smc DA* 55mm F1.4 SDM Pentax smc DA* 16-50mm F2.8 ED AL (IF) SDM Pentax smc DA* 50-135mm F2.8 ED (IF) SDM +11 more
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