Pentax Has No Long Lens
Regards
Add to that a 1.7x T/C and you have a 765mm equivalent lens.
There was a super-telephoto lens planned, it used to be on the roadmap. I haven't looked lately.
Let's not forget the 1.5x crop factor. The DA* 300mm lens has a film equivalent FOV to a 450mm lens (close enough to 500mm for me).
Add to that a 1.7x T/C and you have a 765mm equivalent lens.
There was a super-telephoto lens planned, it used to be on the roadmap. I haven't looked lately.
This topic keeps popping upfrom time to time.
If we say a 300mm lens apears to bring a subject 6 times closer and a 500mm lens brings it 10 times closer, how, by selecting a smaller image size (croped) do we change the magnification factor?
FOV is equivalent but not object image size on any sensor for a given distance. I still work on actual lens focal length.
Always an issue topic this one. Nikon have bodies that auto crop for digital only lenses, that does not alter the actual object image on the sensor. True, the object image covers more area of the sensor if cropped size but then you print up to standard sizes and bring in the 1.5x factor.
I'll stop here before I confuse myself and loose the point.
Best regards
It might help a bit if there was a good one generally available.
There is quite a bit of rumour that a DA* 400mm f5.6 may be coming.
Put my name down for one please, but you'll excuse me if I don't hold my breath.
Is the 600mm f4 still available to special order? £7000 or so?
For those who can afford them there are offerings on eBay from maybe £1000 to £1500 that would fit the bill, although maybe not the pocket.
FOV is equivalent but not object image size on any sensor for a given distance. I still work on actual lens focal length.
Always an issue topic this one. Nikon have bodies that auto crop for digital only lenses, that does not alter the actual object image on the sensor. True, the object image covers more area of the sensor if cropped size but then you print up to standard sizes and bring in the 1.5x factor.
Quite true but you base your focal length on what they do on 35mm since you're used to that.
What if someone is shooting whit a 6x7 camera, for him a focal length of 90mm is standard and 300mm is nothing special.
a 400mm f/5.6 would be welcome addition to pentax, Don't think we need or will see a exotic 600mm f/4 and such lenses.
@John, the 600mm f/4 is now discontinued, at least it listed there on the Japanese site.
The price is 1,417,500 yen (£9535)
I'd cheerfully settle for a DA*400 f5.6 or maybe a DA* 100ish - 400.
FOV is equivalent but not object image size on any sensor for a given distance. I still work on actual lens focal length.
Always an issue topic this one. Nikon have bodies that auto crop for digital only lenses, that does not alter the actual object image on the sensor. True, the object image covers more area of the sensor if cropped size but then you print up to standard sizes and bring in the 1.5x factor.
Quite true but you base your focal length on what they do on 35mm since you're used to that.
What if someone is shooting whit a 6x7 camera, for him a focal length of 90mm is standard and 300mm is nothing special.
a 400mm f/5.6 would be welcome addition to pentax, Don't think we need or will see a exotic 600mm f/4 and such lenses.
@John, the 600mm f/4 is now discontinued, at least it listed there on the Japanese site.
The price is 1,417,500 yen (£9535)
I think we agree?
A 300mm lens on a 35mm is then enlarged by whatever the ratio is, up to 6x7 or there abouts. Do we then say that the 300mm lens is equivalent to 300mm x the ratio? Focal length of a lens is, I believe, fixed. What we do with it's projected image surely cannot alter that?
There has to be a huge difference of course as 35mm is too far off 6x7, where as cropped and 35mm are relatively close
Best regards
What the K10/K20 were good at was being a studio camera. And that is why Pentax concentrated on the prime lens market.
N and C already have the range - why compete until you have a camera that can compete?
I prefer that Pentax spend R&D on improving their cameras then increasing their range of current lenses beyond the 300mm.
Oh, and the old lenses still work perfectly - built to last.
Lenses: DA*16-50, DA18-55WR, DA18-135, DAL35, M50 F2, A50 f1.4, FA50 f1.4, DA*50-135, DA55-300, Tamron 70-300, DFA 100 WR Macro, M135 f3.5, Sigma 120-400 APO DG HSM, Tokina 500 f8.0
Flash: Metz 58, Metz 48
Accessories: BG4, Pentax right angle finder, Pentax mirror adaptor lens, O-ME53 Viewfinder Loupe
Auto 110 System: Auto 110, Winder, 18mm, 24mm, 50mm, 70mm, 20-40mm, AF100P, 1.7x telecon
I think we agree?
A 300mm lens on a 35mm is then enlarged by whatever the ratio is, up to 6x7 or there abouts. Do we then say that the 300mm lens is equivalent to 300mm x the ratio? Focal length of a lens is, I believe, fixed. What we do with it's projected image surely cannot alter that?
There has to be a huge difference of course as 35mm is too far off 6x7, where as cropped and 35mm are relatively close
Best regards
Yes it seems we are thinking the same
The focal length is fixed and the projected image stays the same.
The equivalent focal length is only to get the same AOV.
AOV is important because that's relative to the sensor size and how big on object is on final print (or relative to the sensor).
I'm quite against using equivalent focal length since most users have never had a SLR so they have no idea what a 300mm lens does on that, it's better to forget and simply go with your experience.
To be honist, I am not surprised that Pentax don't currently offer any lens beyond 300mm. Until the Pentax K-7, the shutter/mirror noise was too loud for nature photography and the focus too slow for sports.
I can't really agree with that though, how on earth would we have photos of sport 50 years ago while there wasn't any AF to begin with.
And the shutter sound doesn't carry so far to scare the birds away
Pentax probable didn't make a lens longer then 300mm since their would not be so much demand for that. They probable though it was more important to get the 60-250 out and the 200, 300, 17-70, 55, etc. I believe they did the right thing to be honest.
They now have a solid digital lens range so they can now focus on the bit more exotic lenses.
In reality, they were (and still are when they crop up second hand) just the same sort of price as Nikon and Canon lenses of similar spec. Nikon and Canon users probablt don't spend thousands on their lenses either, but buy Sigma and others. Still expensive but more affordable.
Likewise, you can get these lenses in Pentax fit. I think the idea that we can't get long lenses for our Pentax DSLRs is a bit of an illusion really.
Today I went to SRS at Watford and purchased a Sigma 150-500 APO Lens. They let me test it with my camera and I was pleased with my first impressions of the 500mm performance.
Whilst I was in SRS I looked at a secondhand 500mm SMC Takuma M42 mount and a Sigma 400 manual K mount. They certainly are friendly in SRS.
When I got home I tested the 500mm performance of the Sigma 150-500 APO by photographing coins blue-tacked to the shed door at 10 feet distance. I was pleased with the performance at f8 or f11 with a shutter speed of at least 1/90th, on a Manfrotto. I found that my existing tripod head is not sturdy enough, so I will invest in another.
Graham
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475 posts
22 years
Birmingham UK
Those photographers with Pentax Systems who desire a long lens, have to rely on Sigma, with the 80-400, 150-500 or 50-500. There appears to be no other options, unless you change systems. The Tokina 80-400 is not produced in Pentax mount.
If Pentax cannot develop their own, surely Pentax could collaborate with Tokina and produce a Pentax variant of the Tokina 80-400.
I am currently looking for a long lens and will have to buy a Sigma.
Graham