Visit MPB Visit MPB Visit MPB

Long Pentax Lenses

johnriley
Posted 01/02/2011 - 19:26 Link
There's no doubt that there's a demand on this forum for longer Pentax lenses.

Has anyone tried a 645 lens with the 645 K adapter?
Best regards, John
Dangermouse
Posted 01/02/2011 - 20:19 Link
I've looked at those adapters and the 6x7 one too - do they involve any glass or are they simply an extension tube? I'd imagine you'd get pretty impressive results assuming the latter!
Matt

Shooting the Welsh Wilderness with K-m, KX, MX, ME Super and assorted lenses.
johnriley
Posted 01/02/2011 - 20:23 Link
They are just plain adapters, so I thought there might be some potential in the idea as there are lots of 645 telephoto lenses.
Best regards, John
hefty1
Posted 01/02/2011 - 21:14 Link
I have access to some FA645 lenses but not an adapter - they're not exactly cheap unfortunately...

All the 645 lenses I've tried have been excellent performers on their native platform so I'd think they should be just as good on a DSLR. Maybe a little on the heavy side though.
Joining the Q
johnriley
Posted 01/02/2011 - 21:44 Link
True, but to be fair a long lens for DSLRs isn't going to be cheap either.
Best regards, John
hefty1
Posted 01/02/2011 - 22:44 Link
I know. What I meant was the adapters aren't cheap (rather than the lenses which generally are quite good value - especially the 6x7 ones).

A friend of mine has quite an extensive 645 outfit, built up at a combined cost similar to what you'd pay for a single DA*300. I intend putting my bargain-hunting skills to use in assembling a similar 67 kit over the course of 2011
Joining the Q
JForeigner
Posted 01/02/2011 - 23:03 Link
I have one long 645 lens to overcome the lack of a 300mm plus lens. It took me around a year of hunting on the net to find the adapter at what was a reasonable price to what I have seen them going for. £70 is still a lot of money for what it is, but it works fine. There is no glass involved, just metal. Of course everything is manual, but if you can live with that it works well. The lens is big and slow to use when compared to an auto everything lens. Use the green button, and away you go.

Gary
Armed with a K3, some M, A, FA, DA, and star lens. With an eye open for "just one more lens".

My PPG link
MrCynical
Posted 01/02/2011 - 23:10 Link
johnriley wrote:
True, but to be fair a long lens for DSLRs isn't going to be cheap either.

Even Canon's 100-400 is £1300, which means about 2 grand in Pentax prices
Edited by MrCynical: 01/02/2011 - 23:10
cabstar
Posted 01/02/2011 - 23:10 Link
those 400mm f4 lenses are looking tempting with an adaptor...
PPG Wedding photography Flickr
Concert photography

Currently on a Pentax hiatus until an FF Pentax is released
SmutjeUK
Posted 02/02/2011 - 08:34 Link
Would the focal ratio different from the 645 when using a K-5? I do like the idea as I am really looking for a quality long lens but the F*250-600 is way out of my reach. I know there is the Bigma 150-500 but I rather would have something Pentax.
So, what would I be looking for? Does the adapter gives me Aperture Automatic or even the full AF and f range?
What 645 lens would I be looking for for the long range? Is there a factor I would have to calculate in for the focal range. Does the aperture stays the same or does it changes?
Sorry for all those questions but this is the first time I heard about this idea and I like it but really need much more info.
Any help with this would be welcome!
Kind regards
SmutjeUK

It's nice to be nice!

