The 100mm Macro Lens :

Every time I see some one ask for advice on what lens to start with I see recommendations for the 90 - 105mm Lens . From my limited experience I personally find this lens to be the least forgiving of just about all macro lenses , as well when I see pictures posted with these lenses they often tend to be ( honestly ) not that good . ( Sorry ) . Don't get me wrong , these lenses can take great pictures . But for the less experienced they may be just a little to easy to make mistakes with as these lenses tolerate very little aside from perfection . ( Make a mistake and it shows ) .

What we have to understand is that when we use more magnification , we also magnify mistakes such as movement and poor camera settings . Movement especially is a sharpness killer and will very quickly degrade image quality , be it movement from the subject or the camera operator . Also the shutter speed range is smaller with the larger lens , and dropping too far down will simply highlight movement and soften the image . I see so many people crank the focus distance back to the point where they could be running a 50mm lens . And then so many make the mistake of cropping for macro and just crucifying image quality . But we all have to learn and part of learning is eliminating the things that don't work . If there was ever a lens that needed artificial lighting ( flash ) its the 100mm Macro lens , it just helps to eliminate so many problems and makes the 100mm lens easier to live with .

Go back and read part one ..










Some positive points about the 100mm

Working distance for 1:1 is greater
More magnification ( good and bad )
A very popular lens size

Some of the negatives I think out weight the positives . I think the 100mm might be a good 2nd lens after you are taking good pictures with a 50mm . I see more average pictures taken than really good ones . Its more challenging to use and less forgiving of mistakes . When it comes to used lenses ? Which is more prevalent on Ebay , the 50 or the 100 ?

This lens can do some really nice things , really nice . But I have to say its more for the advanced photographer and if you are just out to try Macro then you just might be buying a lens to put on Ebay . So if you go down this road please be aware that this lens requires more dedication , and will disappoint you far more often than the 50 .

Talking to a fan of the 100mm lens size , I recall one person telling me of there success rate with their beloved 100mm .. Did they say that out of maybe 100 shots they got 10 keepers , and out of those maybe 2 or three were worth sharing on a forum . I have to be honest and say I was stunned that that person actually loved his 100mm lens . ( Ok ) Thankfully I do a bit better than that . Most of the time my keeper rate might be around 70% and my share rate might be around 40 to 50% ( good enough to share ) . And then depending on how many pictures I took I just might pick out the cream ( pictures that look good - composition ) Again , I find the 50mm so much easier to produce great shots with , I rarely have to take more than half a dozen shots and then most of them are cream . ( Hmmm I might like the 50mm )

Now with a Pentax camera the maximum shutter speed we have to play with is 1/180 ( flash sync speed ) , remembering we want to stay above 1/100 that gives the user very little to play with . We must maintain shutter speed to counter movement as the 100mm lens really highlights this and softens the image as a result . ( The more you move - the softer the image and the lower the shutter speed the more the movement is highlighted ) So with the 100 , shutter speed is critical . Another area that becomes a little tricky is your ISO . With so little adjustment available on the shutter and the ISO settings being so course it becomes very easy to burn the image or end up with a dark image ( not enough light ) . This means developing some photo editing skills and correcting such in post production .

I would really like to see some finer ISO and shutter speed options available rather than the antiquated settings we have now . ( Not that macro friendly ) Again it comes down to setting up your camera and practicing and testing to see what results you are getting and then fine tuning .

[BrianR]

C) I dont think my K50 gives more ISO options , certainly I can have less .. ( in menu settings )

Try:

Custom Settings Menu > EV Steps > 1/3 EV Steps

and it looks like you already have, but double check that:

Custom Settings Menu > EV sensitivity > As EV Steps

[old4570]

Try:

Custom Settings Menu > EV Steps > 1/3 EV Steps

and it looks like you already have, but double check that:

Custom Settings Menu > EV sensitivity > As EV Steps

Yep , but I lose on the shutter and I am not prepared to compromise on the 1/180 ..
It would be nice to be able to set shutter speed and ISO separately rather than having them as a linked function .
It is what it is , but thank you for the information , I haven't checked the ISO options with 1/160 ( 1/3 steps ) Good to know - Thank you

[BrianR]

Yep , but I lose on the shutter and I am not prepared to compromise on the 1/180 ..
It would be nice to be able to set shutter speed and ISO separately rather than having them as a linked function .
It is what it is , but thank you for the information , I haven't checked the ISO options with 1/160 ( 1/3 steps ) Good to know - Thank you

No problem. For what it's worth your k-5 has X-sync on the mode dial, this will set the shutter to 1/180 irregardless of the EV step settings and gets you what you're after.

[old4570]

For some strange reason I dont shoot Macro with the K5 .. ( I probably should ) It is my general purpose camera and wears a Sigma 17-70 Macro (?) F2.8 ..
I currently use a K20 for product photos ( Product reviews ) and have been meaning to sell the K20 and switching over to the K5 .
But for the strangest reason I like the K20 ( enough to own two ) , and parting with them feels wrong .
Probably not the end of the world to move the K10 and K20's on and maybe replacing them with a 24MP Pentax ..
2018 will probably see me buy a 24MP camera of one brand or other .

The K5 is a sweet camera - Just dont know why I barely use it these days - Perhaps its just too easy to take good pictures with ? ( Where's the challenge ? )