[Confused]

Hi all,

Having read everyone's comments on the subject, one thing that crossed my mind is the sheer 'bulk' involved in using a full-frame digital camera by comparison to an APS-C sized DSLR. As an example, I was travelling on a ferry from Guernsey to St. Malo last summer and was casually chatting to a guy who was using a C****n IDS MkII when he kindly entrusted me with it for a few minutes whilst he went for a coffee ! Although I couldn't fail to be be initially impressed by all the bells-and-whistles and the instantaneous response of the autofocus etc, I remember saying to the wife afterwards:
"Nice camera, but there's no way I'd want to cart something that bl***dy heavy around with me everywhere. It feels like a tank !"
Some months later I briefly handled a C****n 5D at another photographic store prior to purchasing my K10D and it was just like one of those 'deja vue' moments.......precisely the same response. Simply TOO BIG and TOO HEAVY !
There may well be technical reasons why it is difficult or impossible to build a full-frame DSLR in a smaller lighter body, but until one of the main manufacturer's does so, I'm afraid that I'm simply not interested in purchasing any of the current 'leviathans', despite their much vaunted capabilities. Many years ago I was working in a photographic store and was faced with a similar conundrum, but had no foibles whatsoever about selecting the Olympus OMI system over the N****n brand for precisely the same reasons - Size and Weight (or rather the lack of it !). Funnily enough I took my K10D + Grip + Tamron 18-250mm around to show a friend for the first time last night and his immediate response was "jeez, this lot is heavy"......Go figure !

Best regards
Richard

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Last edited by Confused; 08-28-2007 at 12:52 PM.

[MikePerham]

Pentax don't need a FF sensor; what they should target is the D300. It is in that arena that Pentax can compete and if they were to offer a couple of extra's, such as the masking for 8 X 10 framing, as offerd in the D3, you would have a very competitive camera. Especially with the new lenses Pentax are introducing, and their prime lens line up.

Oh yea ...and they can follow Nikon's lead in eliminating overlap in the zoom lenses. We need a DA* 10-20 as there is too much overlap between the 12-24 and 16-50 as of now. Alternativly a prime 12mm as the 14 is a bit close to the 16-50.

Mike.

[SLC Flyfishing]

Why are all you guys so worried? Pentax has never been in direct competition with the 5D, any of the 1D's or the Nikon pro bodies. We've seen our K10D's compete very respectively with the EOS 30D and the D200, Leaving the D80 and 400D in the dust (and rain). I'm personally very very happy with my K10D and have no plans of replacing it until it bites the dust a few years down the road. When that happens I'll be buying another Pentax, simply because I've always been most happy shooting their products. The images have been fantastic and I've saved a grundle of money.

The think is that the D200 and EOS 30D replacements aren't full frame either. So why does Pentax need to release a full frame camera right now? Unless they want to enter that ring which I think they will when that 645 finally comes out.

SLC

[jms698]

Lots of people have worried that all the DA* glass will be completely useless if Pentax ever decide to go Full Frame. Not so!

In a few years time the megapixel myth will has pushed pixel density to crazy heights. After all, every new camera needs more megapixels, otherwise it won't sell, right ? So, by the time Pentax actually NEEDS to go FF, they could easily just crop the middle of a DA* lens' frame and produce a lower-megapixel image with perfectly acceptable quality. The DA*s would retain their advantage of being lightweight, SDM and weather sealed. Those that want the full effect of the full frame sensor could buy the new FF-DA* lenses that Pentax would gradually release. Added benefit: lower megapixel count on the cropped images would mean less noise, even with the APS-C lenses.

[FotoPete]

Richard (Confused) you are right about FF.

Canon and Nikon are slightly cheating with their FF. There is no way their lenses are smacking the full frame sensors efficiently at their respective flange distances.

Remember that the photosensitive chemicals in a film negative don't care what direction as long as light hits them. But pixels on a digital sensor need light as perpendicular as possible. This means that for any lens, light is hitting the corners at an angle and thus vignetting is incurred. Leica tried to mitigate this in their M8 digital Rangefinder but having the progressively offset microlenses to better capture light at the corners of the sensor plane. Olympus' 4/3rd is designed from the ground up for digital and is the only one exempt from this. Their optical formulas concentrate and direct all the light at the sensor in a perpendicular fashion. This is why even their budget lenses have good performance. Canon's on the other hand, chose to retain their lens fomula/flange distance. This is not enough distance for optimized light contact. They employ vignetting correction (before RAW file) in order to correct this.

If you need a true FF camera with the digital sensor placed optimally, you're looking at a camera as deep/big as a medium format 645 or something like that. Either way you got a BIG camera. (Unless you redesign your lens system like olympus did with their 4/3rds)

2 reasons why FF would desirable for me.[LIST=1][*]
The current models do an excellent job, as you point out. A FF pro body would be a nice addition though. Doubtful that it will happen though, as Pentax has very few current lenses that will work with FF.

And if Pentax released 9 new lenses to go with the new "FF" Pentax?

[FotoPete]

oh hell, if an FF camera came out, I'd go for it so I can get some wide angle. Been struggling with that for a long time. Even a decent 28mm equiv performance would be great.