Pentax K-5 with D-GB4 Grip, to many lenses to mention by now (serious LBA by now), TC's, Lowepro Slingshot 300 AW, Manfrotto 028 & Redsnapper RS-283 with various Heads plus various Camera Clamps (I collect them). Pentax AF 360FGZ, Pentax AF 240FT, several Metz 45 CT-1 & 5 with stands and 'Blow Up' Soft Boxes, Flash Triggers, and various Macro gear.
thoramay
Posted 02/02/2011 - 09:25 Link
I have been using both pentax and mamiya 300mm and 500mm medium format lens on the K5 with an adapter. I am pleased with the results.
The pentax adapters are very expensive. I have bullied the far east adapter concerns to produce a similar adapter for Pentax. This is what I am using. I think it cost under £40.
Those who know these things tell me that the colours are very good but soft.
I now have the Pentax 300mm lens. When the weather changes will do a side by side test and maybe post the results.
thoramay
Posted 02/02/2011 - 09:37 Link
As a follow up. The 645 pentax MF lens is the Ed If F4 and is manual focus. I have tried the pentax 1.7 adapter that should in theory turn this into auto focus but it would take a better photographer that I am to get tnis to produce satisfactory results.
This lens is hefty in comparison to the Pentax 300mm and does take a lot of handling to get sharp results. The mamiya 500 lens is even heftier but is is fun to try these things.
Algernon
Posted 02/02/2011 - 09:38 Link
There's a lot of moaning about Pentax not doing 400mm+ lenses, but when they actually go on sale there's very little interest A few have gone though ebay and there's still a Pentax-A 400mm f5.6 in classifieds which has only had 344 views other classifieds have had 1000+

With better Camera IQ it's possible to get decent results enlarging part of the frame from a 300mm.

If you already have a 400mm there's little point in buying a 500mm because the 500mm FOV isn't a big jump from the 400mm and easily achieved by enlarging the 400mm frame.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
SmutjeUK
Posted 02/02/2011 - 09:40 Link
thoramay wrote:
I have been using both pentax and mamiya 300mm and 500mm medium format lens on the K5 with an adapter. I am pleased with the results.
The pentax adapters are very expensive. I have bullied the far east adapter concerns to produce a similar adapter for Pentax. This is what I am using. I think it cost under £40.
Those who know these things tell me that the colours are very good but soft.
I now have the Pentax 300mm lens. When the weather changes will do a side by side test and maybe post the results.

Where do you get the Pentax and Mamiya adaptors from?
Is the Mamiya bayonet the same as the Pentax or do you need a new adapter for each?
Are they fully manual?
Sorry for all those questions but I am really interested as I want to get a long range lens within the next 6 month or so.
It would be interesting to see a side by side comparison of those.
Many thanks for the information.
Kind regards
SmutjeUK

It's nice to be nice!

Pentax K-5 with D-GB4 Grip, to many lenses to mention by now (serious LBA by now), TC's, Lowepro Slingshot 300 AW, Manfrotto 028 & Redsnapper RS-283 with various Heads plus various Camera Clamps (I collect them). Pentax AF 360FGZ, Pentax AF 240FT, several Metz 45 CT-1 & 5 with stands and 'Blow Up' Soft Boxes, Flash Triggers, and various Macro gear.
hefty1
Posted 02/02/2011 - 09:45 Link
SmutjeUK wrote:
Would the focal ratio different from the 645 when using a K-5? I do like the idea as I am really looking for a quality long lens but the F*250-600 is way out of my reach. I know there is the Bigma 150-500 but I rather would have something Pentax.
So, what would I be looking for? Does the adapter gives me Aperture Automatic or even the full AF and f range?
What 645 lens would I be looking for for the long range? Is there a factor I would have to calculate in for the focal range. Does the aperture stays the same or does it changes?
Sorry for all those questions but this is the first time I heard about this idea and I like it but really need much more info.
Any help with this would be welcome!

The 400mm f/4 lenses for the 645 system will still be 400mm f/4 lenses regardless of which camera you attach them to - nothing changes in that respect.

What does change are the features, the lenses will be fully manual on a K-5 just as if you were attaching an old K-mount or screw mount lens to your camera. No semi-auto modes (Av, Tv, P, etc) and no AF.
Joining the Q

Add Comment

To leave a comment - Log in to Pentax User or create a new account.