[ebooks4pentax]

I have not read all of the answers herein, so I hope I am not repeating previous posts.

The problen began when camera companies decided that the new DSLRS should be able to use 35mm lenses. It all started with an APS-C sized sensor. That is an entirely different format. Lenses should have been made specifically to that format, without factors. The dumbest thing is that companies using the APS-C sized sensor are now making lenses specifically for them and specifically say that these lenses will not work correctly on 35mm cameras. Hello...why didn't give the correct mm size that these lenses have with the smaller sensor? Why that comparison with 35mm format all the time? Medium format users did not have to put up with a factor to compare their lenses to the 35mm format. 35mm cameras users did not use medium format lenses and say this is a 45mm in medium format cameras! It's the same with Large format cameras!

Now, back to full frame sensor. I think it makes a lot of sense. All 35mm lenses will work at their described focal length. Wide angles will be wide angles again. As for telephotos, since the sensors are now much bigger (in size and in megapixels that is) you can still crop the image and get the same results as far as 1.5 factor to telephotos, except at around 6 to 8 megapixels, which is still very good indeed. The noise will be reduced a lot with larger sensors, especially if they use CMOS sensors. They will all use CMOS soon as the prices have gone down, except of course if new technology takes over....like maybe the foveon sensor.

To compensate, most companies have produced super-wide angle lenses, that with the magnification factor still give reasonable equivalent of 20MM in 35mm format. At the end of the day, everyone has been fixing the lens problems with bandaids. What will happen when technology makes much larges sensors available at a reasonable price. You will now have all cameras sensors the size of todays medium format cameras. 35mm lens factor will not work at all then.

Yvon Bourque
k10dbook home

[MikePerham]

To compensate, most companies have produced super-wide angle lenses, that with the magnification factor still give reasonable equivalent of 20MM in 35mm format. At the end of the day, everyone has been fixing the lens problems with bandaids. What will happen when technology makes much larges sensors available at a reasonable price. You will now have all cameras sensors the size of todays medium format cameras. 35mm lens factor will not work at all then.

Yvon Bourque
k10dbook home

So Yvon, are you saying that the APS size sensors should take the place of what was 35mm , and that larger sensors should be used as MF camera's were in analouge days?

Certainly Pentax is well positioned in the market if that were the case, they seem to have committed to lenses for the APS format and have the 645D in the wings ...although the future of MF style camaras seem to be a bit dubioius these days.

Cheers, Mike.

[RBellavance]

Lenses should have been made specifically to that format, without factors. The dumbest thing is that companies using the APS-C sized sensor are now making lenses specifically for them and specifically say that these lenses will not work correctly on 35mm cameras. Hello...why didn't give the correct mm size that these lenses have with the smaller sensor? Why that comparison with 35mm format all the time? Medium format users did not have to put up with a factor to compare their lenses to the 35mm format. 35mm cameras users did not use medium format lenses and say this is a 45mm in medium format cameras! It's the same with Large format cameras!

The comparison and mention of "35mm equivalents" is from the users. The companies *are* making lenses specifically for that format (Pentax's DA, Nikon's DX, Canon's EF-S, etc), and they *are* giving you the correct focal length for the lenses. A 50mm lens is 50mm whether it is mounted on an APS-C camera (where it is a short tele), and 135 film camera (where it is a "normal"), or a 6x4.5 MF body (where it is a wide-angle). The following Wikipedia article explains the "crop factor" quite well: Crop factor - Wikipedia, the free encyclopedia Another good one is on Luminous Lanscape: DSLR Magnification

The "problem" (need to compare) probably comes from the fact that it is possible to use the same lenses on APS-C and 24x36mm bodies.

[ebooks4pentax]

The comparison and mention of "35mm equivalents" is from the users. The companies *are* making lenses specifically for that format (Pentax's DA, Nikon's DX, Canon's EF-S, etc), and they *are* giving you the correct focal length for the lenses. A 50mm lens is 50mm whether it is mounted on an APS-C camera (where it is a short tele), and 135 film camera (where it is a "normal"), or a 6x4.5 MF body (where it is a wide-angle). The following Wikipedia article explains the "crop factor" quite well: Crop factor - Wikipedia, the free encyclopedia Another good one is on Luminous Lanscape: DSLR Magnification

The "problem" (need to compare) probably comes from the fact that it is possible to use the same lenses on APS-C and 24x36mm bodies.

You are correct. Maybe I chose incorrect wording to explain my point of view. The term "standard lens" for example, is a lens that gives a normal looking perspective which is close to what the human eye sees. This occurs when the length of the frame diagonal (Hypotenuse - the square of the length of the hypotenuse equals the sum of the squares of the lengths of the two other sides.)is approximately the same as the focal length. The diagonal of a 6x7 format, for example, is about 100mm which makes a 100mm lens a standard lens in the 6x7 format. The K100D uses an APS-C format size of approximately 23.5mm x 15.7mm. A normal lens for this format is therefore approximately 33mm, or 50mm in 35mm camera format, or 73mm in 645 medium format or 90mm for a 6x7 medium format camera. If you apply this backward, a 90mm lens in the 6x7 format makes a 245mm lens in the APS-C, a factor or approximately 2.7x. The correction factors are approximate as follows: 1.5x for 35mm format lenses, 2.2x for 645 medium format lenses and 2.7x for the 6x7 medium format lenses. A 200mm lens in the 6x7 format gives an effective focal length of 540mm when installed on the K100D. The correction factors may not be 100% accurate as the numbers were rounded off, but you get the idea. You can forget about getting wide angle results with any medium format wide angle lens.

In short, manufacturers should make normal lens and label them as such for the APS-C which would be a approximately 30mm. One company, Sigma, did just that with their new 30mm f/1.4. It's crazy to always have to figure out what the equivalent of a 50mm lens manufactured for 35 mm cameras will be on your APS-C camera.

When I lived in Canada, the systems were changed from English to Metric. For a while, everybody was confused because we were thinking in English measurements in our heads and translated those figures into metric. After a while, the mind was thinking metric and everyone ceased to translate in their minds. A normal lens for the APS-C format is 30mm. Above that its telephoto, 60mm is 2x, 90mm is 3x and so on. It really boils down that each format (maybe more in the future) should clearly explain to the public at large what is a normal lens for that format, as bench mark.

I'm probably as clear as mud.
Pentax dslrs

[distudio]

A 200mm lens in the 6x7 format gives an effective focal length of 540mm when installed on the K100D.

Um, no. A P67 or P645 or 35mm 200mm lens or a DA 200mm lens is a 200mm lens on an APS sensor camera, they will each project the same angle of view on the sensor (which would be the approximate equivalent of a 300mm lens on a 35mm frame).

[ebooks4pentax]

Um, no. A P67 or P645 or 35mm 200mm lens or a DA 200mm lens is a 200mm lens on an APS sensor camera, they will each project the same angle of view on the sensor (which would be the approximate equivalent of a 300mm lens on a 35mm frame).

Its the image circle. The small APS sensor cannot see all of what the bigger lens is projecting on the sensor. Yes a focal length of 200mm is a 200mm no matter what. The diameter of the lens makes a difference. The larger the format the bigger in diameter the lens needs to be to cover the sensor or film. That's the image circle. The rectangular shape of the sensor must fit inside the circle. If it is bigger than the image circle, a + factor will be needed to convert to your format. You actually crop the image giving the same results of a telephoto on the "135" or 35MM format. If it's smaller, the corners will be shown on your picture. The point, a APS sensor needs a lens of approximately 30mm in focal length and no bigger in diameter than what's needed to cover the sensor area. The APS is about 25mm x 17mm and thus should be called a 25mm camera. A normal lenses should be about 30mm (A normal lens is like looking thru glass. Normal because it sees what the naked eye sees. )



My point, is why not call and make normal lenses for the APS size (30MM) Anything above 30mm is telephoto and anything below, a wide angle. When they finally convert all sensors to be the same size as a 35mm film, the translation or comparison problem will go away. They should have started the DSLR revolution with a full 35mm frame sensor to begin with. They of course decided to go with planned obsolescence instead. More $$$$ that way. Maybe it is the digital progression route.

Read this, it explains fully what I mean. Crop factor - Wikipedia, the free encyclopedia or this Focal Length Multiplier: Optical: Glossary: Learn: Digital Photography Review

Regards,

Yvon Bourque
]

[distudio]

The point, a APS sensor needs a lens of approximately 30mm in focal length and no bigger in diameter than what's needed to cover the sensor area. The APS is about 25mm x 17mm and thus should be called a 25mm camera. A normal lenses should be about 30mm (A normal lens is like looking thru glass. Normal because it sees what the naked eye sees. )

If 135 film was so called 35mm because of its relation to lens/frame size then I would agree with your logic but it's not. see the history of 35mm film:

35 mm film - Wikipedia, the free encyclopedia

There is contention as to why 50mm was selected as the "normal" FL for SLRs. Granted it does provide a somewhat normal rendering WRT magnification vs perspective but I suspect it was likely an arbitrary selection rather than being scientifically derived. Given the approx 45.5mm film plane to mount distance it just happens that it's quite easy to design and produce a fast low distortion lens at or around 50-58mm FL.

The equivalent "normal" lens FL for the current Pentax sensor (based on 50mm for a 24x36mm frame) is 32.7mm so that's effectively the new arbitrary magic FL under which it WA and above which is tele ;-)

[ebooks4pentax]

The equivalent "normal" lens FL for the current Pentax sensor (based on 50mm for a 24x36mm frame) is 32.7mm so that's effectively the new arbitrary magic FL under which it WA and above which is tele ;-)[/QUOTE]


You say 32.7mm I say 30mm. I can do the exact calculations as well. In practical terms, the normal lens for the APS size should really be 30mm. It's close enough. In the 135 format, normal lens is anywhere between 45mm and 55mm.

I don't really want to argue about the technicallity of this, my point is that I hate to have to interpolate effective lens equivalency based on 35mm cameras. It's not a 35mm camera, it's a different format...APS-C.